Aeroflot Flight 04 (Russian: Рейс 04 АэрофлотаReys 04 Aeroflota) was a scheduled domestic passenger flight from Khabarovsk to Moscow with a stopover in Irkutsk that crashed on 15 August 1958, killing all 64 passengers and crew aboard the aircraft. It was the first fatal accident involving a Tupolev Tu-104.
The aircraft involved in the accident was a Tupolev Tu-104A equipped with two Mikulin AM-3M engines registered as СССР-L5442 to the Moscow Civil Aviation Directorate of Aeroflot, the national flag carrier. At the time of the accident the aircraft had endured 1041 flight hours and 401 pressurization cycles.
The weather forecast received by the crew for the Khabarovsk-Irkutsk route stated that cumulonimbus and stratiform clouds were present between altitudes of 300–600 meters at Khabarovsk airport, and thunderstorms with rain were present in the Birobidzhan – Magdagachi area. Visibility ranged from 4 to 10 kilometers. The departure from Khabarovsk airport was delayed by 3 hours and 35 minutes, with the passengers and crew not boarding the aircraft until 21:45 local time (14:45 Moscow time).
At 21:50 Flight 04 was instructed to maintain flight at an altitude of 9,000 m (30,000 ft). After flying 150 km (93 mi) en route, the flight encountered towering cumulus clouds with tops too high to safely fly above them. After receiving permission from the controller the crew avoided the clouds before changing altitude as directed by the air traffic controller. While at an altitude of 8,600 m (28,200 ft), the crew requested permission to increase altitude to avoid more cumulus clouds. The air traffic controller gave the flight permission to fly at 11,000 m (36,000 ft) until passing Arkhara where it was to decrease altitude to 9,000 m (30,000 ft). At 11,000 m (36,000 ft) the clouds were still present so the flight was given permission to climb to 12,000 m (39,000 ft). At 22:12 the flight reported passing an altitude of 11,600 m (38,100 ft) and that stars were visible.
At 22:14 the captain reported reaching the altitude of 12,000 m (39,000 ft). The flight crew stated they saw intense cumulus clouds ahead and would return to Khabarovsk if they could not avoid the clouds. At 22:18 the controller contacted Flight 4 but an agitated voice only replied “one minute, one minute”. The second attempt at communications at 22:19 was met with the same response, but Flight 4 did not respond to any later calls. 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. All 64 people on board were killed in the crash.