Category The Genesis of Air Power

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s the threat from the air grew, states took measures to counter it. However, although air defence developed hand-in-hand with airforces, the idea of uniting the two into a single structure met with no success in peacetime. By late 1905 it was clear that France was assessing seriously the possibility of using airships for military ends. Thus the issue of how to prevent aerial attack from airships acquired primary importance. The very first theoretical ideas hit a completely unexpected obstacle. Initially, it was expected that the artillery would be more effective against airships than the infantry. Germans viewed their 1904 model 100mm howitzer, and the light field howitzer, as particularly suited for the role. Both could adopt the required elevation angle without especial preparations or ac­cessories. Flight altitudes until 1914 rarely exceeded 1200m, which explains why the light field howitzer retained its air defence role despite its indifferent ballistic quality.

It was down to practical experience to show the road ahead. The limited area of land testing grounds pointed the military to the sea, and particularly inland waters. This was helped by large arms manufacturers. In 1911, Germany’s Krupps and the Rhein Machine and Metal Products Factory (‘Rheinmetall’) built a 77mm air defence weapon mounted on a truck, with a special mount being designed for it the following year. After their first test firings, the infantry and cavalry pinned their hopes on massed small arms and machine gun fire directed against aircraft which still flew relatively low and within range of these weapons.

Air defence artillery weapons also found a naval application. Since naval installa­tions were fixed, what counted most was good ballistic properties and increased cali­ber, hence firepower. The 88mm ship board gun looked most promising because of its high initial velocity and elevation angles of up to 70 degrees. Powerful spotlights were also foreseen against nocturnal attacks.

Realistic combat-condition testing was still a problem. Unmanned target drones were still in the future. The few aeroplanes available were rather too expensive to be wasted in such tests. Pooling the efforts of the various arms under a single command might have resolved many problems, major ones being taking precise aim in a new way, using principally new weapons, and using principally new instrumentation.

France was one of the leaders in air defence technology. There, the 75mm field gun turned out most suitable for firing at airborne targets. It was also to be mounted

I Highly mobile anti aircraft machine gun platforms such as this one entered service with infantry and cavalry units

on a truck later, and by 1914 equipped mobile batteries within several artillery regi­ments. Combat to come was to show that this was far from adequate.

Other nations failed to create air defence structures until the Great War. Even though the final manoeuvres threw some light on suitable air defence tactics, hard and fast decisions on air defence structures appeared premature. Initially, air defence units were appended to field artillery regiments guarding national borders. Large or­ders were placed for the reasonably capable mobile artillery weapons.

Anti aircraft artillery tactics aimed to disturb enemy flying. The greater the use­fulness of aerial artillery direction and correction, the greater the need to hamper its precision and effectiveness. The necessity of assigning anti aircraft weapons to cavalry corps and divisions became obvious. Tactics used to counter enemy flying, and cam­ouflage as a most effective passive means of air defence were thoroughly overhauled. Less mobile animal-draught artillery units were assigned to protect important targets in the rear. Corps commands which received anti aircraft weapons, machine guns, projectors and communications equipment were advised to act as they saw fit.

The extent of defence afforded depended on target importance. The range of options covered anything from infantry small arms fire to the combined use of rifles, machine guns, field guns and projectors. A communications network began to emerge, to speed the passage of information on enemy aerial movements.

I A French Morane-Saulnier mono­plane in flight

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hether or not air power exists depends on the individual components which constitute it when taken together. In the difficult period when air potential begins to be created, the greatest contribution is made by the scientific and experimental base. Thus, it was unthinkable that man would fly without first having a grasp on the properties of gases; and evolution in the knowledge of gases went alongside knowledge of aerodynamics. Having acquired some understanding of how water behaves (hydrodynam­ics), learned people began experimenting with gases. Their discoveries about lighter-than – air gases were quickly applied in late 18th Century aeronautics. Starting in 1804, Cayley and later Chapman studied different aerofoils, and how they behaved at different inci­dences. As learned societies were established with the purpose of researching flight, indi­vidual endeavour gradually became systematic and shared by the scientific community. The first scientific society was established in France in 1852. Britain’ s Aeronautical Soci­ety was founded in 1866, and the Russian Technical Society’s turn was in 1881. The fruits of this pooling of effort were not slow to emerge: using a home-made wind tunnel, Briton Phillips showed the lift benefits of cambered aerofoils, patenting a number of profiles in 1884. Not five years after Phillips’s work, Lilienthal proved these profiles’ benefits in prac­tice by designing and flying gliders which paved much of the way to powered flight. (Con­current studies of aspect ratio and of the best angle of incidence were no less important.)

Though early knowledge was rather limited, and though experiments were rather less than rigorous and used rather primitive equipment, the body of knowledge ac­quired was a basis for the early successes.

Another major barrier in the way of powered flight was the lack of suitable power – plant. There were two schools of thought among scientists. One stressed further improve­ments in steam engines. And indeed, such engines relative power increased, and times to building up steam pressure reduced. Between 1868 and 1872, steam engine efficiency nearly doubled! The second school of thought on powerplant sought principally new types of engine. Trial use of electric motors for propulsion showed that they were unsuitable. However, the discovery of the internal combustion engine was an important breakthrough for aeronautics and aviation. The working principle of internal combustion dated back to

the 17 th Century. However, the high cylinder temperatures could not be attained with the materials of the time. It was only in 1860 that Frenchman Lenoir built a working model of an internal combustion engine. It was water-cooled and burned lighting gas. But both this engine, and the much later Otto – Langlen one had nothing much to offer set against steam units. Only the four-stroke power unit designed by German Otto late in the late 1870s was worthy of development. Daimler refused to use lighting gas, choosing petrol instead. This removed the need for bulky and heavy gas storage vessels. With time, the needs of aviation began to influence internal combustion engine development. Such powerplant became standard due to its compact size, quick starting and unmatched relative power. At the end of the period under review, their output varied from 40 to 100hp (Table 1, Graph 2) (experimental FIAT units ran at 300hp and even 700hp).

Daimler led the water cooled engine field, followed by Argus. Despite the weight of coolant, such engines were more powerful, longer-lasting and more reliable. How-

T a b l e 1: Aeroengine Weight and Output, 1913-1914 Make Origin Type of engine Ouyput, hp. Cylinders Relative Weight Air-Cooled Gnome France Rotary 50 5 1,5 Gnome France Rotary 80 7 1,2 Rhone France Rotary 80 9 1,4 Renault France V-Formation 100 12 2,9 Water-Cooled Argus Germany Inline 100 6 – Mercedes Germany Inline 100 6 2,0 Astor-D Germany Inline 100 6 2,2 ENV Britain V-Formation 120 8 2,0 Salmson France Radial 130 9 1,8 140 120 100 80 60 40 20 0

ever, many builders preferred the air-cooled French Gnome engine despite its great frontal area (and hence drag): it was lighter and cheaper. Aeroplanes using it were light, had shorter take-off and landing runs, and were more manoeuvrable (yet not as reliable…). Air-cooled engines also burned more lubricant. Yet, controversial aspects aside, the Gnome was licensed for production in Germany and Britain.

Science and research remained the driving force behind the creation of air potential until the close of the first decade of the 20th Century. By that time, a relatively stable base had been established to assist the pursuit of certain tasks in the air. The period began with large-scale production of Parcival-Siegsfeld balloons, the vesting of the DELAG paramil-

itary/civilian Zeppelin operator, and initial series production orders for Wright, Bleriot, Farman, Voisin, Etrich and other aeroplanes. Before the start of the Great War, science determined air power, as demonstrated by the scramble to squeeze ever better technical indicators from all manner of aerial devices. It was also science that sourced the people who were to form design teams and apply their scientific skills in a commercial direction.

Manufacture also grew apace, with 2718 aeroplanes being made in 1914: 1348 in Germany, 541 in France, 535 in Russia, 245 in Britain, and 49 in the USA. Performance grew along with production capacity. Frequent air shows and competitions became an added stimulus for designers and pilots to challenge range, endurance and speed records. Amply subsidised by state and private funds, these events also became marketplaces. Graphs 2, 3, and 4 show how rapidly flying machines progressed in that period.

However, it was clear that these achievements had to have a context of clear and specific requirements. Having emerged, the aeroplane had to become civilised: it had to be made capable of showing its superiority vis-a-vis other types of airborne vessel in practice by becoming a competent and comfortable platform able to perform set tasks

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with ease. Thus, the demonstration of air power was the only way air potential could be actualised. In other words, a sufficient number of aeroplanes had to be utilised by national services specifically formed to operate them. This logically leads to one of the major issues in aviation from its emergence to the present: the issue of security. This in turn depends on the requirements of another important component which came to the fore after the first air arms had been formed: the availability of a sufficient number of reliable and competent aeroplanes.

Poor safety affected aviation development adversely. If 29 pilots had died by 1910, in 1911 they numbered 74, in 1912: 127, and in 1913: 154 (plus several hundred injured survivors). (Graph 5)

Graph 5: Humans’ casualties in airo accidents, 1910-1913

Seattle, Washington: the pilot loses control during a risky demonstration flight and heads into the grandstand. Onlookers fled for their lives, but three died and 12 were hurt

Clearly, if aeroplanes were not to remain an exotic plaything, much had to be done to improve their reliability and safety. Flight safety became a concern from 1910 on­wards. To get things going, the state in the face of relevant offices such as war ministries, set aside prize money for air safety. Britain led the way here, sponsoring some excellent aeroplanes such as the BE2, the Avro 504, a Sopwith, and others. These saw active use into the 1930s, the Avro even serving in Soviet flying schools as the У-1 (U-1). The statistics showed these main causes of accidents: pilot error; poor aeroplane stability causing upsets in bad weather or in inexperienced hands; insufficient aeroplane strength causing structural failures; powerplant unreliability. The stability issue was tackled in two ways. The first one was to enhance aeroplanes’ natural aerodynamic stability. The key here was to select a suitable configuration. In-depth studies were undertaken of wing profiles, control surface action, trim, and propeller/rotary engine torque. The re­sult was an advance in enlightened scientific methods of selecting a configuration. Val­uable data was obtained in early wind tunnels built in Britain, France and Russia. Using data from the Royal Aircraft Factory Research Centre, the British built the RE 1 biplane which flew for ten minutes without any control inputs from its pilot. Apart from being pleasant for the pilot, this ability coincided with military requirements for stable aerial observation platforms. Thus emerged a trend to overestimate the significance of aero­plane stability. This trend was to rule supreme until the first dogfights, when its delete­rious effect was shown. Similar events took place in Germany, Russia, and France: all countries leading aviation ‘fashion’ at the time. The second way in which the stability

Farman aeroplanes enjoyed a good reputation among pilots for their enviable stability

Щ The Curtiss twin-engined flying boat, specially built to fly the Atlantic, is notable for featuring one of the earliest autopilots

issue was tackled was to create a device allowing straight and level flight without pilot input. Such a device had to restore steady flight after atmospheric upsets or involuntary pilot inputs. Over 120 such devices were invented and patented before the First World

War. The poor level of knowledge and experience at the time were reflected in the many and serious defects of such early ‘autopilots,’ rendering all of them impracticable.

Aircraft structures were a great safety problem in themselves. In the dawn of aviation no stress calculation techniques whatsoever were applied to aeroplane struc­tural design. French and British stressmen began static testing of airframes only after the first wing failure crashes in 1911. Little by little, designers relinquished timber for major stress bearing elements, adopting various kinds of metal instead. Another result of the stress studies was the preference for the stiffer biplane configuration, which was to stay in vogue until the mid-1930s. (Graph 6)

Engine reliability also improved, as evidenced by the first flights measured in hours. Multi-engined aeroplanes able to maintain flight and land safely after an engine fail­ure, also appeared. Russia led the way here, Igor Sikorski’s trials of his Russkiy Vityaz and Ilya Muromets proving that the multi-engined formula was a contribution to safe­ty. The latter type was also the world’s first strategic bomber and strategic reconnais­sance aeroplane to enter service.

The arrival of the parachute was another great boost to safety. Known to man for a long time before aero­planes, parachutes were first used for egress from balloon gondolas. The first rucksack parachute was designed by Kotel’nikov in 1911. Similar designs quickly appeared in the USA (1912) and Germany (1913). The first life saved by this progenitor of modern emergency escape devices was that of American pilot Lowe in 1912.

Efforts to improve safety went hand in hand with another very important

u 1909 1910 1911 1912 1913 1914

Graph 6: Monoplanenes % from all aeroplanes production, 1909-1914

component of air power: the availability of adequately trained air and ground personnel. The newly created flying schools began not only to impart flying skills to pilots, but also to train mechanics in aeroplane maintenance. Legislative instruments were adopted to regulate the operation of aeroplanes in the air and on the ground and define rights and responsibilities. The first textbooks and flight manuals were published.

As the number of aeroplanes grew, so did the number of national offices con­cerned in one way or another with their operations, and so did the requirements for crew training. As the nature of tasks performed by crews evolved, so did flying school curricula. The first military flying schools opened, training pilots in the specialist arts of aerial observation and reconnaissance, and the skill of flying at above 1000m: the altitude then considered optimal for such purposes. As mentioned above, those wish­ing to serve in the emergent air arms had to have military wings. Bearers of military wings were specifically trained to fly specially designed army and navy aeroplanes. For instance, one difference between civil and military flying schools was that while the former rarely strayed above 600m, the latter were trained to reach observation alti­tudes of 1000m or more, dive to 600m to avoid artillery fire, and practise dead stick landings with an idling or switched off engine.

By 1913 improving aeroplane reliability and performance allowed quite daring aerial manoeuvres. Independently of one another, Nesterov and Pegoo flew loops, proving that aircraft were capable of sustaining great loadings in the air. This was the start of aerobatic training which included learning spin recovery skills. A danger to the unwary to this very day, spins are uncontrolled falls at high angles of attack while rolling, pitching and yawing. The number of aerobatic-trained pilots grew rapidly, reaching 30 in Russia alone by early 1914. Thus, despite the greater com­plexity of aeroplanes and flying, the flight hours per accident indicator im­proved twenty fold. Whereas in 1909 an accident occurred once every 200 flight hours on average, by 1914 it occurred once every 4000 hours.

Convinced of aeroplanes’ military and civil utility, the governments of nations able to develop aircraft and airship manufacturing set aside con­siderable funds for equipping their new air arms. By 1913, over 1000 aero­planes had entered military service around the world.

An early procedural trainer used to give ab-initio skills to future Antoinette pilots

German pilots duringintensive training a week before the start of the First World War: the helmet has become a compulsory part of the kit

Graph 7: Finance funds spending for aviation in 1913 (in mln. dol.)

Military aviation budgets for 1913 came to 7.4m dollars in France, 5m dollars in Germany and Russia, 3m dollars in Britain, and 2.1m dollars in Italy. (Graph 7)

The trend was for these sums to grow apace, and moreover for the share of avia­tion to grow at the expense of aeronautics. Aeroplanes were gradually becoming rec­ognised as more versatile for the range of tasks set before aviation and aeronautics. Initially, the military bought proven designs for sports and private-owner use, but specialist military designs emerged from 1912. The latter all had two crew members

and stronger landing gear, and were easily reconfigured for transportation by road, riv­er or sea. Before impressment into service, such aeroplanes were tested by special ac­ceptance bodies, often on top of having proven their qualities in numerous fly-offs and competitions. This was then a new de­parture which later found its way to other areas due to its effectiveness.

Alongside the development of aero­planes as such, another component of air power was taking shape: on board and ground equipment. Pre-First World War army and navy aeroplanes were decidedly multi-role. Much experimentation with dif­ferent equipment thought useful for the various armed forces which employed aer­oplanes took place. Specialised airborne cameras appeared whose images helped de­termine the precise location of enemy forc­es. Reliable cameras with moderate focal length optics, comfortable for use from aer-

A Type L planview camera fitted to a B. E.2a

Щ A machine gun equipped Nieuport 4

oplanes and tethered balloons, entered production. This in turn led to the design of mobile photographic labs to process the cameras’ output for immediate use. However, the money involved was huge, and thought unjustified amid prevailing expectations that the coming war would be so swift and mobile, events would overtake photo­graphic intelligence. Thus mobile labs were not mass produced, reliance being placed on field laboratories instead. Observation equipment derived from the artillery also entered wide scale use, especially in naval aviation.

Initial attempts to arm airborne vessels with firearms date back to this period. Their use was directed at both the ground and the air. Despite significant advances, the fitting of machine guns to aeroplanes was still very much an experiment prior to the Great War. The major problem was the difficulty of firing safely through the pro­peller disc, which limited the use of machine guns. Also, the available machine guns were either too primitive, or too heavy.

Experience of manual bombing in the Tripolitanian and Balkan Wars showed that its effect was more psychological than genuinely damaging to the enemy. The bombs used had unknown ballistic properties: they were mostly adaptations of infantry hand grenades. Purpose designed aeroplane bombs, though of a modest size in keeping with the capacity of early aeroplanes, gradually acquired the shape we know today. Most widespread were ‘bat cubs,’ weighing five kilos, drop-shaped and finned so as to drop vertically. Their ap-

| Bombing trials with training bombs near Los Angeles, California; the aeroplane seen is a Farman biplane

pearance led to the design of special bombsights and bomb-holders. Though patented devices were insufficiently effective, individual pilots demonstrated exceptional bombing precision during training or in competitions. One such was Lieutenant Gobert who scored 12 hits in a 20m circle from a height of 200m with his 15 bombs (make not recorded) during a 1912 international military display. In the next heat, the same officer scored eight hits of a 120x50m target from a height of 450m. Other pilots of the period were not far behind, including Bulgarian ones during the preparations for the second stage of the First Balkan War. However, airmen in general entered the Great War unarmed but for their handguns (which they indeed used in anger in the conflict’s opening stages!).

The period saw early attempts to protest airmens’ seats against ground fire. Though easy to fit, however, the steel plate used was too heavy. Armour plating had to wait for sturdier airframes and more powerful engines.

The means and equipment which ensure effective use of military aeroplanes are another important component of air power. Initially, this included bases where men could train and equipment could be tried, and manufacture and maintenance work­shops. Army and navy orders gradually encouraged factory-based aircraft manufac­ture. Specialised engine and propeller companies emerged. By the start of the Great War, the world had no fewer than 75 aircraft and 23 aeroengine makers capable of turning out 1600 aeroplanes and 2200 engines a year. This was in addition to fully equipped military workshops and airfields.

Command and control, the last but not least important component of air power, remained most problematic in its nascence. The reason for this was that radio com­munications were not yet adapted for routine air-to-air or air-to-ground operation. This circumstance introduced delays in the passing on of aerial reconnaissance infor­mation. Even though initial trials in 1910 brought very encouraging results, radio sets were too heavy and bulky for the typical aeroplane then.

However, radio was not the only concern of commanders who had to juggle bal­loons, dirigibles, and aeroplanes around the battlefield. Limited experience had not yet suggested the sort of unit structure that would be right for aviation and aeronau­tics. Part of engineering or communications corps, their commanders lacked the in­dependence and flexibility.

Experience from manoeuvres and local wars gave some clarity on how different types of flying machine are best employed. Those first airborne weapons, spherical balloons, were on their way out. However, despite their known disadvantages, they were still used for secondary and auxiliary tasks such as defending fortresses and tar­gets to the rear. Their place at the battlefront was taken by tethered kite balloons, which were stable observation platforms. In recognition of their still limited mobility, they were intended for static and defensive warfare. Aeroplanes and airships were to be the proactive agents on the battlefront, with aerostatic balloons being used for

observation, aerial reconnaissance, and artillery correction. Forward-positioned aero­stats would conduct stereoscopic photography of enemy formations, allowing their locations, firepower, and force concentrations to be determined precisely. In attack, aerostats were only assigned the artillery correction role.

Observation altitudes reached 1300m, with some 600 to 1000m being average, and 400m being the minimum. Aerostats could only carry one aeronaut to maximum altitude, which made effective data transmission more difficult. A normal three of four-strong crew could ascend to no more than 600m.

Aerostats’ distance from the frontline depended on observation altitude and the pres­ence of enemy artillery (especially long-range guns), and was usually four to six kilometres.

Observers’ effectiveness depended on locale (the presence of characteristic fea­tures) , on how well enemy manpower and equipment was camouflaged, and on the weather. Major weather indicators were visibility and wind speed. Parcival-Siegsfeld balloons could cope with no more than some 15m/s of wind. Fair visibility constituted anything over ten kilometres. Given such conditions, experienced aeronauts could locate a single artillery battery 15 to 18km away by looking for gun flashes.

Aerostats’ good visual range and ability to fly equally well from shipboard as from the shore made them valuable to the fleet, especially in naval blockades. Apart from conducting general lookout and recce duties, naval aeronauts could spot enemy sur-

A French balloon unit filling its vessel with hydrogen

I An Italian semi-rigid airship

face and submarine shipping and mines, correct artillery fire, and relay ship-to-ship or ship-to-shore messages.

Operational and strategic intelligence duties were assigned to airship crews. The last peacetime manoeuvres proved that general staffs’ requirements of early 1914 could only be met by airships. These requirements included the ability to penetrate enemy airspace to a depth of 500 or 600km at a height of 2400m: indicators far beyond the ability of any mass produced heavier-than-air craft at the time.

Another great advantage of airships was their great loadability. This enabled them to bomb fortresses, troop and equipment concentrations, harbours, stores and indus­trial establishments. In penetrations of the order of 600km, airship warloads were not less than 300 kg, with corresponding increases at shorter ranges. However, the fact is that prior to the Great War very few airships boasted anything like the above indica­tors. Those that did were mostly German. (Graph 8)

Wisdom from the initial manoeuvres and local wars in which aeroplanes were involved seemed to suggest they would be most useful for operational reconnaissance. The same events also showed some aeroplane utility in tactical recce, and in artillery

Graph 8: Airships’ payload and range growth, 1900-1914

correction, but this was ignored. Apart from mistrust of aeroplanes among commands, and short-sightedness on the part of military bureaucrats, this was also due to pilots’ dislike of such hard and risky missions which required concerted training and offered no guarantee of success. Yet artillery correction soon became a routine task for avia­tors, especially against well camouflaged targets. Since no manuals and agreed proce­dures of any kind existed, flyers and gunners would thrash things out informally be­fore a flight. Naturally, results were patchy, took long to arrive and were often at odds with gunners’ real needs. Military theoreticians correctly surmised that informal ‘ne­gotiations’ would be unthinkable in the mobile general war they expected, and began developing formalised procedures. Things did not get much further than those early developments, being overtaken by the outbreak of war.

The next task assigned to aviators was to strike enemy targets. The Tripolitanian and Balkan Wars, in which aviators from many non-combatant nations volunteered, convinced experts that there was considerable likelihood of success in bombing from aeroplanes. They concluded that aeroplanes would be best used against targets that were large or covered a great area. Working heights would be between 800 and 1000m. Two approaches were fore­seen: star patterned and squadron attacks. The former involved individual aeroplanes ap­proaching the target from a variety of directions, whereas the latter involved a group ap­proaching together. In both cases the aim was to saturate the target with bombs to an ade­quate extent. In any case, considering the relatively small number of aeroplanes, no special­ised bombing units were formed before the Great War, commanders having to rely on what (if any) strike capacity happened to be available in units under their command.

The Balkan Wars brought the dogfight a stage nearer. Though isolated, the encoun­ters on the Bulgarian/Turkish and Bulgarian/Servian fronts did not escape analysts’ no­tice. However, neither designers, nor strategists offered coherent views on dogfighting. The very idea of one aerial vessel being attacked by another was only addressed in the

I Good portability was among the conditions set before candidates to supply aeroplanes to the military: here a Breguet is seen readied for transportation by road

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case of some airships, which were accordingly fitted with machine guns. Aeroplanes lacked such defensive armament. While France, Britain, Belgium, Russia and Austria – Hungary did some defensive/offensive armament trials, conclusions drawn and solu­tions implemented were disparate. For instance, influenced by the forward-positioned engine and puller propeller, the Austro-Hungarians decided to position the observer aft and let him handle the weapon. Others felt it was better to site the engine aft, use a pusher propeller, and put the observer/gunner at the front.

The use of aeroplanes for liaison between distant columns or units was another long-drawn contentious issue. Since everyone expected a mobile war, aerial liaison scenarios were tried at manoeuvres, and in 1911 some pilots called for a purpose – designed swift and light aeroplane. The call was heard only in Britain, where the satisfactory Scout flew eighteen months later.

Stemming from man’s earliest attempts to break the bonds of gravity, the genesis of air power saw early aeroplanes used not just by the military, but also for transporta­tion and other civilian business. This genesis stimulated great scientific and industrial effort. The following general conclusions may be drawn:

1. Even at their nascence, air power and air potential became a priority in indus­trially developed nations which could afford to keep pace with advancing research and technology;

2. The emergence and development of air power’s various components was evolu­tionary, and was governed as much by the new environment as by the objectives set by national political and military leaders;

3. The tasks set before early aviation led to the creation of specialised institutions at the government and private enterprise levels;

4. The improvement of aeroplanes’ capabilities led to enhanced status for the specialised institutions which started on their way to becoming pillars of national military and economic might;

5. As the components of air power and air potential grew in importance, they began to form a system with its typical interconnections, points of entry and exit, and sources;

6. The major development stimulus for air power and air potential was the drive for supremacy in the new environment of the air. The first local conflicts in which the nascent components of the new system played a part proved that this system had a future in the attainment of political, business and military goals.

The first shots of the world’s first general war put an end to the period of emer­gence in the development of air power. Although regarded romantically today, this period saw many rational solutions which hold true to this very day. Later, air poten­tial would draw on experience gained in this period to develop both its peaceful civil­ian aspects, and its military side.

