Category Soviet x-plenes

In the mid-1960s the tactical arm of the Soviet Air Force (FA) needed a replacement for the elderly Yakovlev Yak-28 Brewer tactical bombers. The Yak-28 proved disappointing due to short range and severe restric­tions in the use of its weapons. By the mid-1960s, two important factors became evident. The first was the superiority of equivalent US designs, such as the General Dynamics F-111, due to higher performance, wider weapons range and outstandingly superior avionics. The second factor was the rapid development in surface-to-air missile technology; this required new tactical bomber to have supersonic low-level attack capa­bility, which placed high demands on airframe strength and required automatic terrain following capability.

Thus the Sukhoi design bureau (OKB) started work on a tactical bomber which would be the Soviet counterpart of the F-111. Initially the designers settled for mid-set wings with 40° leading-edge sweep. Receiving the in-house designation S-6, it was to have a top speed of 2,500 km/h (1,550 mph) and an all up weight of 20,000 kg (44,090 lb). The two crew members sat in tandem, and the two 7,200-kgp (15,870- lb st) Tumanskiy R-21F-300 afterburning turbojets were placed side-by – side in the rear fuselage, breathing through lateral air intakes.

It soon became evident that a conventional layout was inadequate for the project, and attention was turned to variable-geometry wings and lift-jets, the work proceeding in parallel on these two lines. A com­pletely new project designated T-6 was started. The first prototype, known as the T6-1, entered flight test on 2nd July 1967 with test pilot Vladimir S. Il’yushin at the controls. It had double-delta wings with 60° leading-edge sweep on the inner wings. The crew of two was seated side-by-side. Behind the cockpit were four Kolesov RD36-35 lift engines intended to improve field performance. Initially, two Tumanskiy R-27F2-300 cruise engines rated at 10,200 kgp (22,400 lb st) in full after­burner (again fed by variable lateral air intakes) were fitted; the air for the main engines was used to cool the lift-jets. The intended 11,200-kgp (24,750-lb st) Lyul’ka AL-21 F afterburning turbojets were fitted later.

The T6-1 was intended to carry air-to-surface missiles, unguided rockets, air-to-air missiles, bombs and other stores on four wing and two fuselage hardpoints. The wing span was 10.41m (34.14 ft), overall length 23.72 m (77.8 ft), height 6.373 m (20.9 ft) and wing area 45.33 sq. m (487.9 sq. ft). Maximum TOW was 26,100 kg (57,540 lb).

In the course of trials the Soviet Air Force changed its requirements; the ordnance load was increased to such an extent that lift engines were no longer viable. Also, the contradictory requirements of attack at transonic speeds at ground level and short-field capability were still there. Studies by the Central Aero- and Hydrodynamics Institute (TsAGI) showed that variable-geometry wings compared so favourably with every other possible layout that the Sukhoi OKB radically redesigned the T-6 less than six months after the first flight.

The second prototype, designated T6-2I (the T denoting izmenyayemaya [gheometriya], variable geometry) was completed in late 1969 and took to the air on 17th January 1970, again with Vladimir S. Il’yushin at the controls. The most important change was the new VG wings; they had four sweep settings: 16° for take-off and landing, 35° for loitering and cruise, 45° for manoeuvring and 69° for transonic/super – sonic flight. The fuselage was redesigned to increase fuel capacity and the air intakes were modified. The undercarriage was strengthened to let the aircraft carry an increased warload.

Tests of the T6-2I continued until 1976. The aircraft was soon joined by two more prototypes, the T6-3I and T6-4I. The results were encour­aging and in December 1971 the bomber entered series production at the Novosibirsk aircraft factory No. 153, receiving the service designa­tion Su-24; the in-house designation at the plant was “izdeliye (product) 41”. Initial operational capability was achieved in 1973 but it was not until 1975 that the Su-24 was formally included into the inventory. This version was known to the West by the NATO reporting name Fencer-A.

Modifications to the design were continually implemented as pro­duction progressed. E. g., wing span and wing area were increased soon after the beginning of production. Problems with the variable air intakes caused the intakes to be widened from the 4th production batch onwards (1972) when the to give an increased frontal area. Pressure from the WS to increase range led the OKB to increase the capacity of the number 1 fuel tank by 1,000 litres (220 Imp. gal.) starting with Batch 8, with a concurrent saving in weight which could be used for extra fuel. Operational experience showed the airframe was strong enough to carry more weapons, so two more hardpoints were added on the cen­treline, increasing the total to eight and the weapons load to 8,000 kg (17,680 lb). Weapons delivery was controlled by a PNS-24 Tigr naviga – tion/attack system enabling automatic flight along a pre-programmed route, weapons delivery and return to base.

Important changes were introduced in Batch 15 when the shape of the rear fuselage was redesigned to reduce drag. The box-like structure around the engine nozzles was replaced by a more rounded one with a deeply dished bottom between the nozzles and the brake parachute container was moved up. Extensions were added to the fin at the top and along the leading edge; the upper extension supported the A-711 navigation antenna and the leading edge now accommodated the RSDN-10 long-range radio navigation (LORAN) antenna and a cooling air intake for the generators. SPO-15 Beryoza (Birch) passive radar warning antennae in triangular fairings were placed on either side of the fin near the top. Other changes made at this time included the addition of leading-edge flaps to the outer wings and a reduction in the number of flap sections from three to two each side. This version was known to the West as the Fencer-B. An updated version with Beryoza (Birch) radar homing and warning system (RHAWS) antennae on the air intakes and near the top of the fin was code-named Fencer-C.

By 1975 the ongoing problems with the variable air intakes were finally solved by introducing fixed-area intakes from Batch 21 onwards, which also gave a weight saving of 200 kg (440 lb). Aircraft previously built with variable intakes had that control disconnected. As a result, top speed was effectively limited to 1,400 km/h (870 mph) or Mach 1.4 at sea level, except for very short emergency bursts of Mach 2. This was considered an acceptable trade-off against the elimination of previous problems, as 1,400 km/h at S/L had become the standard attack mode. Concurrently the wings were redesigned and given a different airfoil.

Although improvements were constantly incorporated, this did not affect the designation. It was not until 1975 that enough design changes took place to justify a new designation, T6-M or Su-24M (modifi tseerovannyy – modified). The eighth prototype of the Su-24 sans suf – fixe (T6-8) was converted into the Su-24M prototype and redesignated T6-8M, making its first flight on 24th June 1977. Production began in 1978; the aircraft was known at plant No. 153 as izdeliye 44; the NATO reporting name was Fencer-D.

Major changes were made to the avionics; the most fundamental one was the fitment of a new weapons control system – the PNS-24M Tigr NS. To accommodate the new equipment the forward fuselage was extended by 76 cm and lowered by 15 cm. Apart from the reshaped nose, the Su-24M could be identified by the straight air data boom at the tip of the radome replacing the F-shaped antenna assembly of ear­lier versions, nicknamed “goose” because of its shape. A Kai’ra-24M

(Grebe) day/night low light level TV system/laser designator was fitted, enabling the aircraft to carry laser – and TV-guided missiles and "smart bombs”. Also, the number of weapons carried was increased by the addition of a ninth hardpoint.

Combat capability was greatly improved by the addition of an in­flight refuelling system. An L-shaped FPSh-5M retractable IFR probe was installed just ahead of the cockpit to allow refuelling from another Su-24M fitted with a UPAZ-1A Sakhalin "buddy” refuelling pack or an ll’yushin IL-78/IL-78M Midas tanker. A new Karpaty (Carpathian moun­tains) defence system was introduced. Rounded boundary layer fences were initially fitted on the edge of the wing glove in line with the inner wing pylons; on some aircraft they housed chaff/flare dispensers. Later, when it was discovered that the wing fences improved longitudinal sta­bility but impaired directional stability, they were removed and the dis­pensers relocated to the upper rear fuselage.

In the mid-1980s permission was granted to export the Su-24M. In the late 1980s the OKB brought out an export version designated Su-24MK (kommehrcheskiy – “commercial”, i. e., export version) or izdeliye 44M. The first flight took place in 1987 and small-scale produc­tion commenced in 1988. The Su-24MK differed little from the standard Fencer-D – mainly in the avionics (particularly the IFF system) and weapons options; for example, the Su-24MK could carry more bombs – 38 FAB-100s compared with 34 on the Su-24M and four air-to-air mis­siles instead of two. All export Su-24MKs had angular wing fences, even though they were being removed at the time from Soviet Air Force Fencers. Sales reported so far are: to Iraq (24), Libya (15), Syria (12) and Iran (9).

In 1978 the OKB started full-scale development of the T-6MR recon­naissance version of the Su-24M. Intended as a successor to the out­dated and “short-legged" Yak-27R, Yak-28R and MiG-21 R, it was to operate at a depth of up to 400 km (250 miles) from the front line, day or night in any weather. The first flight took place in September 1980; two prototypes (the T6MR-26 and T6MR-34) were tested and the aircraft entered production and service as the Su-24MR ([samolyot-] razved – chik, reconnaissance aircraft) or izdeliye 48. The NATO code name was Fencer-E.

The comprehensive BKR-1 Shtyk (Bayonet) reconnaissance suite included a Shtyk MR-1 synthetic aperture side-looking airborne radar (SLAR) in the nose covering an area of 4 to 28 km (2.5-17.3 miles) from the centreline; a Zima (Winter) thermal imager; an Aist-M (Stork-M) TV camera; a Kadr (Photo exposure) PHOTINT system comprising an AP-102 panoramic camera and an AFA-A-100 oblique camera; an Efir-1 M (Ether-1 M; pronounced efeer) radiation monitor in a pod under the starboard outer wing; and a Tangahzh (Pitch, in the aeronautical sense) radio monitoring pod or a Shpil’-2M (Spire-2M) laser line-scan pod providing an image of almost photographic quality on the fuselage centreline. Data was recorded on tape but could be instantly transmit­ted to ground stations if required. Three underfuselage hardpoints and the built-in cannon were removed; two R-60 or R-60M air-to-air missiles could be carried under the port wing for self-defence.

