Investigation Summary
During the flight, the crew received a low oil pressure warning followed by smoke and flames emanating from the left engine (Ivchenko AI-24). Despite activating the fire suppression system, the fire continued to burn, likely fueled by a failure in the oil system that allowed oil to leak onto hot engine components. The intensity of the fire led to the failure of the engine mounting and threatened the wing structure, forcing the captain to perform an immediate ditching in the shallow waters of the Ob River.
Final Conclusions
The Interstate Aviation Committee (MAK) concluded that the fire was caused by the destruction of the rear bearing of the compressor in the left engine, leading to oil leakage into the engine's hot section. The crew's decision to ditch was necessary due to the uncontrollable nature of the fire, though the impact with the riverbed caused the fuselage to break apart, resulting in the fatalities.
Video Analysis
Russian Plane Crash Antonov An-24 | Explained — An analysis of the 2011 ditching of an Antonov An-24 in the Ob River following a catastrophic engine fire.
Watch on YouTube ↗If playback is blocked, the owner has disabled embedding — use the link above.
Systems & Failure Modes
Ivchenko AI-24 Turboprop
The powerplant which suffered a catastrophic internal failure of the compressor rear bearing.
Fire Suppression System
A multi-stage system designed to flood the engine nacelle with extinguishing agent, which proved ineffective against the oil-fed fire.
Interesting Facts
- 01The aircraft was 36 years old at the time of the accident.
- 02The fire was uncontained and continued even after the engine was feathered and extinguished.
- 03Seven passengers were killed during the impact and subsequent breakup of the fuselage.
- 04The ditching occurred near the village of Medvedevo.
- 05The left engine's magnetic plug had not been checked for metal shavings according to proper maintenance intervals.
Safety Actions & Advisories
Engine Maintenance Overhaul
Russian aviation authorities mandated stricter inspections of the AI-24 engine series, specifically focusing on oil filtration and magnetic plug monitoring for early signs of bearing wear.
An-24 Retirement Discussions
The accident accelerated discussions regarding the retirement of aging Soviet-era turboprops from scheduled passenger service in Russia.