No	Designation/ N ante	Year	Origin	Volume, m3	Length, m	Diameter, m	Power, kWt	Payload, kg	Speed, km/h	Type
1	LZ-1	1900	Germany	11,300	128	11.65	21	n. a.	28.1	Rigid
2	LZ-2	1905	Germany	11,300	128	11.65	126	2800	39.6	Rigid
3	LZ-4	1908	Germany	12,200	136	11.65	144	2900	43.9	Rigid
4	Lebed’	1909	Russia	3700	61.4	11.1	51	920	36	Semi Rigid
5	LZ-5	1909	Germany	15,000	136	13	144	4600	48.6	Rigid
6	Grif	1910	Russia	7300	700	14	162	3700	59	Soft
7	LZ-7	1910	Germany	19,300	148	14	264	6800	60.1	Rigid
8	LZ-10	1911	Germany	17,800	140	14	321	6500	75.6	Rigid
9	Schute-Lanz SL-1	1911	Germany	19,500	131	18.4	368	4500	70.9	Rigid
10	Mayfly	1911	Britain	18,760	156	14.6	265	n. a.	n. a.	Rigid
11	LZ-14	1912	Germany	22,465	158	14.86	363	9400	76.3	Rigid
12	P	1912	Italy	4900	62	12.6	103	1490	65	Semi Rigid
13	PL-17	1912	Germany	9830	85	16	250	2150	64.8	Soft
14	PL-16	1913	Germany	9830	94.15	15.48	265	2716	67.6	Soft
15	LZ-21	1913	Germany	20,870	148	14.86	396	8800	73.8	Rigid
16	Astra	1913	Russia	10,000	78	15	294	5400	59	Soft
17	PL-18	1913	Germany	8800	84	15	265	2200	67	Soft
18	PL-20	1914	Germany	9830	92	15	265	3300	78.1	Soft
19	M	1914	Italy	12,500	82.7	16.9	287	5300	70	Semi Rigid
20	LZ-24	1914	Germany	22,470	158	14.86	441	9200	80.6	Rigid

Designation	Origin	Year	Type	Engine, Rating	Crew	Span, m	Length, m	Wing Area, sq m	Gross Weight, kg	Max Speed, km/h	Range/ time
1	2	3	4	5	6	7	8	9	10	11	12
Flyer 1	USA	1903	Biplane	Wright, 12hp	1	12.3	6.4	47	340	approx 18	285m/59s
Flyer 2	USA	1904	Biplane	Wright, 16hp	1	12.3	6.4	47	360	approx 47	4.8km/5m 4s
Flyer 3	USA	1905	Biplane	Wright, 2 lhp	1	12.3	8.5	47	388	approx 60	39km/38m 3s
14 bis	France	1906	Biplane	Antoinette, 50hp	1	11.5	9.7	52	300	approx 60	220m/21.2s
Voisin-Delagrange	France	1907	Biplane	Anotinette, 50hp	1	10	n. a.	40	n. a.	n. a.	500m/n. a.
Bleriot VI	France	1907	Tandem Wing Biplane	Antoinette, 50hp	1	5.9	n. a.	20	280	n. a.	184m/n. a.
Voisin-Farman 1	France	1907	Biplane	Antoinette, 50hp	1	10.2	13.3	40	520	approx 45	771m/52.6s
Wright A	USA	1908	Biplane	Wright, 30hp	2	12.5	8.9	47.4	500	approx 60	125km/2h 20m 23s
Bleriot VIII	France	1908	Monoplane	Antoinette, 50hp	1	11	10	22	425	approx 76	14 km
REP 2	France	1908	Monoplane	n. a., 30hp	1	8.6	n. a.	15.8	350	n. a.	1.2 km
Verber 9	France	1908	Biplane	Antoinette, 50hp	1	10.5	10.7	30	400	40	500m/n. a.
Cody 1	Britain	1908	Biplane	Antoinette, 50hp	1	15.8	n. a.	n. a.	n. a.	45	450m/n. a.
Voisin-Farman 1 bis	France	1908	Biplane	Antoinette, 50hp	1	10.2	13.3	40	530	54	40km/n. a.
Antoinette 4	France	1908	Monoplane	Antoinette, 50hp	1	12.8	11.5	50	450	65	155km/n. a.
Voisin Standard	France	1908	Biplane	Antoinette, 50hp	1	10	12	40	550	55	n. a.
Grade 1	Germany	1908	Triplane	Grafe, 16hp	1	10	8.5	25	230	70	60m/n. a.
Bleriot XI	Germany	1908	Monoplane	Anzani, 25hp	1	7.8	8.2	14	300	60	n. a.
Golden Flyer	USA	1909	Biplane	Curtiss, 50hp	1	8.7	8.7	24	376	60	n. a.
Farman 3	France	1909	Biplane	Gnome, 50hp	1	10	11.2	40	550	60	223km/n. a.
Antoinette 6	France	1909	Monoplane	Antoinette, 50hp	1	12.8	11.5	50	520	85	180km/n. a.
Kudashyov-1	Russia	1910	Biplane	Anzani, 35hp	2	9	10	32	420	n. a.	60m/n. a.
Gakkel’ 3	Russia	1910	Biplane	Anzani, 35hp	1	7.5	7.5	29	560	80	400m/n. a.
Grizodubov	Russia	1910	Biplane	ARB, 30hp	1	12	10.9	n. a.	600	70	4.4km/n. a.
Laner Simon 1	Austria- Hungary	1910	Biplane	Anzani, 25hp	2	13	n. a.	47	550	70	n. a.

1	2	3	4	5	6	7	8	9	10	11	12
Etrich Taube	Austria- Hungary	1910	Monoplane	Clerget, 50hp	2	14	10	34	430	80	75km/n. a.
C-6A [S-6A]	Russia	1911	Biplane	Argus, lOOhp	2	11.8	8.8	35.4	990	111	n. a.
Curtiss A1	USA	1911	Biplane Flying Boat	Curtiss, 75hp	2	8.74	8.43	30.75	714	105	n. a.
Bristol R1	Britain	1911	Monoplane	Gnome, 50hp	1	9.2	n. a.	15	372	105	n. a.
Fokker Spin	Germany	1911	Monoplane	Argus, lOOhp	2	11	7.75	22	400	90	45km/n. a.
Nieuport 4	France	1911	Monoplane	Gnome, 50hp	1	11.6	8	18	600	105	330km/n. a.
Farman MF7	France	1912	Biplane	Renault, 70hp	2	15.8	n. a.	48	728	90	n. a.
Flenriot D	France	1912	Monoplane	Gnome, 50hp	1	8.9	n. a.	14	480	120	n. a.
Albatros	Germany	1912	Biplane	Argus, lOOhp	2	14.4	n. a.	39	950	100	1200km
Bristol Scout	Britain	1912	Biplane	Gnome, 80hp	1	6.7	n. a.	14.3	280	150	n. a.
Dun DB	Britain	1912	Flying Wing Biplane	Green, 50hp	1	10.97	6.4	21.35	772	97	n. a.
Farman 22	France	1913	Biplane	Gnome, 80hp	2	15	n. a.	41	680	90	n. a.
BA2A	Britain	1913	Biplane	Renault, 70hp	2	10.68	9	32.7	726	112	480km
Caudron G-3	France	1913	Biplane	Gnome, 80hp	2	13.9	n. a.	30	625	90	n. a.
Avro 504	Britain	1913	Biplane	Gnome, 80hp	2	11	8.91	32	625	100	280km
Albatros B2	Germany	1913	Biplane	Mercedes, lOOhp	2	12.8	n. a.	36	900	100	600km
Morane Parasol	France	1913	High Wing Monoplane	Gnome, 80hp	2	10.3	6.38	18	680	115	300km
Morane-Saulnier	France	1913	Monoplane	Gnome, 80hp	1	9.2	7	16	500	130	250km
Sopwith Tabloids	Britain	1913	Biplane	Gnome, 80hp	1	7.8	6.1	22	480	148	n. a.
Deperdussin	France	1913	Monoplane	Gnome, 160hp	1	6.7	6.1	10	500	200	n. a.
Russkiy Vityaz	Russia	1913	Biplane	4 x Argus, lOOhp	4	27	20	120	4200	90	380km
llya-Muromets	Russia	1913	Biplane	4 x Argus, lOOhp	4	32	23	182	4650	95	380km
Curtiss M	USA	1913	Biplane Flying Boat	Curtiss, 85hp	2	8.7	n. a.	32.9	550	80	n. a.
C-10 [S-10]	Russia	1914	Biplane Flying Boat	Argus, lOOhp	2	14	n. a.	36	1080	100	n. a.
Albatros	Germany	1914	Flying Boat Biplane	Mercedes, lOOhp	2	16	n. a.	50	1240	105	n. a.
Rumpler 4S	Germany	1914	Monoplane	Mercedes, lOOhp	2	14	n. a.	29	1000	110	n. a.

[1] 2 Translator’s rendering from the quotation in Bulgarian.

[2] Paradoxically Lilienthal, who did more than anyone before him to breathe life into fixed wings, believed without any reservation that the future lay with ornithopters.

[3] This construction was retained for all Lilienthal’s future gliders.

[4] Of Maxim Gun fame; using recoil energy, his machine gun found worldwide success.

[5] Today he would be Romanian. Translator.

[6] R-7 in Latin script. Translator.

[7] Al’batros in Latin script. Translator.

[8] More usually known as Igor Sikorsky; the complete Russian transliteration is given for comleteness and uniformity. Translator.

[9] Russkiy Vityaz or Russian Knight. Translator.

[10] Il’ya Muromets or Elijah of Murom. Translator.

[11] Province. Translator

[12] Lapseki is on the Asia Minor side of the Dardanelles. Translator.

[13] Notable

G

od created man according to his image and inspired him with a constantly searching spirit. The spirit that gives birth to progress and leads our civilization to the tempting future of a better and free life. Freedom as notion has been defined in various ways and the definition is the product of the hard labour of many great scientists. The feeling of real freedom comes to us, the people, only when thanks to our common sense and skills we succeed to over­come the gravitational law and we leave the warmth of our natural earth environment, heading for the sky. This is a hard way and its beginning lies in ancient times when the dream, and later the idea to fly, was born. This era was followed by centuries of acquiring necessary knowledge and decades of unsuccessful trials used by man to break his earth chains. All of this was compensated by our civili­zation with the blood of its elite of intelligent, searching and brave men whose self-sacrifice was the base to build our heavenly future.

Why was it necessary for man to fly? What is the purpose of dwelling in a space not assigned by God? These are all logical ques­tions answered by scientists hundreds of years ago. Even at that early time, scientists foresaw that the three-dimensional space over us offers unlimited opportunities for making progress and its imple­mentation by man using man-made aircraft would give exceptional chances for rapid development of civilization. Now we understand

how far-sighted this great effort of human mind and will was, irre – gardless of the cost of thousands of human lives. We, contemporary generations owe those heroes the memory and reverence in return to their great deeds.

Commandant of Bulgarian Defence and Stuff College “G. S.Rakovski” Major General Manev

T

he use of airborne weapons in combat characterizes armed con­flict since the end of the 19th Century, and especially since the start of the 20th Century. Today the significance of airborne weap­onry has grown to the point where it plays a decisive role in the outcome of armed and political crises.

This book is dedicated to 100-anniversary from the first control humans‘ flight, aims to clarify the genesis of air power, uncover its essence, and trace the evolution in this term during certain stages of its currency. Official historiography, memoirs, and scientific pa­pers form the base for research.

Subject of the study is air power: how the term emerged, what was meant by it as it developed historically, how it influenced the formulation of doctrines for the utilization of airforces and national air potential as a whole, and how it made its debut in the years prior to 1914. The very new moment is a special part for creation of Air Power in Balkan countries and meaning of new components for the military operations in Balkan wars (1912-1913).

A well-known rule in science is that a phenomenon cannot be understood and studied in each of its aspects. Thus this book seeks to contribute to further clarification of terminology and processes: a clarification which would assist a future streamlining in the devel­opment of national air potential on the road to integration into col-

—————————————— >——————————————————

lective security systems. Ultimately, arrival at a uniform terminolo­gy, and its clarification and amplification are the first steps to genu­ine integra

I

dentifying critical issues and finding optimum solutions to them is a fundamental task of politicians and soldiers at the start of the 21st Century. Methodologies for this include modelling techniques and intensive computer use.

Nevertheless, the road to pinpointing the major problems of today remains thorny. A major job for experts is to clarify the meaning of words and to apply terms rationally and correctly. Anyone who has tackled any significant issue knows the process well.

One may apply a variety of techniques for such purposes. One possibility is to take commercial procedures and modify them as needed. ‘Commercial procedures’ implies Stanford L. Optner’s ideas in Systems Analysis for Business and Industrial Problem Solving. This looks at industry and government, including the military. Is­sues may involve national security and military capacity: particularly tough topics of considerable consequence, and ones comprising a multitude of quantitative and qualitative components. Yet, exactly this sort of elaborate and intractable issue is so fundamental today.

Scientists and researchers are particularly involved in medium and large-scale issues, including air power. Resolving such issues entails creating new hierarchies or modifying existing ones, and adopting policies that may obtain over a long period. The longer the period, the greater the risk of failure. (Moreover, risk here may imply that a policy line initially makes things worse, improving them over a longer term.)

The issue of air power is topical in Bulgaria, a nation going through a trying patch in the history of its sovereign existence. Yet, air power has never been subjected to in­depth professional research, particularly as regards its role as an instrument for attain­ing specific political, economic or military objectives.

Why is air power topical? Because:

– it has existed, exists now, and will continue to exist into the future

– it has always presented planners with a broad range of options, does so now, and will continue to do so in future

– it calls for significant capital investment entailing large measures of risk

– it is highly dependent upon national scientific and technological potential

– it is an exceptionally convoluted and complex matter where decision making and implementation call on a whole range of disparate resources

– it is central to national security.

The methodology for addressing similar issues does not call for a precise definition of success. (Some systems analysis authorities even claim that such issues do not need too close a formulation to be researched.) However, national security matters such as air power and its role in armed conflict are overridingly important. Therefore, it is incumbent before specialists studying air power to define it, and the options for its development, to the greatest attainable degree of precision.

In pursuing the exercise’s objectives, one has to adhere scrupulously to objectivity and logic. Objectivity is essential in monitoring and data processing. Logic is a way of thinking which aims at rational conclusions. The body of evidence under considera­tion forms the substance of the transparency and clarity essential to such studies. Empirical monitoring is the process whereby data gathered forms a system, which in turn provides grounds for recommendations. The latter, in their turn, are logical con­clusions resting on properly selected fact.

As stated above, Bulgarian military science has not yet grappled with the meaning of air power. Due to post-Second World War historical divisions, it still employs Soviet terminology. Yet, contemporary realities call both for the introduction of air power as a concept, and for new ways of interpreting it. They would reflect contemporary na­tional priorities, and enable a proper appreciation of air power in the context of the recent conflict near Bulgaria’s Western borders.

While retaining the hierarchy of fundamental issues, it is crucial to redefine air power, and examine it as an element or subset of national power.

As national potential develops, so do science and technology. They in turn promote further development. National potential determines how nations rank in the world league: a nation’s ability to attain political, commercial and military objectives depends upon it. Never has this been truer than today, as leading na­tions (‘the Superpowers’) enter the information society. However, regardless of the era a country is in, its development depends on proper harnessing of whatever potential it has. National power may be defined as the extent to which national potential can be actualised in the pursuit of set political, commercial or military objectives. It determines a country’s vitality, its ability to endure hard times, and to go on to prosper.

If national power is the extent to which national potential is actualised, we may view it as the result of a process: the outcome of a system of mutually linked components. We may prove that such a system exists by noting its intrinsic com-

ponentry, and its point of entry (the presence of an object affected by the process at play within the system).

New realities require a broader view of national power as a whole, and of each of its components. In researching the issue, the fact that one is observing an open system in which air power is an entry point is significant. Once we agree to regard national power as a system, we also agree to examine its environs: finite objects with a definite influence on the system. Vital to the system’s existence, each of these objects is a source of input into the system. We may call the sources of national power ‘tangible’ and ‘intangible’ (Diagram 1).

Tangible sources include, inter alia, geography, economic potential, infrastructure, the extent of technological development, human resources, and the armed forces. Intangible sources include, inter alia, culture, ideology, national will and morale, gov­ernment powers and resolve, diplomatic skill, and significant political and military success or failure in the past.

Depending on the objectives set before it, national power may be military or non­military. This subjective distinction derives from the sources of national power, which may also acquire the same distinction in turn. The subjectivity deepens by the emer­gence of an information society in advanced nations. There, links between compo­nents of national power grow stronger, while bounds between them grow weaker.

Nevertheless, in your Author’s opinion, the distinction is still necessary because few nations are ‘advanced,’ remaining (according to Toffler’s definition) at the indus – trial/agrarian stage.

According to the same author again, industrial nations’ striving to retain a status quo that gives them world leadership and the ability to shape that world according to their interests, is natural. This striving is one of the reasons for sharp political and economic crises, frequently leading to the use of armed force.

Unarmed power derives from non-military sources that feed the part of the system relating to national political and economic potential. Armed power derives from the military. Both sources may be tangible or intangible, and determine the methods and resources used in pursuing objectives: political and economic, or military goals. The recent clash of arms in the Balkans bears out the correctness of such a classification: it has been degrading Bulgarian national potential for the past ten years.

Discourses on national armed power are particularly apposite in view of the na­ture of the issue under review. Armed power is the sum total of material and morale at national/class/international alliance level, and as the ability of that nation/class/alli – ance to mobilise these resources for combat objectives or in the resolution of other issues. Military prowess depends upon national business, social, scientific and techno­logical prowess, and national morale. A country’s armed forces and their ability to attain objectives set by political leaders are its direct expression.

>
Intangible Sources of National Power: -Culture -Ideology -History -National Will and Morale -Government Power and Resolve -Diplomatic Skill -Past Success and Failure in Peace and War
Tangible Sources of National Power: Geography – Economic Potential Infrastructure Technological Development Human Resources Armed Forces
National Power: The Degree of Actualisation of National Potential in Attaining Objectives
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•+>
Components of by Purpose
National Power and Source
Components of National	Power by Environment
On the High Sea and Waterways
In the Air
Extent of Actualisation of National Air Potential
Diagram 1: The sources and components of national power

Armed forces are classified according to their environment: army, airforce, and navy. The ability of each to perform depends on its armed power. Armed power is the totality of material factors and morale characterising the state of the armed forces and their ability to attain combat objectives. It depends directly on, inter alia: personnel numbers, morale and training, the quantity and quality of combat equipment, and good command. Armed power is the ability and potential to attain a set objective in the context of a specific set of conditions. The major components of armed power (Diagram 2) are:

– personnel and equipment in direct combat: people and machines basic to com­bat potential

– reserve personnel and equipment: technical and logistics backup providing sus­tainability

– command strength and mechanisms: management potential.

Combat potential is basic to armed power. It is the state and potential of person­nel and equipment in direct combat: those directly committed to attaining set com­bat objectives.

Before delineating the bounds of air power as a subsystem of national power, the point that national power is classified by environment (land, water or air) repays reiteration. This best enables countries to utilise land, water and air for objectives relevant to their prosperity and ability to endure.

Diagram 2: The components of armed power

Hitherto, air power theory has been the exclusive province of West European and United States’ theoreticians and experts. Attempts to formulate and explain air pow­er date back to the infancy of aviation. Concepts of naval power provided starting points. Early air power theorists borrowed ideas and basic postulates from naval war­fare fairly uncritically. This worked only occasionally.

The concept of naval power is firmly linked with Alfred Dyer Mahan. He defined naval power as the ability to use the seas for military aims, and thwart the enemy in doing the same. Mahan pointed out that the seas could be used not only as a setting in which to destroy enemy forces representing a genuine threat, but also as one in which to exercise indirect but nonetheless decisive influence on military potential. Mahan’s 1890 treatise, The Influence of Naval Power upon History, also contained the rather too absolute prescription of superiority as a prerequisite in all naval operations: nothing was to be undertaken before superiority was secured. What was needed was a large, centrally commanded fleet whose basic purpose was to destroy enemy capital forces.

Another naval strategy theorist, Sir Julian Corbett, regarded the high seas in their normal state as uncontrollable. His great contribution was to separate the attainment of superiority from its exercise, which he treated as a distinct aim of naval power. These twin aims in turn dictated different armaments, training, and unit structure. Specialists will readily find analogies with contemporary views of air power.

What is the nexus between naval power and air power? At the turn of the 20th Century, it was the striving to seek superiority or mastery in a largely uncontrollable environment. In addition, both naval an air power depended upon — and served the needs of — land operations. This gradually led to the triune configuration of national power, enabling nations to pursue their objectives not only on dry land, but also on the high seas, and in the air.

What were the properties of the new environment over which politicians and soldiers felt challenged to seek superiority?

The first and essential one is its universality. The earliest flying machines suggest­ed to strategists that the new leap of human ingenuity had a future: with develop – ment, it would render any point on Earth accessible, moreover at speeds unknown to land and naval vehicles. Speed gave the new environment its second advantage: greater mobility, granting intrinsic privileges to owners of flying machines. The third advan­tage stems from the ability to move in three dimensions, thus gaining a large measure of invulnerability. Graf Zeppelin’s dirigibles and the Albatros Company’s aeroplanes

abruptly ended a British geographical immunity bestowed by 36 kilometres (21 miles) of English Channel. This immunity had held since the Norman Conquest in 1066, yet henceforth no nation was beyond invasion from the air.

Early flyers grasped the opportunities offered by the new environment (viz. Profes­sor Charles’s views, and Orville Wright’s letters to his government almost a century hence). However, the first soldier and theoretician to state notions of the changes about to hit warfare, was Giulio Douhet. In 1909, this unknown artillery Maggiore wrote:

“It may well seem improbable that the sky shall turn into a battlefield no less important than the land and the seas. However, it would be better if we accept this probability now, and prepare our services for the conflicts to come. The struggle for aerial superiority shall be arduous, yet ostensibly civilised nations shall strive to pros­ecute war insistently, and with all means at their disposal.”[1]

By 1913, Colonele Tenente Douhet was firmly of the opinion that aerial forces must form a separate command. Criticising Italian high command strategy, he de­clared:

“Aerial space shall be independent. A new type of weaponry is being born: aerial weaponry. A new battlefield is being opened: the air. The history of warfare is being infused with a new factor: the principle of aerial warfare has been born.”2

The first military leader who not only saw the significance of nascent air power but also began active work to elevate it as a primary pillar of national power, was the Head of the German General Staff, General-Feldmarschall von Moltke. Before the First World War, he formulated and applied a programme for the promotion of this new weaponry, and for the creation of properly functioning Army and Navy air units.

During the Great War, Generals Trenchard and Mitchell were the first to breach the Klausewitz postulates on warfare (which Foche was following). British soldiers had principal differences with Klausewitz’s paradigms: they had attained and main­tained a 150 year superiority not through set-piece wars but through manoeuvre, lim­ited warfare, attrition and threat. Major General Trenchard and Brigadier Mitchell proved that rather than being tied to close support of the infantry, aerial forces ought to co-operate with them, yet pursue independent objectives.

Reviewing Tripolitanian, Balkan and Great War experience, Generale Douhet attempted the first definition of air power in his 1921 book, Command of the Air. He and subsequent theorists regarded air power merely as a tool for mastery, even after the advent of missiles. For instance, writing in the January 1956 issue of the Air Force Journal, Major Alexandre Seversky defined air power as a function of speed, height, range, mobility, and the ability to project armed power with pinpoint accuracy in time and place at maximum speed.

To this very moment, air power tends to be regarded as a component of national armed power. In this sense, its definitions tend to recycle general concepts of armed power and combat potential. Treating the airforce as a prime command, they address its armed power, combat potential, state, and ability to attain set objectives within a discrete timeframe.

However, there are grounds for believing that air power is in fact the rational combination of all means for operating in the air, and of all means for defending the national interest. Air power determines a country’s ability to harness the military and business benefits of the air for its own ends. In this sense, air power may also be defined as the extent to which national air potential is actualised: the extent to which the elements of national air potential are given tangible shape.

It is reasonable to regard air power as a system comprising components, links and dependencies. In unbreakable unity with their environment — the air — they display interrelationships that give the system its wholeness.

Specific historical conditions determine the significance of air power’s individual components. The dominating significance of its contents is a matter not only of today, but also of tomorrow. In the context of this volume, the military aspects of air power are particularly important, since your Author examines the current and future role of airforces in warfare.

The structure of the air power system is markedly hierarchical. It comprises basic components (ones instrumental in the performance of business or combat tasks), and elements influencing the performance of such tasks to one extent or another. The number of components and elements in the proposed system is not fixed. It, and the extent of their development, depend on a variety of factors and have a purely national character. These factors include, inter alia: degree of national economic development; priority objectives set before nations; major points in national military doctrines; and the political and geographical environment. For instance, most nations have chosen a tripartite armed forces structure; but some (like Israel, Saudi Arabia, Vietnam and former USSR) have a quadripartite structure, with air defence the fourth part. Never­theless, the principles for determining the major components obtain for the force structures of any nation with aircraft and an infrastructure for their operation.

These basic components of air power have been nominated (Diagram 3):

– the Air Force (including air defence forces, with the proviso that in the afore­mentioned countries they are separate commands)

– state and private airlines and general aviation companies

– the naval air arm

– police and border patrol air units

– state and civic air clubs and voluntary defence support organisations

– the air traffic control system

Repair & Airports Maintenance Network
Science & Research Establishment
Flying Schools	Manufacturing Base
Diagram 3: The Major Components of Air Power

– the entire air operations infrastructure

– the research and development (R&D), education and training (E&T), and man­ufacturing sectors.

A proper legislative base is crucial in delineating air power and ensuring normal function to its structures. While one cannot define it as a component of air power, it affects processes and task performance directly, particularly in peacetime.