Design work on the Su-24MP Fencer-F (izdeliye 46) electronic countermeasures (ECM) aircraft began in 1976; its mission was elec­tronic reconnaissance and neutralisation of the enemy’s air defence radars while escorting attack aircraft to their targets. The two prototypes were converted from Su-24M airframes (the T6M-25 and T6M-35) which were then redesignated T6MP-25 and T6MP-35; the P stands for postanovschchik pomekh – ECM platform. (Strictly speaking, the des­ignation ought to have been Su-24PR) The first flight took place in December 1979. Very little technical information relating to this variant has been released, but it is known to have a sophisticated suite for detecting, locating, analysing, identifying and jamming all known elec­tromagnetic emissions. The bulk of this work is handled by the Landysh (Lily of the valley) system and the aircraft can carry active jamming pods, such as the Los’ (Moose), Fasol’ (String bean) or Mimoza (Mimosette), under the fuselage with no apparent loss of performance. Only about twenty Su-24MPs were reportedly built.

Believe it or not, the Su-24 found peaceful uses as well. In the late 1990s the Flight Research Institute in Zhukovskiy operated two Su-24s – Fencer-A “15 White” (c/n 1515301) and Su-24M “11 White” (c/n 1141613) equipped with an air sampling pod for environmental moni­toring purposes.

The Su-24 achieved initial operational capability with the Soviet Air Force (WS) in 1973, even though official acceptance of the type was not given until 1975 – a move not uncommon in the USSR. After being issued to training units, Su-24s were delegated to regiments operating in the Western areas of the USSR and in the Far East. By assigning them to the Ukraine or the Baltic Republics the WS ensured they could be quickly deployed in times of trouble to Eastern Europe. Later, Su-24 units were stationed in East Germany, Poland and Hungary, but the main Fencer force remained in the USSR.

Among those types displaced from bomber divisions of the Tactical Aviation’s Air Armies were the obsolete ll’yushin IL-28 Beagle and Yak-28. A division usually included three bomber regiments, each hav­ing three squadrons with 10 aircraft per squadron. As production rate grew it was decided to equip some of the fighter-bomber divisions in the 4th, 24th and 30th Air Armies with the Su-24 capable of a more strate­gic role. These armies had been created in the early 1970s, reporting to the High Command of the Armed Forces to act as a strategic reserve (rather than to Army Fronts or Defence Districts where there was a risk of their aptitude for attacking behind the battle line being wasted in local situations). It was also easier to maintain a tighter control on the use of the nuclear bombs which these aircraft could carry.

On entering service with FA regiments that had previously operated such types as the Yak-28 and MiG-27, the Su-24 proved to be much more demanding in maintenance and service. Considering the com­plexity of its systems, this was hardly surprising and extra headaches were caused by the fact that this was the Soviet Air Force’s first experi­ence with computerised systems.

The Su-24 required appreciably more time and effort to prepare it for a sortie; on average, it needed 45 minutes work by 15 technicians. This effectively doubled ground crew workload per flight – an insup­portable situation which was tackled with alacrity. The demands of time could not be reduced because 45 minutes was the minimum time taken to spin up the gyroscopes in the navigation/attack system; some mis­sions requiring a greater degree of accuracy needed as much as 1 hour 20 minutes. Nonetheless, improvements could be made to ease the ground crews’ workload.

The biggest headaches to ground and air crews alike came from the avionics. Such was the need for this type of bomber that, as noted ear­lier, it was rushed into service before the State acceptance trials were completed. The complexity of the many systems and the use of an on­board computer stretched the knowledge and patience of the crews. Malfunctions were frequent and there were cases in the early stages of the Fencer’s career when whole squadrons were grounded for several days until remedies were found.

In-flight malfunction of the navigation and targeting system could all too easily put the crew at risk, especially on supersonic nap-of-the-earth (NOE) missions. At best the aircraft was saved but the target missed. It has been known for farms to lose valuable crops, buildings and even livestock when crews failed to realise there was a problem with the equipment and continued the attack in automatic mode, dropping their deadly load on whatever was unlucky enough to be there. There was a case of a crew getting lost, running out of fuel and having to eject because the airmen did not realise in time there was a fault.

The Sukhoi OKB went to great lengths to reduce pre-flight check time by providing easier access to engines, all systems, filters, gover­nors etc. Wheel changing was simplified by eliminating the need for lift­ing equipment. Special attention was given to the reduction of refuelling time by providing single-point pressure refuelling.

Once the teething troubles had been recognised and acknowl­edged, they were relatively easy to resolve. One particular cause for sat­isfaction was the aircraft’s ability to withstand bird strikes; a collision with a large eagle and another with seventeen sparrows resulted in no serious damage – at least not to the aircraft.

In spite of these difficulties, he pilots liked the Su-24, affectionately dubbing it “Chemodahn” (Suitcase) – an allusion to the slab-sided shape of its fuselage. They appreciated the good field of view, the well – planned flight deck and the automatic flight systems, especially on low – level operations. Flight handling was reasonably easy, even though the Su-24 could be less forgiving in certain circumstances. Slowly but sure­ly the restrictions imposed during the service introduction period were lifted until the Su-24 emerged as a first-rate tactical bomber.

The Su-24 has seen action in several armed conflicts, drawing first blood during the Afghan War where the type made its debut in the spring of 1984. With its weapons load of 7 tons (15,430 lb) – more than double that of other Soviet tactical strike aircraft, its impressive range and sophisticated mission avionics, the Fencer would make a valuable addition to the arsenal of the Soviet contingent helping the pro-Soviet Kabul government fight the Mujahideen rebels. Until then the Su-24 had been unavailable for the war, but the need for such an aircraft was now evident. It was decided to use the type from Soviet bases in Uzbekistan and Turkmenia. Thus, two regiments were seconded to the 40th Army, as the group of Soviet forces in Afghanistan was known. In early April 1984 the 143rd BAP (Bomber Regiment) with 26 Su-24Ms, then based in Georgia at Kopitnari (Kutaisi-1) airbase, was detached to Khanabad – the one in south-eastern Uzbekistan (near Karshi), not the one in Afghanistan. At the same time the 149th GvBAP (Guards Bomber Regiment) with Su-24 Fencer-Bs based at Nikolayevka AB in Kazakhstan was relocated to the fighter base at Koka’fdy near Termez, right beside the border.

The primary motive for the presence of Fencers on the Afghan the­atre of operations was the need to subdue Ahmad Shah Massoud, the most capable Mujahideen leader. As a rule, the Su-24s were used against area targets such as Mujahideen fortifications. Prior to the sor­tie, reconnaissance aircraft would photograph the target. Its coordinates would be fed into the bomber’s computer, and everything else was largely automatic; the PNS-24 nav/attack system would take the bomber there and drop the bombs. In the 149th GvBAR Sqn 1 aircraft usually carried four 500-kg bombs each and Sqn 2 and 3 aircraft were armed with twelve 250-kg bombs each; additionally, two drop tanks were always carried.

Su-24 operations in Afghanistan were not very intensive, since the ground forces were more in need of close air support than of carpet bombing. Nor were they particularly successful; the Su-24 had been designed with the relatively flat terrain of Western Europe in mind, and the radar (which could pinpoint small targets such as tanks) had trouble picking out the targets among the jumbled rocks. NOE flying was out of the question because of the many canyons and mountain ridges. Weapons efficiency was low, as guided bombs and missiles showed poor controllability in the rarefied air of the mountains. Bomb-aiming accuracy in level flight was poor; dropping bombs in a 20 to 30-degree dive produced better results but took the bombers within range of the enemy air defences. During the following months, attacks were carried out from altitudes in excess of 5,000 m (16,400 ft) – safely out of range of the Stinger man-portable air defence systems (MANPADS) supplied by the Western Alliance to the rebels.

The next time the Fencer appeared in Afghan skies was in 1988. At this stage, when the Soviet Union was already pulling out of the point­less conflict, Su-24 operations were mostly of a psy-war type, intended to exert a constant pressure on the Mujahideen and keep them busy. Sorties were flown not lower than at 7,000 m (22,965 ft) because of the omnipresent Stingers.

Generally the Su-24 had a good reliability record in Afghanistan. The few failures that did take place were mostly associated with hydraulics, flap and engine controls. Initially there were problems with the main nav/attack computer but these were quickly fixed as Afghan experience built up. Sometimes the drop tanks would refuse to give off fuel and had to be jettisoned – which the crews were reluctant to do, knowing that the tanks were in short supply. Because missions were prepared hastily, programming errors occurred and sometimes the navigation data mod­ules would even be installed on the wrong aircraft.

No Fencers were lost to enemy fire in the Afghan War. However, there were a few accidents and incidents. On the night of 13th December 1988 a 149th GvBAP forgot to set the wings and flaps for takeoff (they were always rotated to full sweep on the ground to save ramp space) and took off with the wings at maximum sweep. The fully fuelled and bombed-up aircraft managed to get unstuck at the last moment, crashing through the fence around the inner marker beacon and destroying the antenna in so doing; then it climbed away with a shocking 27-degree angle of attack and proceeded to the target. The rest of the sortie went normally, except for the flapless landing on return (the flap control unit had been annihilated when the aircraft hit a fence post). The crew was saved by the bomber’s rugged design and the fiat terrain around the base (eyewitnesses said the aircraft “could have run all the way to Afghanistan”!).

In December 1988 a 735th BAP Su-24 went off the side of the run­way when landing at Khanabad in a stiff crosswind. One of the main gear units hit a pothole and collapsed, rupturing a fuel line and causing a massive fire. The crew escaped but the WSO later died from burns.

Despite the Soviet withdrawal, the Su-24s stayed around for anoth­er month, ready to support Najibuilah’s government if the Mujahideen made an attack on Kabul. In the event, however, this was not needed and the aircraft returned to their home bases in March 1989, ending the Fencer’s Afghan involvement.

The type remained in active service in post-Soviet days. Apart from Russia, in the Commonwealth of Independent States (CIS) the Su-24 was operated by the air forces of Azerbaijan, Belarus, Kazakhstan, the Ukraine, Uzbekistan and Tajikistan.

The Russian Su-24s were also actively used in the First Chechen War (1994-96) and the Second Chechen War (1999-2001) against Chechen separatists. These missions did not always go without losses; three Fencers were shot down by MANPADS.

