Tupolev ANT-37 / DB-2
Developed from the uncompleted Tupolev ANT-36 (DB-1), a single-engined long-range bomber based on the ANT-25, the Tupolev ANT-37 (DB-2) long-range bomber was developed by Sukhoi's design brigade under Tupolev's overall control.
The Tupolev DB-2 (ANT-37) long-range bomber, designed in the autumn of 1934, could carry a 2,200 lb bomb load over a range of 3,100 miles at a speed of 155 m.p.h.
The prototype flew on 16 June 1935, powered by two 597kW Gnome-Rhone 14Kdrs engines, broke up in mid-air in August 1935 owing to buffeting of the tail unit. Test pilot K. Popov and the flight engineer managed to bale out, but a third crew member did not survive the crash.
The second prototype, powered by licence built Gnome-Rhone M-85s, was tested and refined throughout 1936. It was then transferred to the Nauchno Issledovatelsky Institut Voyenno-Vozdushnykh Sil (NII V-VS - Scientific Research Institute of the Air Force) for State tests, which continued until mid-1937. It was admitted that the DB-2 was inferior to Ilyushin's DB-3 bomber in several respects, particularly maximum speed (200 m.p.h. and 248 m.p.h. respectively), so further development was abandoned.
When the second DB-2 prototype had completed its State tests it was proposed that it be handed over to the Tsentralniy Aero-Gidrodinarnicheskiy Institut (TsAGI, the Central AeroHydrodynamic institute) for further refinement and additional flight tests. Another DB-2 was completed and handed over to a Soviet Air Force (V-VS) unit for training personnel in endurance and long-range flying.
Having undergone modification, the second prototype was provided for the long-distance flight to be undertaken by Grizodubova, Raskova and Osipenko. it was completely stripped of armament, fitted with additional fuel tanks to ensure a maximum range of 4,350 miles and given new flight instruments and 950 h.p. licence-built Gnome-Rhone M-86 engines.
The DB-2D was followed in turn by the DB-2B or ANT-37bis, of which only three were built as record breakers/research aircraft after rejection of the design in favour of the llyushin DB-3.
Once the crew had been trained they started preparing for the non-stop flight. On August 18, 1938, they took off from the Central Airfield at Moscow for another training flight, but at a height of 165ft the aeroplane suddenly jerked down and almost went out of control. After a difficult landing, it became clear that the shortcomings of the first prototype had not been completely rectified. The tail unit had distorted disastrously during takeoff at maximum weight, and the aircraft was no longer airworthy. The technical team therefore began urgent preparation of the third prototype, the last of the three serviceable machines.
The aircraft's replacement caused deferment of the flight, which in turn led to concern over a successful outcome. Autumn had already set in and weather conditions along the planned route across the Urals and Siberia were deteriorating with each passing day.
The first DB-2B, named Rodina (motherland) was flown to a long-distance women's record by an all-female crew, covering 5908km on 24/25 September 1938 before making an emergency landing.
Examples survived well into the wartime period, flying for Aeroflot or on research projects.
Engine: 2 x M-86
Max take-off weight: 12500 kg / 27558 lb
Empty weight: 5855 kg / 12908 lb
Wingspan: 31.0 m / 102 ft 8 in
Length: 15.0 m / 49 ft 3 in
Wing area: 85.0 sq.m / 914.93 sq ft
Max. speed: 300 km/h / 186 mph
Ceiling: 8000 m / 26250 ft
Range w/max.fuel: 7000 km / 4350 miles
Tupolev ANT-37 / DB-2