Aeroflot Flight 7425 Crashes in USSR Territory

Aeroflot Flight 7425 on the 10 July 1985 was operated by a three-engined Tupolev Tu-154B-2 which departed Tashkent for a flight to Leningrad.

The aircraft was at cruising altitude of 11,600 metres (38,000 ft) at an airspeed of 400 kilometres per hour (250 mph). The low airspeed close to the stall caused the aircraft to vibrate which the aircrew assumed was engine vibration. They reduced engine power to flight idle causing a drop in airspeed to 290 kilometres per hour (180 mph). The aircrew tried to maintain altitude but the aircraft stalled and entered a flat spin crashing into the ground near Uchkuduk, Uzbekistan, which at that time was in the Soviet Union.

It is the deadliest air disaster in the history of Soviet aviation and the highest death toll of any accident involving a Tupolev Tu-154 anywhere in the world

The Tupolev 154 departed Tashkent (TAS) on a flight to Leningrad (LED) via Karshi (KSQ) and Orenburg (REN). The flight crew climbed to the cruising altitude of FL380 (11.600 m) at an airspeed eof 400 km/h, which is close to stall speed under the given conditions. During cruise flight vibrations started because of the low airspeed. The crew assumed that the vibrations were caused by engine surges. They reduced power to flight idle, causing the airspeed to drop to 290 km/h. Trying to maintain altitude, the airplane eventually stalled. The Tu-154 went into a flat spin and crashed.