Category Soviet x-plenes

Purpose: Originally, fast passenger transport; later, long-range experimental aircraft.

Design: SNII GVF; construction at GAZ (Factory) No 81, Moscow Tushino.

In the winter 1933-34 the GUGVF (chief ad­ministration of the civil air fleet) issued a re­quirement for a fast transport aircraft to carry 10 to 12 passengers. Curiously, the two proto­types built to meet this demand were both the work of immigrant designers, the Frenchman Laville (with ZIG-1) and the Italian Bartini. The latter had already produced drawings for a transport to cruise at 400km/h (248mph), which was well in advance of what the GVF had in mind. Always captivated by speed, Stalin decreed that a bomber version should be designed in parallel. Still in charge of de­sign at the SNII GVF, Bartini refined his study into the Stal’-7, the name reflecting its steel construction.

Strongly influenced by the Stalin decree, Bartini created a transport notable for its cramped and inconvenient fuselage, highly
unsuitable for passengers but excellent for bombs, and for long-range flight. The original structure was to be typical Bartini welded steel-tube trusses with fabric covering, but the stress calculations were impossibly diffi­cult, with 200 primary rigid welded intersec­tions between tubes of different diameters. In late 1934 the fuselage was redesigned as a light-alloy stressed-skin structure, with sim­pler connections to the unchanged wing.

Only one aircraft was built, in the work­shops ofZOK, the factory for GVF experimen­tal construction. The first flight was made on an unrecorded date in autumn 1936, the pilot being N P Shebanov. Performance was out­standing, and Shebanov proposed attempting a round-the-world flight. In 1937 the StaP-7 was fitted with 27 fuel tanks with a total ca­pacity of 7,400 litres (1,628 Imperial gallons, 1,955 US gallons). A maximum-range flight was then attempted, but – possibly because of structural failure of a landing gear – the air­craft crashed on take-off. Bartini was arrest­ed, and was in detention (but still designing, initially at OKB-4, Omsk) for 17 years.

The aircraft was repaired, and on 28th Au­gust 1939, at a slightly reduced weight, suc­cessfully made a closed-circuit flight of 5,068km (3,149 miles) in 12hrs Slmin (aver­age speed 404.936km/h, 251.62mph), to set an FAI Class record. The route was Moscow Tushino-Maloe Brusinskoe (Sverdlovsk re – gion)-Sevastopol-Tushino, and the crew comprised Shebanov, copilot VAMatveyev and radio/navigator N A Baikuzov. In Bartini’s absence, the project was seized by his op­portunist co-worker V G Yermolayev, who re­designed it into the outstanding DB-240 and Yer-2 long-range bomber.

The wing was typical Bartini, with pro­nounced straight taper and construction from complex spars built up from multiple steel tubes, almost wholly with fabric covering. Each wing comprised a very large centre sec­tion, with depth almost as great as that of the fuselage, terminating just beyond the engine nacelles 2.8m (9ft 2/4in) from the centreline, with sharp anhedral, and thinner outer panels with dihedral. The trailing edges carried split flaps and Frise ailerons, the left aileron having

a trim tab. One account says that the inverted – gull shape ‘improved stability and provided a cushion effect which reduced take-off and landing distance’, but its only real effect was to raise the wing on the centreline from the low to the mid position.

This was just what the fuselage did not need, because the massive deep spars formed almost impassable obstructions and eliminated any possibility of using the aircraft as a passenger airliner. The fuselage was a light-alloy structure, with an extremely
cramped cross-section with sides sloping in towards the top (almost a round-cornered tri­angle). Entry was via a very small door on the left of the rear fuselage. The cockpit in the nose seated pilots side by side, and had a glazed canopy with sliding side windows and the then-fashionable forward-raked wind­screen. Immediately behind the cockpit there was a station for the navigator/radio operator. The tail surfaces, made of dural/fabric, were of low aspect ratio, the elevators having tabs.

The engines were the 760hp M-100, these being the initial Soviet licence-built version derived by V Ya Klimov from the Hispano – Suiza 12Ybrs. They were installed in neat cowlings at the outer ends of the centre sec­tion, angled slightly outwards and driving pro­pellers with three metal blades which could have pitch adjusted on the ground. One ac­count states that wing-surface radiators were used, but it is obvious from photographs that ordinary frontal radiators were fitted, as in the Tupolev SB bomber. Plain exhaust stubs were fitted, though this may have scorched the wing fabric and one drawing shows ex­haust pipes discharging above the wing. In the course of 1938-39 the original engines were replaced by the derived M-103, rated at 860hp, which improved performance with heavy fuel loads. A hydraulic system was pro­vided to operate the flaps and the fully re­tractable main landing gears, each unit of which had a strong pair of main legs which hinged at mid-length, the unit then swinging back on twin forward radius arms (like a DC – 3 back-to-front). The castoring tailwheel was fixed. In the nose were twin landing lights.

The Stal’-7 was simply a sound aeroplane able to fly at what was in its day a very long way at high speed. As a transport it was in­convenient to the point of being useless, though it was supposed to be able to seat 12 passengers, and it was flawed by its basic lay­out and structure. The Soviet Union was right to take a licence for the Douglas DC-3. On the other hand, Yermolayev transformed the Stal’-7 into an outstanding long-range bomber.

Left: Two views of Stal’-7.

Purpose: To continue stratospheric-flight research with an aircraft superior to BOK-1. Design Bureau: Bureau of Special Design, Smolensk. Chief designer Chizhevskii.

Design of this aircraft began in 1936. The Tupolev RD was again used as the starting point, but with features intended to enable greater heights to be reached. The test pilots were Petrov and Stefanovskii. According to Shavrov the BOK-7 was first flown in 1938, and ‘showed the same characteristics as the BOK-1’. Several two-man crews, including such important long-distance pilots as Gro­mov, Yumashev, Danilin, Spirin, Baidukov, Belyakov and others, spent periods of several days sealed in the GK checking all aspects of human life in preparation for proposed high- altitude long-distance flights in the BOK-15. According to some historians the ultimate ob­jective was a high-altitude circumnavigation, and that the by-function designation of this aircraft was K-17, from Krugosvetnyi (round the world). Photographs originally thought to be of the BOK-7 are now known to show the BOK-11.

The BOK-7 had the full-span wing of the RD, and aft-retracting landing gears, but com­pared with the RD the legs were redesigned for much lighter gross weight, and fitted with single wheels. Attention was concentrated on the fuselage, which unlike the BOK-1 had the GK (pressure cabin) integral with the air­frame, the centre fuselage being a slim cylin­der sealed by gaskets and adhesives, and with grommets fitting round the control wires and other services passing through apertures in the wall. The normal oxygen supply to the pilot and pilot/observer ‘compensated for the insignificant amount of air escaping’. The sealed drum was fitted with two hemispheri­cal domes, the front with eight and the rear with six transparent portholes so that the oc­cupants could see out, with a better view than from the BOK-1. The GK was kept at pressure by a tapping from a centrifugal PTsN (super­charger) blower driven by step-up gears from the engine. The engine was an 890hp M-34FRN fitted with two TK (turbosuper­chargers). It is probable that these delivered compressed air to the PTsN which then fed the engine, the cabin supply being taken off a small bleed pipe. Shavrov states that ‘all sys­tems worked well’, and that the experiments were ‘very interesting’.

According to Shavrov this aircraft had ‘the first GK of the combined type’ with both a sealed compartment kept under pressure and an oxygen supply. Some accounts state that AI Filin at the NIl-WS worked out details of the proposed circumnavigation, in 100- hour stages, but that the project was aban­doned after he was arrested in 1939 and executed in Stalin’s Terror of 1940. This air­craft led to the BOK-8, BOK-11 and BOK-15, but it appears that no illustrations of it have been discovered.

Purpose: To create a light transport with minimum operating cost.

Design Bureau: Kharkov Aviation Institute, Aviavnito brigade led by Aleksandr Alekseyevich Lazarev.

In the 1930s several Soviet designers pro­duced aircraft intended to demonstrate how much could be transported on the l00hp of an M-l 1 engine. These aircraft were as a class called Planerlyet (motor glider). This exam­ple had an unconventional configuration. It first flew on 14th September 1936, dual-con­trolled by V A Borodin and E I Schwartz. Eventually a control linkage was found which by 27th September enabled good turns to be made. Shavrov’s account ends with The

overall conclusion of the tests at Nil GVF (civil aviation test institute) was extremely posi­tive’, but nothing came of this one-off.