One may regard each component of the air power system as a subsystem of con­stituent elements. For instance, airforces comprise units which discharge peace and wartime tasks. One may also regard aviation as one of these elements as a subsystem comprising types of aviation. However, your Author is loath to overanalyse the system and thus risk obfuscation.

Certain components of air power play a special role in its development. There­fore, they repay especial examination whose findings may be used as an entry point into the air power system. They are: the entire air operations infrastructure; R&D, E&T, and manufacturing.

Within the former, one may discern two basic elements: the repairs and mainte­nance sector, and the airports and airfields network. The R&D, E&T and manufac­turing component comprises the entire national science and research establishment, the aviation industry, engineering design and consultancy bodies, and flying schools. Although here these elements rank as mere parts of larger components, and although their presence in most nations’ air power systems is token or nonexistent, their signif­icance to flying and aviation is immense.

National air potential is the basis of air power. Air potential is the state and ability of the components of air power, or the state and ability of forces and material directly involved in task performance. It is not necessary to tap the full measure of national air potential at all times. The precise extent depends on many factors, chief among them the nature of tasks.

One may regard air potential as succour for the air power system, and as a system of several elements (Diagram 4) grouped according to the possibility of actualisation of air power components and elements. They may be regarded as an entry point into the system of air potential, whose final product is the degree of its actualisation.

The elements of air potential include:

– aircraft number and quality

– ground and air personnel numbers, training and career satisfaction

– air and ground equipment state and availability

– state and scope of available backup

– command structure powers and effectiveness.

Air power is the extent to which air potential becomes reality. The assessment of this extent is of necessity subjective. It depends on the extent of actualisation of

various elements of air potential. There are cases where for one reason or another components of air power, or elements of air potential, are missing or undeveloped. This does not mean that air power is absent, or that it cannot rise beyond a certain level. However, it does mean that the ultimate degree of air power is circumscribed.

Apart from depending on objective conditions, the extent of available air power may also be fixed by politicians and soldiers with a view to adequacy in the pursuit of set objectives.

The proposed view of air power makes it obvious that it is an element of national power able to discharge duties both in peace and in wartime. One may glean a fuller picture of its multifarious peacetime duties from this list:

Diagram 4: The Components of air potential 21

– deterring potential aggression

– assisting in disasters or crisis situations

– assisting national business, science and research

– patrolling and controlling national airspace

– maintaining combat readiness and preparedness for a smooth transition from peace to war.

Manifestations of the business role of air power include:

– state and private sector airlines

– R&D establishments and firms with interests in aviation

– the air design and manufacturing sector which bridges the gap between funda­mental research and manufacturing

– the aviation community (those who earn a living in aviation and related interests).

The airforce as a component of air power plays a special role in peacetime. As part

of the armed forces, it is able to display national armed power on the international arena. Politicians often make use of this to demonstrate a threat to adversaries. Ger­man politicians pioneered this use of air power. A similar display arsenal for the use of diplomacy was widely used during the Cold War and remains deployed today. Demon­strations of aerial might often allow the attainment of political objectives without recourse to combat: the mere threat of potential superiority or mastery supplants spilt blood.

In this sense air power has always been an instrument of national policy and a major buttress to peacetime diplomacy. This is helped by the nature of the airforce: constantly combat ready, mobile, and able to concentrate forces rapidly with great accuracy. The ability to influence adversaries simply because the airforce is there bring the creation of air power to the forefront as a priority national issue, and to the fore­front in international politics. Here, Bulgaria’s lack of an adequate level of air poten­tial, and the process of downgrading air potential (in progress as these words are writ­ten) erode Bulgarian leaders’ positions on the international arena.

At the same time air power, along with the other elements of national power, is there to defend the nation in case of attack. Thus, its importance for national safety grows in line with military threat. Primary expression of this aspect of air power is a country’s ability to repel aggression. However, this does not mean that air power ends with the airforce. One must interpret air power primarily as a nation’s ability to har­ness all resources and opportunities at its disposal to the end of utilising airspace. The basic aim here is to boost national prosperity, with defence as part of this aim.

Regarded thus, air power may to some definite extent be seen as synonymous with national economic prowess, whose inalienable constituent it indeed is. It is economic power that determines the level of armed power (hence also of air power); air power has both commercial and military origins.

The reason people invest air power with military meanings is mostly to do with international factors. Threat, and the concomitant need for defence, are immanent in international relations. In this sense, tasks before air power in a conflict include:

– controlling national airspace

– controlling enemy airspace

– continuous aerial reconnaissance and intelligence gathering using the advantag­es of the third dimension

– transport operations.

The relative importance of army, airforce, and navy, has always depended on po­litical and strategic considerations, geography, and international alliances. The army has played first fiddle in some historical periods; in others, primacy has rested with the airforce or navy. The place and role of each armed force in peace and war depends on the technical level of adversaries, their potential, and their geography.

Experience shows that each of the forces makes a definite and always significant contribution to victory. Over the last century (since the arrival of air power) there have been no pure infantry, naval or air wars; neither do military experts foresee any in future. One thing remains unaltered: only the army can secure the results of a campaign or a war. Its sheer physical presence on the ground consolidates the con­quests of hot conflict.

Conditions for the attainment of set objectives arise only where organised, well­armed, and well-trained armed forces are available. Each of them has a specific sphere of application, and modes of interplay with the others. The appropriate utilisation of this specificity determines the degree of success of an operation, campaign, or war. Precisely because of this, the pursuit of balance between the different armed forces (and within each of them) is a major procedure in modern military science. National interests guide this procedure closely as do, inter alia, tasks set by political and military leaders, political and military developments in the region and beyond, national po­tential, and geography. The procedure is also the key to a broader challenge: striking a balance between the components of air power.

In constructing air power, attention must be paid to blend its components most advantageously, and to maintain this blend thereafter. This is only possible after thor­ough scientific analysis of all influences on civil and military aviation. Balancing thus involves military science and addresses historical and technical developments. The issue of balancing also intrigues per se, inviting examination in an historical and mili­tary science aspect.

Military doctrine and national security postulates, as well as the national consti­tution, have to form the basis of balanced development of air power. They must deter­mine the role and place of air power and the airforce within the hierarchy of national power, and national armed power. They must fix its relative weight in the system, its

tasks in peace and war, and the composition and purpose of various force commands and civic volunteer formations.

A conclusion valid for nations with Bulgaria’s economic potential, is that balancing the components of air power means bringing them to a state and blend which allows air power to be multi-role (able to perform a variety of peace and wartime tasks).

In view of the basic requirements before air power (to perform set tasks using its peacetime strength while taking account of geography, and to manoeuvre using avail­able resources), another major procedure is to determine human and material strength. Here, it must be borne in mind that force renewal in today’s swift wars is highly problematic, and generally considered impossible. Thus, the issue of balancing and creating air power is mainly a matter of peacetime planning.

Balancing the components of air power is an ongoing process. It evolves according to historical circumstances. Major factors determining such evolution include: politics (changing balances, military blocs, and changes of regime); economic realities and changes in national commercial/military potential; developments in indigenous and world sci­ence; and changes in the tasks before air power. Tasks set by political leaders and the level of national economic development are prime among these factors.

History is replete with examples of defeat or distress resulting from poor (or non­existent) balance among elements of national power and components of air power. Most of these relate to financial straits, mistaken military doctrines, or short-sighted foreign policies. The national economy then has to make up for such defeat and distress.

Systems analysis represents system objects symbolically; denotes their structures (func­tion, links, organisation, and development), events, properties, objective laws, and for­mal relationships between them; and displays structural similarities, properties, compo­sition, communication, and development as evidence of functional system integrity.

To apply systems theory to a phenomenon means to study that phenomenon thor­oughly, but without recourse to classical experimentation. The aim is to discover the phenomenon’s structure and behaviour. This entails using methods from a number of disciplines. (Indeed, the benefits of the systems approach stem from the fact that it is isomorphic, breaching historical bounds between sciences claiming to study entirely different phenomena.)

Attempts to study air power as a system date back some decades. To your Author’s knowledge, Stephen Possony made the first such attempt in 1949. Writing on Ele­ments of Air Power in the Infantry Journal Press, he listed 15 elements of air power:

– materiel and fuel

– industrial potential; a high level of technological progress and instrument devel­opment

– a network of bases and forces to defend them

– communications and electronics

– logistics support

– auxiliary services

– airborne forces

– guided missiles and nuclear weaponry

– aeroplanes and other aircraft

– human resources

– training

– morale

– intelligence

– inventions and research

– tactics, strategy, and planning.

Possony then described the significance of each element, but ended his article short of stating the need to apply a systems approach.

The 1992 Air Force Manual exhibited a similar level of perception in treating the United States’ aerospace doctrine. Possony was cited verbatim, but without clarifying things in the least; what was omitted includes:

– the internal organisation of air power, and modes of interplay between its com­ponents

– the functions of air power components

– horizontal and vertical links between air power and other structured systems

– mechanisms and factors for system preservation, improvement, and development

– methods and phasing in air power development with a view to defining its histor­ical prospects.

But why examine air power as a system? Indeed, is the systems approach suitable to air power? It recommends itself because:

– air power is created by man and involves components with different natures

– air power has a purpose, and each of its components has an aim (tasks whose performance generally involves the air)

– the scope of air power is very broad, as witnessed by the variety of its compo­nents, and the number of functions and values involved

– air power is sufficiently complex to merit study as a unity. Any internal or envi­ronmental change begets other significant changes. Moreover, inputs and outputs are non-linear, which renders mathematical modelling both exceptionally complex and far too subjective

– inasmuch as adversaries always strive to downgrade air power, it contains an element akin to competition. In the aforementioned business systems, commercial competitors assume the adversary role.

In examining air power, the systems approach entails study of a series of aspects, each of them important, viz.:

– system elements

– system structure

– system function

– system communications

– system integrity

– system history.

The system elements aspect tells us what the system contains. The components of air power are listed above, along with their major elements where relevant. This ought to have made it clear that the system’s net product is to enable a country to use the air in the pursuit of its political, business and military objectives: a topical issue today. This issue has long represented a major priority before any national and military lead­ership that has ever set its public ambitious tasks for the pursuit of national prosperity. It has become particularly pertinent in the light of plentiful recent examples of the benefits of air superiority. These benefits stem from the advantages of three-dimen­sional space, great speed, manoeuvrability, the mobility and flexibility of airborne plat­forms, and the multiplicity of tasks performed.

The conclusion has to be that the system under review has a great many interre­lated properties. These properties do not derive merely from the properties of individ­ual components, nor are they reduced to them. They also depend on the environ­ment and on the elements and subsystems of components. Air power is part of the hierarchy of national power, and is itself a hierarchy: a complex system with a great many interdependencies. This renders formal mathematical descriptions practically impossible: such descriptions would transgress any levels of conditionality deemed useful in practice.

In this and similar cases, the systems approach is not a stage on the road to math­ematical modelling. The main task is not to employ mathematics to detail structures, links and functions —but to research trends. In Bulgarian conditions, this may be paraphrased as finding how to guarantee the retention of air power, and how to main­tain a reasonable level of air potential.

The system structure aspect shows how the system is put together, and how its components may interact. Though they may be shown as equal, the development of one or another of them is a matter of priorities and affordability. Factors determining the relative import and degree of development of individual components include:

– national economic potential

– political and military leaders’ air priorities

– national human resources’ potential (in demographic, intellectual and educa­tional terms)

– national scientific potential

– geography and regional geopolitical encumbrances

– heritage and development prospects.

The degree to which an air power component is present or absent affects the links between others, and may impose system restructuring. For instance, in Bulgaria an element of one of the components (flying schools) has to stand in for the entire head­line component (R&D, E&T, and manufacturing): the rest barely exists. (It must be stressed that the lack, or underdevelopment, of any system component degrades over­all system effectiveness. That is why balancing between components while keeping account of national interests and abilities is so necessary.)

The reason this system is proposed is to facilitate better understanding of the issue, and ultimately to promote better policy in its regard. The system may be used to determine the role of air power in the conduct and outcome of armed conflict. The formation of most components of air power is revealed when examining system func­tion aspects.

On the one hand, the system communications aspect helps delineate the system under review. On the other, it sets air power in the broader context of the system of national power. The formation of some components (due for examination later in the volume) was not only a process of emergence, but also of gradual fitting into the national power hierarchy, and of linking with land and sea power. We shall review this aspect in subsequent volumes, which will cover air power’s increased importance, and its attainment of equality with the other two elements of national power.

Today, air power is a decisive factor in the performance of strategic national tasks. This in no sense downgrades its functions in securing air superiority or mastery, or in offering adequate resistance in the defence of sovereignty over land or sea. On the contrary: it is the very ability of this element of national power to react most rapidly and appropriately to any threat, irrespective of where it arises, that gave it its domi­nating significance vis-a-vis the other two forces.

However, regardless of how great the success at the end of hostilities, consolidat­ing it is down to land and sea power. This mutual dependence has been confirmed repeatedly, and will continue to be confirmed in your Author’s opinion.

The system integrity aspect of air power cannot be regarded as a constant. As will be obvious from the very infancy of air power, the emergence of its various components was evolutionary and uneven in time. It continues to this day, and will continue. Air power is an open system; protagonists at its entry and exit points are both the tangibles and intangibles listed above (Diagram 1), and the tasks and objectives before it.

Air power’s system history is possibly its most important aspect in the context of this study. It provides answers as to how the system came about, what development stages it underwent, and what prospects it faces. History is basic to this volume, and it will inform future volumes in the series. The intention is to show how air power evolved into a system over clearly defined periods, and to attempt to glean general trends for the near future. Apart from that, air power is the product of various nations’ air po­tential: an item also subject to evolution in set periods, and to trends in the future.

The study of air power leads to these conclusions:

– Air power is among the major indicators of national economic and military prow­ess. It expresses a country’s genuine ability to utilise the air in the pursuit of its inter­ests. Thus, it is undoubtedly a primary element of the national security system, and a measure of national prosperity and potency.

– The benefits bestowed by air power and the possession of air potential stem from the air as an environment (high speed, long range, three dimensional manoeuvrabil­ity), and from the promise of further development as science progresses. The air al­lows high mobility, flexibility and universality, and offers politicians and soldiers rapid and effective solutions to complex problems. This helps rank air power as a prime element of national power. The primacy of air power, and its growing importance, means that it is a major issue that would repay study as a system with a set of clearly defined components.

– The number of components and the degree of their development express prior­ities and objectives nations set themselves. They are explicit in national security doc­trines and implicit in geography, and in the state of tangible and intangible sources of national power. This state varies with time. It also relates to the links between system components. In this sense, air power is a complex open system whose entry point features its components and their subsystems, and whose major source is air potential.

– Air power has a multipurpose nature in both peace and war. It is involved in a variety of tasks, each drawing upon a different set of components, thus calling for a proper balance which may be determined according to set principles and criteria. Experience shows that imbalance in component construction and development re­sults in limited ability to perform tasks, and degraded ability to tackle subsidiary tasks. In this connection, the balanced arranging of components, and their subsequent ma­nipulation in order to maintain a suitable balance between them is a challenge to national business, intellectual, and political leaders.

– The utilisation of air power depends on the proper interaction of components which are heterogeneous in nature. Thus, utilising air power does not imply merely summing these components’ potentials, but rather invoking an altogether higher de­gree of unity and potency. Attaining proper balance in the structure of air power depends to a decisive degree on the complex process of scientific management during

its construction and maintenance. This in turn may call for adequate funding; obtain­ing it ought not to be a problem, since air power is always a matter of adequate suffi­ciency in a national context.

– Armed conflicts are direct stimuli for the development of air power and air potential. They have played an unbroken shaping role ever since air power’s emer­gence. Experience from assigning one role or another to air power’s components has read across to military science, and to the formulation of national priorities as a whole. Armed conflict is an extreme state that most rapidly tests the veracity of peacetime assumptions. What is necessary is a thorough study of the influence of air power on the course and outcome of armed conflict (particularly of the influence of air power’s major wartime component: the airforce). Because of their properties, airforces also manifest themselves as prime instruments of national policy in a variety of historical circumstances.

The emergence of air power occupied a relatively brief period. However, this pe – riod was rich in the variety and dynamism of processes it witnessed. Events influenc­ing the emergence of air power and determining its place in the system of national power were numerous. Therefore, your Author proposes to review only the major ones among them. There is also a wish to forecast the future of air power in the context of the information society. Thus, subsequent volumes in the series shall re­view air power and conflict in successive periods:

– the First World War, featuring the rapid evolution of national aerial forces into separate commands able to tackle tactical tasks independently, influence operations, and undertake strategic duties

– the interwar period, marked by developments in doctrinal thinking, and by air power’s growing importance in periodic local armed conflicts

– the Second World War, which conformed airforces’ strategic significance as sep­arate commands equal to the army and navy in determining the outcome of strategic operations

– the postwar period, which witnessed the gradual imposition of a state where leading industrial nations honed their aerospace forces’ readiness to react to any threat immediately and in a measured way, and when these forces assumed the role of prime deterrent in international relations.

>

M

an has dreamed of flying since deep antiquity. Man’s restless spirit felt chal­lenged to master an environment God had denied, and to move in three di­mensions at a speed immeasurably greater than possible on the earth’s surface. The deep blue of the sky fascinated the eye and excited human imagination.

It was probably the thirst for flight that produced the beautiful and didactic story of Icarus. Told more than two millennia ago by Roman poet Ovid, it is the first record­ed expression of the idea of flight.

In 750BC, Cretan King Minos invited Greek sculptor Daedalus to construct a Labyrinth so elaborate as to render any escape impossible. Daedalus arrived on Crete with his son Icarus, and in fulfilling his commission created one of the Wonders of the World.

Reluctant to part with so accomplished a master, Minos did all he could to prevent his return. However, Daedalus decided to flee in a way the tyrant could not foresee. He gathered birds’ feathers and glued them together with wax, mak­ing pairs of wings for himself and Icarus. Training his son for the flight, he told

The legend of Icarus: a source of inspiration and a challenge to human ingenuity

him he would be safe at a height where neither waves would wet the feathers, nor solar heat would melt the wax.

Came the day of the flight, and the pair set off successfully. But when the best part of the journey was behind them, Icarus, taken with the experience and forgetting his father’s advice, shot upward towards the searing sun. The hot rays soon melted the wax, the wings melted, and the sea claimed the youth’s body. Ever since, a portion of the Aegean bears the name of Icarus.

The freedom that flight grants bestows many benefits in battle. Ancient strategists knew this. Their attempts to use flight in warfare employed neither aircraft, nor aero­statics and tethered balloons. It was the kite, invented in China 2300 years ago, that was used by the soldiers of the day to take observers aloft for the purpose of spying on enemy movements. Thirteenth Century Italian traveller Marco Polo observed such an ascent during his journey around China. The same nation also invented missiles (rocket pro­pelled arrows) in time to use them with some success against Mongol invaders in 1232AD.

Kites and rockets later spread to medieval Europe. There is no written confirmation that Europeans used kites to haul men aloft. However, rockets had been tested in battle by the middle of the 15th Century. Though fitted with fins, up until the late 19th Cen­tury they were unstable and imprecise, and this in­hibited their popularity among soldiers.

Be tween 1475 and 1505, scientific genius Le­onardo da Vinci worked on the problem of ena­bling man to inhabit the air and descend safely. His paper entitled On the Flight of Birds dealt in part with how man could copy birds’ movements and hence their ability to fly. Arriving at certain conclusions, Leonardo described and drew appa­ratus for flying. His orni – thopter had the body of a boat, controllable tail sur­faces, and a retractable
undercarriage. Borrowing from nature,

Leonardo formulated principles of lift, and methods of attaining stable control­led flight. In order to increase the sweep of each wing stroke, he employed the combined strength of arms and legs. In his declining years, aware of man’s in­adequate and waning physical prowess, the genius directed more attention to fixed wing flying machines. In the clos­ing year of the 15th Century, he devised an ornithopter with partially fixed sur­faces, and a technique for gliding dur­ing which ornithopter flyers could re­coup their strength.

Leonardo’s helicopter also relied upon muscle power. Its wing was shaped like an Archimedean screw which pushed air downward as it spun. Toys employing this principle had emerged in the first quarter of the 15th Century, and their descendants are available today.

Leonardo even proposed an early parachute. His drawing of it states that if one owns a tent whose sides are 12 sajena in breath and width, one may safely jump from any height. The inventor’s manuscripts archived in Paris contain a sketch of a man

descending with the aid of a flat rectangular surface. Control is stated to be possible by tilting the surface. It is likely that the idea came to Leonardo as he watched sheets of paper fall.

In Leonardo’s day, science and craft had not advanced sufficiently to attain the desired result of flight. One man’s efforts, notwithstanding his genius, were insuffi­cient to accomplish the required leap. Human progress follows its own logic. During the 17 th Century, Englishman Robert Hook and Italian Giovanni Borelli independ­ently reached the conclusion that human strength on its own was insufficient to haul man aloft. Hook succeeded in building a working model of a powered ornithopter, but no documents survive to tell us what it looked like.

In 1643, Italian scientist Torricelli proved the exist­ence of air pressure. Eleven years later, his discovery was confirmed by Otto von Gerricke, an inventor of gauges.

The latter undertook a rather impressive experiment. The air was drawn from a smallish sphere comprising two equal parts. Then each hemisphere was harnessed to eight pairs of horses which tried to separate them: an impossible task.

This led von Gerricke to conclude that similar lightweight spheres filled with rarefied air might be able to fly.

Developing von Gerricke’s conclusions, Italian re­searcher Francisco de Lana Torzi published a treatment describing an aerial ship. This consisted of a boat with sails, 1485
to which were attached four vacuum bal­loons. Torzi claimed such a device might launch rockets to scupper enemy ships or raze enemy cities. From that moment on­ward the idea of using the air in battle was no longer new. Torzi’s project was unfeasi­ble: the materials available would either have made the spheres too weak to with­stand atmospheric pressure as the air was drawn out, or would have been so heavy that flight would have been unthinkable. Ideas of similar apparatus reappeared in the early 20th Century as aluminium alloys be­came available.

Dutch scientist and mechanic Cristiaan Huigens (1629—1695) left a wealth of pa­pers. One of his inventions was a pilotless drone with two airscrews spinning in op­posing directions and powered by twisted and stretched animal tendons: a prototype of today’s bungee chord-powered flying models. The wings were rectangular and had upturned tips for lateral stability. Hui – gens’ airscrews were the first proposal to use blades for motive power in the air. Their prototypes must have been the innumera­ble Dutch windmills, which Huigens is known to have studied over an extended period. No record suggests that this drone was ever built and flown, yet the drawing alone is evidence that Huigens overtook developments by over a century.

Bernouli’s classical work on hydrody­namics appeared in 1738. In it, the Swiss scholar laid the basis of today’s gas dynam­ics by clothing the theory of gas kinematics into mathematics.

Scientists were not alone in showing the way to flight. In 1742, the Marquis de Bac-

—————————————— >——————————————–

queville decided to cross the Seine by air. Having strapped wings to his arms and legs, the sixty-year-old jumped into uncertainty from the roof of a tall Paris hotel. Before the gaze of numerous onlookers, he managed to cover the great distance across the river before falling into a boat moored off the opposite bank. The feat is commemorat­ed in many engravings, and a detailed description of the event survives.

In order to measure air temperatures a thousand metres above the ground, Al­exander Wilson from the University of Glasgow attached a thermometer to the tether rope of a kite in 1749. Three years later, statesman and philosopher Ben­jamin Franklin barely avoided electrocution while studying the nature of lightning with the aid of a kite.

While researching meteorology and gas physics, Russian scientist and researcher Lomonosov also pondered how to elevate measuring apparatus to a great height. At an Academy of Sciences meeting on 4 February 1754, he delivered a general descrip­tion of an Aerodynamic Machine based on Leonardo’s helicopter. Later that year, Lomonosov delivered an account of experiments with the Machine before the Aca­demic Council. Sadly, the experiment had been a failure. For the next half-century, attempts to build heavier-than-air flying devices were confined to small-scale devices more reminiscent of toys than businesslike machines.

The separation of hydrogen, and the devising of a process for its production in quantity by Henry Cavendish in 1766, marked a leap in human attempts to shake off the bounds of Earth. The discovery drew the attention of scholars on both sides of the

I Marquis Bacqueville overflying the Seine

Channel. A decade later, chemist Joseph Priestley published a number of experiments from research with gases.

These efforts gave a powerful impetus to the creation of lighter-than-air flying apparatus. However, the first ascent of a balloon took place far from Europe, and independent of European discoveries. Vanconne, a French missionary in China, came across a document dating back to 1624 in the Peking State Military Archives. This described how, during the celebrations marking the accession of Emperor Fo King in 1306, a hot-air balloon had been launched into the air. The event had remained unknown in far-off Europe, and the chance finding of its written record had no influ­ence there: however, the natural progression of events did follow its logic.

French paper manufacturer Joseph Montgolfiere who lived and worked in An – onis, 55km south-west of Lyons, was one of Priestley’s readers. In 1782, he embarked on a series of experiments with balloons, all making use of the known fact that air is lighter when heated. He burned organic materials to obtain volatile gases, and con­ducted the first trials indoors, using small balloons made of thin silk. Filled with hot air obtained from burning paper, these floated to the ceiling. Later, Joseph successfully tested a balloon with a diameter of 3.5m, which he had made with the help of his brother Etienne.

Encouraged, the brothers embarked on making an 11.4m diameter sphere which they believed would be able to haul a man aloft. The balloon was made of paper-covered broadcloth. The official demonstration on 5 June 1783 was a great success. After the

I Etienne Montgolfier, 1745-1799

I Josef Montgolfier, 1740-1810

I Professor Charles’s first balloon goes through Paris escorted by guards

balloon was duly filled with hot air, its guy ropes were cut and the vessel rose aloft. On reaching a height of 2000m, it descended two kilometres from the place of ascent. The Mongolfieres sent an official record of the event to the Paris Academie des Sciences.

