Tupolev ANT-35

In 1935, Andrei Tupolev ordered a design team led by Alexander Arkhangelsky to start work on a high-speed passenger aircraft based on the ANT-40 (later known as the SB) bomber which had first flown in October 1934.[3][4] The first prototype, powered by two 600 kW (800 hp) Gnome-Rhone 14K radial engines, made its maiden flight on 20 August 1936.[2][5] The ANT-35's cabin, with a headroom of only 1.68 m (5 ft 6 in), and further constricted by having the wing spars pass through it, was very cramped, and the second prototype, designated the ANT-35bis, had the fuselage height increased by 0.15 m (5.9 in), greatly improving space for the passengers, while two 750 kW (1,000 hp) Wright Cyclone G2 engines were fitted.By 1939, Soviet factories had begun license-building the Douglas DC-3 airliner, which used the same engines but could carry twice the passengers over a greater range and production of the ANT-35bis was stopped in 1939, with only nine aircraft (plus the two prototypes), completed.[9] Several PS-35s were destroyed by German bombers shortly after Germany invaded the Soviet Union on 22 June 1941, with the remaining aircraft joining the Kyiv Special Aviation Group, where they were employed to transport ammunition and medical supplies and for agent dropping behind the front lines.