The Aviavnito-3 (often incorrectly called KhAI-3) was essentially an all-wing aircraft. The wing comprised a rectangular centre sec­tion, with the uncowled engine mounted on steel tubes on the front, to which were bolted two outer panels tapered on the leading edge. Aerofoil was V-106, with a t/c ratio of 14 per cent over the centre section, which had a chord of 5.0m (16ft Sin), tapering to 7 per cent at the tips, which incorporated 8° washout. Structurally, the centre section was KhMA steel tube covered by Dl Dural skin, while the outer panels were all wood, with truss ribs supporting closely spaced stringers. Along each outer edge of the centre section was a row of four seats, each front seat being for a pilot (the two pilots had to agree in advance which one should do the flying), covered by a row of sliding canopies. The flight controls comprised large unbalanced cable-operated surfaces divided into inner and outer sections to serve as ailerons and elevators. In addition, spoilers were recessed into the upper surface of each wingtip, driven by the pedals, to en­able co-ordinated turns to be made. A 2m2 (21.5ft2) fin and rudder were added, but it was hoped eventually to do without this. The sim­ple rubber-sprung main landing gears had 800 x 150mm tyres with brakes, and the large tailwheel could castor ±25°. Between the
rows of seats were four Dl tanks giving an 8-hour endurance. During development two additional seats were inserted on each side, pushing the pilots into noses projecting ahead of the wing. To balance these the vertical tail was significantly enlarged.

It is clear that this machine did everything expected of it, and that it was eventually de­veloped to fly safely and controllably. How­ever, even though they were much faster than anything else over vast areas devoid of sur­face transport, nothing came of the rash of Planerlyet designs.

Purpose: To test the guidance system of a cruise missile.

Design Bureau: OKB-155 ofAI Mikoyan.

In late 1947 the Kremlin ordered the develop­ment of a large cruise missile which could be launched (primarily against ships) from the Tu-4. Because of the importance of this pro­ject it was assigned to a joint team formed by OKB No 155 (MiG) and a new semi-political group called SB-1 (Special Bureau Nol). The OKB assigned one of the founders, M I Gure­
vich, as titular head, but the Chief Designer was A Ya Bereznyak who has figured previ­ously on page 29 of this book. Head of SB-1 was S L Beria, son ofthe formidable Politburo member who in 1953 succeeded Stalin. In fact, SB-1 faded from the scene, as it had little to contribute, though it did have P N Kusenko as Chief Designer. Under intense pressure a swept-wing turbojet-engined missile was created, which later went into production as the KS-1 Komet. In early 1949 its guidance sys­tem was tested in an Li-2 (Soviet derivative of
the DC-3), and later in that year a more repre­sentative system was tested in the FK (also called MiG-9L, Laboratoriya). This was too large to be carried aloft by a Tu-4, so it for­mated with the Tu-4 parent aircraft and thence simulated the missile on its flight to the target. Subsequently this aircraft was used to test different cruise-missile guidance systems, assisted by the K-l, a manned ver­sion of the KS-1 missile.

Aircraft FK was a modified MiG-9 twin-jet fighter, the first type of turbojet aircraft to fly in

the Soviet Union. Features included a straight-tapered wing oflaminar profile of9% thickness with large slotted flaps and Frise ailerons, a pressurized cockpit ahead of the wing, a ground-adjustable tailplane mounted part-way up the fin, a nosewheel retracting forwards and main landing gears retracting outwards, and a nose inlet feeding air to two RD-20 turbojets (Soviet copies of the German BMW 003A, each rated at 800kg, l,7641b, thrust) mounted under the wing with jet noz­zles under the trailing edge. The final produc­tion series had an ejection-seat, and the FK was from this batch. The heavy nose arma­ment of three NS-23K guns and all armour
were removed, and the fuselage was extend­ed by splicing in an extra section accommo­dating an unpressurized rear cockpit with a side-hinged canopy for the guidance-system operator. As in the Komet, the missile’s radar dish antenna was mounted above the nose, and a receiver antenna was mounted on the leading edge of each wing. Above the fin was a streamlined container housing the aft-fac­ing transmitter and receiver antennas for the radio-command guidance from the parent aircraft after launch. Once the autopilot had set the correct course the nose radar homed on the parent’s radar signals reflected back from the target. Nearer the target the missile’s
own radar became active, steering by signals received by the leading-edge antennas.

So far as is known, the FK played a valuable role in the development of one of the world’s first turbojet cruise missiles. So did the KSK, a piloted version ofthe missile itself.

Dimensions (FK)

Span 10.0m 32ft9Kin

Length 10.12m 33 ft 2 in

Wing area 18.2m2 195.9ft2

No other data.

Purpose: To design a long-range supersonic bomber.

Design Bureau: OKB-23 of Vladimir Mikhailovich Myasishchev, Moscow.

In 1955, when the Myasishchev OKB was still striving to develop the huge 3M subsonic bomber, this design bureau was assigned the additional and much more difficult task of creating a strategic bomber able to make dash attacks at supersonic speed. The need for this had been spurred by the threat of the USAF Weapon System 110, which materi­alised as the XB-70. The US bomber was de­signed for Mach 3, but in 1955 this was considered an impossible objective for the Soviet Union. From the outset it was recog­nized that there could be no question of com­peting prototypes from different design teams. Even though the Myasishchev OKB was already heavily loaded with completing development of the huge M-4 strategic bomber and redesigning this into the 3M pro­duction version, this was the chosen design bureau. In partnership with CAHI (TsAGI), wind tunnels were built for Mach 0.93,3.0 and 6.0. The two partners analysed more than 30
possible configurations, initially in the Izdeliye (product) ’30’ family (VM-32, tailless VM-33 and VM-34). The basic requirement was finally agreed to specify a combat radius not less than 3,000km (1,864 miles) and if possible much more, combined with a dash speed (with engine afterburners in use) of Mach 2. This demanded an upgraded aircraft, and the result was the ’50’ series, starting with the M-50. Under chief designer Georgi Nazarov this was quickly accepted, and the initial programme comprised a static-test specimen and two flight articles, comprising one M-50 followed by an M-52. OKB pilots N I Goryainov and A S Lipko flew the M-50 on 27th October 1959. Modified with afterburn­ing inboard engines, it continued testing in late 1960, but was by this time judged to be of limited value, and to be consuming funds needed for ICBMs (intercontinental ballistic missiles) and space projects. The OKB-23 was closed, and its personnel were trans­ferred to V N Chelomey to work on ICBMs and spacecraft. Myasishchev was appointed Director of CAHI. To the protestations of some, the virtually complete M-52 was scrapped, and six later 50-series projects re­
mained on the drawing board. However, for propaganda purposes the M-50 was kept air­worthy and made an impressive but rather smoky flypast at the Aviation Day parade at Moscow Tushino on 9th July 1961, naturally causing intense interest in the West. After being photographed with different paint schemes, and the successive radio callsigns 022, 023,12 and 05, it was parked in the nose – high take-off attitude at Monino.