It is nearly 35 years since the first flight of the Su-24 prototype and 30 years since it first entered service with the WS. Despite many improvements to the airframe, avionics and systems, it does not incor­porate the latest state-of-the-art and no attempt has been made to ren­der it stealthy. Therefore, plans were in hand to replace it with a modern strike aircraft from the Sukhoi stable – the Su-34 (Su-32FN), a two-seat side-by-side derivative of the Su-27 Flanker interceptor. Yet budgetary constraints have caused these plans to be delayed, compelling the Russian Air Force to change its approach. Several Russian companies, such as Gefest&T, are offering mid-life updates for the Su-24M. Designated Su-24M2, the first upgraded aircraft having enhanced all- weather/night capability (38 White, c/n 1041643) was unveiled at the MAKS-2001 airshow. No doubt the introduction of the Su-34 will be a high-priority task, but shortage of funds (together with upgrade possi­bilities) will ensure that the Su-24M and MR will still be in Russian tacti­cal bomber and reconnaissance regiments for a few more years.

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Seen here at OKB-51 ‘s flight test facility in Zhukovskiy, the T6-1 (the first prototype of the Sukhoi T-6 tactical bomber) differed a lot from subsequent aircraft in the series. This view shows clearly the cranked delta wings similar to those of the Su – 15TM interceptor, the separately opening port and staboard canopy halves, the V-shaped window of the laser rangefinder ahead of the windscreen, the engine cooling air intakes on the rear fuselage and the land – ing/taxi lights on the sides of the nose. The closed dorsal intakes of the buried Kolesov RD36-35 lift jets in the fuselage are not vis­ible here.

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The T6-1 lacked a dielectric radome, fea­turing an all-metal nose ahead of the cock­pit windshield.

A “toad’s eye view” of the T6-1 seen head – on. Note the shape of the two-dimensional air intakes, the six weapons hardpoints, the straight pitot at the tip of the nose, the back-up pitot near the port wingtip and the nozzles of the lift jets between the under­fuselage pylons. The relatively narrow land­ing gear track is also noteworthy.

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A three-quarters rear view of the T6-1, showing the rectangular section of the fuselage forming a box around the engine nozzles, the lack of ventral fins, the brake parachute container at the base of the fin and the radar warning receiver (RWR) antenna near the fin tip. Note the unusual variant of the Soviet Air Force insignia on this aircraft with a pentagon incorporated into the middle of the star.

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After giving up on the use of lift jets which imposed an unacceptable weight penalty the OKB redesigned the T-6 radically, Incorporating variable-sweep wings to reconcile speed and field performance requirements. This is one of the prototypes of the Su-24 “sans suffixe”in the assembly shop of 0KB-51’s experimental plant in Moscow. This view shows clearly the wings at minimum sweep and the double-slotted flaps. Note that the rear fuselage, which was detachable for engine maintenance/ change, is still unpainted, indicating that the aircraft is undergoing conversion to a new variant (probably the Fencer-B proto­type). The aircraft in the background is the T10-1, the first prototype of the Su-27 fighter (NATO code name Flanker-A).

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The T6-2I (coded 62 Yellow) at the flight test facility during manufacturer’s tests. Note the warning markings near the radome (“Danger, HF radiation”) and the air intake bodies (“Danger, jet intake”). Note also the Sukhoi OKB’s “winged archer” logo beneath the cockpit and the red band near the top of the fin. The land­ing lights are still built into the forward fuselage sides. The all-movable stabilizers “bled” down to maximum nose-down posi­tion when hydraulic pressure fell off after engine shutdown.

The T6-2I at the Flight Research Institute (Lll) airfield in Zhukovskiy. All six hard – points are equipped with MBD3-U6-68 multiple ejector racks carrying 250-kg (551-lb) FAB-250 bombs. Due to take-off weight limitations the two MERs under the fuselage carry five bombs each instead of six; the total number of bombs is 34, equalling a warload of 8.5 tons (18,740 lb). Note the colour of the radome, the differ­ent Sukhoi OKB badge, three test mission markers and cruciform photo calibration markings beneath the cockpit and the blue fin stripe replacing the earlier red one. An ILS aerial is mounted above the air data boom carrying pitch and yaw sensor vanes.

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One more view of the fully loaded T6-2I at Zhukovskiy with wings at maximum sweep. As is the case with some Western strike air­craft, the pylons under the Su-24’s outer wings rotate as wing sweep chages, remaining parallel to the fuselage centre­line. This view shows well the intakes’ boundary layer splitter plates.

One of the Su-24 prototypes with the wings at minimum sweep. The aircraft carries 24 FAB-250s on MERs on the wing pylons and a pair of 500-kg (1,102-lb) FAB-500s on the fuselage stations, which equals an ord­nance load of 7 tons (15,430 lb).

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The sixth prototype Su-24 (T6-6) was coded 66 Yellow. Here the aircraft is armed with SPPU-6 gun pods with depressabie six-barrel 23-mm Gatling machine guns (here with the barrels at the maximum deflection of 45°) on the inner wing pylons, OFAB-250ShN low-drag bombs for low – level strike on the fuselage stations and Kh-23 rockets on the outer wing pylons. The T6-6I still had a straight air data boom with an ILS aerial above it and nose- mounted landing lights (they were moved to the wing roots on production aircraft); the fin top band was white.

Two views of the T6-27 (coded 27 White), another Fencer-B development aircraft, carrying three Kh-29 rockets on the inner wing and centreline pylons plus two Kh-23 rockets on the outer wing pylons. The red colour of the rockets identifies them as inert rounds for initial weapons trials; note the photo calibration markings on the rear fuselage. The wing fences were a recent addition at the time the pictures were taken – they have not been painted yet!

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The T6-8M, the prototype of the Su-24M (NATO code name Fencer-D), at the Lll air­field in Zhukovskiy in original guise. Note the extended nose, the extended wing leading edge root ECM fairings, the non­standard twin nose gear doors which remain open when the gear is down, the patch of bare metal and the absence of sensors on the underside of the nose where modifications have been made, the modified fin leading edge and the photo calibration markings on the fuselage. Despite the redesigned nose, the aircraft retains the "goose" typical of the initial – production Su-24 (compare this to the pro­duction aircraft on the opposite page).

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The T6-8M at a later stage of the trials wearing an unusual three-tone camouflage and the Sukhoi OKB “winged archer” badge beneath the cockpit. The sensor array under the nose has been reinstated. The aircraft carried no tactical code.

Another view of the camouflaged T6-8M, showing the shape of the rear fuselage around the engine nozzles and the ventral fuel jettison pipes under the nozzles. These features are identical to the final production version of the Su-24 «sans suf- fixe» (Fencer-C).

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An early-production Su-24M coded «07 White». Note the long straight air data probe at the tip of the radome and the wing fences (making the NATO reporting name Fencer oddly appropriate). The port canopy half is secured by a retaining rod to keep it from slamming down on some­body’s head or hands when there is no pressure in the hydraulic system.

Another view of Su-24M “07 White’’, show­ing the characteristic profile of the nose radome. Production Su-24s and Su-24Ms were normally painted light grey overall with white undersurfaces.

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Two views of Su-24s parked on a rain – lashed hardstand at Ostrov airbase near Pskov, north-western Russia. The base, whose name means “island” in Russian, hosts the Russian Navy’s Combat and Conversion Training Centre (i. e., opera­tional conversion unit).

The examples in these photos are repre­sentative of the very first production ver­sion known as the Fencer-A, as indicated by the boxy structure around the engine nozzles and the placement of the brake parachute container very close to the noz­zles. Oddly, the starboard airbrake-cum – mainwheel-well-door is open on all aircraft in the lineup while the port one is closed, as it should be on the ground. Note the fuel jettison pipe between the engine nozzles.

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Su-24 “29 White” seen at OstrovAB in 1998 is an example of the penultimate version of the Su-24 “sans suffixe” called Fencer-В in NATO parlance. Note the 3,000-litre (660 Imp. gal.) PTB-3000 drop tank suspended on the centreline pylon.

A trio of Fencer-As at Ostrov AB; note the different location and smaller size of the yellow radiation and air intake warning tri­angles. While the aircraft are in flyable stor­age, the resident Fencer-As were awaiting retirement and disposal on site.

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Su-24 “05 White” is an example of the final variant of the Su-24 “sans suffixe ” known as the Fencer-C. Theis version can be identi­fied by the ECM antenna fairings on the air intake bodies and the fin sides.

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Another view of Su-24s with PTB-3000 drop tanks under the wings in storage at OstrovABin 1998. The incredible fact that two neighbouring Fencer-As in the line-up carry the same tactical code, 29 White (quite apart from the Fencer-B shown on the preceding page!), is explained by the fact that the Su-24s were ferried to Ostrov for storage from various units and all three bombers obviously belonged to different regiments.

Close-up of the PTB-3000 on the centre­line hardpoint of Fencer-B “29 White”. The fins were set at more than 90° in order to provide adequate clearance between tank and wing/fuselage. Typically of the Soviet/Russian Air Force, drop tanks and such were marked with the aircraft’s tacti­cal code to stop them from being stolen and used on another aircraft – but clearly that did not always help; this drop tank comes from a sister ship coded 23! The yellow rectangles on the fuselage carry maintenance stencils.

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Front view of Su-24 Fencer-B “29 White”. The canopy is closed by a heavy canvas cover which protects the Perspex from the ultraviolet radiation of the sun, delaying the appearence of micro-cracks which gener­ate annoying reflections (this phenomenon is known as “silvering”).

The tails of these Fencer-As show how the Su-24 ’s rudder is cut away from below, with a radar warning receiver aerial at the base. On later versions the space between it and the fuselage was occupied by the brake parachute container which was moved up considerably.

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The Su-24’s wings were moved aft into fully swept position after landing to save space on the hardstand. This view shows the Su – 24’s large spoilers used for roll control.

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This Fencer-A (52 White) at Ostrov AB has had the entire forward fuselage wrapped in tarpaulins. The wraps bear the aircraft’s tactical code on a black circle. The aircraft is a late-production example, as indicated by the dorsal heat exchanger fairing usually found on later variants.

