The Petlyakov Pe-8 was a Soviet heavy bomber designed prior to World War II. It was used to boost morale, by targeting weak points in Axis lines, such as when it bombed Berlin in August 1941. Pe-8 aircraft, however, were easy targets for Luftwaffe interceptors and many were lost. Most were withdrawn from use after World War II.
The Pe-8 was originally designed in order to replace the aging Tupolev TB-3. The requirements dictated that the aircraft had to be able to fly at a speed of over 440 kilometres an hour. It was also required that the new bomber could have a bomb load of 2,000 kilograms, an operational range of 4,500 kilometres, and an ability to fly at an altitude of ten kilometres.
The Tupolev Design Bureau was given the job, after which a four-engined monoplane bomber was constructed. The prototype was initially designated the TB-7. The bomber was mostly made of duralumin. Two steel spars were put in the wings. Room for a fifth engine, a Klimov M-100, was saved within the fuselage. The purpose of this mechanism was to drive a supercharger that supplied pressurized air to the Mikulin AM-34FRN engines, the primary engines. This installation was dubbed the ATsN-2. A ShVAK cannon was present in the nose, as well as the tail. Two ShKAS machine guns were also mounted on the aircraft, one mounted in the back of the ATsN-2, and a second mounted in a ventral hatch. The most unusual feature of the prototype was arguably the fact that there were ShVAK autocannons that had to be manned in the back of all of the inner engine nacelles. The plane's external bomb racks could each hold a FAB-500 bomb, while the internal bomb racks could carry up to 4,000 kilograms of payload. The aircraft conducted its first flight on 27 December, 1936.
A second prototype was created shortly after the first one was tested. The old engines were replaced by superior AM-34FRNV engines. The fuselage was widened, as well. Also, the new aircraft came with a modified tail. The armament was modified, with twin ShKAS guns present in the nose, nacelle and tail turrets, along with dorsal turret mounting a ShVAK, which deducted the need for a ventral gun. Another new feature of the prototype was the addition of provisions for VAP-500 and VAP-1000 gas dispensers. The bomb bay was revised for a 5,000 kilogram FAB-5000 bomb to be loaded and dropped. The prototype made its maiden flight on 26 July, 1938.
Numerous other modifications were made during production, which included but were not limited to the substitution of the AM-34FRNV engines with Mikulin MA-35's, as well as the replacement of nose turrets with manually operated ShKAS machine guns.
The Pe-8 saw service in the Great Patriotic War. A notable example of its effectiveness was when it successfully bombed the capital of Germany in August, 1941, despite the fact that the Germans were winning the war at the time. However, the primary job of the Pe-8 was to attack German airfields, supply lines, and other areas, during the night. One was used to fly the Soviet People's Commissar of Foreign Affairs, Vyacheslav Molotov from the Soviet Union to the United States, in 1942.
After the war, most surviving Pe-8's were withdrawn from active service. Some became transport aircraft, while others were used for testing. Others yet were used in Soviet operations in the Arctic, up until the 1950s.