Investigation Summary
The flight was the second leg of a route from Khabarovsk to Almaty with a stopover in Novosibirsk. As the Tupolev Tu-104A approached Almaty, a fire erupted in the left engine nacelle. Despite the emergency, the crew continued the approach. Witnesses on the ground observed the aircraft trailing flames 15 kilometers from the airport. Forensic evidence later revealed that the cabin was infiltrated by carbon monoxide during the descent, likely affecting the occupants before the impact. As the pilots reduced speed to configure the aircraft for landing, the lack of high-speed airflow allowed the fire to intensify, eventually severing or jamming the flight control linkages. The aircraft performed an uncommanded climb from 180 meters to 300 meters before stalling and diving into a snow-covered field.
Final Conclusions
The investigation concluded that the primary cause was an uncontained engine fire in the left engine that lasted between 10 and 15 minutes. The fire eventually compromised the structural integrity of the wing and the flight control systems. The reduction in airspeed during the final approach phase was a critical factor, as it decreased the cooling effect of the slipstream, allowing the fire to grow and cause catastrophic mechanical failure of the controls.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Left Engine
Experienced a persistent fire that eventually led to the destruction of nearby control mechanisms.
Flight Controls
Damaged by the intense heat of the engine fire, leading to a loss of pitch and roll authority during the final approach.
Interesting Facts
- 01The aircraft had accumulated 27,189 flight hours and 12,819 cycles since its delivery in 1958.
- 02Forensic examinations confirmed passengers were exposed to carbon monoxide poisoning prior to the crash.
- 03A youth hockey team narrowly avoided the disaster because their competition was postponed, causing them to miss the flight.
- 04The impact was so severe that the fuselage broke in two and the forward section buried itself 2 metres into the ground.
- 05The fire was estimated to have burned for 10 to 15 minutes before the final loss of control.
Safety Actions & Advisories
Fire Suppression and Control Routing
The accident highlighted the vulnerability of Tu-104 control cables to engine bay fires, leading to reviews of fireproofing and the separation of redundant control paths in Soviet transport aircraft.