Aeroflot Flight 04
[1] The aircraft involved in the accident was a Tupolev Tu-104A equipped with two Mikulin AM-3M engines registered as СССР-Л5442 to the Moscow Civil Aviation Directorate of Aeroflot, the national flag carrier.Sometime between 22:20 and 22:25 the aircraft crashed into a dense forest 215 km (134 mi) northwest of Khabarovsk airport, impacting the ground at an angle of 60°, leaving a 450 m (1,480 ft) wide debris field.Two Tupolev Tu-16 bombers flying approximately 150–200 km (93–124 mi) north of the route of flight 4 between 11,000 and 12,000 m (36,000 and 39,000 ft) reported the presence of strong updrafts within cumulonimbus clouds.Weather conditions in the Birobidzhan - Arkhara - Magdagachi region were more complex than the description received by the crew described, with cumulonimbus clouds reaching altitudes of over 12,000 m (39,000 ft).[3] Secondary causes of the accident were cited as follows:[3] Later accidents demonstrated that when a Tu-104 flew in certain atmospheric conditions, both clear weather and near thunderstorms, the aircraft was prone to losing longitudinal stability, that could be followed by the landing gear dropping, engine failure, and artificial horizon failure.