Investigation Summary
The flight was delayed for several hours due to poor weather at both the origin and destination. Shortly after lifting off at 19:32, a fire alarm for the left engine activated. Although the alarm was later determined to be false, caused by a disconnected anti-icing pipe that leaked hot air into the engine compartment, the crew treated it as a genuine emergency. The aircraft was operating at a weight 10,201 kg above its maximum allowable landing weight. During the return approach, the crew failed to coordinate effectively; the navigator did not announce the decision height, and the Ground Proximity Warning System (GPWS) was deactivated. The aircraft descended rapidly in a single-engine configuration with a tailwind, eventually impacting the ground 1,548 meters from the runway threshold.
Final Conclusions
The investigation concluded the crash was caused by a combination of technical failure and operational errors. The primary technical trigger was a false fire alarm resulting from a mismatch of parts and a disconnected anti-icing pipe. Operational contributors included the decision to attempt an emergency landing while 10,201 kg over the maximum allowable landing weight (MLW), poor cockpit resource management, failure to monitor instruments during the final approach, and descending below the minimum descent altitude (MDA) in marginal weather conditions.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
The Captain had only 32 hours of flight time on the Tu-104 type.
Systems & Failure Modes
Engine Fire Detection System
Triggered a false alarm due to a disconnected anti-icing pipe leaking hot air into the engine compartment.
GPWS
The Ground Proximity Warning System was deactivated by the crew, preventing an automated alert of the premature descent.
Anti-icing System
A disconnected pipe in this system caused the localized overheating that mimicked an engine fire.
Interesting Facts
- 01The aircraft was overloaded by 10,201 kg beyond its maximum landing weight.
- 02The fire alarm was false, triggered by a temperature increase to 253 degrees C due to a disconnected anti-icing pipe.
- 03The Ground Proximity Warning System (GPWS) was deactivated during the approach.
- 04Fatality counts vary by source, with reports ranging from 58 to 59 deaths.
- 05The aircraft struck cables on the Moscow-Kiev highway during its premature descent.
- 06The Tu-104 was the first Soviet jet airliner, and this crash ended its civil career.
Safety Actions & Advisories
Tu-104 Retirement
Following the investigation, the Soviet Ministry of Civil Aviation ordered the retirement of all Tupolev Tu-104 aircraft from civil service in November 1979.