Petlyakov Pe-3bis Heavy Twin-Engine Fighter.
In April 1942, the Pe-3bis, an improved version of the Pe-3, began full-scale production. The most significant improvements concerned the main armament: a 20 mm ShVAK cannon with 250 rounds was installed in the nose fuselage section. Two 12.7mm Berezin UBK machine guns were placed under the center wing section where the Pe-2's bomb bay once had been. The starboard gun had 230 rounds, whereas the port gun was given 265 rounds. A VUB-1 defensive turret was mounted at the navigator's station and had a 12.7mm UBK machine gun with a pneumatic reloading system and 200 rounds. A 7.62mm fixed ShKAS machine gun with 250 rounds was put in the tail cone.
Various changes and improvements were introduced into the airframe structure and the plane's equipment. The wing panels of the Pe-3bis were equipped with automatic leading edge flaps. The crash pylon was removed from the crew cockpit to improve the navigator's working conditions, and the cockpit armor was reinforced. Only a part of the glazing on the nose fuselage section was left, namely a pair of narrow side blisters and a small navigator's porthole to aim when bombing. Blackout shutters were provided for the whole of the cockpit glazing.
The nitrogen fuel tank pressurization system was replaced with one that used cooled inert gases fed to the tanks from the engine exhaust. Transferring the battery of guns to the center wing section required reduction of the capacity of fuselage fuel tank No. 7 by 100 liters. An asbestos bulkhead separated the tank from the machine guns and, at the same time, protected the weapons from dripping gasoline.
121 Pe-3bis aircraft were built in 1942. The industry provided the front lines with 13 more planes at the beginning of 1943. Due to the relatively small production volume, different changes were introduced occasionally in the Pe-3bis design and were subsequently applied to full-scale production Pe-2s, if these changes had proven to be effective. The following items appeared and were tested on production Pe-3bis planes: a VUB-1 upper turret, a new canopy for the pilot's cockpit, increased forward projection of the main landing gear legs, an advanced fuel supply system, and an inert gas fuel tank pressurization system.
An attempt to resume the production of Pe-3 fighters was made at the beginning of 1944. For a variety of reasons, this version of the fighter did not meet the Air Force's requirements. Its armament was outright weak: one 12.7mm UBK machine gun in the nose fairing and only one 20mm ShVAK cannon in the center wing section.
Since the DEU-1 remote-controlled defensive mount which had been planned for installation was not ready, two DAG-10 grenade launchers with AG-2 aerial grenades were fitted in the rear fuselage section, instead.
Due to the aircraft's obvious non-compliance with the requirements of the specification, only 19 production Pe-3 planes of this variant were built.
Pe-3/Pe-3bis fighters were in service only with the Air Force of the Workers' and Peasants' Red Army and naval aviation. As part of the Air Force of the Northern Fleet, several planes outlasted the war and served until 1946, and the final Pe-3s survived up to the beginning of the 50s.