This achievement by a non-scientist was a challenge to metropolitan scholars, who felt slighted by a provincial backwater taking the lead. An appeal quickly raised 10,000 francs. By resolution of the Academie, Parisian scholars turned to 37-year-old Physics professor Jacques-Alexandre Charles. The young scientist took up the chal­lenge with verve. Hiring the artisan brothers Robert as assistants, he ordered them to make a sphere of fine taffeta with a rubber backing, a diameter of four metres, and a volume of 33.5cu m. He decided to fill this with the newly discovered gas, hydrogen, which is 14 times lighter than air. Preparations for the filling began on 23 August. An enormous crowd gathered to watch. Three days later, filling was pronounced satisfac­tory to lift the balloon to a height of 30 to 35m. Held down by ropes, the flying ma­chine passed triumphantly through the streets of Paris to the Champs de Mars escort­ed by mounted guards. The ascent was set for 27 August. After a 45-minute flight, the balloon landed near a village 25km from Paris. Taking it for a monster, the locals there had it dismembered into small pieces in a matter of minutes.

After an unsuccessful ascent attempt on 19 September, the Montgolfieres organised a demonstration before the Royal Family at Versailles. The balloon had a 13.5m diame­ter and a volume of almost 1300 cu m. The ascent was to a height of just 600m, the flight

The Montgolfier brothers’ demonstration before the Royal Family at Versailles

I The first ascent of a hydrogen-filled balloon on 1 December 1783

lasting eight minutes. After a soft landing four kilometres from the Royal stand, the pioneer­ing Aeronauts were recovered safe. Louis XVI and Queen Marie-Antoinette were impressed and congratulated the Montgolfieres on their success.

Observers of the Versailles demonstration included 26-year-old physicist Pilatres de Ro – sieres. He was later to devise a tethered bal­loon and accomplish several test ascents dur­ing which he took additional fuel into the gon­dola. He proved that ascent and descent could be controlled by the rate of combustion. On 21 November 1783, Rosieres and the Mar­quis d’Arland were the first to make a free flight in a man-made apparatus. This had the impressive size of 14m diameter and over 1400m3 volume, and enabled eight kilome­tres to be covered in 25 minutes.

A hydrogen balloon departed the Tuilleries on 1 December 1783, carrying Profes­sor Charles and the elder of the Robert brothers. Having flown for two hours at a height of 650m and covered 40km, they descended to a soft landing by dumping part of the hydrogen through a specially designed valve. Robert stayed on the ground, while Charles ascended to 3500m.

French success did not remain unnoticed elsewhere in Europe. In February 1784, Paolo Andreanni of Milan accomplished the first Italian flight in a hot-air balloon alongside the two artisans who made the balloon. The flight lasted 20 minutes. Seven months later Vicenzo Lunardi de Lucca, a clerk at the Neapolitan Embassy to Lon­don, ascended from the Honourable Artillery Company’s grounds in Moorfields in a hydrogen-filled balloon, accompanied by a dog, a cat, and a pigeon. He flew for 33km, attempting to control flight altitude and direction by means of paddle-like surfaces.

The title of first British aeronaut, more for courage than achievement, goes to James Titler of Edinburgh. In the late summer of 1784, he employed a crude balloon and the properties of hot air to make a couple of brief hops into the air. The first such hop was on 25 August: three weeks prior to Lunardi’s historic flight. The second and last hop was on 1 September. However, the pioneer British aeronaut in the proper sense was James Se – dler. His first ascent was on 4 October 1784, when he covered the distance between Oxford and Islip in a hot-air-balloon. His next flight was on 12 November. On that occasion he used hydrogen to fill the balloon, hoping for a more notable result. And

indeed, the change proved justified: he covered the 23km from Oxford to Hartwell in 17 minutes. In 1785 Sedler made five flights which included an 80km flight. He then gave up ballooning for 25 years.

Other feats, which made aeronautics something of a craze rather than a risky pur­suit, included the ascents of Francois Blanchard. If we exclude Lunardi, Blanchard was the first professional aeronaut. Accompanied by anatomist John Shelton in a hydrogen- filled balloon, on 16 October 1784 Blanchard covered the 115km from Chelsea to Ram­say in Hampshire. Success drove the Frenchman undertake a risky attempt to fly the Channel. The epic 12-hour flight took place on 7 January 1785, in the company of American Doctor John Geoffrey: financier of the attempt determined to convince him­self that the aeronaut would not cheat. Between 1785 and 1789, Blanchard made a series of demonstration flights in various European countries, using hydrogen more of­ten than hot air. He set a 480km distance record with the aid of air currents.

After the start of the French Revolution, Blanchard was accused of anti monarchist propaganda in Austria and was arrested there but managed to flee to the USA. There on 9 January 1793 he performed the first ascent in America. This was in Philadelphia, using a hydrogen filled balloon. Returning to France in 1798, he resumed receiving the

pension awarded him by Jouis XVI on the occasion of overflying the Channel.

This exceptional man died of a heart attack in 1809 after his 60 th ascent.

Aeronautics claimed its first victim all too soon. Two years after his first as­cent, Pilatres de Rosieres perished while attempting to fly the Channel, taking with him co-traveller Pierre Romain.

Before Englishman Charles Green used lighting gas in a balloon, a serious drawback of hydrogen was the consider­able time and effort expended in filling balloons. Hydrogen could not be gener­ated in flight; ascents could only be made where the heavy process plant and none too widely available materials could be procured. On the other hand, hot-air bal­loons needed nothing more than match­es, readily available fuel, and a furnace box. However, they had limited endur – ■ The death of Pilatres de Rosieres ance and payload. In both cases, aero­nauts were at the mercy of wind speed and direction: Lunardi’s and Blanchard’s guidance devices were of no help at all. Balloons strictly followed the wind. A dirigible could not have been built in the late 18th Century due to the lack of any suitable powerplant.

The above account forms the background to the formation of the first component of nascent air power: the invention of a sufficient number of reliable flying machines. Initially, balloons were used for research; but the issue of their other uses arose soon enough. Charles’s Flying Sphere made him ponder possible applications. Seeing far beyond the 4m diameter sphere, the Professor stressed balloons’ military promise in letters to friends in Philadelphia, London, and Vienna.

Data on enemy positions, movements and actions on the battlefield and beyond were considered the key to military success. The use of spies and informers always put their lives at risk. The cavalry was trained for rapid raids around the field of battle, partly to discover enemy locations. Invariably, the purpose was to determine the sta­tus of the other side: to ‘look over the hill’ or over the horizon, so to speak. And even while still primitive, balloons were ideal for this purpose.

In 1794, an anonymous French author published a monograph, LArt de Guerre change par l’Usage de Machines Aerostatiques. This early study of the significance of

balloons in combat claimed that they could lead to a sea change in the art of war. In the early 1790s, the eminent chemist Guiton de Morveaux laid down the basics of aerial re­connaissance by tethered balloon. French Army officer Meunier, a capable engineer and physicist, presented a paper describing gas balloons’ safety and stability before the Academie des Sciences. He went on to make a spherical balloon with the basic propelling and controlling devices of an elevator and three large propellers. Meunier’s remarkable project embodied all achievements up to that moment. Its major disadvantage was the lack of an engine: in its absence, the designer had to rely upon the combined muscle power of the balloon’s occupants.

France became embroiled in Revolution and the war against Austria. Meunier was killed near Meinz in 1793. On 14 July the same year, a Convent session approved the use of balloons for military purposes. Means and premises for war balloon produc­tion were set aside, with the proviso that sulphur oxide, vital to the artillery, was not to be diverted for hydrogen production. An officer, Jean Coutelle, was put in charge of testing. He managed the task of obtaining large amounts of hydrogen in field con­ditions brilliantly. The first installation was built near Meudon. Meanwhile, an elastic varnish had been discovered to seal balloons against gas leakage, treated balloons maintaining their shape for two to three months. Tests of the LEntreprenant combat balloon intended for quantity production ended successfully, and in April 1794 the basis of the eventual planned Balloon Division was laid. Initially, it comprised a single Balloon Company. To try out the Eyes in the Sky concept in combat, the Convent ordered Captain Coutelle to Belgium at the disposal of General Jourdain. The latter, and the majority of officers viewed the new arrival with incredulity.

On 2 June 1794, Capt Coutelle took his place in the gondola along with his assist­ant and gave orders for ascent. Two groups of soldiers, each 32-strong, began releasing the guy ropes. Soon the aeronauts were a thousand feet up and began history’s first aerial reconnaissance, comparing their maps with the battlefield they surveyed.

When the Battle of Mobeuge began two days later, General Jourdain’s Adjutant Morleaux was in the gondola alongside Coutelle. Over the next eight hours, the two sent a stream of messages regarding the rapidly evolving situation. The battle was won with the active help of the aerial observers.

I The Battle of Mobeauges: the use of an airborne vehcle in warfare becomes fact

Regardless of the heavy intallations, some of them stationary and having to be built in situ, the balloon was shown to be a reasonably effective means of observing and directing artillery fire. General Jourdain’s command sent apologies for its initial doubts. A new order sent the Balloon Company to the aid of French troops near Fleurix, some 20km distant from its camp.

The journey turned out fraught. The balloon was transported erect, tethered at a height sufficient to clear roof tops. Coal dust smokescreens masked its progress. Fif­teen hours after it had set off, the unit was ready for action.

The French Army faced difficulties. After heavy battles for control of Charleroi, Gen Jourdain split the 73,000 men under his command into three, posting them west, north-east and north of the city with the order to defend it. The approaching Allied Army was of approximately the same size, but its commander, Prince Ferdinand of Saxe-Coburg-Gotha, made a fateful error at the outset. He split the attackers five ways and set seven directions of advance. The tactic was not unusual in its day, but the Austrian noble had no inkling of the new French way of getting reconnaissance.

On 29 June 1794, Gen Jourdain himself is likely to have been in the gondola along with Capt Coutelle. The two men witnessed an impressive sight. Camouflage and decep­tion were arts that would develop over a century later (indeed, a reason for their late

development was the prior lack of means to observe armies from the air!). Allied units in bright, elaborate uniforms, made not the slightest effort to hide their thrust towards French positions. Each infantry regiment had its own distinctive wear. All this eased the French command’s orientation in the course of battle, and helped it adopt correct decisions.

Coutelle would observe the battlefield through a telescope and apply his findings to a map. Individual units’ bright colouring clearly delineated infantry from ulans, Dragoons and other armed units. The first aerial spy determined cavalry and artillery strengths rather precisely, pinpointed the site of the Austrian Command, and noted backup units arriving from up to 60km off. Several-hour long sojourns in the air were by now routine. Coutelle would periodically tie his information to bags of sand, and would lower it to the ground by long lengths of string. Thus, according to researcher Hodgston, “the information sent as signals to Gen Jourdain was a proven material factor in securing French victory over the Allies.”

The Battle of Fleriux was the first in human history in which an air unit was employed in a planned and purposeful fashion. The result was a practical example of the benefits the new environment bestows. Following the brilliant despatches regard­ing the activity of the Balloon Company, preparations for forming a second such Com­pany started as early as 23 June. By late summer, four balloons were in active service,

Щ The Battle of Flerius

each with ground equipment, aeronauts, and backup crews. They helped achieve victory at Urtes near Liege and reconnoitred at Augsburg, Stuttgart, Vorzburg, and Donauworth, providing valuable information on enemy movements.

However, enthusiasm was short lived. After successful operation in Europe, Capt Coutelle’s Balloon Company accompanied Napoleon to Egypt in 1798. Before the unit could unload its equipment at Abukir near Alexandria, Counter-Admiral Nel­son’s main British fleet appeared. The battle of 1 August reversed plans for the con­quest of Egypt, and the Balloon Company’s property was completely destroyed.

Upon returning to France the following year, Napoleon disbanded the Aeronauti­cal Division. The testing and training establishment at Meudon also closed. On the one hand, this could be seen as an expression of the young Emperor’s vain belief in his infallible ability to divine enemy locations and intentions. On the other, the decision was not devoid of some merit. The poor reliability of tethered spherical balloons, the arduous transportation of heavy equipment, and the lengthy gas filling cycle ham­pered the mobility of associated units, particularly artillery batteries, for whose benefit the balloons were supposed to act. Nevertheless, some Napoleonic Wars researchers claim that the availability of balloons might have saved the Emperor from defeat at Waterloo, changing the course of subsequent European history.

I An artist’s impression of Napoleon’s plans to invade Britain

I The Meudon balloon manufacturing workshop

Barely emergent aeronautics had already influenced the art of war. Some of the componentry of air power, slated to become topical a century hence, was also in place. Despite its inherent lack of safety and stability, flying apparatus did exist, providing platforms for aerial reconnaissance. Also available was personnel, poorly trained though it was. Another component was the ballooning school, though service units lacked a proper method of training which took account of the specifics of warfare. Airborne and ground equipment was still rather primitive. Observation was through standard field telescopes which were rendered unusable by any stiffish wind at altitude. Thus gondola crews did little more than look out onto the battlefield, albeit in some depth behind enemy lines. Backup means also emerged.

Limited finance delayed the creation of a manufacturing base, and ultimately the Emperor’s hasty decision destroyed what little had been achieved. There was no sys­tem to govern the actions of aeronauts, nor was there any systematic method of com­munication between officers on the ground and in the air. Information transfer meth­ods were also primitive, as could be expected of the period. In certain situations this rendered balloons useless.

However, all this ought not to obscure the main point in any way. It was another six decades before military men were to return to the air: this alone shows French strategists’ forward thinking in battlefield assessment during the Revolution.

Pioneering attempts to overcome gravity with heavier-than-air apparatus date to about the same time. In 1784, Frenchmen Lenois and Bienvenue demonstrated a heli­copter model in Paris. This had an elementary clockwork motor which transmitted power to lifting blades calculated to lift the model off the ground at a certain rotational

I John Cayley, 1773-1857 ш A drawing of Cayleyfs helicopter, 1796

speed. As in the case of Lomonosov thirty years prior, no documentary evidence on this test reaches us to enable an assessment of its contribution to aviation.

In 1796, Yorkshire Baronet and philanthropist Sir John Cayley combined his pe­cuniary means and remarkable engineering bent to create another working model of a helicopter. This was essentially identical with that of Lonois and Bienvenue. After some improvements, he demonstrated it in public, causing interest on both sides of the Channel. Money was raised by voluntary subscription and with it the Baronet set up a charity with the major purpose of creating a heavier-than-air flying machine.

Given the choice between lighter-than-air and heavier-than-air flying machines, almost all inventors bent on conquering the air focused on the former: it seemed that balloons would do the job more easily. Cayley was one of the few who stayed faithful to the idea of dynamic flight. It is to him that we owe the theory of flight with fixed wing aircraft. He viewed the motorised aeroplane as a kite whose towrope had been replaced by an engine, and formulated the real issues of powered flight: using the wing surface to create lift, and overcoming drag. The lack of suitable engines directed his attention to gliders. Cayley reached the conclusion that in them (excepting towed gliders) the re­sultant force of the structure plus a man or other load could overcome drag.

For his first attempt to test this contention, Cayley designed a boat-like flying machine with a wing square in plan and set high at a slight angle to its longitudinal axis. Tail surfaces provided longitudinal and lateral control. No evidence exists that a model was built or tested. However, despite its shortcomings, this represented a step forward to the creation of an aeroplane. For the first time, we have the basic compo­nents in place: fixed wing, fuselage, and empennage.

I A drawing of a typical early Cayley aeroplane model

Having gathered theoretical knowledge, by 1804 Cayley built history’s first freely flying model of a fixed wing flying machine. The wing has an area of 0.1sq m and six degrees’ fixed angle of incidence to the fuselage. The model had a cruciform empen­nage for control and trim. Testing proved that flight was possible with fixed wing apparatus, the glider covering distances from 18m to 27m at a speed of some 5m/sec.

Meanwhile, ballooning continued to be a pursuit for the wealthy, a trade for the reckless, and a wide-open field of research. A scientific flight was recorded in Russia on 30 June 1804. This was preceded by several Academy of Sciences’ sessions which discussed the programme and listed materials and gauges the researchers needed. The actual flight was held up to await the Tsar (who never arrived). The crew did finally fly at a quarter past seven in the evening, by when conditions were against them (at dusk the gas cools and its lifting power declines). Weather conditions limited the ascent to not more than 2000m. Nevertheless, the test programme was accomplished. It proved that altitude could be determined by echo sounding: directing sound at the earth’s surface, and measuring the time it took to reflect back up to the balloon. The crew stayed aloft for three and a half hours and landed 30 versts from Sankt Peterburg. Before landing they lowered a bundle of unnecessary items to the ground, this being the first guyrope in history.

In the second half of 1805, Staff Doctor Kashinskiy made a demonstration flight over Moscow. Prior to the event, his aerostat was displayed to curious Muscovites at the Grand Hall of the Petrine Theatre.

After Blanchard and Robertson’s successful flights over the Austrian capital, Vien­na clockmaker Jakob Degan set off to make a controllable flying machine. He studied aeronautical literature in detail and paid particular attention to ornithopters. Using reed, oiled paper, silk thread and timber lathes, the structure he produced weighed just 14 kilos. Degan made several flight attempts and concluded that success required the attachment of his ornithopter to a hydrogen balloon. On 12 November 1808 he suc­ceeded in staying airborne for some minutes before a huge crowd. There was a definite impression of control, since the apparatus alternately lifted, descended and moved side­ways. The effect was astonishing. The Austrian Emperor awarded Degan 4000 guilders, and Austrian newspapermen spread the news that controllable flight had been achieved

A contemporary drawing of Jakob Degan and his strange flying contraption

throughout the Old Continent. However, foreign newspapers sowed doubt as to the authenticity of the flight. To dispel them, Degan travelled to Paris in 1812.

On his first attempt on 10 June, he failed to become airborne. The same hap­pened on his second attempt on 7 July, despite widespread reports that he flew but failed to manoeuvre as required. The third attempt took place on the Champs de Mars on 5 October, and was also a failure. The angry crowd attacked the ‘prestidigita – teur,’ reducing his apparatus to pieces. The papers declared Degan a charlatan and soon the name of this industrious and intelligent man was forgotten even in his homeland.

On 17 July 1817, Whitham Sedler, younger son of James Sedler, crossed the Irish sea from Dublin to Anglesea by hydrogen filled balloon in five hours. In 1836, Charles Green broke all distance and endurance records in ballooning in the company of two fellow travellers. In 18 hours he covered the 800km from London to Wilburg near Frankfurt. He filled his balloon with lighting gas which offered less than half of hydro­gen’s lift but was cheaper and more easily produced.

Three years after Green’s remarkable flight, American aeronaut John Weiss designed and fitted a special rapid gas discharge flap to a balloon, enabling rapid descent in emer­gency. His invention significantly improved safety and subsequently became standard. Weiss’s successes did not end there. In 1859, accompanied by John la Mautin (‘Gegard’)

I The later version of Jakob Degan’s flying machine Щ Charles Green, 1785-1870

and a newspaperman, he flew the 1300km form Saint Louis, Missouri to Henderson. Encouraged by this, the trio decided to beat their own record and fly the Atlantic using their proven balloon. However, the idea remained in the realm of intentions.

Their major competitor was another American professional aeronaut, Thaddeus Loewy. Also aiming to conquer the ocean, he had designed a balloon with an even larger volume. A sudden whirlwind an hour and a half prior to departure put an end to the flight by destroying the balloon which was being filled at the time.

Meanwhile, Cayley had accumulated much knowledge and experience in heavi – er-than-air flying machines. One of his greatest achievements was to conceive the first multi-plane flying machine. In 1849, forty years after his first fixed wing aircraft, he assembled a triplane with auxiliary manually activated flapping surfaces. Cayley’s rationale in adopting a multiple wing consisting of three surfaces one beneath the other was to reduce span (and hence weight), while keeping wing area (and hence lift) unchanged. The Baronet’s coach driver and a ten-year-old boy tested the ma­chine: pulling it downhill or into wind, they attempted to get airborne. Sadly the best results were counted in metres: wing aspect ratio was insufficient, and the three wings were too close to each other, resulting in poor lift.

I In his historic 1836 ascent, Charles Green flew a distance of 800km

Щ A sketch of Cayley’s triplane

Cayley followed this up with a series of gliders in which he incrementally im­proved various elements, reducing drag and improving stability. In 1853, the last of these flew 60m. Over almost half a century the Baronet published a number of papers, some giving ‘masterclasses’ on the principles of flight aerodynamics and controllabili­ty, and others dealing with emergency escapes from balloons using aerodynamically stable gliders. These caused much interest and their ideas found adherents.

One such adherent was William Samuel Hanson, manufacturer of rope and lace making machines. In 1843 he registered a patent for an Aerial Steam Car for the transportation of mail, goods and persons by air. Though never built, the project marked an important step forward in aviation. It was the first design to envisage all basic elements of propeller aeroplanes of a century hence, and was the first aircraft to capture the mass imagination. No book on the history of aviation is complete without a mention of this exceptional machine. It was a high wing monoplane with two six-bladed pusher propellers. The fuselage was completely faired and contained the steam engine, fuel, and room for freight and the crew. The Steam Car had elevators and rudder, and wheeled landing gear. Takeoff was to be accomplished along a downward sloping surface. To reduce the weight of the powerplant (a 25/ 30hp steam engine), the designer replaced the usual steam boiler by a series of cone-shaped vessels and air condensers. Calculated gross weight was some 1350 kilos, wing area was 420sq m, and the empennage measured 140sq m. The design’s most significant advance was the choice of motive power: flapping surfaces were abandoned and propellers proposed.

Hanson’s Steam Car was never built, but drawings and artist’s impressions of it travelled the world, begetting much discussion. Decades later, aeroplanes with an

An axonometric cutaway of Hanson’s Steam Car taken from its patent licence

I An artist’s impression of Hanson’s Steam Car in flight

identical configuration (but with engines using a completely different working princi­ple and having significantly greater relative power) would take over human attempts to conquer the air.

On concluding his project, Hanson and his friend Stringfellow built the first mod­el aeroplanes. The third such scale prototype was built almost entirely by Stringfellow due to Hanson’s leaving for the America. All models looked like the Aerial Steam Car and had miniature steam engines. The largest weighed 12kg and had a span of 6.7m. Insufficient power rendered them unable to perform genuine flights.

Early work on heavier-than-air flying machines did not attract visible military inter­est. During the half century from the French Revolution and the first use of airborne apparatus, only British Admiral Knowles suggested the use of tethered balloons for Navy needs. British conservatism had the final word and the idea was rejected.

Austrian troops suppressing the 1849 Italian Risorgimento against the Habsburg Empire fought long and hard against the defenders of Venice. The lagoon city was invulnerable to artillery fire from dry land, so the command of the besieging army decided to use airborne devices in a novel way: to bombard the city form the air. Their 82 m3 hot-air balloons were made of non-porous paper. Below the ventral aperture was a ring to which were attached 15kg explosive and incendiary bombs.

I Photograph of one of Stringfellow’s aeroplane models from the late 1840s

Dropping and activation times were governed by the length of fuse which was light­ed a short time prior to the start of ascent. Each bombing run was preceded by a trial ascent to determine wing speed and direction. A launch site was then chosen and flight time to overhead the target (and hence the length of fuse needed) was calculated. The average launch time was almost six minutes. The idea was to make some 200 sorties, each lasting about half an hour. A hundred balloons were pro­duced, but despite the idea’s originality, it did not work well in practice. This was due to the poor selection of launch sites, changes in wind direction and speed, and a variety of other reasons. Those balloons that did reach their targets caused only slight damage. However, by mere fluke one such bomb landed right in the city cen­tre, on the Piazza San Marco, and showed that even ineffective aerial bombard­ment could visit much distress upon the public.

During Napoleon Ill’s 1859 Italian Campaign, the French army tried hot air bal­loons for field reconnaissance, but their shortcomings limited endurance and they were not used in combat.

Щ Drawing of Pierre Julien’s dirigible

I Drawing of Henri Gifard’s dirigible in flight; note the gondola and the net by which it is suspended from the balloon body

Controllability was proving an insuperable problem. Powerplant progress was rap­id from 1850 onwards. French clockmaker Pierre Julien demonstrated an aerodynam­ic model of an airship driven by two propellers actuated by a clockwork engine.

Public acclaim for the model made talented engineer and inventor Henri Gifard design a controlled lighter-than-air flying machine. This was driven by an enormous propeller actuated by a 3hp steam engine. Powerplant weight, including the steam accu­mulator, came to some 150kg. The balloon body was faired so as to be longitudinally symmetrical, with pointed ends. For safety, the crew, engine, fuel and ballast were housed in a gondola hanging some 13.5m below the balloon on rope rigging. The exhaust stack was pointed downward and to the rear, directing sparks away from inflammable items.

Etienne Lenois’s 1860 invention of a gas engine opened new possibilities before aviation and aeronautics. Five years later Austrian Paul Henlein patented the instal­lation of a gas engine in a dirigible, but another seven years would elapse before the project was realised.

The 1861 to 1865 American Civil War saw leading US aeronauts offering their services to the North. John Weiss designed a field hydrogen generator. However, its high cost made it practically unaffordable and the military did not finance the project. Instead they opted for an idea proposed by Thadeus Loewy. Twelve of his generators were manufactured and entered service. Feedstocks included sulphur oxide and met­al swarf. The device could fill an observation balloon in under three hours. Though rather heavy and difficult to transport, the lack of any alternative made the genera­tors indispensable until the end of active aeronaut duty.

Another original idea of Loewy’s was to employ river barges as mobile bases for teth­ered balloons. To assist nocturnal missions, each barge had four navigation lights: iron lamps with their own uninterrupted gas sup­ply. The newly invented telegraph was in­tended to be used to transmit observation data to the ground. This was first tested in the air on 24 September 1861 at the Battle of Falls Church. To facilitate data simultane­ous transmission from several balloons close to one another, one was designated as an airborne base to gather, process and retransmit data. Another innovation in aerial reconnaissance was aerial photography, first prac­tised by Frenchman Felix Nadar in 1858. All this gradually went to construct two basic control effectiveness components of air power: on-board and surface equipment.

