Petlyakov Pe-2 Peshka Part I

This Pe-2FT served with an unknown bomber regiment on the Eastern Front in 1944; after 1942 the ‘British style’ camouflage was very unusual. Also depicted is the original VK-105 engine installation with a separate supercharger air inlet just behind the spinner, and with the oil-cooler inlet smaller and further aft than in the VK-105PF, which was used in the Pe-2FT. All aircraft of this series had the main coolant radiators inside the wing, fed by leading-edge inlets and exhausting through the upper surface. Note the small wind vane on the MV-3 turret (a product of the Mozharovskii-Venyevidov bureau) which assisted the gunner to slew it rapidly. The square hatch in the roof of the radio operator’s compartment was normally closed by left/right hinged doors.

 

Top: PE-211 was one of three early production Pe-2s captured from the Russians and put into service by the Finnish PLeLv 48. Note the required yellow theatre band, as carried by all German-allied aircraft on the Eastern Front. No. 211 had a ventral D/F loop (not visible) and operated on strategic reconnaissance missions from Onttola.

Bottom: This early production Pe-2 is distinguished by the cowlings for the M-105RA engines, which differ in many details from the final cleaned-up pattern. It is shown in winter garb while serving with the 46th BAP (Bomber Air Regiment), Moscow Military District, in the winter of 1941-42. Note the rear mount of the radio/pitot mast and the glazed nose.

Petlyakov’s Pe-2 was the Soviet Union’s Mosquito, though made entirely of metal. Little known outside its homeland, it was built in far larger numbers than its British counterpart and undertook as many different roles. Flying from 1940 and supporting the Soviet offensives soon after that, it contributed greatly to the final victory on the Eastern Front.

On 22 June 1941 the world’s most formidable army and air force began to smash their way into the Soviet Union. Outside that country’ little was known publicly of its modern aircraft; certainly in the first week of the German onslaught it looked as if such know ledge would be academic, because most of the Soviet air force was wiped out. But resistance was dogged, and in the autumn two RAF Hawker Hurricane squadrons, formed into No. 151 Wing, were sent to Murmansk to help bolster the defences and teach the Soviets how to fly the Hurricane.

On No. 151 Wing’s first combat mission it was tasked as escort to a regiment equipped with the Pe-2 bomber. This beautiful aircraft was unknown to the RAF, but it made quite an impression, because the Hurricanes had the greatest difficulty in keeping up. It was not then generally known that on combat missions it was common Soviet practice to fly at virtually full throttle all the way. In both climb and speed the twin-finned bombers easily outperformed their escorting fighters, and Wing Commander Ramsbottom-Isherwood’s pilots had the agonising choice of pushing their throttles wide open to try to keep up, so risking engine failure and running out of fuel, or of falling behind. To say this was a surprise is an understatement.

The Pe-2 was the one gigantic success of Vladimir M. Petlyakov, who from 1921 (when he was 30) had worked at TsAGI, the national aerodynamic and hydrodynamic research centre. He became the leading expert on metal wing design, and designed the wings for all the early Tupolev heavy bombers, and managed the entire design of the biggest aircraft of all, the ANT-16, ANT-20 and ANT-26. In 1936 he was appointed head of the ZOK experimental brigade to produce a large new bomber, which began life as the ANT-42, entered service as the TB-7 and finally, in World War II, matured as the Pe-8, honouring its designer. But Petlyakov had only 18 months on that programme, because in the Stalinist terror of 1937 he was one of the thousands arrested on trumped-up charges. Incarcerated in the TsKB-29 special prison at GAZ (aircraft factory) No. 156, Petlyakov was told to organise a design bureau called KB-100, and to create the VI-100, VI standing for high-altitude fighter.

At a time when the rest of the world thought all Soviets could do was copy others, the VI-100 was created from the proverbial clean sheet of paper to a higher standard (in aerodynamics, structure, and several aspects of systems and equipment) than anything previously existing elsewhere (and Petlyakov’s team was not the only one to do this). The stressed-skin structure was superb, being faulted only on the score of complexity. The wing comprised a flat centre-section and tapered outer panels, mounted low in a fuselage of minimum cross section. All control surfaces were fabric-covered. The twin liquid-cooled engines were beautifully cowled, and as on many other Soviet twins of the period the coolant radiators were inside the wings between the lattice spars, fed by ducts from the leading edge and exhausting through flush shutter-controlled apertures in the upper skin, which were intended to give forward thrust. The engines had turbochargers for high-altitude power and drove constant-speed feathering propellers, which were totally unavailable in the UK at the time. It had been planned to fit a pressure cabin, such things having been extensively tested in the Soviet Union, but this was not produced in time, so the pilot and radio operator (who doubled as observer and rear gunner) were in normal cockpits separated by the main fuel tanks. Armament comprised four 20-mm ShVAK cannon in the nose, each with 150 rounds, the backseater having a ShKAS machine-gun firing at 1,800 rounds per minute. Following US practice, the power services were totally electric, some 20 DC motors driving the landing gear, split flaps, radiator shutters, tank booster pumps, trim tabs and many other items.