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As the wings are moved back into maximum sweep position the centre of gravity shifts aft, causing the Su-24 to assume a nose-up position. Fortunately, unlike some variable – geometry aircraft, even an unladen Fencer does not exhibit a tendency to tip over on its tail in this situation.

This Fencer-C undergoing maintenance has had a support placed under the tail – just in case. All wheel well doors are fully open. Note that skin panels mounting the centre portions of the ventral fins have been removed for access to some of the equip­ment in the rear fuselage.

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Fencer-A “26 White” at Ostrov AB. The slope behind it faced with concrete slabs functions both as a revetment wall and as a jet blast deflector, allowing the engines to be run after the aircraft has been aligned with the taxiway.

This late-production Fencer-A (note heat exchanger) operated by the Russian Navy’s Black Sea Fleet is rather more fortu­nate. When this picture was taken in 1998 it was fully operational and based at Gvardeyskoye AB in the Crimea which the Ukraine has leased to the Russian Naval Air Arm. Note the generally better surface fin­ish on this aircraft and the different design of the nosewheel mudguard. It is hard to say why a car tire has been place on top of the aircraft. The vehicle in the background is an APA-5 ground power unit on a Ural – 375D truck chassis.

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Su-24 Fencer-C “23 White” on the hard – stand at Gvardeyskoye AB in the summer of 1998. This view illustrates the large, high – set brake parachute container and the fin leading edge air intake which are charac­teristic of the Fencer-B/C.

Preparations are in hand for another day’s flying training over the Black Sea as a gag­gle of Su-24s basks in the sun at Gvardeyskoye AB. The nearest aircraft is provided not with the usual tarpaulin but with a modern cockpit cover made of reflective metallised fabric which also keeps the cockpit from turning into a steam bath in the summer season.

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Gvardeyskoye AB is a large and well – equipped base with a large flight line boasting an excellent surface and a con­crete-lined jet blast deflector, in post – Soviet days, however, it was not much used, and the arrival of the Russian Fencers (the Ukraine operates the type, too) was a welcome spell of activity. Note the bicycle leaned against the aircraft; ser­vicemen cycling around CIS airbases are a pretty common sight. Small wonder, as legging it around the place can get quite tiresome.

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Su-24s «01 White», «21 White» and «07 White» in the maintenance area at Gvardeyskoye AB. The second aircraft is unserviceable, being minus the port engine.

Another angle on the maintenance ramp, with a fourth aircraft («27 White») on the left. Note the trestle under the tail of Fencer-B «21 White». Fencer-Cs «01 White» and «27 White» are obviously recod­ed, the tactical code being applied over a blotch of darker paint.

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Fencer-C “28 White” (c/n 1715324) differs slightly in the design of the «goose» and undernose aerial from «27 White» on page 26. Interestingly, the port air intake cover comes from another example coded «26 White» (c/n 2215334).

A trailer-mounted ground power unit stands beside Fencer-C «01 White» to pro­vide electric power during maintenance.

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Many operational Su-24s show consider­able signs of wear and tear, as exemplified by Fencer-C «27 White» at Gvardeyskoye. Note the unit badge beneath the wind­screen. Again, the aircraft is obviously recoded, the part of the intake body with the tactical code making a marked contrast with the rest of the weather-stained air­frame.

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A pair of Su-24Ms coded «53 Red» and «57 Red» makes a banked turn over the Volga River near Akhtoobinsk, seat of the Air Force Research Institute. The camera ship is a slow transport, so the bombers fly with the wings at 16° to keep formation.

This view of a Su-24M shows that the wing and stabilator leading edges are parallel when the wings are at 69° maximum sweep. The radome on this particular example is unspeakably dirty, and more dirt emanates from the wing glove fairings near the wing pivots. The retractable FPSh-5M refuelling probe is positioned on the centreline ahead of the windscreen. Note the white colour­ing of the wing/stabilator leading edges and the offset position of the dorsal heat exchanger.

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Su-24M «67 White» parked at the Russian Navy Combat and Conversion Training Centre, OstrovAB. Note the red covers on the dipole aerial aft of the cockpit and the hemispherical sensor of the Mak-UFM missile warning sensor further aft.

Two more Su-24Ms, «64 White» and «68 White», under wraps at the Russian Navy Combat and Conversion Training Centre. Unlike the Fencer-As depicted earlier, these aircraft are not in storage but are actually based at Ostrov and belong to the 240th GvOSAP (Guards Independent Composite Air Regiment).

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Su-24M «66 White» is one of the Fencer-Ds belonging to the Russian Navy Combat and Conversion Training Centre. This example carries an L-080 Fantasmagoriya-A (Phantasm-A) electronic reconnaissance (ELI NT) pod on the centreline pylon.

Three more views of Su-24Ms «64 White» and «68 White». The main gear doors are fully open. Note the kinked nose gear door consisting of two parts, a characteristic feature of the Su-24M, and the curvature of the colour division line across the wing fences. Note that the tactical code is repeated on the «pig snout» plate at the tip of the nose pitot cover.

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In accordance with the 240th GvOSAP’s status Su-24M «66 White», seen here soak­ing under a horrendous downpour at Ostrov AB, wears a Guards badge (the old Soviet – style version) on the starboard side.

This late Fencer-D, a Batch 10 aircraft (c/n 1041611?) belonging to the 239th TsPAT (Aviation Hardware Demonstration Centre) at Kubinka AB, represents the export ver­sion designated Su-24MK. The blue tactical code is noteworthy, but the dark green/ dark earth tactical camouflage with pale blue undersurfaces similar to the one worn by Iraqi Air Force examples is even more unusual for a Russian Air Force Su-24. Note the lack of wing fences on this aircraft.

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«94 Blue» is prepared for a mission amid a jumble of ground support equipment that

comes with other Su-24s. Note the packed _______________________________________

brake parachutes on the left. 239th TsPAT Su-24MKs await the next sor-

tie. The Su-24 hardstand at Kubinka is well equipped, with an energy supply system obviating the need for mobile ground power units.

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Two more views of Su-24MK «94 Blue» (c/n 1241613) as is taxies out for a training sor­tie at Kubinka AB, the canopy still open. Unlike the other Fencers operated by the 239th TsPAT, this aircraft wears the stan­dard grey/white colour scheme. Also, this aircraft lacks the wing fences; these were removed from many Su-24s in service.

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«93 Blue», another camouflaged 239th TsPAT Su-24MK (c/n 1041623), taxies out for a training sortie. The aircraft is armed with S-25-OF heavy unguided rockets on the wing glove pylons and R-73 air-to-air missiles on the outer wing pylons. The «wet» centreline pylon mounts an UPAZ – 1A Sakhalin «buddy» refuelling pod allowing the Su-24 to refuel other tactical aircraft. The angular wing fences of «93 Blue» house APP-50 chaff/flare dispensers.

«94 Blue» is prepared for engine starting, using an APA-5D GPU in this instance; the brake parachute pack lies beside, ready for loading. The APA-5’s lateral cable booms swing out to the sides, allowing the vehicle to power up two aircraft at a time

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«92 Blue», the second of three camou­flaged Su-24MKs operated by the 239th TsPAT, fires up its Lyui’ka AL-21Fafterburn­ing turbofans at Kubinka on a bleak winter’s day. The aircraft shows signs of operational wear and tear, with weathered areas on the forward fuselage side touched up in fresher blue paint.

«92 Blue» taxies out, showing the steel plates protecting the inboard portions of the wing flaps from damage when they slide inside the wing gloves as wing sweep is changed.

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Due to the unit’s «showcase» nature the Su-24MKs at Kubinka AB were frequently displayed to various visiting military dele­gations and at open doors days. In the upper photo «91 Blue» is seen together with a Su-25 of the Nebesnyye Goosary (Celestial Hussars) display team which was disbanded soon afterwards.

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Two more views of Su-24MK «91 Blue» during displays at Kubinka. The aircraft is fitted with six MBD3-U6-68 MERs (two of them in tandem on the

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Su-24M «11 White» (c/n 1141613) belong­ing to the Sukhoi OKB performs a simulat­ed refuelling of Su-30 «597 White» (c/n 79371010101) belonging to the Ispytateli (Celestial Hussars) display team of the Flight Research Institute during the MAKS-97 airshow.

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SU-24MK «93 Blue» (c/n 1041623) refuels a sister aircraft coded «91 Blue» during an open doors day at Kubinka AB.

Two Su-24Ms can take on fuel simultane­ously from an IL-78 tanker, as demonstrat­ed by Fencer-Ds «17 White» and «19 White» formating with IL-78M «30 Blue» over Kubinka AB.

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Su-24M «45 Red» is one of several operat­ed by the 968th IISAP (Instructional & Test Composite Air Regiment) which is part of the Russian Air Force’s 4th TsBP і PLS (Combat and Conversion Training Centre) in Lipetsk. Note the unit badge and the five mission markers on the nose applied to mark successful live weapons training sor­ties.

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Su-24M «42 Red» is prepared for the day’s flying at Lipetsk AB. Like the other resident Fencers, the aircraft has been recoded. The GPU in this case is an APA-5DM based on a diesel-powered Ural-4320.

«41 Red», another 968th IISAP Su-24M (seen here sharing the ramp at Lipetsk with a Mikoyan MiG-29), wears 14 mission markers. It is equipped with a UPAZ-1A refuelling pod.

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Su-24M «41 Red» features APP-50 chaff/flare dispensers on the upper side of the rear fuselage to enhance the aircraft’s protection against heat-seeking missiles (see also page 44).

Another view of the flight line at Lipetsk.

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Interestingly, none of the 4th Combat and Conversion Training Centre’s Su-24Ms has the tactical code repeated on the fin, as is customary in the Russian Air Force. On the other hand, the tactical code is repeated on the nose gear door, which is certainly unusual.

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The flight line in Lipetsk is equipped with removable jet blast deflectors made of steel. This type of structure is more com­mon at Soviet/CIS airbases than the «built – in» version of the kind seen at OstrovAB.

Although the Su-24M’s entire nose ahead of the windshield is painted white, not all of it is dielectric. Here the extent of the actual radome is clearly visible, as the special radio-transparent white paint used on dielectric fairings has become so weath­ered as to turn a dirty grey colour.