By late 1862, the North had seven tethered balloons with an overall volume of 450-900m3. They were purpose built for combat, usually operating at some 1500m altitude. John La Montaigne was the most active aeronaut. Making use of prevailing winds at altitude, he made several free flights over Confederate positions. The bal­loon corps gained great confidence in senior Washington, D. C. circles, particularly after it saved Federal forces from defeat at Four Oaks and Gaines Mill. In both cases,

Preparations for the first flight of an airborne telegraphic device: Falls Church, September 1861

balloonists had delivered timely warnings of enemy breaches of Federal flanks. How­ever, aeronauts turned out a wayward bunch. Aiming for personal recognition, they were in constant conflict with each other. The authorities had erred in not giving them officer commissions and in leaving them outside army structures, unbound by military discipline.

Making the best of limited finance, the Confederacy adopted simple yet effective countermeasures: the blackout, and luminary mimicry. For the first time in history, all lamps and fires were doused upon a signal at dusk, while false encampments were plentifully illuminated. Apart from that, the South also attempted to employ bal­loons, John Randolph Brien making several flights at the start of hostilities. His poorly designed hot-air balloon with limited endurance was duly replaced by one filled with lighting gas and made from a patchwork of multicoloured silk pieces. (Thus arose the legend that the women of Richmond, Virginia, had sacrificed their dresses for the cause.) The original ‘silk dress’ balloon was captured by Federal forces at Turkey Bend in 1862. The Confederacy then put a similar balloon into service, this seeing active service for 12 months before being blown across the lines by a gust of wind, and also turning into a trophy (though without an aeronaut on board).

There had not been a qualitative leap in the combat use of flying machines since the French Revolution, but Loewy’s achievements in America impressed military ob­servers. Some of the latter were to leave a trace in the history of aviation. Young German Army officer graf von Zeppelin was one. What he witnessed gave him the

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I Stringfellow’s triplane

idea to which he would dedicate his entire subsequent life. Another was British mili­tary observer Captain Beaumont. Upon returning to England, he and Capt Grover tried to draw War Office attention to the possibility of using airborne devices in com­bat. They flew two demonstrations using a balloon hired from Henry Coswell, Brit­ain’s best aeronaut at the time. Grover went on to fund a military balloon programme at his own expense; fifteen years would pass before it attracted genuine interest.

After twenty years of none too successful work on gliders, and influenced by the hostile comments Cayley and Hanson’s monoplanes drew, Stringfellow looked at mul­tiplanes. At the Crystal Palace Aeronautics Exhibition, he showed a triplane model which looked rather archaic by comparison with his 1848 monoplanes.

This had three flat profile superimposed wings braced by vertical struts. It was powered by a 0.33hp steam engine located in a fairing beneath the lower and middle wings, and actuating two pusher propellers. Span was 2m, and weight: 5.4 kg. Due to fire precautions, Exhibition organisers prohibited flying, with demonstrations limited to runs along a guide wire. Subsequent open air testing was unsuccessful, the onrush of air extinguishing the jet of burning spirit which heated the boiler.

Despite this, Stringfellow’s triplane marked an advance in multiplane design and was influential in the choice the Wright Brothers were to make.

Another inventor who made quality aeroplane models was Alphonse Pennault. The son of a French Admiral, he improved on Pierre Julien’s invention of elastic to power flying models. Where Julien used a flat band of elastic, Pennault used twisted bungee, thus obviating the need for transmission between unravelling elastic and spinning propeller, and lightening and simplifying things. Alongside this, Pennault paid much heed to stability. In 1870, he created a most successful helicopter model. A year later came the tiny Planophore monoplane which had great stability in all three axes. In pitch, this was granted by aft horisontal tail surfaces, and in roll: by vertical

endplates and a fin. The Planophore was extraordinarily simple. Just 0.5m long, it had approximately the same span, and weighed just 16g, 5.5g of which was the bungee cord. Tested on 18 August 1871 in Paris, the model demonstrated exceptionally stable flight, always ending with soft landings. The maximum distances of some 40m to 50m were covered in 11 to 13 seconds.

This fragile toy represented an exceptional event in the story of aviation. For the first time the public could observe feasible flight in a device that was heavier than air, had a fixed wing, and used its own power. Reports of the flights circled the globe, stimulating numerous enthusiasts.

By the mid-1870s France alone had several similar aeroplane models. Later, elas­tic-powered aeroplanes appeared in Russia, England, and Austria. The fact that mod­ern elastic-powered aeroplane models do not differ significantly from the Planophore is a testament to its advanced design. Pennault was also the first model maker to pay heed to commerce. Selling at reasonable prices, his models brought the invention into many households.

While aviation was still at the model aeroplane stage, aeronautics enjoyed a new renaissance. At the outbreak of the 1870-1871 Franco-Prussian War, Prussian forces possessed two balloons which were not used in combat. After the fall of Sedan, the French made several observation and reconnaissance ascents in tethered balloons. Privately owned and designed for free flight, they were unsuited to this task.

Attention to flying machines picked up quickly after the Prussians surrounded Paris. The besieged garrison badly needed to communicate with the high command and government in Tours. At the instigation of several aeronauts, the postal authori­ties set up a balloon mail. An improvised balloon factory was established on the premises of a redundant railway station, employing seamstresses and seamen. From September 1870 to January 1871, 66 balloons left Paris, carrying over ten tonnes of mail, 160 privileged persons, several hundred pigeons, and five dogs. These balloons also threw propaganda over enemy positions. Over 60 of the pigeons returned to the city with messages, and some flew the trip twice. However, though sent out with similar inten­tions and fitted with special collars, the dogs failed to return.

To systematise the knowledge acquired, in 1874 the French Government estab­lished an Aerial Communications Council. This recommended the reestablishment of the Military Aeronautics Institute on its old Meudon site. Following this example,

I Preparations for the raising of a spherical balloon, Paris, 1870

Britain, Italy, Germany, and Russia also set up aeronautics schools and research estab­lishments between 1878 and 1893. The USA also systematised its experience of aero­nautics, albeit with a thirty year delay. Due to the low technological level of flying apparatus, no combat units could be formed yet.

Even after the Franco-Prussian War, the main problem of aeronauts remained that of control. Development continued to be hampered by the lack of suitable en­gines. However, research continued. A large dirigible commissioned by the French government was completed on 2 February 1872. Designed by Naval Engineer Henri Dupuis de Loms, it did not feature an engine but was driven by a large four-bladed propeller driven by eight men turning a crankshaft. Still air speed was comparable with that attained by Gifard. However, reaching it required such physical exertion that the test was not deemed successful.

Ready for testing in 1872, Paul Henlein’s dirigible had an engine which drew gas from the balloon. Catamaran shaped, it was 55m long. Flights took place on 13 and 14 December. Hard to control, the craft needed to be accompanied by troops in case of difficulties for the crew. A speed of 15km/h was reached but further testing did not take place due to the lack of funds. The craft was dismembered and sold at auction.

Charles Ritchell’s single seat balloon was tested near Hartford, Connecticutt, in 1878. Powered by a pedal-driven propeller, it was 27m long. Flying a closed circuit, Ritchell attained a speed of 5.7km/h.

Artist’s impression of Henri Dupuis de Loms’s airship

Щ Arduous labour in the airship’s gondola

During the 1881 Electrical Exhibition in Paris, brothers Gaston and Albert Tes – sandiere caused great interest with their model of an electrically-powered airship. The designers decided to build a full scale version capable of accommodating a man. As distinct from Gifard’s design, this airship had greater volume and rounder shape. A propeller driven by a 1.5hp Siemens electric motor powered it. Since the batteries alone weighed more than the combined weight of a steam engine and steam tank, the craft attained just half its design speed.

The airship designed in 1884 by French military engineers Charles Ronard and Arthur Krebs had more powerful electric motors. Similar to Henlein’s, it differed in being half a metre longer. Initially fitted with a 7.5hp motor, it was later fitted with one rated at 8.5hp. Flying seven times in two years, it reached a maximum still air speed of 24km/h. All but two of the flights ended on the spot where they began. The powerplant did bestow control, but only in essentially still air.

Again in 1884, a steel cylinder containing hydrogen under pressure was designed in Britain. This granted much greater mobility to emergent military balloon units. Thanks to this, a three-balloon Royal Engineers detachment participated in the mil­itary expedition to Bechuanaland (today’s Botswana). A year later, the British active­ly used balloons in the Eastern Sudan, followed by the Italians in Eritrea in 1887 and ’88. However, balloon combat efficiency in the late 1800s was not that much higher than it had been during the French Revolution. Despite greater mobility, balloons

Tessandiere’s electric-engined airship was Siemens-powered

I Henlein’s airship

remained unstable and at the mercy of numerous circumstances. Despite early com­bat experience, not one of the components of air power was yet firmly in place.

A decade after Stringfellow’s first model tests, French naval officer Felix de Temple de la Croix and his brother Louis built a clockwork-powered aeroplane. This achieved record success, being able to take off, fly, and land. Later, the clockwork was replaced by a steam engine. In 1857, de la Croix was granted a patent for a propeller driven mono­plane. The design featured several impressive and advanced ideas. Made largely of alu­minium, it had an unencumbered wing and a damped-strut retractable undercarriage.

After model tests, the inventor began building the full sized model, intending to fly it. Construction took until 1874. Practical limitations imposed some simplifications: the landing gear was fixed, and the wing had a single spar instead of the intended two. Despite this, the 260kg structure weight was over twice what had been predicted.

The aeroplane was a steam-engined monoplane with a six bladed propeller. The open-topped fuselage was 2.5m long and 0.8m wide. Its welded steel tube structure also carried the wing, tail surfaces and tricycle undercarriage.

Weighing 59kg and developing 3 to 4hp, the steam engine was located forward. The boiler was superheated with fuel oil, with the fuselage structural tubing used to condense the used steam. The pilot sat behind the engine. Wing structural elements were steel tubes. Cloth-covered, the wing spanned almost 30m. Of similar structure, the empennage comprised movable horizontal and vertical surfaces. The stalky un­dercarriage gave a ground run incidence of some 20-25 degrees.

Ground tests showed insufficient structural strength. Lack of money forced Felix de la Temple de la Croix to curtail further development. Even though not one at­tempt to take off was made, the designer deserved due recognition. He was the first to progress the idea of heavier-than-air manned flight from scale models to a practical full sized aeroplane which he had every intention of flying. In this sense, de la Croix’s achievement marked a stage in aviation research.

The lack of development in engines during the late 1860s and early 1870s, com­bined with a lack of clarity and an absence of scientific and financial assistance, doomed the efforts of a generation of designers such as Evard (Russia, 1861), Teleshyov (Rus­sia, 1864), Claude (France, 1864), Louvriere and Mouillard (France, 1865), Battler (Britain, 1867), Renard (France, 1871), and May and Shill (Britain, 1875).

I Patent drawings of Felix de Temple de la Croix’s aeroplane as envisaged in 1874

Meanwhile, after building an ornithopter model with P. Go – chault, in 1876 Alphonse Pennault designed and patented a large two seat flying wing monoplane. This was amphibious, intended to de­part and alight equally well on wa­ter, or on land. Pitch stability was achieved by locating the centre of gravity forward of the wing’s cen­tre of lift. Roll stability was attained by wing dihedral, and longitudinal stability was bestowed by a fin. Controls included an elevator and drag rudders at the wingtips.

The design had many advanced features. The multi-spar wing was to be metal cov­ered, and the cockpit was to be glazed and fitted with a single control stick actuating both elevator and drag rudders. A neat instrument binnacle, whose likes were to remain in the realm of wishes as late as the First World War, was designed. It included a com­pass, a barometric altimeter, a speedometer and an incidence indicator. An automatic pilot was also foreseen, comprising a sensor (suspended below the fuselage to warn of ground proximity), and an electrical mechanism controlling elevator and drag rudders. The four-wheeled undercarriage had rubber and pneumatic damping. The propeller blades featured variable pitch, intended to make better use of the 30hp engine on take-

| Approximate model of de la Croix’s aeroplane displayed at the Musee de l’Aviation in Paris

Teleshov’s 1867 delta-winged aeroplane was among the more visionary designs of its time

off: early in the run, the pilot was to keep pitch coarse, allowing engine revolutions and momentum to build up. Prior to unstick, he would suddenly set very fine pitch, transfer­ring power to the propeller. The latter was to be made of metal for greater stiffness.

When taking off and landing on water, the aeroplane was to float on its belly or on ski-like surfaces. Additional floats were to be fitted to the wing for longer stays on water. Calculated gross weight with a two-man crew was up to 1200kg, and speed was up to 90km/h. Embodying some very forward thinking, Pennault and Gochot’s aero­plane was many decades ahead of its time.

Progress in designing heavier-than-air flying machines was also hampered by the lack of scientific understanding of aerodynamics. Important contributions to fixed wing heav – ier-than-air flight were made by the Comte Ferdinand d’Estergnaut, L. P Molliard, and Otto Lilienthal. The latter carefully researched bird flight and described how birds glide and maintain height. In 1863 photographer Felix Tournachon, better known as ‘Nadar,’ established a Society for the Encouragement of Flight With Machines Heavier than Air in Paris. At the first meeting of the United Kingdom Aeronautical Union on 27 June 1866, Naval Engineer Francis Herbert Venham proposed a scientific study of wing shape and profile. His major source had been the observation of nature. Noting that birds’ wings were thicker at the front and the root, and tapered towards the rear and away from the root, he concluded that long, narrow wings (with greater aspect ratio) would give more lift. Another aerodynamics pioneer, H. F. Phillips, used the wind tunnel he had invented for a series of experiments with convex wings of various thickness and degrees of convexity.

Completing his work in 1884, he proved that lift derives from the difference in air pressure above and below the wing, and patented a number of wing profiles.

By the early 1880s, differently powered aeroplane designs had been produced by, inter alia, Mouillard (France, 1876), Mikulin (Russia, 1877), Taitin (France, 1879), Kerhoven and Speers (Britain, 1881), Shishkov (Russia, 1882). But most remarkable for its time was the design by Aleksandr Fyodorovich Mozhayskiy. He had experimented with flying models until early 1877, achieving a measure of suc­cess. He then sent the War Ministry a project for a full scale aeroplane, and set about drawing it without awaiting the reply. The drawings showed a monoplane with a single puller and two pusher propellers. Mozhayskiy proposed a flat wing of modest aspect ratio, set at an incidence to create lift like a kite. Total cost was estimated at 19,000 roubles. The War Ministry failed to appreciate the project’s potential and made available a small sum, spent before the aeroplane’s model was built. Nevertheless, Mozhayskiy went on pursuing his goal. In 1881 he received Russia’s first patent for a flying machine. Construction of the aeroplane began the same year. Two steam engines built to Mozhayskiy’s specifications arrived from Brit­ain. The following year, part of a military estate near Sankt Peterburg was allocated for the project’s needs. Work was completed by mid 1883, and on 7 June an Appli­cation for the Performance of Flights with Airborne Apparatus was sent to the Sankt Peterburg Military Region Guards Staff.

Records depict Mozhayskiy’s aeroplane as a twin engined monoplane with a boat­shaped fuselage and cloth-covered timber structural elements. The fuselage also housed fuel and the pilots. The wing was fixed to the fuselage’s upper edge. It spanned 23m, and had an area of 330sq m. The empennage was fixed to the aft fuselage and com­prised an elevator and rudder for directional and pitch control.

Model of Mozhayskiy’s aeroplane at the Monino Museum of Aviation and the Air Forces

THE MOZHAYSKIY’S AEROPLANE, 1881

Powerplant comprised the aforementioned two steam engines which shared a nap­tha-heated boiler. Their respective outputs were 10 and 20hp. For maximum weight reduction, many parts were hollow. This, and other design features resulted in a pow­er to weight ratio of 5.5hp/kg (engine weight plus boiler, condenser and separator): a figure without equal at the time. The smaller engine was located forward and drove a puller propeller with four blades. The bigger engine sat in the mid-fuselage, at one third of wing chord. It drove two pusher propellers located within the wing. All pro­pellers were wooden and had a 4m diameter.

The aeroplane was to depart from a timber ramp (which could be set a different slope angles to assist acceleration) on a four-wheeled undercarriage. Three roll indi­cators, a compass, and a barometer were to be fitted.

Mozhayskiy tested his aeroplane in 1884 and 1885. Trials included engine starts, taxiing and an attempted take-off. Even though the machine failed to become air­borne, it provided valuable data for later use. The poor aerodynamics of low aspect ratio wings became apparent, as did the issue of lateral stability, and the need for completely different engines with reasonable power and relatively low weight and size. Despite Mozhayskiy’s attempts to improve engine output at the Obukhov Works, the futility of such an exercise became apparent, and work ended.

The efforts of numerous scientists, engineers, inventors and enthusiasts to solve the engine problem began bearing fruit. Following in the footsteps of compatriot N. A. Otto, German Gottlieb Daimler developed a new type of gas engine fuelled by a volatile liquid known as gasoline. Fitting such an engine to a flying machine was a safety challenge. This applied especially to lighter-than-air machines where gasoline would coexist with an enormous quantity of hydrogen. Nevertheless, the new en­gine’s great power to weight ratio, and the lack of heavy subsidiary devices such as steam tanks, accumulators and condensers, made it very tempting.

Having read of Carl Wolfert’s work on small man-powered aerial vessels, Daimler approached him with a proposal to pool their work. Trials of a single seater gas balloon fitted with a single cylinder Daimler engine started in 1888. At a power rating of 2hp, the flying machine showed reasonable results. Since the engine was rather close to the balloon envelope, exhaust gases were ducted away along a special pipe. However, even this was far from safe, but Wolfert felt he was on the right track and started planning a larger vessel.

While the engine breakthrough had arrived, the new engines’ power to weight ratios were still too low for the needs of powered heavier-than-air flight. This is why aeroplane designers in the last decade of the 19 th Century continued looking to steam. In 1890 French engineer Clement Ader completed a rather strange looking aero­plane. Design and construction had taken a long time, having started in 1882. The gifted engineer had chosen the bat as prototype. All work proceeded under a cloak of secrecy, using Ader’s adequate private funds.

True to intention, the Aeole did indeed look like a bat. This flying wing monoplane with a wing area of almost 28sq m, and 14m span, was made of cloth-covered bamboo.

The enclosed fuselage housed a steam en­gine, controls, and the pilot. There was no fin. A four bladed propeller of 2m diameter pulled the craft. Movement along the ground was on a tricycle undercarriage with a guard wheel forward. Thanks to its lightweight structure, empty equipped weight was just 175kg, with a gross weight of 296kg.

A most intriguing Aeole component was the 20hp steam engine. Thanks to Ad – er’s refinements, its power to weight ratio was some 3hp per kilo: the Aeole’s had five times more overall power per unit of weight than Mozhayskiy’s aeroplane! Another novelty concerned control. Copying the move­ments of bats’ wings, Ader articulated the Aeole’s wing to allow changes in sweep, span, camber, and tip deflection. Though these could be made individually or simulta­neously, no explanation underpinned the sense behind any of them. Overall, the con­trols were exceptionally complex and hard to manage.

I Model of the Aeole

I Working drawing of the Aeole

Trials began on 9 October 1890 in secrecy. This explains why data reaching us today is so scant. In an unfinished report, one of Ader’s assistants describes the Aeole, control­led by the designer, lifting a few centimetres off the ground, staying airborne for five seconds, and covering some 50m. This result could hardly be called a flight, and in any case the craft’s instability and uncontrollability would have rendered longer hops impos­sible. Nevertheless, the event was significant in the aviation, being the first recorded instance of an aeroplane taking off from a flat surface under its own power. The Aeole showed that aeroplane makers were about to overcome the power barrier.

Although sufficient effort was expended to keep these events from becoming public knowledge, they did not remain unknown to the French military. The latter saw in them prospects for the future, and a superior alternative to the unstable and uncontrollable tethered balloons they were using for observation and reconnais­sance. Hoping that Ader would be able to build an improved model to supplant balloons and deliver air strikes, they subsidised him with 650,000 francs. Work was to continue in deep secrecy.

This financial injection allowed Ader to recruit more assistants. Design, production and assembly continued from 1882 to 1887. The Avion-3 resembled the Aeole: a bat­like flying wing monoplane. Main difference was the addition of a second engine. The twin 20hp steam units shared a boiler and spun two 3m diameter propellers. Mounted on the leading edge, the propellers turned in opposing directions to cancel out torque. Less articulated than that of the Aeole, the wing had a span of 16m and an area of 56sq m. Only sweep remained adjustable, being changed simultaneously for both wing halves.

I The Avion-3 ready to attempt to fly

A fin gave lateral stability, and there was a steerable tailwheel beneath. Turns were to be accomplished by varying propeller speeds. The pilot sat in an open cockpit behind the engine which resulted in poor forward visibility and problems in steering straight while taxiing and ground running. Gross weight reached 400kg.

First trials took place on 12 October 1897. Plans included accelerating along a specially constructed runway. This was circular, with a 1500m perimeter and a width of 40m. Weather after passage of a rain front was perfect, and the ground was dry. During acceleration, Avion-3 reached 24km/h, Ader using a small portion of engine output. Ground tracks after passing 18km/h were practically unnoticeable, which made

those present consider the chances of suc­cessful flight very good.

The flight attempt came on 14 Octo­ber, Ader considering himself sufficiently ready. Unfortunately, a gusting wind ap­peared. During the takeoff run a powerful gust from the side deflected the light­weight machine from the runway, point­ing it at a fence. The pilot remained calm, managing to brake and emerge unharmed. However, the machine’s wing, landing gear and propellers were seriously dam­aged. This put an end to the talented en­gineer’s aviation efforts. Testing halted. The military lost interest in the project and stopped funding. Though Avion-3 was restored, its future career was as a dis­play item in the Paris Musee des Arts. In aviation history, this bat-like device re­mains the first heavier-than-air flying machine to have overcome the power bar-

The Avion-3 with wings folded for transporting

Щ The Avion-3 as displayed at the Palais des Arts ae des [crafts] in Paris

rier (and that with a steam engine). Some specialists claim that Ader’s failure was due to slavish copying of bats. This certainly resulted in both imperfections and overcom­plexity. Nevertheless, man’s effort to conquer the air — or to complete air power’s first component, to put it another way — continued.

In 1890, the Russian War Ministry accepted a proposal by Vladimir Kon­stantinovich German for a human – powered or petrol engined monoplane. This was Russia’s first attempt to put an internal combustion engine (rated at 0.5hp) into an aeroplane. In other ways, the design was rather unsophis­ticated, and funding was declined.

The same year, Frenchman Graffi- ni proposed a kite – like flying machine powered by an engine using com­pressed carbon oxide gas. It was esti­mated to fly at 36km/h and have sev­eral hours’ endurance. In case of en­gine failure, the wing was to act like a parachute, permitting a safe landing.

The lack of suitable engines at the end of the 19th Century was one of the reasons why gifted designers directed efforts at unpowered flight. A leading figure here was Otto Lilienthal, a German engineer from Pomerania.[2] His first 1889 glider was a prim­itive contraption of cloth-covered timber.[3] It insufficient strength and the lack of stabilisers spelt its demise. In 1890 Lilienthal built two more gliders, the second of which had a fin. This was the first device to accomplish a successful glide. However, its performance was poor due to excessive wing curvature. This was corrected in the next design which also featured a tailplane. The benefits were apparent, especially in stronger winds. In 1892, the designer attained an eight to one glide ratio.

A year later, Lilienthal built the glider that would serve as prototype for his subse­quent monoplanes. A novelty alongside the strengthened wing, was the movable tail – plane. Counteracting a spring, aerodynamic loads could deflect it upwards, this flaring the wing for softer landings. Lilienthal performed a number of successful flights with this device. Distances covered reached 250m, with flight times of up to half a minute. The glider’s properties encouraged construction of two improved versions. One was an 8m span monoplane fitted with a 2hp single cylinder engine. This was to be used as a subsid­iary aid while gliding between thermal currents. Moving the wing, and specifically its feather-like tips, created propellant thrust. Powerplant weight was 20kg and the design-

I Otto Lilienthal accelerating with his Glider No3 in 1891

Щ Lilienthal’s motorised glider

er had envisaged that the engine would work for not more than half an hour. In any case, engine problems meant that the device was tested only as a pure glider.

Engine problems made Lilienthal return to unpowered gliders, and in 1894 he built his smallestone, spanning just six metres. A similar model can be seen at the Vienna Technische Museum to this day. The same year also saw Lilienthal’s ‘standard’ glider, whose wings could fold for transport and storage. The tailplane was moved a

THE OTTO LILIENTHAL’S ‘STANDARD’ GLIDER

Щ Lilienthal’s ‘standard’ glider which found a fair following among late 19th Century birdmen

metre further aft to improve stability. Nine such gliders were made, making the device the first heavier-than-air craft to be produced in numbers.

Despite his growing fame, Lilienthal realised that his gliders were rather unsafe for widespread use by untrained people. He therefore built a special experimental glider with automatic leading edge droop to prevent sudden dives. Another novelty was the ability to cut speed using the movable tail, and the dihedral control mechanism. The pilot hung vertically, changing flight direction by swinging his legs and lower body, the additional features working automatically to assist his intentions.

After several flights without much success, Lilienthal abandoned such designs and went on to build biplanes. The first of these saw light of day in 1895. The idea was to allow flight in crosswinds of up to 5-6m/s. The glider demonstrated perfect stability, rewarding its designer by overcoming sidewinds of up to 10m/s.