Apart from the totally different wing, in overall configuration, size and weight the M-50 exactly followed the M-4 and 3M family. Despite this every part was totally new, to the last tyre and hydraulic pump. The wing was of pure delta shape, with CAHI R-II profile of only 3.5 to 3.7 per cent thickness, and with a leading-edge angle of 50° from the root to the inboard engines at 55 per cent semi-span, and 41° 30′ from there to the tip. The tip was cropped to provide mountings for the out­board engines. The leading edge was cam­bered but fixed, while the trailing edge carried rectangular double-slotted flaps and tapered outboard flaperons. At the time this was by far the largest supersonic wing ever flown. Structurally it was based on a
rectangular grid with four transverse spars and seven forged ribs on each side, the skin being formed by forged and machined pan­els. The enormous fuselage was of almost perfect streamline form, which like the wing was skinned with forged and machined pan­els. Only a small two-bay section in the nose formed the pressure cabin for the pilot and navigator seated in tandem downward-eject­ing seats. These were lowered on cables for the crew to be strapped in at ground level, then winching themselves into place. There was neither a fin nor fixed tailplanes. Instead the tail comprised three surfaces, each with a forward-projecting anti-flutter weight and driven by a quadruple power unit in the twin duplex hydraulic systems. A back-up me­chanical control was provided, with rods and levers, but it was expected that this would later be removed. Several possible engines were studied, the finalists being VADo – brynin’s VD-10 and P F Zubts’ 16-17, which was replaced by the 17-18. Construction of the aircraft outpaced both, and in the end the M-50 had to be powered by two Dobrynin VD-7 turbojets on the underwing pylons and two more on the wingtips. As these were tem­porary they were installed in simple nacelles with plain fixed-geometry inlets. Rated at 9,750kg (21,4951b), these were basically the same engines as those of the 3M. Likewise the main landing gears appeared to be simi­lar to those of the previous bomber, but in fact they were totally new. One of the basic design problems was that the weapons bay had to be long enough to carry the llm (36ft) M-61 cruise missile internally. This forced the rear truck, bearing 63 per cent of the weight, to be quite near the tail, reducing the effective mo­ment arm of the tailplanes and threatening to make it impossible for the pilot to rotate the aircraft on take-off. One answer would have been to use enormous tailplanes, greatly in­creasing drag, but a better solution was to do what the OKB had pioneered with the M-4 and 3M and equip the steerable front four – wheel landing gear with a double-extension hydraulic strut. Triggered by the airspeed reaching 300km/h (186mph), this forcibly ro­tated the aircraft 10° nose-up. Another unique feature was that each main gear incorporated a unique steel-shod shoe which, after land­ing, was hydraulically forced down on to the runway, creating a shower of sparks but pro­ducing powerful deceleration, even on snow. For stability on the ground twin-wheel tip pro­tection gears were fitted, retracting forwards immediately inboard of the wingtip engines. All fuel was housed in the fuselage, and yet another unique feature was that to cancel out the powerful change in longitudinal trim caused by the transonic acceleration to su­personic flight fuel was rapidly pumped from Nol tank behind the pressure cabin to No 8 tank in the extreme tail (and pumped back on deceleration to subsonic flight). Over 10 years later the same idea, credited by Myasishchev to L Minkin, was used on Concorde. Flight testing of the M-50 at Zhukovskii was remark­ably rapid, though the aircraft proved stub­bornly subsonic, stopping at Mach 0.99 even in a shallow dive at full power. In early 1960 the M-50 was modified with afterburning VD-7M engines with a maximum rating of 16,000kg (35,275 Ib) on the inboard pylons and derated VD-7B engines rated at 9,500kg (20,944 Ib) on the wingtips. This was consid­ered to offer the best compromise between available thrust, mission radius and propul­sion reliability. The engine installations were redesigned, all four having large secondary cooling airflows served by projecting ram in­lets above the nacelle. The outer engines were mounted on extensions to the wing housing new wingtip landing gears which re­tracted backwards.

The M-52 was under construction from No­vember 1958 and differed in many respects. It was to be powered by four Zubts 17-18 bypass engines each rated at 17,700kg (39,021 Ib). All four were served by efficient variable multi­shock inlets. The inner engines were ‘set at an angle in relation to the chord line’ and the outers were attached to larger pylons with forward sweep. The nose was redesigned and housed navigation/bombing radar, the crew sat side-by-side, a small horizontal sur­face was added on top of the rudder, a re­tractable flight-refuelling probe was added, the interior was rearranged, a remotely con­trolled barbette was fitted in the tail with twin GSh-23 guns, and provision was made to carry one M-61 internally or four Kh-22 cruise missiles scabbed on semi-externally in pairs conforming to the Area Rule. This aircraft was structurally complete in 1960 but when OKB – 23 was closed it was scrapped.

The M-50 was an extraordinary example of an aircraft which physically and financially was on a huge scale yet which had very limit­ed military value. Not least of the remarkable features of this programme was its relative freedom from technical troubles, even though virtually every part was totally new.

Purpose: To transport outsize cargoes. Design Bureau: EMZ (Eksperimental’nyi Mashinostroitel’nyi Zavod, experimental engineering works) named for V M Myasishchev.

After directing CAHI (TsAGI) from 1960, Mya­sishchev returned to OKB No 23 in early 1978 in order to study how a 3M strategic bomber might be modified to convey large space launchers and similar payloads. In particular
an aircraft was needed to transport to the Baikonur launch site four kinds of load: the nose of the Energiya launcher; the second portion of Energiya; the Energiya tank; and the Buran spacecraft, with vertical tail and engines removed. These loads typically weighed 40 tonnes (88,183 Ib) and had a diameter of 8m (26ft). Myasishchev had pre­viously calculated that such loads could be flown mounted above a modified 3M bomber. He died on 14th October 1978, the programme being continued by V Fedotov. While design went ahead, three 3MN-II tanker aircraft were taken to SibNIA (the Siberian State Research Instiutute named for

SAChaplygin) and put through a detailed structural audit preparatory to grafting on a new rear fuselage and tail, and mountings for the external payload. The modified aircraft were designated 3M-T. All were rebuilt with zero-life airframes and new engines, but ini­tially without payload attachments. One was static-tested at CAHI while the other two were completed and flown, tne first on 29th April 1981. After a brief flight-test programme they were equipped to carry pick-a-back pay­loads, and in Myasishchev’s honour redesig­nated VM-T Atlant. The first flight with a payload was made by AKucherenko and crew on 6th January 1982. Subsequently the two Atlant aircraft carried more than 150 pay­loads to Baikonur.

The most obvious modification of these air-

craft was that the rear fuselage was replaced by a new structure 7m (23ft) longer and with an upward tilt, carrying a completely new tail. This comprised modified tailplanes and ele­vators with pronounced dihedral carrying in­ward-sloping fins and rudders of almost perfectly rectangular shape, with increased total area and outside the turbulent wake

flight-control and autopilot system. The for­ward fuselage was furnished with work sta­tions for a crew of six. The aircraft were given civilian paint schemes, one being registered RF-01502 and the other being RF-01402 and fitted with a flight-refuelling probe. To support their missions the PKU-50 loading and un­
loading facility was constructed at spacecraft factories, including NPO Energiya at Moscow Khimki, and at the Baikonur Cosmodrome. These incorporated a giant gantry for careful­ly placing the payloads on the carrier aircraft.

Despite the turbulent aerodynamics down­stream of the external payloads, this dramat­

ic reconstruction proved completely success­ful. In the USA a 747 was used to airlift Shuttle Orbiters, but no other aircraft could have car­ried the sections of Energiya.

Purpose: To fly reconnaissance missions at very high altitude.

Design Bureau: EMZ named for V M Myasishchev.

Though not an experimental aircraft, the M-17 qualifies for this book because of its nature, its ancestry, and the fact that it was the basis for the M-55 research aircraft. The concept of manned reconnaissance aircraft penetrating hostile airspace at extreme altitude was com­
mon in the Second World War, and in the Cold War reached a flash point on 1st May 1960 when the U-2 ofF G Powers, a CIA pilot, was shot down over Sverdlovsk. One of the American alternatives studied and then actu­ally used was unmanned balloons launched in such a way that prevailing winds would carry them across Soviet territory. They could change altitude, and could carry not only re­connaissance systems but also explosive charges. This threat could have been serious,

and the PVO (air defence forces) found it dif­ficult to counter. Though still at CAHI, Mya­sishchev was made head of a secret EMZ tasked with Subject 34, a high-altitude bal­loon destroyer. Called Chaika (Gull) from its inverted-gull wing, it was to be powered by a single Kolesov RD-36-52 turbojet of 12,000kg (26,4551b) thrust. To reduce jetpipe length the tail was carried on twin booms. In the nose was to be radar and the highly pressur­ized cockpit, while between the engine inlet ducts was a remotely controlled turret hous­ing a twin-barrel GSh-23 gun. Secretly built at Kumertau helicopter plant in Bashkirya, the Chaika was first flown in December 1978 by K V Chernobrovkin. He had been engaged in taxi tests, and had not meant to take off but in a snowstorm became airborne to avoid hit­ting the wall of snow on the right side of the runway. In zero visibility he hit a hillside. The programme was relocated at Smolensk, where the second aircraft was constructed to a modified design, designated M-l 7. The first, No 17401, was first flown by E VChePtsov at Zhukovskii on 26th May 1982. It achieved a lift/drag ratio of 30, and between March and May 1990 set 25 international speed/climb/ height records. In 1992 it investigated the ‘hole’ in the ozone layer over the Antarctic. The second M-17, No 17103, was equipped with a different suite of sensors. From the M – 17 was derived the M-55 Geofizka described next.

