Petlyakov Pe-8

The Petlyakov Pe-8, also known as TB-7 was a Soviet heavy bomber aircraft of World War II, the only four-engined bomber the USSR built during the war.

Design and development

Development of Pe-8 was initiated in the Tupolev's OKB as ANT-42 in July 1934. The maiden flight of the first prototype was in December 1936 by M.M.Gromov. The aircraft actually has five engines - an auxiliary M-100 ATsN-2 was fitted inside the airframe. This drove a supercharger to supply pressurised air to the main engines.

Only 93 or 96 (including two prototypes) were built from 1936-1944 - older sources claim a number of 81 including prototypes, with production stopping in 1940; this seems to indicate that indeed only replacement aircraft were built after 1940. Some had Charomski M-30B/ACh-30B or M-40/ACh-40 diesel engines and the later aircraft were fitted 1,380 kW (1,850 hp) Shvetsov ASh-82 radials due to low availability of the AM-35A. Neither variant was as successful as the original, the diesel engines giving poorer performance and the radial delivering better performance but often being unreliable. It is a testimony to the soundness of the design however, that the examples which survived WWII were retained in service until the late 1950s despite the availability of the Tu-4. Altogether, the Pe-8, despite suffering from low priority of the strategic bombing role in the USSR military doctrine of its time and problems with the engines, compares well with other four-engined bombers designed in the late 1930s.

From a technical standpoint, the Pe-8 is remarkable because it had defensive machine-gun positions installed in the rear of the inboard engine nacelles. These were deleted when the nacelles were reconstructed for accommodation of the radial engines.

An airliner version was designed as the PS-42 with capacity for seventy passengers.

Operational history

File:Petlyakov Pe-8.jpg

Pe-8 at snow-covered airbase.

The USSR had no plans for strategic bombardment, and only a few Pe-8 attacks on Germany were flown, the first in early August, 1941 (only weeks after the German attack on the USSR had started), when aircraft of the 81 DBAD (Long Range Bomber Division) bombed Berlin. Most Pe-8 attacks on Berlin were 'nuisance' bombings involving only a handful of aircraft (e.g. 14 in the first raid). It was used in the strategic bomber role to attack targets in German-held Eastern Europe and as a tactical bomber to support ground forces in the battles of Stalingrad and Kursk. The Pe-8 at first equipped a single bomber regiment, the 432 BAP (ON) (432nd Special Bomber Regiment) and its reserve unit, the 433rd; they were later reorganized into the 746 and 890 BAP (bomber regiment).

The Pe-8's most important claim to fame is flying Soviet foreign minister Molotov and his delegation from Moscow to London and Washington DC and back for talks on the opening of a second front against Nazi Germany (May 19th-Jun 13th, 1942), on the return trip crossing German-controlled airspace without incident.

Operators

Template:USSR

• Soviet Air Force

Specifications (Pe-8)

Sources vary on the exact measurements and performance. The values given here must be considered approximate.

General characteristics

• Crew: Eleven
• Length: 23.59 m (77 ft 5 in)
• Wingspan: 39.10 m (128 ft 3 in)
• Height: 6.20 m (20 ft 4 in)
• Wing area: 188.7 m² (2,030 ft²)
• Empty weight: 19,986 kg (43,969 lb)
• Loaded weight: 27,000 kg (59,400 lb)
• Max takeoff weight: 35,000 kg (77,000 lb)
• Powerplant: 4× Mikulin AM-35A liquid-cooled V-12 and then Shvetsov designed air-cooled M-82FN and sometimes diesel M-30 and M-40, 1,000 kW AM-35A 1380 kW M-82FN (1,350 hp AM-35A 1850 hp M-82FN) each

Performance

• Maximum speed: 443 km/h (276 mph)
• Range: 3,600 km (2,245 mi)
• Service ceiling: 9,300 m (30,504 ft)
• Rate of climb: 5.9 m/s (1,154 ft/min)
• Wing loading: 143 kg/m² (29 lb/ft²)
• Power/mass: 140 W/kg (0.2 hp/lb)

Armament

• 2x 20 mm ShVAK cannons (dorsal and tail turret)
• 2x 12.7 mm UBT machine guns (engine nacelles)
• 1-2x 7.62 mm ShKAS machine guns (nose turret)
• Up to 4,000 kg (8,800 lb) of bombs
  • Could carry one 5,000 kg (11,000 lb) bomb

See also

Designation sequence
Pe-2 - Pe-3 - Pe-4 - Pe-8

References

Bibliography

• Gordon, Yefim and Khazanov, Dmitri. Soviet Combat Aircraft of the Second World War, Volume 2: Twin-Engined Fighters, Attack Aircraft and Bombers. Earl Shilton, UK: Midland Publishing Ltd., 2006. ISBN 1-85780-084-2.
• Kulikov Victor and Michael C. Masslov. Les Bombardiers Quadrimoteurs Sovjetiques Tupolev TB3 & Petkyakov PE8 (in French). Outreau, France: Lela Presse, 2001. ISBN 2-91401-705-7.
• Maslow, Michail. Petlyakov TB-7/Pe-8 (Wydawnictwo Militaria 274) (in Polish with english summary and photocaptions). Warszawa, Poland: Wydawnictwo Militaria, 2007. ISBN 83-7219-274-5.
• Taylor, Michael J. H. Jane's Encyclopedia of Aviation. Studio Editions: London, 1989.
• Unger, Ulrich. Pe-8, Der Sowjetische Fernbomber (in German). Berlin, Germany: Brandenburgisches Verlagshaus, 1993. ISBN 3-89488-048-1.

External links

• www.aviation.ru Pe-8
• www.airpages.ru Pe-8
• avia.russian.ee Pe-8

The initial version of this article was based on material from aviation.ru. It has been released under the GFDL by the copyright holder.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Petlyakov Pe-8".