Lilienthal had not given up the idea of powered gliders with moving motive surfaces. As distinct from the 1893 model, the new design featured a two-cylinder engine. Only the airframe was completed in 1896. This monoplane spanning 8m, and with an area of 17sq m, was never tested due to Lilienthal’s untimely demise

I One of the last photographs of Lilienthal, this time with his No17 ornithopter/glider

while gliding. The famous German had flown over 2000 times and left many trained disciples.

Unaware of Ader’s work, prominent British inventor Hiram Maxim[4] set off to build a steam powered aeroplane in 1890. He studied the propulsive efficiency of different propeller shapes in a wind tunnel of his own design, using custom instrumen­tation. Upon gathering some empirical data, he determined optimum blade and wing shapes and over the following three years built, at a cost of some 20,000 pounds Ster­ling, an aeroplane which differed from all previous designs in size and propulsion sys­tem. Span came to 32m, and wing area to 370sq m. Twin elevators were located fore and aft of the wing, but there was no fin or rudder. Gross weight reached 3.5 tons.

Powerplant consisted of two compound steam engines manufactured of high grade steel. Carried on a steel tube cradle beneath the upper wing, they turned two 5.4m diameter propellers. System power to weight ratio was 1.2kg per horsepower. Fuel was naphtha. The crew sat behind the boiler and condenser. Overall cradle and engine weight was almost a ton.

Maxim underestimated the importance of balance and controllability. Control was limited to the twin elevators. Maxim was convinced that dihedral by itself be­stowed sufficient lateral stability. A 600m long rail track with buffers at the distant end was built for the trials. Maxim also provided a height governor which limited

I Hiram Maxim’s aeroplane on its acceleration rail

excursions to 0.6m off the ground. This was to be used initially as a precaution against mishap. Famous sportsman and mechanic De Lambert, experienced aeronaut and speed boat tester, was invited to pilot the craft. After several test runs, a date was set for the flight attempt on which the engines would work at full steam.

On 31 July 1894 De Lambert waited for steam to build up and released the enor­mous craft’s brakes. Acceleration was rapid, the two front wheels lifting clear of the rail. Since the entire weight was now over the rear wheels, they bent the rails, but the latter coped. Maxim claims that 300m after the start of the run the aircraft lifted off the rails, banked slightly and fell to earth, the wheels sinking into soft ground. Ac­cording to Maxim’s calculations, lift had reached some five tons in the closing stages of the run: half as much again as the gross weight; this was sufficient not just for horisontal flight, but also for climbing and certain manoeuvres. As with Ader’s exper­iments, the power barrier had been breached, stability and controllability coming to the fore. Maxim undertook no further trials, but showed his machine to friends for a further year, turning it into something of a local attraction.

Otto Lilienthal’s former students and assistants made a great contribution to avi­ation development. At the time, their newspaper photographs had travelled the world giving them universal fame. One of them was Scottish naval engineer Percy Sinclair Pilcher. After working with Maxim for some time, he went to Lilienthal in Germany and learned to glide. In 1896, Pilcher patented a monoplane distinguished by large

wing area. Its trials confirmed Lilienthal’s belief that a small aircraft could be control­led adequately by body balancing. However, the Gull crashed twice in high winds, and Pilcher stopped using it. The same year he completed his Hawk, very similar to his mentor’s ‘standard’ glider. The pilot occupied a cutout in the centre wing, and the moving tail gave good controllability, especially at high angles of attack. The four­wheeled sprung undercarriage was a novelty helping ground acceleration and soften­ing landings.

Initially, Pilcher attained distances of up to 90m in the Hawk, this being bettered to over 200m the following year. Thanks to its adequate stability and modest size and weight, the glider had good controllability for its time. Pilcher was able to make turns and control landing speeds.

Right from the start, Pilcher intended to fit engines to some of his designs. The Hawk being most suitable, he decided to fit it with an internal combustion engine driving a pusher propeller. The craft would be launched as a glider, its pilot running downhill. Once airborne, the 2-4hp class engine would be started to help maintain a 30km/h speed. Control would be by balancing, the pilot switching positions or swing­ing his legs and pelvis. Sadly, a suitable engine was found only in late 1899, and this was never tried, Pilcher finding his demise in a gliding crash. British aviation hopes were severely dashed with the loss of this man who combined the requisite technical background and flying experience.

Otto Lilienthal’s work had attracted the notice of one Octave Chanute: French Baron by origin, US citizen by choice, and Chicago structural engineer. Aware of Cayley, Hanson, Stringfellow and other aviation pioneers’ work, in 1894 he published The Progress of Flying Machines. Lilienthal’s example made him think of trying his

I Pilcher’s Hawk glider

luck at designing his own flying machine. In 1896, aged 64, Chanute built two gliders. Advancing age meant he had to ask young engineer Augustus Herring to fly them. The first glider failed to live up to expectations due to poor finish and low controlla­bility. But the second one, a simple, lightweight and tough device, turned out to be the best balanced glider of its time. Assessed by specialists as setting new aviation design standards, it was used by the Wright brothers in their work some time later.

The glider’s most notable feature was its wing. A biplane, it had a structure of timber spars, ribs and stays: bridge design knowledge applied to aeroplanes. The ruddered fin allowed the glider to counter crosswinds of up to 14m/s. To ease control, the pilot sat suspended in a sling. Spanning some 4.9m, the glider weighed just 10.5kg. In 1896, the biplane was tested at the sand dunes on Lake Michigan’s shore, flying some 1000 times. The greatest distance covered was 100m, in 14 seconds.

Later Herring was to build his own large tri­plane glider which would cover 280m. (Ex­plaining this achievement, he stressed not the glider’s superiority, but the growth of his own piloting ability.)

Herring learned to make smooth turns and flew around hills in search of thermal currents.

Encouraged by success, the engineer decided to go for the next step: powered flight. Initial­ly he intended using two lightweight petrol engines of some 2hp each. Sadly, this class of щ Octave Chanute’s biplane glider which engine was rather heavy at the time, so Her – flew successfully between 1896 and 1904

ring opted for a compressed air powerplant. The twin cylinder engine weighed six kilos and developed 3 to 5hp for some 30 seconds.

Completed in summer 1898, the monoplane was tested at the Michigan lakeshore between 10 and 22 October, with decidedly mediocre results. The longest hop achieved was just 22m in a little under ten seconds. This convinced the designer that he had to have a more powerful engine which would work longer. However, by weighing down the craft, this clashed with its very concept. Circumstances dictated a different accel­eration method and precluded control by balancing. Herring failed to find the right solution and gave up.

Meanwhile, Wolfert and Daimler’s joint efforts continued. The result was a large airship fitted with a 6hp two cylinder internal combustion engine with exhaust pipes. (From now on, the exhaust would feature in all of Daimler’s engines.) The machine was demonstrated at the 1896 Berlin Exhibition. Kaiser Wilhelm II showed interest in it but declined to ride it. A major disadvantage was the engine’s proximity to the balloon envelope. Critics noted that rapid gas discharges for emergency landings could lead to dire consequences. Wolfert did not view this as good reason to introduce design changes, his only response being to limit flight altitude.

The Kaiser’s attention occasioned great interest in the craft at the Tempelhof aeronautic exhibition which opened on 12 June 1897. A demonstration flight was

I Wolfert’s dirigible at Tempelhof on 14 June 1896

planned to demonstrate the airship to German officers and the Diplomatic Corps. A Prussian Balloon Corps officer was invited to ride with Wolfert and his mechanic. Last-minute inspections revealed skin damage where guyropes had scuffed the enve­lope. However, the hydrogen leakage was not considered really hazardous or prejudi­cial to performance. Wolfert did however decided to reduce the load so as to impress the military assessment committee with good climb rates despite the damage. Thus the Prussian officer stayed on the ground, while the airship rapidly climbed to 1000m. At that altitude, Wolfert ordered the engine to be started, and the craft turned into a falling ball of flame. Both aeronauts perished.

Five months later, Tempelhof was to witness a dirigible of completely different design, built by Austrian engineer David Schwartz. In 1896, Frenchman Herault and American Hall invented electrolysis independently of each other. The process was suited to industrial production of aluminium. Schwarz’s dirigible had an envelope and gondola of aluminium sheet over a skeleton of alluminium tubing. The 52m long, shiny, artillery shell-like object was the first rigid airship. Regrettably Schwarz fell gravely ill and died on 11 January 1897. The honour of testing his dirigible in flight fell to Jagel, his capable mechanic, who had no experience as an aeronaut. To add to his troubles, a stiff wind blew up on the day set aside for the first ascent. Alone in the gondola at a height of 300m, the rookie aeronaut tried keeping steering straight but

I David Schwartz’s airship was the first of the all-metal rigid type; it is seen here exhibited at Tempel­hof on 3 November 1896

panicked and broke a control cable. The emergency descent which followed was com­plicated by unnecessarily rapid gas discharge, causing the craft to strike the ground hard. Jagel managed to jump clear, but the machine was in pieces.

The tragedy did not stop count Ferdinand von Zeppelin from completing an enor­mous rigid dirigible. The reserve cavalry General had observed the American Civil War between 1864 and 1865 and seen active service in the Franco-Prussian War. He was convinced that even imperfect tethered balloons could influence the outcome of battle. On leaving the army, he began developing a lighter-than-air craft with much broader combat competence. His new weapon was intended to transform the power of Germany’s rearming army. Design was completed in 1895 and the nobleman was awarded a patent. He set up the Society for the Advancement of Aeronautics, a limited company with an equity of a million marks, half of it invested by himself. Workshops and an airship hangar were built on von Zeppelin’s Bodensee estate. Work began in spring 1899, and a year later the finished article was ready for testing.

The 140m long dirigible had two Daimler marine engines, each rated at 16hp. However, not more than 24hp was actually produced from both engines in ground tests. As distinct from Schwartz, von Zeppelin used not aluminium but cloth to cover the tube structure. The interior was divided into 17 compartments. With two

exceptions, they contained gas bags (ballon – ets) with a combined volume of 11,000cu m. The airship was designed to lift a five-man

I The LZ-1 before completion

crew and enough fuel for a ten hour flight. Designated the LZ, it made an 18 minute maiden sailing from the Lake Konstanz naval hangar on 2 July. An 80 minute sailing was recorded on 17 October. Testing showed up insufficient stiffness and poor load trim, re­sulting in control difficulties. The engines were also insufficiently powerful. Despite this, another sailing was made on 24 October be­fore the designer decided to halt further tests. Forced to repay creditors, von Zeppelin had to sell his airship hangar, dismiss workers and cut the airship for scrap.

Samuel Langley’s steam powered model aeroplane was the 19th Century’s most advanced aeroplane. During its 1896 tests, it covered over a kilometre. Some years were to pass for this exceptional record to be bettered. These tests also marked the end of the model aeroplane era in aviation development. The possibility of making a powered heav-

ier-than-air flying machine was now proven. The US government showed an interest in Langley’s work. The 1898 Spanish-American War spurred American ambitions to pos­sess an all-new weapon which could grant the US regional and world supremacy. The significant sum of 50,000 dollars was set aside to subsidise developments.

The airframe of Langley’s aeroplane was ready by late 1900. What distinguished it was its tandem wing layout and cruciform tail. Overall wing area was 95sq m. The body was a flat frame supporting an open cockpit. Body length was 14.5m. The earlier models’ superb stability recommended the replication of their control surfaces in full scale form. The aeroplane had a 50hp water-cooled steam engine weighing 94kg: the lightest aero engine of its period.

The scale model flights and the availability of a powerful and light engine raised hopes of success. Regrettably, both flight attempts failed. Pilot Manley got into trou­ble from which only quick thinking and reflex saved him.

Failure turned the press against Langley and project funding halted, forcing him to stop fur­ther work.

Not surprisingly, Wolfert’s tragic fate turned official circles against non-rigid balloons fitted with internal combustion en­gines. However, balloonists con­tinued flying such rigs. Formed in Paris in 1898, France’s first Aero Club could use the Saint Cloud airfield. One of its most enthusiastic members was Bra­zilian Alberto Santos-Dumont.

and after

Opening of the French Aero Club, Saint Cloud, 1898

After a false start on 28 September 1898, two days later he performed the first in a series of successful ascents with a de Dion petrol-engined non-rigid airship. In 1901 Santos-Dumont won a large cash prize for flying from Saint Cloud to the Eiffel Tow­er and back: a distance of some 24km cov­ered in an hour and a half.

While not a major designer, Santos- Dumont was a superb pilot and had the great advantage of sufficient money to carry on improving. He was a ‘born aero­naut,’ and if Meunier, Gifard and Renard showed the world how to build non-rigid airships, Santos-Dumont showed it how they ought to be flown.

Despite its inherent conservatism, Britain did not lag behind in the rapid de – velopment of aeronautics at the turn of the Century. Animated discussions were held about the relative merits of lighter versus heavier-than-air craft. Established in 1866, the Aeronautical Society grew

I Santos-Dumont’s historic flight

rapidly, becoming an Aero Club in 1901 (later The Royal Aero Club). Despite this activity, powered balloon trials were rather fewer than in France. The turning point came with Stanley Spencer’s 1902 flight. His 28.5m long, 6.6m diameter airship had a single seat cabin and a 3.5hp Sims water cooled engine. This ran at 2500rpm: so fast for its time that a reductor was needed. On 22 September 1902 Spencer flew from Crystal Palace in South East London to Inchcoates in Middlesex, covering the 100km distance in 100 minutes. Later the same design made other successful flights. Having acquired serious experience, Spencer built a larger airship which, however, failed to live up to expectations.

The same year French engineer Henri Juliotte completed a semi-rigid airship. It had been commissioned by sugar refinery owners, the brothers Paul and Pierre Lebau – di. The elongated balloon envelope was 62m long. Powerplant was a 40hp Daimler engine. Form early in the winter in 1902 until summer 1903, 30 flights were per­formed from the Matesse base. Maximum still air speed was 40km/h. One of the flights, in November 1902, was symbolic: from Matesse to the Champs de Mars in Paris, where Professor Charles had flown the first hydrogen balloon in 1783. Mean cruise speed was 35.5km/h.

Despite dirigible successes, the military stayed faithful to non-rigid and semi-rigid tethered balloons: they were battle proven. Armed forces in several countries made efforts to improve such balloons for reconnaissance purposes. Naturally, this was still far from the creation of a component of air power. Until the late 19 th Century, the military had used almost exclusively spherical balloons. Despite being useful in Afri­can colonial wars, they also had numerous limitations. For instance, in Southern Af-

I Newspaper drawing of Paul and Pierre Lebaudis’s airship

rica the British Army found that wind speeds of over 35km/h rendered ascents impos­sible due to drag. The balloons swayed unacceptably even in slight gusts, making the observer unable to use optics. This resulted in altitude restrictions which reduced the area under observation. Clearly, a stable aerial platform was needed.

Encouraged by the War Office, after the Boer Wars some British inventors test­ed man-lifting kites. Most active was Texan-born Samuel Cody. He built kites sim­ilar to those made by Baden-Laulel and used Hargrave’s sling system. Experiments in Britain and Russia confirmed concerns that the kites would be worse than bal­loons in strong winds. Another direction of work involved attaching kites to bal­loons to stabilise the latter. Such experiments had a history dating to before 1885, and showed much promise.

The military were hastily seeking new and sufficiently effective reconnaissance platforms. Almost half a century earlier, Klausewitz had stressed information procure­ment by writing that whichever side knew more about its adversary had the battle half-won. Developments of the new type of balloon proceeded fastest in Germany. There, scientists were working on a new and stable aerial observation and artillery direction platform. As early as 1886, Major August von Parcival and Captain Bartch von Siegsfeldt had patented an unfortunate looking but practical kite balloon. Trials of the new design started in 1893, and the following five years saw variations with volumes of between 600 and 1200cu m tested. They ultimately evolved into ‘sausage’ balloons used on both sides in the Great War, and to guard London, Moscow and other cities from air raids in the Second World War. Main material was rubberised

A British balloon unit during the Boer Wars

Lawrence Hargrave preparing one of his kites for a flight

cotton. Anchored by guy ropes, kite balloons flew into wind at some 30 or 40 degrees of incidence. The airstream created additional lift. For greater stability, the design incorporated a guide sleeve and a guide sail on each side of the main envelope. Obser­vation was from an altitude of 2000m, entirely adequate for normal reconnaissance.

Instructional drawing of a Parcival-Siegsfeld kite balloon

Combat proved the benefits of the new balloons. At the onset of the 1904-1905 Russo-Japanese War, the Russian side used indigenous spherical balloons to support its forces and coastal defence in the Port Artur area. The Russian engineering unit officers who operated them soon encountered the customary stability problems. They then tried kites, to no appreciable improvement. Only the introduction of Parcival-Siegsfeldt kite balloons made a difference. Navy needs were served by a specially equipped mother ship which would launch kite balloons. However, due to engine trouble, the cruiser did not see active service. Russian specialists also developed a new, lighter method of charging balloons with hydrogen, allowing them to be replenished closer to their ascent sites. The fact that between 1914 and 1918 the warring sides used no fewer than 5500 kite bal­loons shows how well the two Germans handled their task.

The emergence of the basic component of air power did not involve only aero­nautics and aerostatics. At the turn of the century, two brothers who manufactured bicycles in Dayton, Ohio, began actively researching aviation. Influenced by Otto Lilienthal’s famous successes, in early 1899 Wilbur Wright wrote to the Smithsonian Institution asking for books and papers on heavier-than-air craft, giving Chanute’s monograph as an example.

Soon after receiving the requested literature, he and his brother Orville built a biplane kite. The aim of this first experiment was to test Orville’s contention that birds balance and turn by twisting their wings. The kite had a special control cable which changed wing camber as need­ed to react to wind direction and speed.

This control system was amplified by a canard elevator (one fixed forward of the wing).

The following year Wilbur wrote to Chanute asking for comments and ad­vice on the brothers’ new biplane glid­er. Spanning 5.5m, this resembled Cha­nute’s design in its structure, but every­thing else was the fruit of the Wrights’ own creative thought. They believed that if they coped with controlling the glider, they would succeed in building their own powered aeroplane. The idea was to make an unstable aerial platform whose trim would depend on the pilot’s coordinated movements, much as a bi­cycle depends on the rider’s balancing

I Octave Chanute visiting the Wrights at Kitty Hawk

movements. Lilienthal controlled his gliders by swinging his almost vertical body, but the Wrights chose a prone control position from the outset. The pilot was to twist the wings to maintain an optimum glide angle, and use the canard elevator to control sud­den downward pitch (such as the one which had killed Lilienthal).

Trials of the glider began in late summer 1900, near the town of Kitty Hawk, North Carolina. The Wrights had chosen the hilly site because of its excellent year – round weather. The proximity of the Atlantic provided a stiff breeze of constant direc­

tion and speed. Most flights were un­manned, the glider flying as a kite. Some tethered flights also took place. Just one pi­loted glide was flown.

In July and August 1901, the Wrights began trials of a larger glider, spanning 7.3m. Though essentially unchanged, its control system was developed and improved. This time the Wrights went to Kill Devil Hills, four and a half miles south of Kitty Hawk. While one piloted, the other helped by steadying the glider and running alongside until it was airborne. Several exceptionally successful glides were performed, including one of 110m. The designers noted a ten­dency to sideslip when one wing half was twisted independently of the other.

On returning from this season’s flying, the Wrights reassessed their theory in the light of practical experience. They also carried out a number of tunnel tests using a pedal – driven wind tunnel. By late summer 1902 the brothers built their third biplane glider, with a span of 9.15m. To counter sideslip and ease turns, the tail now featured two extra fins.

In the second half of September, the glider was taken to the Kill Devil Hills sand dunes. During initial flights, wilful or accidntal (caused by the wind) camber changes to one wing half were found to result in yawing and rolling. The problem was solved only when the twin fins were replaced with one and this was made to swivel by being geared to wing camber changes. The modified glider could now turn fairly flatly and was even controllable in Beaufort Force Seven winds. The brothers patented their method of control by jointly twisting the wing and fin, but the patent was to lie fallow until 1906: other flyers were far behind in their endeavours.

Launching a Wright glider

A Wright glider about to land, October 1902

Successful glides of over a minute’s du­ration firmly prompted the Wrights to make an aeroplane. The engine installation and propeller were built in the winter and spring of 1902 and 1903. Progress was easy because, as distinct from all their predecessors, the brothers were not aiming at a super light powerplant. All they had to do was adapt a water-cooled four-cylinder petrol engine by stripping away unnecessary road-going com­plications and weight. It weighted 90kg and developed 12hp: a power to weight ratio of 7.5kg per horsepower, or rather worse than the steam units of the late 19th Century.

Still, good aerodynamics meant that the engine was perfectly capable of hauling the flying machine into the air.

The propeller resulted from exhaustive wind tunnel testing in 1902 and 1903. The Wrights viewed it as a spinning wing and tried to find the best profile for each spanwise propeller section. The result was a new record in propeller efficiency: 66 per cent. Transmission was by bicycle chains which also acted as reductors. Overall trans­mission and propeller weight was 41kg.

In other respects, the aeroplane was similar to the 1902 glider. The higher weight called for a span increase to 12.2m and for increased control surface area, the latter achieved simply by installing a second elevator and rudder. Skids were mounted un­der the wing to soften landings: wheels would be of little use on the sands of the North Carolina coast.

The craft was taken to the test site where it was assembled by November 1903. It was a canard biplane with twin 2.6m diameter pusher propellers turning in opposing directions to cancel out torque. The engine was on the lower wing, alongside the prone pilot. The latter controlled wing camber by thigh movements. Two other levers were mounted in front of him: one for controlling the elevator, and the other for starting the engine. Gross weight was 340kg, length: 6.4m, wing area: 42sq m, and span: 12.3m.

Takeoffs were performed using an 18m long steel-plated wooden rail which could be turned to face directly into wind. On departure, the craft travelled on a small wheeled dolly which remained on the ground.

Initial tests involved running the engine on the ground. These showed up weak­ness in the hollow propeller shafts which had to be replaced with solid units, raising structure weight. On 12 December, the Wrights decided they were ready to fly. They waited for good weather and made their first attempt on 14 December. After a 16m

ground run the aeroplane lifted, pitching up sharply and falling to the ground from a height of 5m. The 32m hop had taken 3.5 seconds. Pilot Wilbur Wright was unhurt and damage was insignificant. The designers realised that the mishap had resulted from incautious handling of the elevator.

The second flight was on 17 December. The wind was stronger on that day, and the guide rail was set almost flat. The flight was successful, lasting 12s. Three further at­tempts were made, each improving on the duration of the first one. Overall airborne time was almost two minutes, with the final flight lasing 59 seconds and covering 280m.

The Flyer, first successful aeroplane in history, before being put on its starting rail

Щ The Flyer on its starting rail

17 December 1903: the second of the day’s flights

Naturally, these were not flights in the proper sense of the word, since Wilbur Wright made no attempt to vary the Flyer’s speed or direction. Nevertheless, that day saw the first recorded aeroplane flight with proper control over speed and height.

Using their predecessors’ experience, the Wrights made a craft which not only pos­sessed the necessary power, but also effective pitch and roll control. Due to its static instability, the Flyer called for fine piloting skills: something the Wrights had only begun building up in late 1903. The tests were the first successful flight of a heavier-than-air machine: powered take off, level flight, and landing with a man on board.

There now followed a reassessment of the Flyer leading to its improvement. Flyer 2 was completed in May 1904. It differed mainly in having a 16hp engine, but power to weight ratio remained low due to higher all-up weight. Elevator shape was changed and wing profile flattened. The airframe had to be strengthened, increasing empty weight to 320kg. Since tests were to be on flat pastureland near Dayton, Ohio, the craft was reliant on strong headwinds. This limited flying opportunities and made the Wrights dependent on weather. Their answer was an improvised catapult: they built a tower from which a half ton weight attached to the aeroplane would be dropped, launching it along its rail.

The first catapult take off was on 7 September 1904. The flight went well, con­firming that tests would be possible without relying on the wind. Flights were becom­ing routine, and the Wrights’ piloting skills grew. Still, flying was still along straight lines, and still over in mere seconds. The meadow’s size limited flight distances of necessity, and each hop ended with the tedious task of hauling the machine back to the rail. Eventually, the idea of circling flights commended itself.

The first departure with the intention of flying a closed circuit was on 15 Septem­ber. However, due to the great radius of the turn, Flyer II flew too close to a fence and

I One of the Wrights’ early demonstration flights at Fort Myer. The pyramid-shaped toner which assisted takeffs is clearly visible

had to be landed prematurely. The first successful circling flight was on 20 September. Wilbur Wright completed a 360 degree turn, staying aloft for two and a quarter min­utes. It was clear that this method of flying made possible significant endurance with­out straying off the safety of the ‘airfield.’ Another achievement was marked on 9 November, when 4.8km were flown in 5m 4s. Flyer II was used until 1910, making over 80 successful flights. Nevertheless, the Wrights were dissatisfied with its control­lability. Hazardous situations caused by Flyer Il’s unwillingness to comply were com­monplace in 1904. Further work was needed.

Flyer 3 was finished in June 1905. The engine was unchanged, but judicious tun­ing had increased power to 21hp. The airframe was additionally strengthened. The elevators and fins were moved further away from the centre of gravity (which coincid­ed almost entirely with the centre of lift). To reduce sideslip in turns and rolls, two vertical plates were fitted between the twin elevators. Despite these improvements, initial flights suffered from temporary loss of control. By late September, the designers realised their control problem was due to stalling of the control surfaces when reduc­ing speed. Future flights, flown at flatter angles of attack, confirmed this. The control issue was solved!

To ease piloting, controls for wing and rudder twisting were separated. Coordinat­ed rolling turns without sideslip were now possible, reducing the demand on engine

power when turning, rolling and flying figures-of-eight. In summer and autumn 1905, Flyer 3 performed some forty flights near Dayton. On 5 October, the craft covered a closed circuit of 39km in 38 minutes and three seconds: an average speed of 60km/h.

