Investigation Summary
The Ilyushin Il-62M was departing for a long-haul flight to Freetown via Dakar, carrying a significant fuel load that brought its weight to 164,514 kg, very close to its maximum takeoff weight. Just eight seconds after the landing gear was retracted, a fire warning for the No. 1 engine activated. Following standard operating procedures, the crew shut down the engine and discharged fire suppression bottles. Thirty seconds later, a second warning indicated a fire in the No. 2 engine. The crew shut this engine down as well, leaving the aircraft with only the two right-side engines operational. At an altitude of only 160 meters and a speed of 320 km/h, the aircraft lacked the performance to climb or maintain level flight in its current configuration. As the pilots attempted a right-hand turn to return to the airport, the airspeed bled off, the angle of attack increased, and the aircraft stalled at 75 meters above the ground. It impacted the terrain in a steep 70 degree left bank.
Final Conclusions
The investigation confirmed that there was no actual fire in either engine, meaning the warnings were false. While the fire warning system was too badly damaged by the impact and post-crash fire to provide definitive physical evidence of a leak, investigators concluded that a ruptured air conditioning pipe directing hot bleed air onto temperature sensors was the most probable cause. This conclusion was supported by nine similar documented instances of bleed air leaks causing false fire warnings on the Il-62 fleet between 1975 and 1982. The investigation cleared the pilots of wrongdoing, noting they followed the Flight Manual procedures for engine fires. However, the manual at the time lacked guidance for a dual-engine failure at low altitude and high weight, and the dark, swampy terrain made a successful forced landing impossible.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Crew Experience
Captain
Alexander Vitkovsky
Systems & Failure Modes
Fire Detection System
Triggered false alarms due to hot air from a ruptured air conditioning pipe blowing on sensors.
Air Conditioning / Bleed Air System
A ruptured pipe in this system was the root cause of the false fire indications.
Soloviev D-30KU Engines
The aircraft's four rear-mounted engines; two were shut down by the crew in response to the false alarms.
Interesting Facts
- 01The aircraft was only two years old at the time of the accident.
- 02Post-crash inspection confirmed the engines were functional and showed no signs of fire damage.
- 03The Il-62M's engines are mounted in pairs at the rear; shutting down both left engines created significant thrust asymmetry.
- 04Between 1975 and 1982, there were nine reported instances of bleed air leaks causing false fire warnings on Il-62 aircraft.
- 05The aircraft weight at takeoff was 164,514 kg, nearly its maximum limit.
Safety Actions & Advisories
Flight Manual Revision
The investigation highlighted a lack of procedures for dual-engine failure at high weight and low altitude, leading to calls for updated emergency checklists.