The M-17 had an all-metal stressed-skin structure designed to the low factor of 2. The remarkable wing had an aerofoil of P-173-9 profile and aspect ratio of 11.9, and on the ground it sagged to an anhedral of-2° 30′. The original wing had 16 sections of Fowler flap and short ailerons at the tips, but it was re­designed to have a kinked trailing edge with simplified flaps and longer-span two-part ailerons. Large areas of wing and tail were skinned with honeycomb panels. Flight con­trols were manually operated, in conjunction with a PK-17 autopilot. The tricycle landing gears retracted hydraulically, the 210kg/cm2 (3,000 lb/in2) system also operating other ser-

vices including three airbrakes above each wing. The engine was an RD-36-51V, with a take-off rating of 12,000kg (26,455 Ib) and nominal thrust of half this value. Cruise thrust at 21,000m (68,898ft) was 600kg (1,32315). T – 8V kerosene was housed in two 2,650 litre main tanks, two 1,550 litre reserve tanks and a 1,600 litre collector tank, a total of 10,000 litres (2,200 Imperial gallons). The pressur­ized and air-conditioned cockpit housed a
very fully equipped K-36L seat, and among other equipment the pilot wore a VKK-6D suit and VK-3M ventilated suit, and a ZSh-3M pro­tective helmet and KM-32 mask overlain by a GSh-6A pressurized helmet. Avionics were extremely comprehensive.

The M-17 fulfilled all its design objectives. The successive changes in both mission and aircraft design were caused solely by political factors.

Purpose: To study the ozone layer and perform many other surveillance tasks. Design Bureau: EMZ named for V M Myasishchev, General Designer V K Novikov.

The M-l 7 proved so successful in its basically politico-military role that it was decided in 1985 to produce a derived aircraft specifically tailored to Earth environmental studies. The first M-55, No 01552, was first flown on 16th August 1988, the pilot being Nil Merited Pilot Eduard V Chel’tsov who had carried out the initial testing ofthe M-1 7. Three further exam­ples were built, Nos 55203/4/5. Further single – seaters, plus the M-55UTS dual trainer, the Geofizka-2 two-seat research aircraft and other derived versions, have been shelved through lack of funds.

Structurally the M-55 was designed to a load factor increased from 2 to 5. This result­ed in a new wing which instead of having left/right panels joined on the centre line has inner and outer panels joined to a centre sec­tion. Aspect ratio is reduced to 10.7, and aero­dynamically the wing retains the P-173-9 profile but has redesigned flaps, ailerons and upper-surface airbrakes. The horizontal tail is modified, with full-span elevator tabs and square tips. The fuel capacity is increased to

10,375 litres (2,282 Imperial gallons), and range/endurance was further increased by changing to a pair of P A Solov’yov D-30-10V turbofans each rated at 9,500kg (20,944 Ib) take-off thrust, and with a combined cruise thrust at 21km (68,898ft) of 670kg (l,4771b). Apart from the landing gear the aircraft was almost totally redesigned, the front of the na­celle being much deeper and more capa­cious, the engine bays being lengthened, and the flight controls being operated by a dual­channel digital system with manual rever­sion. In standard form the M-55 carries a payload of up to 1.5 tonnes (3,307 Ib), typical­ly comprising a Radius scanning radiometer with swath width of 20km (12.4 miles), a
choice ofIR linescanners with swath width of 25km (15.5 miles), an Argos optical scanner with swath width of 28km (17.4 miles), an A-84 optical camera with swath width of 120km (74.6 miles) and a choice of SLARs (sideways-looking airborne radars) with max­imum swath width of 50km (starting at 30km and extending to 80km) on each side. Cover­age of 100,000km2 (38,610 square miles) per hour is matched to an instrumentation trans­mission rate of 16 Mbits per second.

The EMZ have created a versatile research and geophysical aircraft which is being pro­moted for such varied tasks as search/rescue, mapping, ozone studies, hailstorm preven­tion and agricultural monitoring.

Purpose: To exceed Mach 1 and possibly serve as the basis for a fighter.

Design Bureau: P O Sukhoi, Moscow.

Note: this aircraft was not related to later aircraft with the same designation.

In late 1947 the Council of Ministers issued a plan for 1948-49 calling for the construction of new experimental aircraft. One type was to research high-subsonic, transonic and low supersonic speeds, and also if possible pro­vide the basis for the design of a supersonic tactical fighter. Contracts were issued to Yakovlev (Type 1000) and Sukhoi (Aircraft R). In each case funds were provided for one flight article and one static test specimen, and Sukhoi’s design proceeded rapidly. From the outset provision was made for two heavy can­non, and in 1949 the WS designation Su-17 was issued. As early as July 1949 the flight ar­ticle was taken to LIl-MAP at Zhukovskii, where the assigned pilot, Sergei Anokhin, car­ried out increasingly fast taxi tests. Just as he was about to make the first flight the Su-15 radar-equipped interceptor suffered violent flutter and crashed, Anokhin ejecting. Rather precipitately, CAHI (TsAGI) blamed Sukhoi, and moreover claimed that the wing of Air­craft R was also torsionally weak and would flutter at high airspeeds. CAHI therefore re­fused to issue flight clearance for this aircraft. In turn this led Stalin to order that Sukhoi’s OKB should be liquidated on 1st November 1949. It was reopened in 1953 after Stalin’s death.

This outstanding design was made possi­ble by the rapid development of the powerful TR-3 (later called AL-5) afterburning axial tur­bojet by A M Lyul’ka, qualified in January 1950 at4,600kg (10,141 Ib), with a dry rating of 4 tonnes (8,8181b). Had the Su-17 continued it would certainly have later flown with more powerful Lyul’ka engines. The propulsion system was ‘straight through’ from the plain nose inlet, which immediately divided to pass each side of the cockpit, to the tail. Amid­
ships, at Frames 15/15A and 20/20A, the main wing spars passed through at mid-level. The wing had CAHI (TsAGI)-9030 profile at the root, changing to symmetric SR-3-12s at the tip, the!4-chord sweep being 50°. Above each wing were two full-chord fences plus another from the leading edge to the aileron. Three tracks carried each of the Fowler-type flaps. High on the large vertical tail was mounted the fixed tailplane, again with 50° A-chord sweep and ground adjustable over the range ± 1.5°. The port aileron and starboard elevator had tabs, and the rudder had a section of ‘knife’ (thin strip behind the trailing edge). This aircraft pioneered Soviet use of hydrauli­cally boosted flight controls, on all axes. All units of the landing gear had levered suspen­sion, using high-pressure shock absorbers pi­oneered on the Su-15, and retracted into the fuselage. The nose unit had a 530 x 230mm tyre and retracted to the rear, while each main unit had an 800 x 225mm tyre and pneu­matic plate brake and retracted forwards about a skewed axis under the wing root, to be covered by a large door. The ventral bulge under the tail had a steel underside and made provision for housing a cruciform braking parachute. On each side of the rear fuselage was a door-type airbrake, opened to 60°, which like the flaps, landing gear and flight controls, was operated by a hydraulic system at what was then a new high pressure of 211kg/cm2 (207-MPa, 3,000lb/in2). The cock­pit was pressurized, maintaining 0.65kg/cm2 (9.2 lb/in2) up to 7km (22,966ft) and holding a constant dp of 0.3kg/cm2 (4.3 lb/in2) above that level. Like several previous Soviet air­craft, the pilot’s ejection-seat was mounted in a nose section designed to separate from the fuselage in an emergency. The planar joint, sealed by an inflatable ring, sloped forward to avoid the nose-gear, and it could be broken by firing a cordite charge at the bottom joint, allowing the nose to pivot and separate from the two upper connections. Separation was triggered automatically if vertical accelera­
tion reached ± 18 g, or under pilot commcind. The separated nose streamed a drogue which after a delay extracted the main ribbon parachute. The pilot could then eject, experi­encing a maximum of 5 g. The pilot could also eject normally, from the intact aircraft, but only after jettisoning the sideways-hinged canopy. A total of 1,219 litres (268 Imperial gallons) of fuel was housed in the fuselage, there being one metal and two bladder tanks behind the cockpit and three metal tanks (one a toroidal hollow ring) around the jet- pipe. Provision was made for a jettisonable 300 litre (66 Imperial gallon) tank to be scabbed under each wing, and for two N-37 guns, each with 40 rounds, to be mounted in the fuselage. The avionics were comprehen­sive, including vhf, radio compass, an IFF transponder and precision radio altimeter.

There is no reason to doubt that this aircraft would have been most valuable, and prevent­ing it from flying appears in retrospect to have been a serious error. The Soviet Union suf­fered from its thoughtless precipitate actions.