The Wright brothers’ flights were almost totally ignored by the press. Newspaper­men refused to take the rumours of successful American powered flights seriously. Airships, with their impressive size and considerably better achievements, made a much better story. The few (factually wrong) press reports that did appear were greet­ed with a large measure of doubt. One of those who did believe them was Lieutenant Colonel Cooper of the Royal Engineers’ School of Aeronautics. In 1904, the War Office sent him to the Saint Louis, Missouri, Technical Exhibition. While there, he got in touch with the Wrights at Dayton. On returning, he wrote a full report regard­ing the claimed 1903 flights, adding he was convinced of their authenticity.

THE FLYER III, 1905

101

The British visit and the US government’s interest in Langley’s project convinced the Wrights they had a product they could sell for a lot of money. They believed in the future of the aeroplane as a means of international communication and trade, and harbinger of goodwill. They also foresaw for it a future as a means of warfare. This is why in selling their project they first addressed the United States’ Department of Defense, Orville Wright writing these words on 18 January 1905:

“The series of aeronautical experiments upon which we have been committed these last five years ended with the creation of a flying machine capable of practical use… The numerous flights made confirm that flying can be used in a great many ways, one of which is intelligence gathering and the transfer of messages in wartime.”1

In a 9 October 1905 letter addressed to the Secretary of State for Defense, Orville reminds him of the newly created flying machine capable of use for intelligence pur­poses. However, perhaps for reinsurance after Langley’s failure, the military did not hasten to buy. Their reasons were reasonable enough. The Wrights’ aeroplanes were unsuited to genuine combat: for one thing, the pilot lay prone, fully exposed to ground fire; for another, there was no room for a second crew member who could observe and recconnoiter from the air. And even the most improved Flyer could hardly maintain a set altitude to enable effective use of optical instruments and cameras. Also, the small amount of fuel limited endurance to below any reasonable duration. Taking into ac­count the Wrights’ high asking price, the double refusal of the Department of Defense becomes understandable.

Negotiations with the Admiralty in London and the French government ended the same way. Despite the interest shown in future improved flying machines, the pioneers lost heart. They were wary of displaying their machines in public, lest their technical secrets be stolen by competitors. After the 16 October 1905 flight, their two and a half years of active flying were over. Mothballed, the machines stayed in storage until spring 1908.

After count Zeppelin’s first attempt to build a dirigible with the sort of perform­ance the military sought, the Schute Lanz company also came up with a rigid airship. Main structural material was timber which was rather heavy, affecting performance. Von Zeppelin gradually became undisputed leader in rigid airships. In 1905, he com­pleted his LZ-2. Similar in size to the LZ-1, its powerplant was significantly more powerful. It was this powerplant that failed on the LZ-2’s maiden sailing on 17 January 1906. Rendered unable to cope with bad weather, and hit by a sudden storm, the Count had to land far from his base. Such was the severity of damage that the craft had to be disassembled where it landed.

None of this was reason to despair (and in any case despair was something unknown to the old soldier). The LZ-3 emerged from its hangar soon enough, and in 1906 and

1 Translator’s rendering from the quotation in Bulgarian.

102

The Schute-Lanz airship being walked from its hangar for tests

1907 went on to make a series of successful voyages. It was bought by the Ministry of War who designated it the Z-1. At the same time, von Zeppelin designed the 147m long LZ-4 and offered it to the government. One of the conditions the latter put to him was that it should make an uninterrupted 24-hour voyage. Zeppelin planned to sail from Friedrichshafen to overhead Basle, and along the Rhine to Meinz. In fine summer weather this was easy for the vessel, provided its twin 110hp Daimler-Mercedes engines held out. The LZ-4 lifted off on 4 August 1908 with 12 persons on board (including its designer), The day was warm and conditions looked ideal. Many inhabitants of Basel, Strassbourg,

The LZ-2, moments after its accident

I The LZ-3 over Berlin

and Mannheim came out to watch the huge creation of man fly overhead. However, the hot sun overheated the structure and the valves let a great quantity of hydrogen escape from the gas bags. Between Mannheim and Meinz, after more than half the planned voyage was completed, one of the the LZ-1’s engines failed. Count Zeppelin assessed the situation and decided to put down near Oltenheim. Repairs took three and a half hours, and the flight resumed with a reduced load. The next morning, after covering 610km and with just 110km to go, engine trouble again caused an unscheduled landing. The airship touched down gently near the Daimler factory in Stuttgart. Lacking anything better, local volunteers moored it to an undertaker’s coach. A summer storm struck in the afternoon, tearing the airship off its improvised mooring. A fire broke out and the craft was rendered unfit for further use.

The bloodless calamity increased von Zeppelin’s stock. A sympathetic public raised cash to assist his further activities. This made series production of airships and their associated equipment possible. The world press announced the laying down of eight airships and a government prize for the designer. The Count, for whom riches meant little, refused to make non-rigid or semi-rigid airships, however quick the returns. At the time, soft balloons continued to be the only means of aerial observation bought by armies and navies. What really motivated von Zeppelin was to boost German gran­deur with an instrument of air power without equal.

At the close of 1909 he assented to the founding of the German Aeronautical Public Equity Company, DELAG. This was to operate seven airships, which in the event made over 16,000 flights carrying over 35,000 passengers before the start of war.

DELAG’s Schwaben airship about to alight

The fleet was also used for crew training and moving troops. During the same period the Friedrichshaven airship works manufactured 25 airships. Apart from DELAG’s machines, 12 sold to the Army, three to the Navy, and three remained on the compa­ny’s books.

Right since the debut of rigid airships, the German war ministry saw in them a new and powerful strategic weapon. Its great benefit was the great depth of projec­tion, and that in an environment previously untouched by man. Apart from anything else, airship warloads could reach six and a half tonnes. The operational war plan for the Western approaches formulated in 1906 by von Schliffen foresaw German troops entering France and an Army group passing through Belgium. The plan assigned air­ships to operational and tactical tasks in the service of the Supreme Command and Army Commands. Airships were to bomb strategic targets, perform reconnaissance and strike targets under observation, and perform transportation tasks. The General Staff felt that a lone airship would be able to disperse troops, force the capitulation of fortified garrisons, paralyse communications and supply, cause panic in large cities, and have a psychological effect on troops and civilians. The Germans paid for their overestimation of airships in the initial stages of the Great War: the idea of using them in combat had to be curtailed hastily, and the fascination with them held back Ger­man aeroplane making for years.

The initial period of man’s search for reliable methods of conquering the sky end­ed with the Wright brothers halting flights, Parcival-Ziegsfeld balloons entering pro­duction, and the LZ-4 making its first voyage. Three ways to build the first component of national air power. These roads were defined by the nature of flying apparatus, and by the future tasks suitable to each.

The first such road went via non-rigid lighter-than-air vessels: balloons. Going back over a century, their history had led to the tethered kite balloon: an excellent aerial observation platform. Though the nature of their tasks had hardly changed since the French Revolution, they offered much better conditions for the use of sight­ing and photographic optics. This made them invariable participants in manoeuvres and colonial conflict at the turn of the 20 th Century, and invaluable in reconnais­sance gathering and artillery directing. In view of their comparatively long evolution and the considerable accumulated experience in their use, they were both most per­fected and most widespread.

The second road led to lighter-than-air vessels of non-rigid, semi-rigid and rigid construction, able to fly freely thanks to being powered. They had evolved from the first balloons which freely followed air currents. The lack of suitable and sufficiently powerful engines was the main hindrance in the way of airships. They failed to find a practical application until the end of the 19th Century. It was only after the appear­ance of the internal combustion engine that strategists in France and Germany began writing airships into their war plans as strategic intelligence collection and attack platforms. But plans are intentions, not reality: the first airships lacked adequate per­formance. Army and navy experts were very critical of their slowness, their depend­ence on medium altitude winds, and their low flight altitude which made them vul­nerable even to small-arms fire.

The third and newest road was represented by aeroplanes: heavier-than-air flying machines. Though fragile, the Wrights’ Flyer nevertheless staked a claim for the fu­ture with its mobility and compactness. A period of breakneck development over a very short time was about to unfold.

| A Zeppelin airship under construction

Regardless of human advance towards the conquest of the air, the components of air power were barely nascent. Most developed was the availability of flying apparatus capable of performing military or civil tasks in a sustained fashion. Yet such apparatus as there was played purely subsidiary roles and lacked any penetration in depth. Such flying schools as were soon to appear trained a very limited contingent of pilots and ground staff. The creation of German airship operator DELAG was a step forward, in that it gave fine training to many flight and ground crews. However, there was still no combat training system in operation. What military theories existed trod well estab­lished infantry and naval paths, failing to take into account both the specifics of the new weaponry and that of the environment it was designed for. As to aviation, it was literally still on its starting blocks. One could not speak of the second component: the sufficient availability of skilled pilots and ground crews.

The third component, ground and air equipment, was only developed to any ex­tent in aeronautics. Airborne equipment comprised sighting optics and early aerial cameras. Ground equipment comprised hydrogen production and filling stations. The arrival of airships increased demand for facilities where they could be moored and maintained. This led to the appearance of the first hangars, mooring towers and other station facilities. As aeroplanes developed, so would airfields and eventually airports. Support facilities were limited to a few factories for the manufacture of tethered bal­loons and workshops catering to the amateur aeronaut trade. Zeppelin’s company, whose core and only activity was aeronautics, was an exception (though it soon be­came the rule in the industrial nations). It is difficult to discern any command or coordinating structure or system, let alone discuss its powers or effectiveness. Tele­graphic transmission tests did take place, but failed to become routine both in the armed forces and in private operators.

The early stage of development determined the limited opportunities of using the air for civil and military ends. The emergence of air potential depended on scaling a number of problems: a challenge calling for both time and money.

Even the scant attention given to the Wright brothers’ glider trials between 1900 and 1902 stimulated French aeronautics students’ desire to build real aeroplanes. After Lilienthal’s death, European progress in heavier-than-air flying apparatus had come to a standstill. French artillery officer Capt Ferdinand Ferber made the first effort to a resumption. In early 1902, Octave Chanute sent him a copy of the paper on gliding delivered by Orville Wright the previous September. Ferber decided to make a glider similar to that of the Americans, but without the roll control system. He used bamboo and normal timber, and completed the job in 1903. The glider was intended to be powered, and Ferber acquired a 6hp Bouchet internal combustion engine for the purpose, marrying it to two puller propellers. The aeroplane was tested later the same year, being put through its paces while suspended from the gib of an 18 metre high stand. This showed up the engine’s insufficient power: it had to sustain a 235kg machine in flight.

In 1904, Ferber improved the aeroplane, fit­ting a tailplane aft of the wing. The wings were given some anhedral in an attempt to improve longitudinal stability. A new and more reliable

I Ferber’s attempted free flight in 1905

Peugeot engine, again rated at 6hp, was fitted. The puller propeller was between the wing assembly and the forward mounted elevator.

A flight attempt was made on 27 May 1905 when Ferber intentionally cut the holding rope. However, all that the weak engine did was merely reduce the gradient of the precipitous glide. Nevertheless, the puller propeller/biplane aerodynamic configu­ration was rational, and was to spread far and wide a few years hence.

The enthusiastic gunner went on to build a third aeroplane in 1906. This featured a significantly more powerful Antoinette engine, whose output reached 24hp at 600rpm. Regrettably, the aeroplane was destroyed by a storm on 19 November, a little while before its planned first flight.

When the Wrights stopped flying, aviation advance palpably slowed. Ferber was not the only one to try and acquit the Old World. Transylvanian[5] Traian Vuia, who lived in France, conceived a Flying Automobile. Its road-going progenitor left a strong imprint on the finished article which had four leaf-sprung, pneumatic-strutted and tyred wheels; a steering wheel controlled the rudder. The wing folded for easy trans­port by road. Control was to be achieved by tilting the wing, and longitudinal trim: by sliding the seat fore and aft. The steel tube and cloth article weighed 192kg, had an erect span of 8.7m and a wing area of 20sq m. The engine, a 24hp Serpols unit, drove a two-bladed puller propeller with a 1.5m diameter.

The Vuia 1 entered testing in March 1906. On 18 March it took off and flew for 12m at a height of a metre. Five months later, this distance was doubled but the landing was a crash. Despite the modest achievements, these hops boosted interest in monoplanes. Vuia’s later improvements to his apparatus, which included modifying the controls, led nowhere: testing in October showed it to be incapable of sustaining level flight.

Traian Vuia with his Aerial Automobile at its debut on 18 March 1906

Gabriel Voisin was one of the most famous of pioneer aviators. He was a French mechanic who had designed and built his own gliders. In 1905, he made a float-equipped glider with a strange wing. It took off by being pulled along the Seine by a motor boat, and testing proved that boxing the wing as in a kite resulted in good stability, as well as improving structural strength for a given weight.

Using his glider experience, in spring 1906 Voisin built the Bleriot III (thus called because it was or­dered by Louis Bleriot, later to be a renowned design­er, maker and flyer in his own right). In profile, the wing was ellipsoid. The idea was to box it and give it anhedral for roll stability in one. The rudder was within the wing. The aeroplane was intended to depart and alight from and on water, as the glider had, and it was fitted with two fore and one aft floats. A 24hp engine drove two forward propellers via bicycle chains.

Testing began in May 1906 and soon revealed that the powerplant caused strong wing vibrations at cer­tain regimes. Nevertheless, on 12 September the de­signer did fly a distance of 42m at a metre above the surface, and an average speed of 57km/h. It turned out that such hops afforded no control whatever. The

The float-equipped Voisin glider being towed on the Seine at Paris in 1905

The Bleriot III, in which the later-famous Bleriot first tried to fly

attempt to get rid of vibrations by fitting two engines, each driving its own propeller, ended in failure: the heavier machine could not improve on its earlier parameters.

After a fruitful summer, Gabriel and Charles Voisin formed the world’s first aero­plane making company. Orders piled in, especially after a famous flight by eminent aeronaut Santos-Dumont. The Bazilian had designed the 14-bis aeroplane. A hybrid between the Wrights’ Flyers and Hargrave’s kite, this was a canard biplane with a biplane forward elevator and a pusher propeller. A peculiarity of the design was its pronounced dihedral. The engine was a 24hp Antoinette. The structure was of tim­ber and bamboo. The pilot stood upright in a basket-like container. The rest of the fuselage was of square section, entirely cloth-covered.

Santos-Dumont began tests in 1906. The Aeroplane was towed behind a dirigible (again designed by himself, hence the bis in the designation). In late August, an attempt was made to fly free, but the contraption failed to get off the ground. Subsequent run­ups ended in failure. One reason for this was the weak engine, which was changed for a more powerful 50hp Antoinette. The modi­fied aeroplane flew for some 70 to 80m at 3m on 23 October. This was enough for all mem­bers of a French Aero Club committee, who witnessed the flight, to admit that Santos – Dumont qualified for the Prix Archdecon, instituted for the first man to fly a distance of not less than 25m.

On 21 November the designer won a sec­ond similar prize, this time for a flight cover­ing not less than 100m. This time he rose to

6m and covering a distance of 220m. Of course, this was not the first powered aeroplane flight, and indeed the 14 bis was only just an aeroplane, being immensely unstable and yawing uncontrollably. The yawing was not cured even after ailerons were installed. Its great many imperfections make it clear that the credit for its flights lies mainly with the excellent engine and well-chosen weather. A crash in early 1907 was the natural end to its career. Nonetheless, the enormous enthusiasm caused by reports of its flights stimu­lated the efforts of many pioneers, and the acclaim of the public.

One of Voisin’s early clients was French sculptor Leon Delagrange. His Viosin – Delagrange 1 was a motorised version of the Voisin-built floatplane glider. The engine was the proven 50hp Antoinette, and a wheeled undercarriage replaced the floats. The aeroplane had a biplane elevator, with the side members of the tailplane acting as rudders. Span was 10m and wing area, 40sq m. Fitted directly to the engine output shaft, without a reductor, the metal pusher propeller spun at up to 1000rpm.

First trials set tor 28 February 1907 re­sulted in some successful hops. On 30 March Charles Voisin covered a distance of some 80m. Then the wheeled undercarriage was removed and replaced with floats, but when this did not increase flight lengths, the de­signers reverted to wheels. On 3 November 1907, Leon Delagrange flew a distance of 500m but crashed on landing.

The Antoinette engines which were be­coming favourites to inventors of early aero­planes, were designed by French engineer Leon Levavasseur. Initially intended for light maritime applications, they were later adapt­ed for airborne use. Two major versions were Ш Leon Levavasseur, 1863-1922

Щ On 30 March 1907, a Voisin-Delagrange covered a distance of 60m

made: 24hp and 50hp, both extremely compact for the time. In seeking potential Euro­pean buyers, Levasseur tried to make his own aeroplane. It was to share the name of the engine, which had been named after Levasseur’s employer’s daughter, Mademoiselle Antoinete Gastambid. The Antoinette 1 was to have been a canard monoplane with a pusher propeller, but regrettably the project did not reach conclusion.

In 1908, Levavasseur designed a second monoplane. This had a long fuselage and a rather advanced wing profile, with a great thickness to chord ratio and different upper and lower curvatures. The wing planform was a trapeze with an area of 24sq m and a span of 10.5m. Weight reached 350kg. The more powerful 50hp engine was chosen for the aeroplane, but even this was insufficient for a proper flight, trials result­ing in a few hops. This did not out off the designer, but rather, spurred him on. In July 1908 he completed detail work on the Gastambid-Mangen-2 by fitting it with triangu­lar ailerons at the wing tips. On 21 August the new machine flew a circular flight lasting 1m36s. The Gastambid-Mangen-2 was the first manned monoplane to fly.

The Antoinette 4 appeared in 1908. Similar to Levasseur’s early designs, this had a trapezoid wing, a puller propeller, and a long thin fuselage. All-up weight reached 460kg. The engine was the same as in the previous design. To cut drag, the cloth covering the wing’s upper surface was varnished to a gleam. Wing and body structural elements were made of metal. The undercarriage was of the single pivot type, with pneumatic damping. The wing undersides had skids, with another skid guarding the propeller from striking the ground in heavy landings.

The aeroplane showed excellent qualities, prompting French pilot Latham to at­tempt to fly the Channel. On a good July day in 1909, he set off superbly, but shortly before reaching the English coast problems developed and the machine had to land on water. In August the saem year, an Antoinette 4 piloted by Latham flew the dis­tance of 155km in 2h17m at the first international air races in Rheims. The aeroplane was widely exported in the years before the Great War.

The builders of the Gastambid-Mangen 2 checking its undercarriage before a flight attempt

A year earier, in July 1908, Ferber completed his last aeroplane, the Ferber 9. Built by Antoinette, it was a puller propeller biplane and a forward positioned elevator. Span was 10.5m, wing area was 30sq m, weight was 400kg, and the engine was a 50hp Anto­inette. Trials began in the summer and were successful. The aeroplane was exceptional­ly stable, covering a distance of 500m in September. This was Ferber’s first and last aeroplane to make it into the air. The designer was to die in an air crash in autumn 1909.

As mentioned above, Maj Parcival was a successful designer of non-rigid airships. On leaving the army in 1907, he organised airship manufacture for civil and military use. Between 1909 and 1913, his company built 18 examples, some of which went on to transport passengers, while others were bought by the German, Austro-Hungarian, British, Italian, Japanese, Russian, and Turkish armies.

The British became worried by the interest the German military lavished on the LZ-4. Disquiet became pronounced with the news that after the craft’s widely publi-

An Antoinette 7 before its second Channel flight attempt on 27 July 1909 …

… and after it

THE FERBER 9

The Ferber 9, also known as the Antoinette 3

cised demise, patriotically minded Germans had subscribed money for yet more air­ships. At a time of intense Anglo-German naval rivalry, it became clear that Germa­ny, possessor of Europe’s (and possibly the World’s) most powerful land army, was now aiming for naval and aerial supremacy.

How was this challenge to be met? The question turned out rather difficult. In 1907 the Army Balloon Factory built a small sausage-shaped airship. Named the Nulli Secundus, its first flight covered the distance between Farnborough and Crystal Pal-

A Parcival P IV non-rigid airship

ace, overflying St Paul’s Cathedral en route. Covering the fifty miles took a little under three and a half hours. In 1908 the vessel was modernised, but the resulting Nulli Secundus II was also rather tardy to have any military significance.

In fact, British hopes of competing with the Germans rested with large rigid airships. This was the class of vessel the Admiralty wanted. The task was assigned to Vickers, Sons and Maxim Ltd (soon to be just Vickers after Sir Hiram Maxim left the board). The company had built Britain’s first submarine. Initial plans included the wide scale use of duralumin, a new German-discovered light alloy, which Vickers also made.

When the project was first presented, head of the Maritime Armaments Depart­ment head Capt Bacon was dissatisfied and decided on a course of constant inspections during construction and preparatory work. Thus he personally supervised compliance between what was wanted by the War Office Maritime Design Department and what was being done at Vickers. Bacon was a firm adherent to the ideas of air power and of adapting airships for Navy needs. His findings found favour with the Admiralty which in turn held him responsible for their implementation. Sadly, no sooner had the project started than Bacon resigned as part of a heated argument between Admiral Lord Charles Beresford and First Lord of the Admiralty, Sir John Fisher. Bacon was succeeded by Capt Murray Suiter, another firm adherent of naval aeronautics. Sadly, Suiter knew little about aeronautics. He took the job of Inspecting Captain well aware he had to trust Vickers. The responsibility for failure was thus passed down to Vickers’ maritime design managers who had no aeronautic experience, and no background in the construction of rigid dirigibles or the new special materials used in them.

To construct the vessel, Vickers began building a huge airship hangar near Bar­row-in-Furness. This turned out so hugely expensive that it absorbed the entire project’s budget. Suiter turned to the War Office for additional funds. His application led to another round of inconclusive discussions about the number of airships versus aero­planes on order for the Navy and Army.

When the job was nearing completion, a mathematician consulting Vickers on stresses reported that the numerous departures from initial design specifications meant the airship would lack the requisite strength. Nonetheless, completion went ahead with the added proviso of additional ground tests prior to first sailing.

In late spring 1911, the 137m long Mayfly, as it had been popularly dubbed, was ready to fly. Moored at a purpose built tower, it had overcome strong winds successful­ly. However, serious defects were discovered in its lifting engines, and it was walked back into its hangar for modifications. The date of 24 September was set for further tests. As the Mayfly was being walked out on that day, its upper parts struck the hangar, sustaining irreparable damage. Fortunately for posterity, photographers man­aged to document its final appearance shortly before the accident. Navy officers present were unanimous in declaring the airship “more the work of lunatics than anything

I Russia’s most competent pre-World War airship was the Al’batros

else”. An enquiry reached the verdict that structural weakness had lain at the bottom of the events, recommending the cessation of further work. The hundred thousand pounds Sterling spent on the Mayfly project were ultimately written off, the Admiral­ty redirecting efforts at heavier-than-air apparatus.

Some years after the defeat of the Russo-Japanese War, in early 1909 the Russian Army and Navy bought indigenous and foreign-made airships. By 1912, the Army had ten dirigibles. They were of the semi-rigid class, with a single long gondola for the pay/warload. Largest was the P-7[6], a 70m long Parcival type vessel which had a radio station broadcasting within a 500km radius. By 1914, Russian dirigibles had grown to 15: German, French and British designs, some of them manufactured in Russia. Elev­en of them had limited performance, being limited to some 50km/h. Only four genu­inely met military specifications. Best among them was the Al’batros,[7] a 10,000cu m design with a ceiling of 2000m, and a 75km/h true cruise speed. Its complement was between eight and twelve men.

The aeronautical situation in France and Italy was similar. Germany was the un – oubted leader in giant airships. Their performance allowed them to perform a great variety of tasks, with operational and strategic reconnaissance assigned as their main use in a future war.

Meanwhile, the performance of heavier-than-air machines was improving by the day. Progress threw up new names fated to become legends in aviation. One such was Henry Farman. Known in France as ‘Henri,’ he was one of the three sons of British journalists working in that country. Fascinated by the achievements of pioneer flyers, he ordered an aeroplane from the Voisins. This was to be the constructors’ first depar­ture from their early aeroplanes’ trademark box-wing biplane construction. The aero­plane had an unusual layout. It was a triplane with a span of 6.3m, an elongated body,

The Voisin-built biplane in which Henry Farman made his first successful flight

Henry Farman speaking with a trainee pilot about to fly a Farman

and a biplane tail. It was fitted with a Renault automobile engine driving a pusher propeller. Elevators and rudder were forward-mounted. No evidence of flights with this strange machine survives. Farman must have been disappointed and began mod­ifying the design. The new version had four ailerons: one on each of the four wingtips. They deflected only downward, but their large area made them effective enough. Wing area was 40sq m with a span of 10m. The engine remained the same, its 50hp rating being sufficient for the 530kg all-up weight.

Initial tests showed adequate flying qualities. On 2 October 1908, Henry Farman set a distance and height record for a French built aeroplane by flying 40km in 44m 31s. On 30 October the same machine performed aviation’s first city-to-city flight when it

The Farman 1 biplane

ifcfe. «****** Щ The Standard Voisin had a box wing construction

departed from Bouis and landed in Rheims (the two are 27km distant). This marked the end of the Voisins’ fruitful period of cooperation with Farman.

The former truned their attention to their ‘Standard Voisin’ which was assembled and towed out in December 1908. This was to be their first series-produced design. Within six months, 16 machines were built for clients which included the Odessa Aero Club in Russia. The original Voisin glider could still be divined in the aero­plane’s appearance. Engines were different, but all drove a pusher propeller. Major materials were timber and cloth, the latter covering only the upper surface of the wing, and the exterior of the ‘stabilisers’ and some parts of the body. Only the under­carriage was of steel for strength. The biplane had the same span and wing area as Farman’s design, and a length of 12m. Maximum recorded speed was 55km/h.