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A This view of a Su-24M shows the wings at minimum sweep, the high-lift devices (slot­ted flaps and leading-edge slats) and the four underfuselage hardpoints (two in tan­dem and two side by side). The foremost pylon and the two side-by-side pylons are fitted in this case. The airbrakes/main gear doors are just about to close as the aircraft «cleans up» after take-off.

Su-24M «44 Red» «burns rubber» at the moment of touchdown in Lipetsk. This is one of several Fencer-Ds upgraded by the Russian avionics/weapons integrator Gefest & T. The mid-life update can be identified by the faired chaff-flare dis­pensers on top of the aft fuselage; the fair­ings have small air intakes at the front. The aircraft carries RBK-500 cluster bombs on the centreline pylons. ◄

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Close-up of the Gefest & T logo on the air intake ofSu-24M «40 Red», another exam­ple upgraded by the company. Note the «cross-hairs» in the middle of the Cyrillic letter F.

The Su-24Ms of the 4th TsBP і PLS are by far the most actively flying Fencers in Russia, surpassing even those the naval examples based at OstrovAB.

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The Su-24Ms of the 968th IISAP wear a badge depicting a rampant bull with the word «Vsegda» («always» in Russian). The badge signifies readiness to take on any adversary, anytime, anywhere (equvalent to the «Semper paratus» motto of some Western squadrons). A more unofficial interpretation is «we’ll have everybody, everywhere, every time and in every possi­ble way».

Su-24Ms «45 Red», «46 Red» and «40 Red» make a smoky flypast in echelon starboard formation. All three aircraft carry small bombs on the centreline; a minimum ord­nance load is enough for weapons training.

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The Su-24M served as a basis for the Su-24MR Fencer-E reconnaissance air­craft. This head-on view shows the recon­naissance version’s characteristic asym­metric external stores arrangement with a Efir – 1M electronic intelligence (ELINT) pod on the starboard wing pylon and a dual missile rack with two R-60 AAMs for self – defence under the port wing.

The Su-24MR has a much smaller nose radome, as revealed by the discolouration of the dielectric parts on the T6MR-1 pro­totype («26 White») converted from a Fencer-A (c/n 0115305). The space aft of it is occupied by a Shtyk MR-1 side-looking aircraft radar (SLAR) with elongated flush dielectric panels. The prototype lacked the IFR probe of production examples.

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The nose of the Su-24MR is painted white right up to the windshield, just as on the regular Fencer-D, in order to conceal its special nature from the adversary’s aerial reconnaissance and space surveillance assets. This example coded «15 White» carries an Shpil’-2M laser line-scan pod on the centreline pylon. The white «hump» on the dorsal heat exchanger fairing is not a cap of snow but a dielectric panel. Note that the drop tanks apparently come from another aircraft; even writing the tactical code in really huge digits does not help!

Su-24MR «12 White», seen here at the moment of rotation, carries a large photo reconnaissance/ELINT pod on the centre­line pylon.

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This Su-24MR coded «40 Yellow» (c/n 0941648) is used as a demonstrator by the Sukhoi Design Bureau and based in Zhukovskiy, hence the flashy colour scheme in the Russian flag colours of fhite, blue and red. Here the aircraft is fitted with a PHOTINT/ELINT pod; the open camera port is visible here.

Su-24MR c/n 0941648 in the static park of MosAeroShow-92. In this instance it car­ries an Shpil’-2M pod; this near head-on persoective illustrates the pod’s elliptical cross-section. Note that the AAM adapter under the starboard wing is the wrong one, i. e., it is intended for the starboard side (the upper missile should be on the outer side!).

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Su-24MR «40 Yellow» (c/n 0941648) – this time with no external stores – takes off from Zhukovskiy’s runway 12 fora demon­stration flight during one of the MAKS air – shows.

«40 Yellow» completes its landing roll on runway 30 at Zhukovskiy. The aircraft is a regular participant of the flying programme during Moscow airshows.

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Su-24MR «40 Yellow» passes in front of the crowd. Note the Vee shape of the colour division lines on the underside and the dirty marks sloping downwards from the stabila – tor pivots (a result of the stabilators’ habit of«bleeding» down to maximum deflection when the engines are inoperative).

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The other special mission derivative of the Su-24M was the Su-24MP Fencer-F elec­tronic countermeasures aircraft. This view shows the square-shaped dielectric panels on the sides of the nose (hiding jammer antennas), the characteristic ECM aerials under the nose and on the air intakes, and the centreline Fasol’ jammer pod.

The few Su-24MPs were stationed in the Far East and the Ukraine (the latter aircraft were retained by the newly-independent Ukraine after the break-up of the Soviet Union). Here, a Russian Air Force Su-24MP in wraps sits on a snowbound ramp at Lipetsk. Note that the outer wings are wrapped up, too.

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This 4th TsBP і PLS Su-24MP coded «15 White» is apparently due to awaken from winter sleep and make a training flight; mechanics are about to remove the canvas covers from the airframe.

«15 White», a Ukrainian Air Force Su-24MP, sits in front of a hardened aircraft shelter (HAS) at Chortkov AB. The immaculate fin­ish on this aircraft is noteworthy.

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Another view of Ukrainian AF Su-24MP «15 White». The nose gear doors are open for maintenance. The 118th OAPREB (Independent ECM Regiment) at Chortkov operating the type transitioned to the Su-24MP from the Yakovlev Yak-28PP.

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This Ukrainian Air Force Su-24M coded «19 White» carries UAF roundels on the forward fuselage (which makes an interesting com­parison with the aircraft on the opposite page) and dragon artwork. Note the L-080 Fanmtasmagoriya-A ELINTpod on the cen­treline station.

Ukrainian Air Force Su-24 Fencer-B «49 White» (c/n 1615324) undergoing mainte­nance at its home base, Chortkov AB. The radome swings open to port, revealing the two antenna dishes; the larger one is for the Puma fire control radar while the small one underneath is for the terrain following radar.

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Two more views of Ukrainian Air Force Su – 24 «49 White» (c/n 1615324) unbuttoned for maintenance, showing the positioning of the UAF roundels on the wings and the removable panels on the upper fuselage for access to the control runs and other systems.

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The nighbouring aircraft coded «50 White» is also being worked upon. The drop tank is inscribed «50 starboard» but the «5» has almost vanished – though it is hard to say why.

The Ukrainian Air Force also managed to keep some Fencer-As flying, as illustrated by «65 White» here. Note the variance in the shield-and-trident tail insignia on individual aircraft; the crudely overpainted red star is showing from under the UAF insignia on this one. The panels carrying the middle por­tions of the ventral fins are removed, show­ing that «65 White» is a bit unairworthy for the time being.

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Soviet/CIS Air Force tactical bomber units sometimes operated a mix of different Su-24 versions, as illustrated by Fencer-A «65 White» sharing the flight line with a Fencer-C. The removed access panels with the middle portions of the ventral fins are lying behind the aircraft.

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The Islamic Republic of Iran Air Force (IRIAF) was one of the few export cus­tomers for the Su-24. Apart from the Su – 24MKs delivered directly from Russia, the IRIAF retained several ex-Iraqi examples which sought shelter in neutral Iran at the closing stage of the 1991 Gulf War. Here, IRIAF Su-24MKs serialled 3-6853 (above) and 3-3810 (right) are seen at military hard­ware exhibitions at Teheran International airport.

Two IRIAF SU-24MK (3-6807 and 3-6811) cruise over the snow-covered mountains of northern Iran. These photos illustrate the two-tone camouflage worn by export Fencers.

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The rear fuselage and tail unit of the Fencer-A, the first production version of the Su-24, showing the low-set brake para­chute container. This particular aircraft serving as a ground instructional airframe at the Ukrainian Air Force Technical School near Kiev is the T6-19 development aircraft («619 White»; c/n 0215307?). Note the photo calibration marking on the tail.

This view clearly illustrates the difference in rear end treatment between the Fencer-A (background) and the Fencer-C. Note the antenna and cooling air intake built into the latter aircraft’s fin leading edge.

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A The rear fuselage and tail unit of the Su-24M (illustrated here by 239th TsPAT «92 Blue»), except for the shorter, upward – curved fuel jettison pipes.

Close-up of the Su-24M’s brake parachute container, with the radar homing and warn­ing system (RHAWS) antenna array above ◄

The outer wing pylons rotate as wing sweep changes, remaining parallel to the fuselage axis. This aircraft carries 32-round UB-32 rocket pods for firing 57-mm S-5 folding – fin aircraft rockets (FFARs).

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MBD3-U6-68 multiple ejector racks can be carried on any of the Su-24’s hard points. Up to six of these MERs can be fitted at a time for carrying FAB-250 HE bombs. The starboard one of the two elongated ventral fairings visible in the left photo houses a 30- mm Gryazev/Shipoonov GSh-6-30 six-bar­rel Gatling cannon; the muzzle opening is closed by «eyelid» shutters.

Double launcher adapters for R-73 air-to – air missiles can be carried on the outer wing pylons. These are usually fitted to the Su-24MR (here, «40 Yellow», c/n 0941648) and Su-24MP.

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The Su-24’s hefty wing pivot box is manu­factured as a singe whole with the fuse­lage. This is the port wing pivot and the riv­eted structure around it. Note the shallos strake which organses the airflow around the wing/fuselage joint.

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Up to three 3,000-litre (660 Imp. gal.) PTB-3000 drop tanks can be carried on the fuselage and inner wing hardpoints. Small canards with negative incidence are fitted at the front to facilitate separation when the tank is jettisoned.

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Close-up of the antenna dishes of the Orion-A fire control radar and the Rei’yef terrain following radar below it forming the PNS-24 Tigr navigation/attack avionics suite. The antenns are mounted on a solid frame which swings out to starboard for access to the radar sets. The stencils on the antenna dishes read «Attention! Tuned, do not touch». Note also the V-shaped win­dow of the TP-23E infra-red seeker.

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The Su-24 features a sharply swept two – piece windshield made of strong polycar­bonate. It is designed to minimise drag at high speed and withstand birdstrikes which are quite likely during low-level dashes. Note the PVD-7 pitot head in line with the windshield.