Bouncy landings

Piotr Stefanovsky and engineer Ivan Markov flew the first of two VI-100 prototypes, possibly on 7 May 1939 (there is confusion about the date) and took part in the 1940 May Day flypast over Red Square. The aircraft’s main fault was a tendency to violent bouncing on landing, which for some reason was difficult to cure. There is a persistent report that bomb-aiming was found difficult at high altitude, which conflicts with existing Soviet records which make no mention of any requirement for bombs. Altogether the VI-100 could surely have become an excellent day and night fighter and reconnaissance aircraft, its speed being 630 km/h (391 mph) at 10000 m (32,810 ft). The Soviets were as bad as others at chopping and changing, however, and the decision was taken to expand the KB-100 bureau to handle a mass-production programme, not of the VI-100 but of a three-seat bomber derived from it. Some articles suggest the decision was taken in May 1940, but this is impossible, as the first PB-100 (PB is the abbreviation for dive-bomber) undoubtedly flew not later than 3 June 1940, and it could hardly have been designed and built in a month!

Only a single PB-100 prototype is known, and it differed from the VI-100 in many respects. The outer wings had dive breaks and different taper adjusted to the new centre of gravity position, the fuselage was redesigned, the tailplane dihedral was increased, the vertical tails were enlarged and positioned on the tips of the tailplane, and the engine turbochargers were first changed to the smaller TK-2 type and then omitted entirely. The new fuselage provided back-to back cockpits for the pilot and navigator/bomb-aimer, who near the target could squeeze forward to his prone sighting position in the new glazed nose. A single large multi-pane canopy covered both cockpits. Aft of the fuselage tank was the new third crewman, who entered via a roof hatch and managed the radio and a lower rear gun, sighting not through his side windows (which merely let light in) but with a ventral periscopic sight similar to that used on several Soviet attack bombers, including the Tu-2.

An important engineering change was the installation of an hydraulic system, though this was energised by electrically-driven pumps. Services worked by this system included the twin-strut main and steerable tail landing gears, their twin doors, the split Maps, the Venetian-blind dive brakes and, in some aircraft, the bomb doors. All other services, including armament controls, remained electric. Standard bombload comprised four FAB-250 (250-kg/551-lb) or six FAB-100 (100-kg/220.5-lb) bombs in the main bay; with the latter load, two additional FAB-100 bombs could be carried in small door enclosed compartments at the rear of the nacelles. As an overload, with six internal FAB-100 bombs it was possible to carry four more FAB-100 bombs externally under the wing roots. Late in the war some aircraft carried four FAB-250 bombs externally, a total load of 1800 kg (3,968 lb). Normal gun armament comprised two 7.62-mm (0.3-in) ShKAS machine-guns firing ahead and aimed by the pilot, plus a single ShKAS aimed by the navigator/bomb-aimer to the upper rear and another aimed by the radioman to the lower rear, in each case aiming by hand.

Full details of the PB-100 are still lacking. A photograph exists showing ground-attack armament housed in a large ventral bathtub, with two 20-mm ShVAK cannon on the right and two 7.62-mm (0.3- in) ShKAS guns on the left, all pivoted down at a shallow angle for strafing ground targets. A drawing exists showing the normal bomber armament doubled, with four forward-firing ShKAS guns and two pairs at the rear. There is also uncertainty about when the engine turbochargers were removed. Certainly every illustration known of the PB-100 shows long exhaust pipes, and this is also a feature of the initial production version, which in 1941 was redesignated Pe-2 in honour of the lead designer, who with his team was freed from detention in January of that year, and later awarded a Stalin Prize. Use of piped exhausts does not necessarily betoken installation of turbochargers, but it was well into 1942 before the Pe-2 switched to separate ejector stub exhausts.

Speedy progress

There is evidence that preparations for production began long before the completion of Nil (state) trials of the PB-100, and the first production drawings (still designated PB-100) were released to GAZ-22 at Fili, north of Moscow, as early as 7 July 1940. Various modifications naturally took place as a result of PB-100 flight trials, one being to give the pilot simple manual open/shut control of the dive brakes, replacing the complex AP-1 automatic dive control which modulated the brakes according to the dive angle and air speed. Crew armour was improved, the ruling thickness being increased to 9 mm (0.35 in) throughout, the navigator/bomb-aimer was given a swivelling seat, and all five fuel tanks were made self-sealing and continuously inert ed, at first by bottled nitrogen and later by cooled and filtered exhaust gas.

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