The lack of ailerons (or an other means of roll control) meant the machine was not particularly manoeuvrable. Turns had to be flat, taking a long time and covering a great area. Despite this shortcoming, the aeroplane was among the most popular de­signs of the next few years. Thanks to its stability, even in strong wind, the Standard Voisin was preferred for initial pilot training. It saw action as a recce and light bomb-

THE STANDARD VOISIN

ing platform in the Tripolitanian, First and Second Balkan, and the initial stages of the Great War.

The crash of the 14 bis did not set that eternal seeker, Santos-Dumont, back. He built the 15 bis, which however inverted on its first take off and was damaged. Santos – Dumont resotred it, but did not fly it any more, directing his efforts at monoplanes.

The 19 was finished in late 1907. The machine was extraordinarily compact and rational looking. Span was barely 5m, and wing area was 11sq m. This was history’s first micro aeroplane. To cut weight, bamboo and cloth had been used almost exclu­sively. Calculations showed that a 20hp engine would be sufficient to haul the sub – 200kg craft into the air and give it good controllability. Yet the lack of ailerons and the ineffectiveness of the other controls meant a difficult test career.

The aeroplane suffered a failure on its third takeoff attempt. The Brazilian refused to repair it, preferring to devote what means he had to the 20, or the Demoiselle, as the 19’s modified successor was to be called. The structure was strengthened with thin metal piping used instead of bamboo for structural elements. Without practically any change to the craft’s appearance, the control system was changed to allow the pilot to control the aeroplane by shifting his body around, as well as by moving levers. The same 30hp engine type as in the previous version was located between the two wing halves, near the leading edge. Despite being flown successfully and attaining a 90km/h

Щ The 15 bis biplane being towed by designer Santos-Dumont; the visibly great dihedral was intended for roll stability

H Santos-Dumont’s Demoiselle looked similar to his 19 and 20

speed, the Demoiselle was insufficiently developed. It was to be the eminent Brazilian’s ultimate design.

The appearance of European designers able to attain impressive indicators shook the Wright brothers’ conviction that they would remain unchallenged for a long time. Their patent was threatened: aeroplane making was developing well regardless of their absence. In order to salvage something from their invention, in 1905 they cut the asking price for a French licence by half to 500,000 franks. Flyer III was sold to the US Government for 25,000 dollars. Negotiations started with British and German aviation hopefuls. One of the contracts called on the Wrights to fly demonstrations in an aeroplane similar to the Flyer III, but with two seats, and with pilot and passenger sitting upright. The fuel tank was also increased for greater range and endurance. The new pilot position called for modifications to the controls. The engine, another Wright,

Щ Alberto Santos-Dumont surrounded as usual by an adulating crowd

THE SANTOS-DUMONT 19

I A Wright single-seater

THE WRIGHT TYPE A

was also new, this time producing 30hp. Length was 8.9m, span was 12.5m, and wing area was 47sq m. There was still no undercarriage, the aeroplane landing on skids.

In May 1908, before departing for Europe the Wrights began testing their new type. History’s first biplane flight with a passenger on board was on 14 May. The passenger was W. Fernas, Wilbur Wright’s assistant, who was in the air for a total of 20 seconds. Soon after, Orville Wright notched up a 3m 40s flight.

The demonstration flights began in August 1908. The brothers parted, Wilbur going to France. In the short time between 8 and 31 August he performed 104 flights lasting a total of 25 hours over the Old World. His last flight, in which he covered 129km in 180 minutes won him a 20,000 frank prize. Meanwhile, Orville flew near Fort Myer, Virginia, demonstrating the second example fo the new design. He made ten flights, four of them lasting over an hour. The last one, on 17 September, ended in a crash. The reason turned out to be a defect in one of the propellers. The pilot was badly hurt, and his passenger, friend and Army engineer Thomas Selfridge, died.

The European aviation community was impressed with the manoeuvrability of the Wright brothers’ aeroplane. They witnessed turns with banks of up to 25 degrees, executed not just with a rudder (as in contemporaneous European types), but also with ailerons and wing camber control which moreover were not just used for coun­tering the odd involuntary roll.

Another good idea was the use of gearing for the propellers. Thanks to the Wrights’ reductor, they used larger timber propellers which worked more efficiently. European designs had more primitive metal props with direct drives. As a result of its superiority,

I Moments after Orville Wright’s crash which killed passenger Thomas Selfridge

the Wright A flew considerably better with almost half the installed power of Voisins, Levasseurs, and Santos-Dumonts.

The Europeans reacted swiftly: ailerons became a compulsory feature of subse­quent designs, gearing was fitted to reduce propeller speeds, and the latter were now made of timber and grew in size. By early 1909, newly-designed French aeroplanes could match or outdo the Wright A. Some were more stable and controllable, while others had lighter and more powerful engines and were more autonomous due to their wheeled undercarriages.

I Wrights during detnonstrations in France

Щ A Wright in front of a hangar

The Wrights’ most serious competitor was one of aviation’s legends: French­man Louis Bleriot. His road to success and fame was hard. After a short and not altogether satisfactory spell of working with Gabriel Voisin, Bleriot modified his private Voisin and renamed it the Bleriot IV. Fitted with floats for testing from water, this failed to get airborne, as it also failed when using a wheeled undercar­riage: the engine was too weak. But the designer was also clear that the overall concept needed changing. The Bleriot V of April 1905 was the first of a series of trademark monoplanes. It was a canard with a span of 7.8m and a wing area of 13sq m. The engine was a 24hp Antoinette driving a pusher propeller in the aft fuselage. Gross weight was just 236kg thanks to, among other things, the ma­chine’s paper covering. It was this aeroplane that rewarded its creator with his first hops of a few metres each. The last of these ended dramatically. Being inex-

| The Bleriot V after its crash-landing

Louis Bleriot’s tandem monoplane

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perienced in the use of the elevator, Bleriot handled it roughly, causing the mon­oplane to stall, drop its wing and crash. While its maker was unhurt, the aero­plane was so damaged that repairing made no sense.

The next attempt involved seeking the ideal configuration. Bleriot chose a tan­dem with great dihedral. Spanning just 5.9m, it had a 20sq m wing area. The engine was as before. The control method was changed. The forward wing had elevons at its tips, in addition to which the designer used balancing by sliding his seat fore and aft for pitch control.

The Bleriot VI was tested in July 1907, being flown also by Ferber and Peyret. Distances flown had now grown to over 100m. The designer felt that a yet more powerful engine was needed, and fitted a 60hp Antoinette. The heavy six-cylinder unit affected trim in what was already a rather unstable machine. The anticipated control problems reared their head, a trying first flight ending with a heavy landing; only Bleriot’s cool head avoided a worse outcome. Worse for wear, and with his un­gainly creation in even poorer shape, he received an Aero Club prize for covering a distance of 184m.

The next step was the building in November 1907 of the Bleriot VII. This was a clean looking machine some 20 years ahead of its time. The low-wing monoplane with its long and entirely cloth-faired fuselage, forward propeller, and tailplane and fin evoked more a 1930s feel than a pioneering effort. Structural materials were moixed, steel tubing being used in an attempt to bargain between lightness and strength; tim­ber, cloth and paper appearing elsewhere. Eight metres long, spanning 11m, and with a 25sq m area, the monoplane weighed in at 425kg. A powerful 50hp Antoinette spun a four-bladed metal prop.

I The Bleriot VII monoplane

Щ The Bleriot VIII after its crash; note the empennage

In November and December 1907, Bleriot made six flights of up to 500m. The few timorous attempts at manoeuvring confirmed fears of ineffective controls, espe­cially in roll. This defect was the reason for the crash on 18 December.

The energetic Frenchman needed just six months to synthesise his achievements so far and create the Bleriot VIII. Layout was the same, and was to prove its worth in the years to come. However, the controls were changed. For the first time, the design featured modern ailerons faired within the wing contour. Elevators were also fea­tured. Dimensions remained approximately unchanged. What change there was aimed to affect trim. This was how Bleriot’s first businesslike aeroplane emerged. On 6 July 1908 he flew it in a circle around his testing ground for 8m 28s. On 31 October, he flew the 14km distance from Tours to Artenes in 11 minutes.

The successes of aeroplane makers increased in geometric progression. While France had attained pole position, other nations were not far behind. Despite Germany’s fascination with airships, Otto Lilienthal’s rich testament was not for­gotten. Karl Jato was an amateur birdman who had first flown in a Lilienthal-type glider. In 1903 he built an aeroplane with an internal combustion engine. This was a tailless triplane with no built-in longitudinal or pitch stability whatever. Four fins positioned between the upper and mid wings acted as rudders. Testing of the unusual device began in August 1903. A gust of wind at the end of that month inverted it, and when repairing it Jato decided to get rid of the uppermost wing. Tests resumed but the best that could be attained by the unstable and almost uncontrollable craft powered by a 12hp Bouchet engine was a 60m hop at a height of two to three metres.

Building on his experience, in 1908 Jato made his second aeroplane. This was a biplane with a wing area of 54sq m and a 35hp engine driving a 2.5m diameter

Jato’s biplane before an attempted flight in summer 1903

propeller. The elevator was forward mounted. Longitudinal and pitch control were by means of the upper wing whose incidence was variable, as well as by elevators mounted between the wings. Despite the more powerful engine, the aeroplane’s

Щ Carl Jato’s 1907 design

>

Щ Hans Grade’s 1908 triplane

behaviour was about the same as before, and Jato failed to become Germany’s first powered aeroplane flyer.

Another German, Ing. Hans Grade, had better chances. His fascination with fly­ing had also formed under the influence of Lilienthal. He began designing his aero­plane in 1902 but only finished it in 1908. The triplane wing spanning 8m had an area of 25sq m. The empennage comprised elevators and a rudder. Basic materials were bamboo and thin cotton. The engine, of Grade’s own design, was a six-cylinder unit producing 36hp. Several hops were achieved by the year’s end, by when it was clear that the design was incapable of more. Modifications involved increasing the wing area, improving the controls, and fitting a more efficient propeller. The result was Germany’s first aeroplane flights. Barely covering several hundred metres, they were sufficient to enter Grade into history as Germany’s first designer of a heavier-than-air flying machine to fly it successfully.

Щ Grade’s aeroplane in modified form

THE GRADE AEROPLANE (1909)

British-domiciled American Samuel Cody designed kites for the Royal Army. In 1907 he fitted a 12hp Bouchet engine to a kite of his own design which spanned 12m. Initial tests were unmanned, the kite being tethered in an intricate way. Analysing his experience, Cody improved the design with the result that the Army Balloon Factory began building an aeroplane with a military purpose in 1907. The Wrights’ Flyers acted as patterns, as is obvious from a glance at the machine. The Cody 1 was a biplane with two pusher propellers and a forward mounted elevator. It had a wheeled undercarriage and an aft mounted fin. Roll control was by wing twisting. The bamboo structure was cloth-covered.

Several attempts to get off the ground were made in September. Despite the lack of success, trials continued, Cody managing a 50m hop. His biggest success was on 16 October, when he flew 450m at a speed of 45km/h. Sadly, the return to earth was a crash landing. The craft was repaired and improved. In May 1909 Cody flew a mile in

I Cody’s Army Aeroplane being towed in September 1908

Cody’s biplane as modified with elevators

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it; in July, he covered almost six miles; and in September he achieved a record 39 miles. Despite being a foreign subject, Cody was recognised by the Royal Aeronautical Society as the first man to fly successfully in Britain.

Meanwhile, the British War Office was funding another aeroplane which looked strange even by the standards of today when practically anything has been tried. It was a flying-wing biplane. Stability was granted by the wings’ shape. It spanned 12m and was swept back 30 degrees. Lt John Dunn, who led the project at the Balloon Factory, chose a 12hp Bouchet engine driving a two blade pusher propeller. No struc­ture testing methods were available at the time, nor were there yet any means of calculating stresses. The Dunn 1 fell apart during its first takeoff run. The military lost

Lieutenant Dunn’s ‘flying wing after a successful flight

Lieutenant Dunn’s ‘flying wing after a successful flight

interest in the project, but the Lieutenant continued developing it, increasing engine power, improving controls and structural stiffness, and ultimately coming up with the Dunn D.5 in 1910: the first successful flying wing.

The Wrights were not America’s only aeroplane makers. As early as late 1900, an exceptionally far-sighted and inventive man by the name of Glenn Hammond Curtiss founded an aeroplane company. The company’s first design was the Golden Flyer. This was similar to the Silver Dart which Canadian Mark Curdey was to fit with a Curtiss engine in 1908. The difference was in its lighter structure and the 50hp produced by the Curtiss V8 engine. Between June and September 1908 the

THE DUNN 8 (1912)

I Glenn Hammond Curtiss

aeroplane made 54 flights. Since the Wrights had not registered their achievements officially before the end of that year, Curtiss was declared the first Amreican to cover a kilometre, and the first to fly a circling flight. In 1909, the same craft flew at the international air show near Rheims, reaching a speed of 70km/h and winning a prize for this speed. Over the next few years, Curtiss was to design a number of excellent aeroplanes which exported widely.

Russians were also trying to keep in step with developments. For a long time, efforts to design heavier-than-air machines were dogged by failure. It was only in May

I Curtiss’s John Bag in flight, 1908

I Curtiss’s Golden Flyer biplane in front of the Curtiss Company’s hangar at the 1909 Rheims Air Show

1910 that Kiev Polytechnical Institute lecturer Aleksandr Sergeevich Kudashyov su- ceeded in building an aeroplane. The design was a canard triplane with a length of 10m, and a span of 9m. The craft was fitted with an 35hp Anzani engine. The design­er had flown near Nice in the company of famous Russian pilot Efimov and felt com­petent to test-fly his creation. On 23 May 1910 he managed to make a few hops at a height of two to three metres. The event was not officially registered since the appro­priate institutions had not been invited to witness it.

A month later, electrical engineer Yakov Modestovich Galkkel’ completed a most original aeroplane. The Gakkel’ 3 was the world’s first biplane with an inverted section wing: the leading and trailing edges were turned upward rather than down. The aeroplane had a tailplane, elevator and rudder. The engine, a 35hp Anzani, drove a two-bladed forward propeller. Structure was cloth-cov­ered timber, weighing 560kg.

THE GOLDEN FLYER

THE GAKKEL-3

On 6 June 1910 an All-Russian Aeroclub committee recorded the first flight of a Russian designed aeroplane. However, poor engine performance resulted in disap­pointing performance. The problem was later solved and Gakkel’s biplanes and his monoplane were to be equal to any.

Despite Hans Grade’s flight, German political and military leaders were becoming concerned at otherwise falling behind in aviation. To make up for this, in 1910 they bought the licence for the Austro-Hungarian Taube monoplane. That aeroplane’s story was rather interesting. The wing’s profile and planform were a replica of the winged seed of the tropical Zanonia plant. German scientist D. Alborn was impressed by this seed’s flat glide and surmised that it might serve as model for a flying machine.

I A Taube’s unfaired structure

I A sports Etrich Taube with an Austro-Daimler 100hp engine

THE ETRICH TAUBE

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The idea was developed by industrialist Hugo Etrich and engineer Franz Wells in the form of a glider rather similar to the natural original. The designers performed several flights in it in 1906, rearing distances of over 200m.

After the Zanonia flying wing was fitted with a 24hp Antoinette engine driving a two-bladed propeller, and with a twin-wheel undercarriage, it was tested again. Fears that the lack of an empennage would damage controllability were confirmed. An empen­nage was successfully designed and fitted lat­er the same year, giving birth to the famous ■ The flying seed of the Zanonia plant Taube: most widely used German and Aus – which impressed Alborn trian aeroplane in the 1910 to 1915 period,

I The Zanonia glider built by Etrich Taube in 1906

Щ The Zanonia-derived Antoinette-engined flying wing monoplane

The Zanonia-derived Antoinette-engined flying wing monoplane

and the first enemy aeroplane to fly over Paris after the outbreak of the First World War.

Aeroplane production was now picking up. The tense international situation made the military look more closely at the new-fangled, rather unreliable, kite-like flying machines. The main quality measure of the emerging component of the new measure of each nation’s potential was what records had been set and what achievements notched up. Bleriot was again among the leaders. In January 1909 he finished work on the Bleriot XI: the design that would bring him worldwide fame. On 25 July the same year, he flew it over the Channel. This was a leap forward in aviation development, which showed its great potential for the future.

The Bleriot XI was a high wing monoplane with a space-frame fuselage whose forward portion (housing the cabin and engine) were cloth-faired. Instead of ailerons, roll was controlled by wing warping. This was controlled by the same lever which moved the conventionally sited elevator. The rudder was pedal-controlled. This is how today’s aeroplane controls work!

Major structural material was chestnut. The wing was cloth-faired on both surfac­es. The aeroplane was 8m long, had a span of 7.8m, and weighed 300kg. Maximum recorded speed was some 60km/h.

In My 1909, before his historic flight, Bleriot had modified the design. Instead of the capricious 30hp R. E.P engines, he fitted an Anzani motorcycle unit and married it to a new, more efficient prop, and a sealed fuel tank which gave buoyancy in case of a forced landing on water.

The aeroplane’s excellence apart, luck was also on Bleriot’s side. The most crit­ical moment came when the engine overheated above the blue expanse of the strait.

I The Bleriot XI at the 1909 Paris Automobile and Aeroplane Salon

Louis Bleriot on arrival in England on 25 July 1909 after his historic Channel crossing

The cliffs of England were clearly visible, but height was insufficient to allow a dead – stick landing. At that moment, Providence itself seemed to help, sending cooling rain down and speeding Bleriot on.

The Bleriot XI became as celebrated as Bleriot the aviator. The machine was built in some numbers and exported widely. Its appearance and configuration were to influ­ence many other enthusiasts.

Without a doubt, the most successful Bleriot XI development was Edouard Nie – uport’s aeroplane. Externally, it was almost identical to its progenitor, but had a broader body. This made it more aerodynamic: both in itself, and because it now housed the engine, cabin, and fuel tank. Less drag meant more range, a 50hp engine propelling the machine for over 100km.

THE BLERIOT XI

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I The Nieuport monoplane designed in 1910

The Nieuport 4 was most popular, being licence-produced in Russia and Italy. The machine was very manoeuvrable, and it is probably no accident that Russian pilot Nesterov performed the world’s first aerial loop in a Nieuport 4. The type’s mil­itary career began as a reconnaissance platform, but more importantly the type went on to become the world’s first fighter.

The first great air race near Rheims caused a ripple of interest in aviation to circle the world. Held in late summer 1909, it was attended by leading aircraft and aeroen­gine makers. Demonstrations of 38 aeroplanes were scheduled, 23 of these actually managing to make it into the air. Only three of the demonstrations were by the Wright brothers, the show being dominated by the French: Voisin, Bleriot, Farman, and Le – vasseur.

Many nations sent observers, including military men intent on seeing things at first hand and gathering comparable information. The British Government was one of those which monitored the event, subsequently resolving to boost the design and production of British aeroplanes. The first step was to subdivide the War Office de­partment responsible for aeronautics into two, to address lighter and heavier-than-air vessels. The Army Aeroplane Factory was founded in 1911, renamed the Royal Aer­oplane Factory when the Royal Air Corps was established a year later. Private enter­prise was invited to lead the process of setting aeronautical standards.

This is an example of how emergent air power was incorporated into national structures. Each nation followed its own road in the resolution of problems linked with its presence in the air, this being determined by what others were doing, as well as by affordability and the intellect of is political and military elites.

Aviation fora continued to serve as signposts of progress. Involvement in them by national institutions, i. e. the state, also grew. The process was possibly best exempli­fied by developments in Britain. In summer 1912, some 30 aeroplanes took part in an

THE NIEUPORT 4

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I Pilot Eugene Lefebvre banks a Wright a couple of feet off the ground as he turns around the control pylon at the Rheims demonstrations

Captain Ferber watches the Henry Farman fly from his vantage point in the Curtiss (left)

air show near Salisbury. The ulterior motive behind this must have been purely mili­tary: performance assessments included aeroplanes’ maximum level and landing speeds, rate of climb and other parameters important in a combat setting.

Undoubted winner of the show was the twin-seat BE2 biplane designed at Farn – borough. Designer Geoffrey de Havilland failed to win a personal award, yet in flying his machine, he reached a speed of 112km/h, a landing speed of 65km/h, a rate of climb of some 120m per minute, and a ceiling of almost 3500m. These indi­cators were achieved with a second man on board and a fuel load sufficient for a three-hour flight. Later de Havilland was to improve his design, retaining its speed and manoeuvrability, yet imparting phenomenal pitch and roll stability to it and sig-

THE B. E.2A (1913)

nificantly easing controllability. Over the next few years the Royal Air Corps was to take delivery of over 2000 of this exceptionally simple and rational aeroplane.

As distinct from their march in France, monoplanes failed to impress the British. The findings after a series of crashes in summer 1912 (which cost the lives of two pilots) were that this layout was insufficiently strong. This was to leave a strong im­print on British aircraft manufacture. Notwithstanding the attainment of the amazing (for its time) speed of 200km/h by a Deperdussin at the 1913 Rheims air show, the British put their bets on biplanes with forward propellers.

An early exponent of this layout was the Bristol B. S.1 Scout. Designed by de Havil – land, it was compace and weighed 280kg. The powerful 80hp Gnome engine permit-

THE BRISTOL TABLOID (1913)

ted a speed of 150km/h. The machine had a conventional elevator and rudder. Roll control was by wing warping, later replaced by ailerons. The aeroplane was intended to be a racer, but its high speed and good manoeuvrability recommended it to the military, and it was soon to equip the first high-speed reconnaissance units. After being fitted with a machine gun, the Scout was a reasonable fighter. Typical of British aeroplanes of the Great War, its configuration was repeated in the 1913 Avro 504, whose great conservatism did not stop it becoming one of the world’s most popular aeroplanes, being used in training establishments until the early 30s.

Armand Deperdussin’s 1913 racing monoplane was the undoubted peak of the French design school. A development of Bleriot and Nieuport’s ideas, everything in it

THE AVRO 504 (1913)

was subjected to the reduction of drag and the attainment of the maximum possible speed. The fuselage was a monocoque, with load-bearing 4mm plywood skinning. Deperdussin faired-over and smoothed everything that could create drag. The ma­chine was compact: 6.1m long, and spanning 6.6m, gross weight was 500kg. Engine was an air-cooled 14-cylinder two-row Gnome developing 160hp.

THE DEPERDUSSIN B (1911)

I The World Speed Record Deperdussin racer

The objective was reached. On 29 September, pilot Maurice Prevot covered a 200km distance in under an hour. The record was to stand for almost a decade, and remains one of the most outstanding ones. To contemporaries, the Deperdussin racer was not just an excellent flying machine, but also a fighter in sheep’s skin. However,

The Albatros B-l teas Germany’s standard intelligence gatherer after the outbreak of the First

World War

Reinhard Boehm with his Albatros after their record flight on 10 and 11 July 1914

both the British and French were to prefer biplanes for this role, and would pay heav­ily for this at the start of the Great War.

With the accumulated experience of Taube construction and operations, German designer Groman drew the twin-seat Albatros. The aeroplane lacked sparkling per­formance, yet had an irreplaceable quality preferred by pilots: great reliability. This was mostly attributable to its water-cooled 100hp Mercedes engine. Even though on the heavy side compared with French Gnomes and Rhones, this powerplant worked unfailingly and burned little fuel and oil. On 10 and 11 July 1914, pilot Reinhard Boehm flew an Albatros non-stop for 24 hours 12 minutes, beating all endurance records. The Albatros’s 100km/h maximum speed and its 300km combat radius made it one of the most successful aeroplanes of the First World War. During the conflict, the aeroplane was to be used mainly as a recce platform, and later as a pilot trainer.

Despite lagging behind, Russia left a lasting trace in pre-Great War aviation history. The major contributor to this was Igor’ Ivanovich Sikorskiy,[8] creator of the world’s first multi-engined aeroplane. The design of ‘a large aeroplane for strategic reconnaissance’ began in 1911. Construction at the Russo-Baltic Carriage Works in Riga took until early 1913. The result was a biplane with a 27m span and a wing area of 120sq m. Nothing else had anywhere near these dimensions. Powerplant installation was intersting. The four 100hp Argus engines were originally located in

THE RUSSKIY VITYAZ

I The Russkiy Vityaz: world’s first multi-engined aeroplane

twin tandems, two per lower wng-mounted nacelle. Thus two propellers pulled, while the oth­er two pushed. When it was found that the efficiency of the pusher props was rather low, all four engines were given individ­ual nacelles on the lower wing.

The fuselage was long and thin, its aft end supporting the tail. Forward was a large glazed cabin comprising a control com­partment, two passenger cabin,

and compartments for tools and

spares. The nose was occupied by an open deck. Rather than being for promenad­ing in flight, this was intended for night observation spotlights, or for machine guns. The giant was controlled by ailerons, rudder, and elevator. It had an eight-wheel undercarriage.

Few believed the aeroplane would fly. Some were of the opinion that it would be doomed if an engine failed in mid-air. Tests were to prove them entirely wrong. The Russkiy Vityaz[9] could return safely to base with just two working engines. Its maxi­mum level speed was 90km/h. On 2 August the crew and seven passengers flew non­stop for two hours, recording a world record. The famous Il’ya Muromets[10] the world’s

I One of Sikorsky’s most famous project: the Il’ya Muromets strategic reconnaissance and bomber aircraft first flown in 1913

first strategic reconnaissance and bombing aeroplane, which was produced in some numbers, was a development of the Russian Knight.

The era when the first component of air power was created came to an end. A difficult start was followed by stormy advance. The total number of aeroplanes built during Europe’s five ultimate years of peace was significantly larger than anything seen before. But the ability to design aeroplanes capable of fulfilling set combat tasks was not sufficient to guarantee an aerial presence to the nations that could afford it. Additional requirements soon made themselves felt, all of them acquiring key impor­tance in the emergence of air power.