For interest, drawings are reproduced here of various projects which stemmed from the RSR. The first shows the way CAHI (TsAGI) wanted it. The purist aerodynamicists in that establishment were convinced that this su­personic-cruise aircraft ought to have true su­personic wings, with sharp edges and a trapezoidal (parallel double wedge) profile instead of a traditional curved aerofoil. As this would have meant a very long take-off run they proposed to add substantial wings out­board of the engines, giving a span of 14.5m (47ft 6%in), requiring total redesign and a dra­matically inferior aircraft. The next drawing shows the awesome A-57, proposed in 1957 by R L Bartini, who featured on previous pages. There were several versions of this and the considerably smaller Ye-57. The A-57 shown would have been powered by five Kuznetsov NK-10 engines, each of 25,000kg (55,115 Ib) thrust. This 320 tonne (705,467 Ib) vehicle, with a length of 69.5m (228ft) and wing area of 755m2 (8,127ft2), was to have been water-based for operational flexibility and to avoid having to use vulnerable airfields (though it also had skids for airfield landings if necessary). It would have carried a 244N thermonuclear bomb internally, as well as a 2RS (later RSR) carried pick-a-back to the tar­get at 2,500km/h (l,553mph, Mach 2.35) to serve as an accompanying reconnaissance aircraft. Together they could cover targets within a radius of 5,000km (3,107 miles), the Tsybin 2RS reconnaissance vehicle using its fuel only on the return flight. The final draw­ing shows the Tsybin RGSP, also dating from 1957. This too would have been water-based, with a planing bottom, engines moved above the wings to avoid the spray (minimised by the down-angled water fins), and with the ex­ternal tanks serving as wingtip buoyancy bod­ies. This version was not equipped for airfield landings.

Purpose: To build an improved fighter armed with APK-4 guns.

Design Bureau: Brigade led by Viktor Nikolayevich Chernyshov inAGOS (Department of Aeroplane and Hydroplane Construction), whose Chief Constructor was A N Tupolev.

Towards the end of the 1930s there was great activity in the still chaotic aircraft industry of the embryonic Soviet Union. Part of this ef­fort was concerned with making use of the large-calibre recoilless guns devised by L V Kurchevskii. These had various designations
but the most common was APK (Avto – matichyeskaya Pushka Kurchevskogo, auto­matic cannon Kurchevskii). Such guns were invented by Cdr Cleland Davis, ofthe US Navy, and developed in England from 1915. The idea was that, if the recoil of the projectile could be balanced by a blast of gas and pos­sibly an inert mass fired to the rear, then air­craft could use lightly made weapons of large calibres. Russian copies were produced by Professor B S Stechkin in 1922-26, and in 1930 Leonid Vasil’yevich Kurchevskii restarted this work and developed a range of weapons of different calibres. Of these the most immedi-

ately important was the APK-4, with a calibre of 76.2mm (Sin). Together with the Grig – orovich Z (later I-Z) described earlier, the ANT-23 was the first aircraft specially de­signed to use these guns. The AGOS design­ers had the idea that, instead of just hanging the guns under the wings, they could be put inside strong tubes which could then attach the tail to the wing. This enabled the central nacelle to have an engine at each end, giving outstanding flight performance. Design began in June 1930, and the first flight was made by Ivan Frolovich Kozlov on 29th August 1931. On 21st March 1932 he was

undertaking firing trials at about 1,000m (3,280ft) when the diffuser section at the rear of the left gun exploded. This severed the tail controls in that boom, but he managed to make a normal landing, the boom collapsing during the landing run (he received the Order of the Red Star). The fault was soon correct­ed, and from autumn 1931 a second proto­type (called a doobler), the ANT-236/s, was built. This received service designation I-12, and was also named Baumanskii Komsomo – lets after the revolutionary who until his death in 1905 had worked next to the AGOS site. It incorporated various minor improvements, one of which was to arrange for the pilot in emergency to detonate a charge which sev­ered the drive shaft to the rear propeller prior to baling out. Work was halted during the in­vestigation into the accident to the first air­craft, and by 1933 the I-12 was overtaken by the Grigorovich IP family and the DIP, ANT-29. Work on it was stopped on 1st January 1934.

Structurally the ANT-23 followed Tupolev tradition in that it was a cantilever monoplane made entirely ofaluminium alloy, but it broke new ground in that corrugated sheet was not used except on the fin and rudder. Instead, the central nacelle had smooth skin, and the wings were skinned in sheets cut to a uniform
width of 150mm (Gin), wrapped round the leading edge. The edge of each strip was rolled to have a channel section, so that the complete wing appeared to have a skin with widely spaced corrugations. In usual Tupolev fashion, the aileron chord extended behind the trailing edge ofthe wing. The nacelle was welded from KhMA steel tube, with much of the light-alloy skin being in the form of de­tachable panels. At each end was an import­ed 480hp Gnome-Rhone GR9K (licence-built Bristol Jupiter) in a cowling with helmets over the cylinders. Above each wing was attached a precision-made tube of high-strength steel formed by screwing together three sections each machined to an internal diameter of 170mm (6%in). Wall thickness varied from 1 to 3mm. Over the wing the tube was faired in by thin aluminium sheet, and at the tail end was a gas diffuser. Above this was a shallow platform to which was attached the tailplane, carrying the strut-braced fin in the centre. Tall sprung tailskids were attached under each tube, and originally the rubber-sprung main landing gears had spats, though these were later omitted. Inside each tail boom was in­stalled the 76.2mm APK-4, with the front of the barrel projecting. Soon the engines were replaced by the 570hp version made under
licence in the Soviet Union as the M-22, and the helmets were incorporated into ring cowls. Another modification was to replace the ver­tical tail by a redesigned structure with the same kind of skin as the rest of the aircraft.

When work began it was thought that this aircraft might be a world-beater. It was soon evident that the performance was well short of expectations, partly because ofthe fact that the rear propeller worked in the slipstream of that in front. Perhaps the greatest shortcom­ing of this aircraft was the fact that the am­munition supply for each gun was limited to two rounds.

Purpose: A heavy fighter with large-calibre recoilless guns.

Design Bureau: KOSOS-CAHI (department of experimental aeroplane construction, central aero-hydrodynamics institute), Chief Constructor A N Tupolev.

This large fighter was a natural successor to the ANT-21 MI-3 (MI = multi-seat fighter) or­dered in January 1932 and flown in May 1933. Whereas that aircraft had had conventional armament, the ANT-29 or DIP (Dvukhmestnyi Istrebitel’ Pushechnyi, two-seat cannon [armed] fighter) was designed around two of the largest available calibre of APK recoilless guns (see preceding story). Funds for a single prototype were made available by the WS in September 1932. Tupolev entrusted the de­sign to his first deputy P O Sukhoi. Normally the aircraft would have flown in about a year, but priority was given to the ANT-40 fast bomber (which flew in 1934 as the SB), and the ANT-2 9 was not completed until February 1935. Flight testing was started by S A Korzin – shchikov, who reported that the flight con­trols, especially the ailerons and rudder, were unacceptably ineffective. This prototype was returned to CAHI’s ZOK (factory for prototype construction) for rectification, the main task being to re-skin the control surfaces. Testing resumed in late 1935, but by this time the ANT-46 (DI-8) was flying. The ANT-29 be­longed to the previous generation, and it was abandoned in March 1936.