The two halves on the canopy can be opened individually, leaving a splitter run­ning down the middle. The construction number is normally stencilled on this (though not on this particular aircraft).

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Close-up of the faired centreline pylons carrying MBD3-U6-68 MERs.

Close-up of the Chaika (Seagull) under­nose forward-looking infra-red seeker (FLIR)/laser ranger window and Filin (Horned owl) ESM antennas.

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The instrument panel of the Su-24 featured illuminated push-button switches; some of the engine instruments are of the vertical strip type. The diagram in the centre with the aircraft silhouette and radial beams is the RHAWS indicator.

Overall view of the cockpit. The naviga – tor/weapons systems officer (WSO) sits on the right, detecting targets on the orange – coloured radar screen and the display above it. This aircraft is c/n 1215301 (note «12-01» stencilled in the WSO’s footwell).

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Another view of the cockpit with its conven­tional electromechanical flight instruments. The throttles are on the captain’s side con­sole.

As the Su-24 can only land safely with the wings at minimum sweep, a read emer­gency wing actuating handle is located on the l/l/SO’s instrument panel to the left of the airspeed indicator.

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Aptly coded «62 Yellow», the T6-2I was the first variable-geometry prototype.

The T6-27 during weapons trials. The aircraft is a Fencer-B.

«40 White», a 149th Guards Fighter Regiment Su-24 Fencer-B which saw action in Afghanistan, operating out of Kokaidy, Uzbekistan. Note the 13 mission markers.

Another Su-24M in a highly unusual colour scheme applied in the early 1990s. Note the «eyes» painted on the forward fuselage for bird-scaring. The Russian flag addition to the red star was short-lived.

A Ukrainian Air Force Su-24MR. Note the old-style round tail insignia and the Guards badge.

An Iraqi Air Force (a! Quwwat al-Jawwiya al-lraqiya) Su-24MK serialled 24246.

A production Su-24M with the wings at 69" sweep.

Purpose: Experimental jet bomber.

Design Bureau: OKB-1, Podberez’ye and later at Kimry, General Director from October 1948 S M Alekseyev.

The first official history of OKB-1 to be pub­lished (in Kryl’ya Rodiny for December 1987, written by I Sultanov) stated that it was led by Alekseyev, whose own OKB had been closed, and that this aircraft was ‘designed in close collaboration with CAHI (TsAGI), the leading experts on aerodynamics and struc­tures being V N Belyayev, AI Makarevskii, G P Svishchev and S A Khristianovich’. At the end it briefly noted that ‘a group from Ger­many, led by B Baade, participated…’ It would have been more accurate to explain that OKB-1 was specifically formed on 22nd October 1946 in order to put to use several hundred German design engineers, led by Prof Brunolf Baade and Hans Wocke, who had been forcibly taken with their families to a location 120km east of Moscow where they were put to work in a single large office block. For the first three years they were fully occu­pied on the Types 131 and 140 described pre­viously. However, mainly because of doubts that the forward-swept wing would ever be
made to work, even before they left Germany they had completed preliminary drawings for a bomber of similar size but with a conven­tional backswept wing. By 1948 this had be­come an official OKB-1 project, called 150. The original Chief Designer was P N Obrubov, but Alekseyev took his place when he arrived. Workers were increasingly transferred to the 150, which grew in size and weight from the original 25 tonnes to produce a bomber inter­mediate between the IL-28 and Tu-16. The brief specification issued by the WS called for a take-off weight between 38 and 47 tonnes, a maximum speed rising from 790 km/h at sea level to 970km/h at 5km, a service ceiling of 12.5km and a range varying with bomb load from 1,500 to 4,500km (932 to 2,796 miles). Only a single flight article was funded, and this had to wait a year for its en­gines. At last it was flown by Ya I Vernikov on 14th May 1951. On Flight 16 on 9th May 1952 the aircraft stalled on the landing approach, and though the aircraft was marginally re­pairable nobody bothered, because of the clearly greater potential of the Tu-88 (proto­type Tu-16). The dice were in any case loaded against a German-designed aircraft. In late 1953 Baade and most of the Germans re­
turned to their own country, where in Dres­den they formed a company called VEB which used the Type 150 as the [highly unsuitable] basis for the BB-152 passenger airliner.

A modern all-metal aircraft, the 150 had a shoulder-high wing with a fixed leading edge swept at 35°. As this wing had hardly any taper the tips were extraordinarily broad, leaving plenty of room for slim fairings housing the re­tracted tip landing gears. The concept of tan­dem centreline landing gears with small wheels at the wingtips had been evaluated with Alekseyev’s own I-215D. At rest the wing had anhedral of-4°, reduced to about -1° 20′ in flight. Each wing had two shallow fences from the leading edge to the slotted flap. Out­board were three-part ailerons. The fuselage was of circular section, tapering slightly aft of the wing to oval. Fixed seats were provided in the pressurized forward section for two pilots, a navigator/bombardier and a radio operator who also had periscopic control of a dorsal turret with two NR-23 cannon. Underthe floor was the RPB-4 navigation/bombing radar, with twin landing lamps recessed in the front. Behind this was the steerable twin-wheel nose gear. Next came the large bomb bay, 2.65m (8ft Sin) wide and high and 7m (23ft)

long, with a load limit of 6 tonnes (13,228 Ib). Next came the rear twin-wheel truck, which on take-off could be suddenly shortened to tilt the aircraft 3° 30′ nose-up for a clean liftoff. The large fin was swept at 45°, with a two-part rudder and carrying on top the 45°-swept tailplane and three-part elevators with dihe­dral of 8°. In the tail was a rear gunner with a turret mounting two NR-23 cannon. Under each wing was a forward-swept pylon carry­ing a Lyul’ka AL-5 turbojet rated at 4,600kg (lO. HOlb). A total of 35,875 litres (7,892 Im­perial gallons) of fuel was housed in eight cells along the upper part of the fuselage, and additional tanks could be carried in the bomb bay. On each side of the rear fuselage was a door-type airbrake. Like almost everything else these surfaces were operated electrical­ly, the high-power duplicated DC system in­cluding an emergency drop-out windmill generator. Each flight-control surface was op­erated by a high-speed rotary screwjack.

Though flight testing revealed some buffet­ing and vibration, especially at full power at high altitude, the numerous innovations in­troduced on this aircraft worked well. Never­theless, it would have been politically undesirable for what was essentially a Ger­man aircraft to be accepted for production. Thus, hitting the ground short of the runway was convenient.

Dimensions Span 24.1m 79 ft 1 in Length (excluding guns) 26. 74 m 87 ft 8% in Wing area 125m2 1,346ft2 Weights Empty 23,064kg 50,84715 Loaded 54 tonnes 119,00015 Performance Maximum speed at sea level, 850 km/h 528 mph at 10 km (32,808 ft) 930 km/h 578 mph Service ceiling about 13km 42,650ft No other data, except that design range (see a5ove) was exceeded.

Soviet X-Planes. in colour Posted by admin in Soviet x-plenes on November 9, 2015

Top: Mikoyan Ye-4 with RD-9I engine Centre: Mikoyan Ye-2A Bottom: Mikoyan Ye-5

Photographs on the opposite page: Top: Mikoyan I-3U in late 1956. Bottom: Mikoyan I-7U.

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Top: Mikoyan Ye-152/Awith K-9 missiles.

Right and bottom: Two views of the Mikoyan Ye-152P.

Photographs on the opposite page:

Top and centre: Two views of the Mikoyan Ye-8/2.

Bottom: Mikoyan Ye-50/3.

Photographs on the opposite page:

Top: Mikoyan Ye-152M (Ye-166) record version at Monino.

Centre. MiG-211/1 ‘Analog’.

Bottom: MiG-21PD (’23-31′).

Top: One ofthe Myasischev M-17 prototypes at Monino

Above, right and below: Three views of the Myasischev M-55.

Photographs on the opposite page:

Top and centre left: Two views of the Myasischev VM-T.

Centre left and bottom: Two views of the Sukhoi T-4 (‘101’).

Photographs on the opposite page:

Top and centre: Two views of the Sukhoi P-42 record aircraft.

Bottom left and right: Two views of the Sukhoi Su-27UB-PS test-bed.

Three views of the Sukhoi S-37, the lower two taken at the MAKS-99 air show. ,

Photographs on the opposite page: Top: Sukhoi Su-37 (T10M-11). Bottom: Sukhoi Su-37 ‘Berkut’.

Top: Tupolev Tu-155 test-bed at Zhukovskii.

Cen/re: YakovlevYak-141 at Khodynka.

Bottom: YakovlevYak-141 second prototype.

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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.

Dimensions
Span (wing)	28.5m	93 ft 6 in
(over lateral-control pods)	30.0 m	98 ft 5 in
Length (as built, excluding PVD
instrumentation boom)	25.97 m	85 ft 2% in
later	30.0m	98 ft 5 in
Wing area	217.788m2	2,344ft2
Total lifting area	280 m2	3,014 ft2
Weights
Empty (in final form)	23,236 kg	5 1 ,226 Ib
(intended weight with lift jets) 35,356 kg	77,945 Ib
Maximum take-offweight	52,000kg	1 14,638 Ib

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.

Dimensions Span 21.6m 70 ft 1014 in Length 9.78 m 32 ft 1 in Wing area 56.87m2 612ft2 Note: various other figures for span (21.4 m) and wing area (59 m2) have appeared.
Weights
Empty (also given as 5,655 kg) 6,004 kg	13,236 Ib
Normal loaded weight	9,061 kg	19,976 Ib
Max loaded weight	10,672kg	23,528 Ib
(also given as 9,285 kg)
Performance
Max speed at sea level,	395 km/h	245 mph
at 5,100m (16,730 ft)	488 km/h	303 mph
Take-off speed	1 45 km/h	90 mph
Max rate of climb	6.15m/s	l,210ft/min
Time to climb to 3,000 m	8.2 min	(9,843ft)
Time to climb to 5,000 m	1 3.6 min	(16,404ft)
Service ceiling	8,500 m	27,890ft
Range (with 1,000 kg bombload)
at normal gross weight	1 ,270 km	789 miles
maximum	2,900 km	1,800 miles
Landing speed	1 50 km/h	93 mph

Four views of DB-LK, one showing landing-gear failure.

