The purpose of the training flight was to practice takeoffs and landings at night without the use of aircraft lights. After landing, the crew made a decision to perform an unscheduled take-off and for this purpose sharply pushed the throttle from 0ø to maximum. Before the aircraft took off, the propeller of the right engine was feathered, which the crew did not notice in time and continued takeoff. Having discovered the auto-shutdown of the engine at an altitude of 70 m and a speed of 200 km/h, the crew made three failed attempts to start the auxiliary power unit. Contrary to the requirements of the Airplane Flight Manual, the crew began to start the starboard engine at an unacceptably low altitude and speed. The plane stalled, touched the roof of a two-storey country house, fell into a small pond, collapsed and partially burned down. The disaster occurred at a distance of 15 km from the Chkalovsky airfield.