Like its predecessor, the ANT-21, the ANT – 29 was an aerodynamically clean monoplane powered by two liquid-cooled engines. The wings were aerodynamically similar but to­tally different structurally, and the engines likewise were quite new. They were two of the first 760hp Hispano-Suiza 12Ybrs 12-cylin­der engines to be imported into the Soviet Union. Later this engine was developed by VYaKlimov into the VK-103 and VK-105, of which over 129,000 were constructed. In this aircraft they drove imported French Chau – viere three-blade variable-pitch propellers of 3.5m (138in) diameter. Carburettor air en­tered through a small inlet under the wing leading edge, and the radiator was in a shut­ter-controlled duct directly under the engine. The wing had a modern structure with two plate spars, made as a 3m (9ft 1 0in) horizon­tal centre section and 5.9m (19ft 4in) outer panels with taper and dihedral. Like the rest of the airframe the outer wing skins were smooth. In this Sukhoi broke new ground, previous ‘ANT’ aircraft having had corrugated metal skins showing that they originated in Junkers technology of the early 1920s. The short fuselage was of tall oval section and

seated the pilot in the nose under a rearward – sliding canopy and a backseater over the trail­ing edge under a forward-sliding canopy (as in early versions of the SB). The backseater would have worked radio had it been fitted, but his main task was to check the automatic reloading of the guns and clear stoppages. The wings were fitted with large two-part ailerons and split flaps, while the tail carried the wire-braced tailplane high up the fin, the elevators and rudder having large Flettner (servo) tabs. Like the ANT-21 and SB, the main landing gears had single shock-struts with a fork carrying the axle for a braked wheel with a 900 x 280mm tyre which, after retraction to the rear, partially projected to minimise damage in a wheels-up landing. At the rear was a large tailskid. Main-gear re­traction, like flap operation, was hydraulic. The primary armament comprised two APK – 8 recoilless guns, also known as DRP (Dy – namo-Reaktivnaya Pushka), mounted one above the other. The feed was via two chutes on opposite sides of the fuselage. Each gun
had an unrifled barrel about 4m (13ft lin) long, with a calibre of 102mm (4in). The firing chamber was connected at the rear to a re­coil tube terminating in the recoil-cancelling divergent rear nozzle, extended a safe dis­tance behind the rudder, through which pro­pellant gas blasted when each round was fired. Sighting was done with an optical sight in a prominent fairing ahead of the wind­screen, and could be assisted by firing tracer from two 7.62mm ShKAS machine guns in the wing roots (these are shown in Shavrov’s drawings, but unlike the main armament they do not appear ever to have been installed). It was intended also to fit a pivot-mounted ShKAS in the rear cockpit. There was no pro­vision for a bomb load. Arguments over ar­mament continued, but no attempt was made to test the ANT-29 with the alternative forward-firing armament ofa20mm ShVAK in each wing root.

By the time it was on test this was no longer an important aircraft, and (for reasons not recorded) it failed NIl-WS testing.

Purpose: An improved heavy fighter with large-calibre recoilless guns.

Design Bureau: KOSOS-CAHI, chief constructor A N Tupolev, who assigned this aircraft to A A Arkhangel’ skii.

This aircraft was a derivative of the SB (ANT-40) fast bomber. The single prototype was ordered in November 1934, on condition that the SB (the first prototype of which had flown a month previously) had priority and would not }n any way be delayed. The DI-8 was created quickly and was flown by Yu A Alekseyev on 1 st August (also reported as 9th August) 1935. Factory testing was con­tinued to June 1936, but the ‘liquidation’ of

Kurchevskii’s gun bureau and the arrest for treason and spying of Tupolev halted the pro­gramme.

Until recently little was known about the ANT-46, and only one photograph had been discovered. This did not show the nose clear­ly, and published accounts stated that the ANT-46 was based on the SB but had a metal­skinned nose containing machine guns. It is now known that it had a glazed nose identi­cal to that of the bomber. Instead of being a two-seat aircraft it also had a navigator/ bomb-aimer in the nose, and an internal bomb bay (for example, for eight FAB-100 bombs) with bomb doors. The interesting feature was that incorporated in each wing
outboard of the fuel tanks, between the split flaps and the ailerons, were single DRP (APK – 11) recoilless guns, each fed by an automati­cally indexed supply of 45mm (IXin) ammunition, the rear blast tubes projecting behind the trailing edge. Like the first SB the fin and rudder had a squared-off top, and the engines were not as previously thought GR14s but, as on the first SB, nine-cylinder Wright Cyclones of 710hp, driving Hamilton two-blade propellers. Like the ANT-29, this aircraft carried CAHI titles and the ANT num­ber 46 on the tail.

This aircraft fulfilled expectations, but was considered an outdated concept.

Purpose: To explore the characteristics of a vehicle able to fly as an aeroplane or skim the ocean surface as an Ekranoplan (literally ‘screen plan’, a device covering an area with a screen).

Design Bureau: TANTK named for G M Beriev Taganrog.

Ever one to consider radical solutions, Bartini spent part of 1959 scheming a giant marine vehicle called M. Seaborne at rest, this was to be able to rise from the water and fly at high speed over long distances. It was to make true flights at high altitude, but also have the capability of ‘flying’ just above the sea surface. Such a vehicle was initially seen as urgently needed to destroy US Navy Polaris – missile submarines, but it could have many other applications. The idea was refined into one called 2500, from its weight in tonnes, and ultimately designated M-62 or MVA-62.

TANTK Beriev investigated stability, control and performance of the proposed configura­tion with the small Be-1. This looked vaguely like a jet fighter, with a front cockpit, large centroplan (central wing) with a turbojet on top, twin floats, outer wings and twin fins and rudders. Under each float was a surface­piercing V-type hydrofoil, which was not to be a feature of the full-scale vehicle.

Pending funding for this monster, TANTK Beriev were ordered to build three WA-14 prototypes, this being a practical basis for a multirole vehicle. Missions were to include sea/air search and rescue, defence against all kinds of hostile submarines and surface war­ships, and patrol around the Soviet coastlines. Production craft were to be kept at readiness on coastal airfields. The vehicle was classed as an amphibious aircraft. It was to be devel­oped in three phases. The WA-14M1 was to be an aerodynamics and technology test-bed, initially with rigid pontoons on the ends of the centroplan, and later with these replaced by PVPU inflatable pontoons (which took years to develop). The WA-14M2 was to be more advanced, with two extra main engines to blast under the centroplan to give lift and later with a battery of lift engines to give VTOL ca­pability, and with fly-by-wire flight controls. The third stage would see the VTOL vehicle fully equipped with armament and with the Burevestnik computerised ASW (anti-subma­rine warfare) system, Bor-1 MAD (magnetic – anomaly detection) and other operational equipment.

Following very extensive research, and tests with simulators, the first vehicle, Nol9172, was completed as an aeroplane. It was tested at the Taganrog WS flying school, which had a concrete runway. Accompanied
by numerous engineers, including deputy chief designer Nikolai A Pogorelov, the test crew of Yu M Kupriyanov and navigator/sys – tems engineer L F Kuznetsov opened the flight test programme with a conventional take-off on 4th September 1972. The only problem was serious vibration of hydraulic pipes, which resulted in total loss offluidfrom one of the two systems.

In 1974 the PVPU inflatable pontoons were at last installed, though their expansion and retraction caused many problems. Flotation and water taxi tests followed, culminating in the start of flighttesting of the amphibious air­craft on 11 th June 1975. Everyone was amazed that Bartini was proved correct in his belief that the rubber/fabric pontoons would retain their shape at high airspeeds. On water they were limited to 36km/h, so later they were re­placed by rigid pontoons, with skegs (axial strakes). The forward fuselage was length­ened and the starting (cushion-blowing) en­gines added. On the debit side, Bartini was also right in predicting that the Lotarev bu­reau would never deliver the intended battery of 12 RD-36-35PR lift engines, and this made the second and third prototypes redundant.

Bartini died in 1974, and the now truncated programme continued with trickle funding. The blowing engines caused resonance which resulted in breakage of landing-gear doors and buffeting of the rear control flaps. The vehicle never flew again, but did carry out manoeuvre tests on water with reversers added to the blowing engines. TANTK was given higher-priority work with the A-40, A-50 and IL-78.

The entire structure was marinised light alloy, much of the external skin being of hon­eycomb sandwich. The airframe was based on the fuselage, centroplan of short span but
very long chord, and cigar-like floats carrying the tails. Above the rear on the centreline were the two main engines. The starting en­gines were mounted on the sides of the nose, and the (unused) lift-engine bay was dis­posed around the centre of gravity amidships. On each side of this area projected the outer wings, with straight equal taper and thick – ness/chord ratio of 12 per cent, with full-span leading-edge slats, ailerons and flaps hinged 1m (3ft 31/2in) below the wing.

The propulsion and starting (cushion-blow­ing) engines were all Solov’yov D-30M turbo­fans, each rated at 6,800kg (14,991 Ib). The starting engines were equipped with cas­cade-type thrust deflectors, and later with clamshell-type reversers. A TA-6AAPU (auxil­iary power unit) was carried to provide elec­tric power and pneumatic power. Bleed air served the cabin conditioning system and hot-air deicing of all leading edges. A total of 15,500kg (34,171 Ib) of fuel was housed in two metal tanks and 12 soft cells.