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

Weights Empty Loaded Maximum speed No other data.

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.

KhAI-4: (a) with swept-back wing; (b) with a fixed foreplane.

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.

Design Bureau: In most cases, the OKB-155 ofAI Mikoyan.

Made possible by Britain’s export of Rolls – Royce Nene turbojets to Moscow in Septem­ber 1946, the Aircraft S marked a dramatic leap forward in Soviet fighter design. First flown on 30th December 1947, it was far ahead of any other fighter in Europe. In 1949 it went into large-scale production as the MiG – 15. In the Korean war (1950-53) it completely outperformed Allied aircraft (the F-86 was the only rival in the same class) and put the name ‘MiG’ in the limelight around the world, where it remains to this day. A total of 11,073 of all versions were constructed in the USSR, and the global total exceeded 16,085 (the Chi­nese output is not known precisely). Many have served in experimental programmes. These, and other MiG types, require treat­ment that is not apposite in the context of this book. What follows therefore is the specifica­tion for a typical standard late production ver­sion, the MiG-15b/s, incorporating numerous aerodynamic, control, systems and engine improvements overthe original MiG-15. Much more detail of experimental MiG-15s will be included in an Aerofax on the MiG-15 which will be published in 2001. The engine of the MiG-15b/s was the VK-1, derived from the Nene and rated at 2,700kg (5,952 Ib).

Dimensions Span Length (excluding guns) Wing area	10.085m 10.102m 20.6m2	33 ft 1 in 33 ft 1% in 221.75ft2
Weights
Empty	3,681 kg	8,1151b
Internal fuel	1,173kg	2,586 Ib
Loaded (clean)	5,055 kg	1 1,144 Ib
(maximum)	6,106kg	13,461 Ib
Performance
Max speed at sea level	l,076km/h	669 mph
at 3,000m (9,842 ft)	1,107 km/h	688 mph
Rate of climb (clean)	46m/s	9,055 ft/min
Service ceiling	15,500m	50,850 ft
Range (clean)	1,330km	826 miles
Take-off (clean)	475m	1,558ft
Landing speed/	178 km/h	1 1 1 mph
run	670m	2,198ft

su

One of the experimental versions of the basic (not £>/s) aircraft was given the OKB designa­tion SU. Originally a standard fighter, MiG-15 No 109035, with callsign 935 painted on the fuselage, it was used to test the V-I-25/Sh-3. This was the designation for a fighter arma­ment system developed by the Shpital’nyi weapons bureau. The standard quick-change armament pack housing one 37mm and two 23mm guns was replaced by a fixed installa­tion of two powerful Sh-3 23mm guns, each
with 115 rounds. Each gun was mounted below the fuselage in a streamlined fairing. The barrel projected through a vertical slot so that, mounted on trunnions and driven by an irreversible electric screwjack, it could be el­evated to +11° and depressed to -7° (there was no lateral movement). The Ministry order for this conversion was signed on 14th Sep­tember 1950, and the SU was factory-tested between 2nd January and 27th March 1951. NIl-WS testing followed from 30th June to 10th August 1951. The general opinion was that in tight turning combat the system was useful in bringing the guns to bear, and it also enabled a head-on attack to be made with less risk of collision. The NIl-WS report called for a better sight, and for the guns to pivot over a greater angular range.

SYe

Written SE in Cyrillic characters, this was a tangible result of years of research into the endemic problem of poor or even reversed lateral control, wing drop and inadequate yaw (directional) control, especially at high Mach numbers. Most of the research was done at CAHI (TsAGI), but two workers at LIl-MAP (the Ministry flight research insti-

tute), I M Pashkovskii and D I Mazurskii, also took a hand. After various tests they made recommendations to AI Mikoyan, who or­dered the OKB to construct two SYe aircraft, based on the MiG-156/s. An obvious modifi­cation was that the fin leading edge was kinked to maintain a, broad chord to the top. Among other changes the wings were stiff­ened and fitted with ailerons of higher aspect ratio ending in square tips. The first SYe, call­sign 510, was assigned to LIl-MAP pilot D M Tyuterev, who dived it to Mach 0.985 despite having unboosted ailerons. The ailerons were then fitted with BU-1 boosters, whereupon on 18th October 1949 Tyuterev dived it to beyond Mach 1, the first MiG aircraft to achieve this.

Burlaki

One ofthe deeper problems of the Soviet ADD (Strategic Aviation) was how to escort the Tu-4. No fighter, especially a jet, had anything like adequate range. Aircraft designer A S Yakovlev suggested making the bombers tow fighters to the target area (see Yak-25E). Mikoyan briefly worked on a similar Burlaki (barge-hauler) scheme, fitting a MiG-155/s with a harpoon clamp above the nose which the pilot could hook on a crossbar on the end ofa long cable reeled out from the Tu-4. Ifhos- tile fighters were encountered the MiG pilot would start the engine, release the tow and en­gage combat. In theory he could then hook on
again for the ride home. It was not considered a viable idea, one reason being that with the engine inoperative the MiG pilot had no cock­pit pressurization and also became frozen.

Refuelling test-beds

An alternative to the Burlaki method was Dozapravka v Vozdukhe, refuelling in flight. Extensive trials took place in 1949-53 using
various MiG-15 s and Tu-4 tankers. Eventually a system was used almost identical to that de­vised by the British Flight Refuelling Ltd, with hoses trailed from the tanker’s wingtips and a probe on the nose of the fighter. Apart from the basic piloting difficulty, problems includ­ed probe breakage, pumping of bulk fuel into the fighter’s engine and the need for an im­proved beacon homing method for finding the tanker at night or in bad weather.

Purpose: T o build a more efficient light transport.

Design Bureau: NIAI, initials from Scientific Research Aero Institute, Leningrad, formed by the LIIPS, the Leningrad Institute for Aerial Communication; designers AI Lisichkin and V F Rentel.

Even though it went into production and everyday use, this aircraft qualifies by virtue of

its extraordinary layout, with the wing blend­ed into the fuselage. The prototype, with civil registration LI 300, was first flown by A Ya Ivanov in May 1933. Despite the fact that the pilot had no view except over a sector of about 100° to the left side, Ivanov’s opinion was favourable because the aircraft handled well. After four months of testing in Leningrad the LK-1 was flown to Moscow. There it was tested by the Nil, as a result of which a small
series of 20 were built. These saw Aeroflot service in the Arctic, on occasion being fitted with skis or floats.

LK stood for Leningradskii Kombinat, and the prototype was also unofficially called Fan – era-2 (Plywood 2). Though basically a simple all-wood machine, powered by a l00hp M-l 1 engine, it strove to gain in lift/drag ratio by blending the wing root into the fuselage. In­deed, it could be considered as an all-wing

LK-1 senesaircraft

aircraft with the nose engine and rear fuse­lage attached to the thickened centre wing. This central portion contained two pairs of seats, that on the left in front being for the pilot. The entire front and top of this cabin was skinned in transparent panels, those along the sides sloping at 60°, two of them forming doors. The prototype had a ring – cowled engine, spatted main wheels and a broad but squat fin and rudder. Production aircraft had no cowling or spats, but had a re­designed wing root and a narrower rear fuse­lage and completely redesigned vertical tail.

Several designers attempted a cabin of this kind, but all the others were very large air-

Purpose: To create a supersonic radar – equipped interceptor.

Design Bureau: Reopened OKB-51 of P O Sukhoi, Moscow.

After closure of his OKB, in December 1949 Sukhoi became deputy to his old colleague A N Tupolev, where among other things he collaborated with CAHI (TsAGI) in establish­ing the best wing for supersonic fighters. He played the central role in deciding on two contrasting forms. For tactical fighters the choice was an S (Strelovidnoye, arrow like) swept wing with a!4-chord sweep angle of 60° or 62°, and for radar-equipped interceptors the best answer was a T (Treoogol’noye, three-angled, ie delta) wing with J4-chord sweep angle of 57° or 60°. For obvious rea­sons, the latter type of wing was soon dubbed Balalaika. On Stalin’s death Sukhoi applied for permission to reopen his OKB. This was at once granted, and in May 1953 he gathered his team at the original premises at 23A Po – likarpov Street. Following from his aerody­namic research he received MAP contracts for basically similar aircraft, S-l with the S wing and T-l with the T wing. As he chose to build large aircraft powered by a powerful Lyul’ka engine, which matured rapidly, their development was swift. S-l led to the pro­duction Su-7 and many other aircraft. T-l was replaced on the drawing board by T-3, and
this was flown by V N Makhalin on 26th May 1956. Just over a month later it was the final aircraft in the parade of new fighters at Tushi – no on 24th June, causing intense interest and great confusion in the West. A few weeks be­hind came the PT-7. These were tested inten­sively by a pilot team which included Pronyarkin, Koznov, Kobishkan and the fu­ture Sukhoi chief test pilot Vladimir Ilyushin, son of the General Designer.