The cockpit contained three K-36L ejec­tion-seats, for the pilot, navigator and weapon-systems operator. Flight controls were linked through the SAU-M autopilot and complex military navigation and weapon-de­livery systems. Had the aircraft undertaken VTOL flights the reaction-control system would have come into use, with six pairs of high-power bleed-air nozzles disposed at the wingtips and longitudinal extremities. For op­eration from land No 19172 was fitted with the nose and a single main landing gear of a Tu-22, both on the centreline, and the com­plete outrigger-gear pods of a Myasishchev 3M heavy bomber. Maximum ordnance load, carried on IL-38 racks, comprised 4 tonnes (8,8181b), made up of AT-1 or -2 torpedoes, PLAB-250-120 orother bombs, various mines up to UDM-1500 size, RYu-2 depth charges and various sonobuoys (such as 144 RGB-1U).

One of the incomplete WA-14s was dam­aged by fire, the third being abandoned at an early stage. The one with which all the flying was done, Nol9172, was retired to the Moni – no museum in a dismantled state, where it carries the number ‘10687’ and ‘Aeroflot’. TANTK had various proj ects for intended pro­duction amphibious derivatives. These were grouped under letter T, and two such are illustrated here for the first time.

The WA-14 was an outstandingly bold concept which very nearly came off. There is little doubt it could have led to a practical ver – hicle for many oceanic purposes. In the long term all it achieved was to give T ANTK-B eriev considerable experience in many new disci­plines, especially in challenging avionics and flight-control areas. Such a programme would have almost no chance of being funded today.

Performance

Max speed at 6,000m (19,685 ft) 760km/h 472 mph

Patrol speed (also minimum flight speed at low level) 360 km/h 224 mph

Service ceiling 9,000-1 0,000m 32,800 ft (max)

Practical range 2,450 km 1 ,522 miles

Patrol duration at a radius of 800 km (497 miles) 2 hrs 15 min

Above: Three-view of WA-14M2 with retractable landing gear. Left: A more detailed side elevation of WA-14M2.

Below: Two of the ‘T’ projects.

Purpose: To test an experimental wing. Design bureau: Kazan Aeronautical Institute, Kazan, Tatar ASSR.

The concept of the wing was that of V N Belyayev, but in order to test it he collab­orated with VI Yukharin of the KAI. Partly be­cause it would have been difficult to match centre of lift with centre of gravity by retro­fitting the wing to an existing aircraft, it was decided to design an aircraft specially for this purpose. It was called Babochka (butterfly). The project was launched in 1937, and draw­ings were completed late the following year. Throughout, Belyayev was devoting most of his time to the EOI (see page 27). The single Babochka was being readied for flight when the Soviet Union was invaded. Even though Kazan was far to the East of Moscow, this pro­ject was not considered important and those working on it were drafted elsewhere.

This aircraft was essentially a straightfor­ward low-wing monoplane, of fighter-like appearance, with a single (relatively large) piston engine. It is believed that the structure was almost all-metal stressed skin. The key item, the wing, had a high aspect ratio, swept – forward inboard sections and swept-back outer panels. The objective was to make a wing that was flexible yet which in severe positive manoeuvres would deflect upwards without causing a longitudinal pitch problem. Under load, the inner wings deflected up­wards, tending to twist with positive angle of incidence, automatically countered by the negative twist of the outer panels. This was hoped to lead to an extension of Belyayev’s concept of a wing that was inherently stable longitudinally.

The inner wings were fitted with inboard and outboard split flaps, while the smaller outer panels carried two-section ailerons.

The engine was mounted on the nose on a steel-tube truss. According to historian V B Shavrov the engine was a ‘Renault 430hp’ (which would have had 12 cylinders and a central air-cooling inlet). In fact it must have been an MV-6, a licence-built Renault with six aircooled cylinders, rated at 210hp. Tandem enclosed cockpits were provided for the pilot and test observer. The tail, remarkably small (reflecting the designer’s belief in the stabili­ty of the wing) positioned the horizontal tail wholly in front of the rudder. The landing gears were fully retractable, the main wheels folding inwards into the extended-chord wing roots.

Though there is no reason to doubt that the Babochka would have flown successfully, there is equally no reason to believe that it would have shown any significant advantage over an aircraft with a conventional straight – tapered wing.

Purpose: The initials stood for ‘long-range bomber, flying wing’.

Design Bureau: Designer’s own brigade at the Central Aerodynamics and Hydrodynamics Institute.

Viktor Nikolayevich Belyayev, born in 1896, began his career as a stressman in the OMOS bureau in 1925. He subsequently worked in AGOS, KOSOS-CAH1 (TsAGl), the Tupolev OKB, AviAvnito and Aeroflot. He liked tailless aircraft, and had a fixation on a ‘bat wing’, with slight forward sweep and curved-back tips, which he considered not only gave such aircraft good longitudinal stability but also minimised induced drag. He tested such a wing in his BP-2 glider of 1933, which was towed by an R-5 from Koktebel (Crimea) to Moscow. In 1934 he entered an AviAvnito competition for a transport with a design hav­ing twin fuselages, each with a 750hp Wright Cyclone engine and ten passenger seats, but this was not built.

From this he derived the DB-LK bomber. Designed in 1938, the single prototype was completed in November 1939, but (according to unofficial reports) pilots declined to do more than make fast taxi runs, the aircraft being dubbed Kuritsa (chicken) in conse­quence. In early 1940 this unacceptable situ­
ation was ended by the appointment by GK Nil WS (direction of the air force scientific test institute) of M A Nyukhtikov as test pilot, assisted by lead engineer TTSamarin and test observer N I Shaurov. Test flying began in early 1940, at which time Mark Gallai also joined the test team. Nyukhtikov complained that the flight-control system was inadequate and that the landing-gear shock absorbers were weak. In the investigation that followed, the Commission agreed with the first point, but the Head of Nil WS, AI Filin, thought the landing gear satisfactory. He then changed his mind when a leg collapsed with himself at the controls (see photo). Later the main legs were not only redesigned but were also in­clined forward, to improve directional stabili­ty on the ground and avoid dangerous swing.

Later in 1940 the Nil WS ordered the DB-LK to be abandoned, despite its outstanding per­formance, and the planned imminent instal­lation of l,100hp M-88 engines. Belyayev had by this time designed a refined version with 1,700hp M-71 engines, but was told that the DB-3F (later redesignated IL-4) would remain the standard long-range bomber.

Belyayev left comprehensive aerodynamic details, showing that the strange wing was of CAHI (TsAGI) MV-6bis profile over the long – chord centroplan (centre section) but Gottin­
gen 387 profile over the supposed ‘bat-like’ outer panels. Overall aspect ratio was no less than 8.2, and the outer wings had a leading – edge sweep of minus 5° 42′, with a taper ratio of 7. The airframe was almost entirely a mod­ern light-alloy stressed-skin structure, the wing having five spars. There is evidence the structural design was modern, with most components pressed or even machined from sheet. The outer wings had flaps of the un­usual Zapp type, extended to 45°, with Frise ailerons outboard, which even had miniature sections on the back-raked tips. Ahead of the ailerons were slats.

At each end of the centroplan was a fuse­lage, ofbasically circular section. On the front ofeach was a Tumanskii (Mikulin KB) M-87B 14-cylinder radial engine (Gnome-Rhone an­cestry) rated at 950hp, driving a VISh-23D three-blade variable-pitch propeller of 3.3m (10ft l0in) diameter weighing 152kg (335 Ib). The engines were housed in modern long – chord cowlings, with pilot-operated cooling gills. Tanks in the wings and fuselages housed 3,444 litres (757.6 Imperial gallons, 910 US gal­lons) of fuel, with all tanks protected by nitro­gen inerting.

On the centreline at the rear was a large (7.0m2, 75.3ft2) single fin and a 1.94m2 (20.9ft2) rudder with a large trim tab. High on the fin,

above the rudder, was fixed a small (0.85m2, 9.15ft2) tailplane to which were pivoted the enormous elevators of 4.8m2 (51.7ft2) total area, each with a large tab.

Each fuselage was provided with a main landing gear, with a single oleo strut on the outer side of the axle for a single wheel with a 900 x 300mm tyre, with a hydraulic brake. Each unit retracted rearwards hydraulically. On the centreline at the rear was the fixed castoring tailwheel, with a 450 x 150 tyre.

The intention was that the series (produc­tion) DB-LK should have a pilot in the front of the left fuselage, a navigator in front on the right, and gunners in each tailcone. The gun­ners, entering like the others via roof hatches, should manage the radio as well as pairs of ShKAS 7.62mm machine guns, with a ±10° field of fire in all directions. Two more ShKAS fired ahead on the centreline, aimed by the pilot, and for the six guns a total of 4,500 rounds were provided. Behind each main- gear bay was a bomb bay, with powered doors (see underside view). Each could carry an FAB-1000 (2,205 Ib) bomb, or four FAB-250 (551 Ib) bombs, or many other smaller stores. Predictably, the full military equipment was never fitted, though radio was installed throughout the flight trials.

Despite its strikingly unconventional appear­ance, the DB-LK appeared to be a practical bomber with outstanding flight performance. Compared with the established WS bomber it had the same number of similar engines, and even half the number of landing-gear oleos, despite having twice the number of fuselages and weapon bays. From today’s distance, it might have been worth pursuing this formula a little further.

Purpose: Experimental dive-bomber fighter. Design Bureau: V N Belyayev.

No descriptive material has come to light regarding the proposed FBI (Russian for dive – bomber fighter). Only recently have pho­tographs of the mock-up been discovered, marked SEKRETNO and dated 19/1I-40. When these photographs were unearthed and identified nothing was known of such an aircraft, and it was concluded that this was the mock-up of the EOI fighter, especially as Shavrov said this was a twin-boom aircraft. Studying the photographs makes it obvious that the FBI was what its designation states, and not primarily a fighter. Almost the only fact deducible under the heading ‘History’ is that the date is one month after the evacua­tion of the factories in the Moscow area.

In some respects the FBI design is similar to the EOI fighter. The forward fuselage has two cannon in the same undernose position, the single-seat cockpit has similar features, the wing is in the same mid-position, imme­diately behind it is the engine driving a three- blade pusher propeller and the twin booms and tail are similar. The differences are that the cockpit area is almost completely glazed, and the landing gears are taller to facilitate loading bombs on five racks (apparently an FAB-500 on the centreline and for an FAB-100 and FAB-50 under each wing).

It is unlikely that Belyayev – even assisted by his team of P N Obrubov, L L Selyakov, E I Korzhenevskii, D A Zatvan, B S Beki and

N Ye Leont’yev – could simultaneously have worked on the DB-LK, Babochka and two ad­vanced pusher fighters and bombers. The in­ference has to be that the FBI did not progress far beyond the mock-up. This may have been photographed after the workers had left, im­mediately before it was destroyed, or alterna­tively it may have been safely located (but abandoned) somewhere East of Moscow.

Specification. No figures known.

Purpose: To devise an armament system for the BOK-11.

Design Bureau: Bureau of Special Design, Smolensk.

In 1937 the BOK began work on the BOK-11 (see below) and decided that it should have defensive armament. The BOK-8 was schemed to test this armament. Design was entrusted to BOK engineers V S Kostyshkin and K B Zhbanov. The complete installation was on test by December 1939. Few details have survived, and the aircraft never flew.

The armament system comprised two power-driven barbettes or turrets each hous­ing guns (one report says cannon but Shavrov says ‘machine guns’) outside the pressure cabin, aimed by a synchronous tracking sys­tem with thyratron servo control. The gunner, to have been the third member of the BOK-11 crew, had a Rezunov optical sight system, and the guns were slaved to follow the sight­line to the target. Shavrov comments that this system was tested three years before a simi­lar scheme was devised for the Boeing B-29.

The armament scheme was never fitted to the BOK-11 for reasons given in the descrip­tion of that aircraft.

No data.

BOK-11

Purpose: Strategic reconnaissance.

Design Bureau: Bureau of Special Design, Smolensk. Chief designer Chizhevskii.

Having created aircraft with impressive range and high-altitude capability it was logical to go on and derive an aircraft able to fly with im­punity for great distances over hostile territory carrying long-focus cameras. After argument it was decided to make this aircraft a three – seater, the third man being a gunner control­ling the defensive system tested with the BOK-8. Design began in 1938. Two BOK-11 prototypes were ordered, and the first was flown in 1940. However, in 1938 Chizhevskii and several of his colleagues had been ar­rested (as was Filin soon after, see BOK-7), and this put the whole of BOK’s operations under a cloud. As with many programmes at this time of terror, nobody wanted to do any­thing that might lead to any kind of failure. So, even though the first BOK-11 was delivered to the NIl-WS (where its official walk-round photographs were taken on 4th November 1940), test flying was soon abandoned. There seems little doubt that reports of the ‘BOK-15’ really refer to the BOK-11, in which case, for Nil testing, the Nol aircraft was assigned to A B Yumashev and the No 2 to G F Baidukov.

In general the BOK-1 Is were similar to the BOK-7, apart from having the massive 1,500hp Charomskii ACh-40 diesel engine to give increased range. The large radiator was in a duct under the leading edge. Each of the long-span ailerons had two mass-balances on its underside, the tailplane was wire – braced, and the elevators and tabbed rudder were fabric-covered. The armament system and gunner station were never installed.

There is no reason to doubt that a properly developed BOK-11 could have given the Sovi­et Union a strategic-reconnaissance capabili­ty considerably better than that of any other country. As noted under the BOK-7, the at­mosphere of fear in 1940 led to this pro­gramme being abandoned.

Dimensions

Span 34.0m Illft63/4in

Length 12.9m 42 ft 4 in

Wing area 87m2 936.5ft2

4,090 kg 9,01 7 Ib

10,000kg 22,046 Ib

252 knYh 157 mph

Purpose: To test a tailless light aircraft. Design Bureau: Kharkov Aviation Institute, joint design by P G Bening, A A Lazarev and AAKrol’.

Also known as the Iskra (spark) and as the Osoaviakhimovets Ukrainy for the local Osoaviakhim branch, the KhAI-4 was com­pleted in summer 1934, and first tested in Oc­tober of that year by B N Kudrin. He found the elevens almost useless, but discovered that at ISOkm/h (112mph) the KhAI-4 could just be­come airborne provided the airfield was bumpy! Once in the air he found that the downthrust of the propeller (because of its sloping thrust axis) resulted in a poor rate of climb, while the small moment arm of the elevens made longitudinal control extremely poor. To cap it all, the wingtip surfaces, away from the slipstream, were ineffective, making the aircraft directionally unstable. Kudrin was able to creep round the circuit by holding the control column neutral, and to land at high speed with a small angle of attack, not trying to raise the nose. He did fly the KhAI-4 twice more, but that was enough.

The KhAI-4 tested several ideas and even actual components which were later built into the larger Avia vnito- 3. Its obj ecti ve was to explore handing of a tailless machine, and also one with a castoring nosewheel (the first such landing gear in the Soviet Union). Aero­dynamically it comprised a short central na­celle on a wing tapered on the leading edge, fitted with various controls. Initially the wing had six trailing-edge surfaces, all operated differentially by rotation of the pilot’s hand­wheel. A push/pull movement operated the two innermost surfaces, which were thus elevens. Movement of the pedals operated rudders on the wingtip fins. Later swept-back wings with distinct ailerons and elevators were tested, and the drawing even shows the addition of small fixed foreplanes. Despite the difference in size and weight the engine was the same type of l00hp M-ll as used for the Aviavnito-3, but driving a pusher propeller. The short landing gears had balloon tyres, the main shock struts having a hydraulic con­necting pipe so that, if one wheel went over a bump, the other leg would extend to hold the wings level and avoid scraping the tip. The construction was wood, but with overall fab­ric covering. The nacelle had two seats in tandem.

The Kharkov designers deliberately em­barked on this tricky and untried layout, but failed to make it work. Dropping the idea was probably largely due to the pilot’s wish to survive.

Kharkov KhAI-2

Purpose: To build a turbojet aircraft. Design Bureau: Arkhip M Lyul’ka and A P Yeremenko, working at Kharkov Aviation Institute.

Dimensions

Span 6.95m 22 ft 9% in

Length 7.2m 23 ft 7Vm

This drawing was discovered in 1993. It shows a small aircraft proposed by Yere­menko to test the first turbojet designed by Lyul’ka, who later became one of the Soviet Union’s greatest jet engineers. There are two puzzles: the designation KhAI-2 is conspicu­ously absent from the official history of the KhAI published in 1990; and this designation was in any case used for the Institute’s modi­fication of the Po-2 (likewise not mentioned in the book, perhaps because it was not an original Kharkov design). The drawing shows the centrifugal turbojet (which Lyul’ka had not made but calculated to give 525kg [l,1571b] thrust) fed by a ventral inlet, with the nozzle under the rear fuselage. It also sug­gests that the cockpit could be jettisoned in emergency. Co-author Gunston believes the date must have been rather later than 1936, but this can still claim to have been the world’s first design for a jet aircraft.