Like S-l, the T-3 had a barrel-like fuselage, much of its length being occupied by the big afterburning AL-7F engine, rated at 9,000kg (19,840 Ib) with afterburner and 6,500kg (14,330 Ib) dry. The tails of the two aircraft were almost identical, and there were only minor differences in the cockpit, landing gear and most of the systems. The wings of both aircraft were in the low/mid position, at­tached by precision bolts to strong forged root ribs on heavy forged fuselage frames. The wing had S-9s profile with a thickness/chord ratio of4.2 per cent over most of the span. The shape was almost a perfect delta, with a lead­ing-edge angle of 60°. The leading edge was fixed, while the trailing edge comprised rec­tangular slotted flaps with a maximum angle of 25° and sharply tapered ailerons with inset hinges which extended to the near-pointed tips. Incidence was 0° and dihedral -2° (ie, 2° anhedral). Structurally the wing had three main spars, each principally a machined forg­
ing, plus a rear spar to carry the trailing-edge surfaces. The leading edge was attached to the front of a further spar forming the front of the structural box. The forward triangle ahead of Spar 1 and the volume between Spars 2 and 3 were sealed and formed inte­gral fuel tanks. The whole space between Spars 1 and 2 was occupied by the retracted main landing gear. The flaps were driven at their inboard ends by electro-hydraulic power units inside fairings under the lower wing surface. The circular-section fuselage was liberally covered with access doors and hatches. The nose was just one of several contrasting answers tested by Sukhoi to the problem of fitting radar into a supersonic fighter. The fire-control system was to be one of the Uragan (Hurricane) family, with the search scanner at the top of the nose and the Almaz (Diamond) ranging radar underneath inside the inlet. The main scanner was inside a low-drag radome in the form of a flattened cone (with a curious upward tilt) from which projected the PVD-7 instrumentation boom combining the pitot/static heads with pitch and yaw vanes. Additional instrument booms were mounted inboard of each wingtip. Even though the T-3 was to be a supersonic aircraft there seemed no alternative to making the radome over the ranging set a bluff hemi­sphere, which had an adverse effect on pres­sure recovery in the air inlet. The latter
immediately divided into left and right ducts which quickly expanded into vertically sym­metric ducts along each fuselage wall. These combined behind the cockpit into a circular tube passing above the wing and then ex­panding to fill virtually the entire fuselage cross-section to mate with the face of the en­gine compressor at Frame 29. Between Frames 31 and 32 on each side of the top of
the fuselage was a large grilled aperture through which hot air could be violently ex­pelled from the compressor during engine start. At Frame 32 a bolted joint enabled the entire rear fuselage to be removed for servic­ing or changing the engine. At Frame 38 were hinged four door-type airbrakes with large slot perforations. At Frame 43 were the skewed pivots for the horizontal tailplanes, each of which was a single-piece ‘slab’ with a leading-edge sweep of 60° and an anti-flutter mass projecting forwards near each tip. The large fin curved away from a dorsal extension
in which a screwed panel gave access to the power unit driving the rudder, which was hung on three inset hinges. Each tail sur­face had chem-milled skins attached to ribs at 90° to the surface rear spar. The fuselage tail end was mainly of titanium. The nose landing gear had a 660 x 200 tyre and retract­ed forwards. Each main unit had an 880 x 230 tyre and, unlike the swept-wing Sukhois, re­tracted straight inwards. Track was 4.65m (15ft Sin) and wheelbase 5.05m (16ft 7in). The cockpit housed an ejection-seat and had a bulletproof windscreen and one-piece

Below: Two views of T-3.

frameless canopy sliding to the rear. Among the comprehensive avionics suite were two items with antennas in the top of the fin, the slots for the Svod (Arch) navaid and SOD-57 transponder and the RSIU-5V inside the di­electric fin cap. The wings were plumbed for drop tanks, to be carried on pylons only just in­board of the instrument booms. The planned armament was two guns (Sukhoi assumed the NR-30), and steel blast panels were pro­
vided in the sides of the forward fuselage. Be­fore the T-3 was completed the guns were re­placed by missiles. The intended weapon was the K-6, to be carried on interfaces attached where the tanks would have been.

The PT-7 differed mainly in having an area – ruled fuselage, with a visibly waisted middle section, and a new ranging radar with a point­ed downward-inclined radome projecting from the bottom ofthe nose. Other differences
included unperforated airbrakes and a revised fin-cap antenna which extended around the top of the slightly shortened rudder.

These aircraft were the first in what proved to be a long succession of prototype and ex­perimental aircraft in the search for the best interceptor. This underscored the Soviet Union’s determination to accept nothing but the best, because any of these aircraft could have been accepted for production.

Dimensions (T-3) Span 8.7 m 28ft6!fln Length (inc instrument boom) 18.82 m 61 ft m in Wing area (net) 24.9 m! 268.8ft2 Weights Empty 7,490kg 16,512 Ib Loaded (normal) 9,060 kg 19,974 Ib Maximum 11,200kg 24,691 Ib Performance Maximum speed at 10 km (32,808 ft) 2,100 km/h 1,305 mph (Mach 1.98) Service ceiling 18km 59,055 ft Range (internal fuel) 1,440km 895 miles (maximum) 1,840km 1,143 miles Take-off and landing runs, both about 1,100m 3,600 ft

Top: The T-3 at the 1956 Tushino Fly Past. Bottom: PT-7 inlet.

T-3

T-5

PT-7

Purpose: To use Tu-2 aircraft for various experimental purposes.

Design Bureau: Originally, CCB-29 (or TsKB-29) and GAZ (Factory) No 156.

Created during A N Tupolev’s period in de­tention under a ludicrously false ‘show trial’ charge, the Tu-2 (previously ‘Aircraft 103’, but really the 58th ‘ANT’ design), was an out­standing multirole tactical bomber. Its ridicu­lous gestation, with its creator working on a drawing board in a locked cell, meant that it did not enter service until May 1942, but de­spite this some 3,300 were delivered from Factories 156, 166 and 125. As soon as spare examples became available they were snapped up for use as test-beds. The very first series aircraft, No 100716, was used to test the ASh-83 engine, rated at l,900hp, driving four-blade AV-5V propellers (replacing the standard 1,850hp ASh-82FN driving the three – blade AV-5V-167 or four-blade square-tip AV-9VF-21K). Maximum speed of this test­bed was 635km/h (395mph) at 7,100m (23,294ft).

Numerous test versions appeared in 1944, including the first two of three Shturmovik (armoured ground attack) versions with spe­cial armament, all proposed by Tupolev’s ar­mament brigade leader A D Nadashkevich. The first, actually given the designation Tu-2Sh, had its capacious weapon bay occu­pied by a specially designed aluminium box housing 88 modified PPSh-41 infantry ma­
chine carbines (sub-machine guns). These fired standard 7.62mm pistol ammunition, and all fired together pointing obliquely down at a 30° angle. The obvious shortcoming was that, even though the drum magazines held 71 rounds, they were quickly emptied.

The second 1944 Sh version had a massive 75mm gun under the fuselage, reloaded by the navigator. Two more ground-attack ver­sions appeared in 1946. The first had the dev­astating forward-facing armament of two 20mm ShVAK, two NS-37 and two NS-45. The 37mm gun was 267mm (101/2in) long and weighed 150kg (33lib). The 45mm version had a shorter barrel but still fired its 1.065kg (2.35 Ib) projectiles at 850m (2,790ft) per sec­ond, and weighed 152kg (335 Ib).

The last of these variants was the two-seat RShR, or Tu-2RShR. This was a dedicated anti-armour aircraft, carrying a high-velocity 57mm RShR automatic cannon with the bar­rel projecting ahead of the metal-skinned nose and fitted with a prominent recoil brake.

The most startling modification was the Tu-2 Paravan (paravane). Two of these were built, to test a crude way of surviving impact with barrage-balloon cables. A special cable woven from high-tensile steel was run from one wingtip to the other via the end of a monocoque cone projecting over 6m (20ft) ahead of the nose. The nose and wingtips were reinforced. First flown in September 1944, this lash-up still reached 537km/h (334mph) despite the strange installation and
a 150kg (331 Ib) balancing weight in the tail. These trials were not considered to have been successful.

Yet another 1944 modification was the Tu-2K (Katapult), fitted with test ejection – seats. The first Tu-2K fitted the test seat in the navigator’s cockpit just behind the pilot. A second ejection-seat tester had the experi­mental seat mounted in an open cockpit at what had been the radio operator’s station in the rear fuselage.

In early 1945 the Type 104 radar-intercep­tion system began flight testing (the first to be airborne in the Soviet Union). The system had been designed from 1943, by a team led by A L Mints, and the Type 104 test aircraft had begun flighttesting on 18th July 1944 but with the vital radar simulated by ballast. The pilot had a modified sight, which was later linked to the radar, and fired two VYa-23 cannon in­stalled under the forward fuselage. The rear fuselage was faired over and contained noth­ing but a balancing mass.

The designation Tupolev Tu-2G was ap­plied to several Gruzovoi (cargo) conver­sions. It appears that all of these were experimental, carrying special loads either in the remarkably large bomb bay or slung ex­ternally, and in many cases the load was dropped by parachute. No fewer than 49 GAZ – 67b armoured reconnaissance cars were dropped, the Tu-2G in this case being limited to a height of 6km (19,685ft) and a speed of 378km/h (235mph).

As explained in the stories of the Pe-2 and Pe-8 experimental versions, the German Fi 103 (‘V. 1’) flying bomb was the basis for a large Soviet programme of air-launched cruise missiles in the immediate post-war era. One ofthe later variants was the 16Kh Pri – boi (surf, breaking waves). The fact this was fitted with twin engines meant that it could be carried under the Tu-2. The first modified Tu-2 launch aircraft began testing at LII on 28th January 1948, and live missile launchings took place on the Akhtuba range between 22nd July and 25th December 1948, testing the D-312 and D-14-4 engines and various electric or pneumatic flight-control systems. The Tu-2 launch aircraft continued in the
process of refining guidance and improving reliability until at least 4th November 1950, by which time the Tu-4 was being modified as carrier aircraft with one missile under each outer nacelle. The WS rejected the 16Kh on grounds of poor accuracy, and eventually the argument reached Stalin who shortly before his death terminated this missile.

Experimental Tu-2 aircraft were also used to develop air-refuelling.

Not least, in the immediate post-war era the Tu-2 was the most important aircraft con­verted to air-test turbojet engines. Occasion­ally the designation Tu-2LL (flying laboratory) was used, but one of the most important was (possibly unofficially) designated Tu-2N,
because it was allocated to test the imported Rolls-Royce Nene. This required the test engine to be mounted in a nacelle of large diameter (basic engine diameter 1.26m, 4ft 11/2in). Later more than one Tu-2 was used to test Soviet RD-45 and VK-1 derivatives of the Nene, including variants with an afterburner. However, these were all preceded by aircraft, some of which had been Tupolev Type 61 prototypes, which were converted to test cap­tured German axial engines: the BMW 003A (Soviet designation RD-20) and the Junkers Jumo 004B (Soviet designation RD-10). An­other 61 prototype was used to test the first Soviet turbojet to fly, the Lyul’kaTR-1, in 1946.