Investigation Summary
The accident began just 30 feet above the runway when the left engine suffered a catastrophic, uncontained failure. Despite the loss of power, the crew continued the climb, retracting flaps at 90 feet and initiating a left turn at 120 feet. The aircraft's low altitude and bank angle brought it into contact with industrial infrastructure in the Caspian Sea. The left wingtip struck a cable attached to an oil rig, which sheared off a portion of the wing. The damaged aircraft could no longer maintain flight, striking a pipeline before coming to rest near a highway. While the initial engine failure was the mechanical trigger, the investigation also noted the aircraft was slightly overloaded by 193 kilograms.
Final Conclusions
The investigation determined the primary cause was an uncontained engine failure resulting from the degradation of turbine blades. This degradation was attributed to chronic overheating, which could be caused by improper start-up procedures, inherent design flaws, or the lack of adequate instrumentation to detect such overheating. The subsequent collision with an oil rig cable at low altitude made the emergency situation unrecoverable.
Video Analysis
No video analysis linked for this case file yet.
Airframe & Maintenance
Systems & Failure Modes
Turbine Blades
Degradation and failure of these components due to overheating led to the uncontained engine failure.
Engine Instrumentation
The cockpit lacked visual or instrument indications capable of warning the crew about the specific overheating condition.
Interesting Facts
- 01The aircraft was overloaded by approximately 193 kilograms (425 pounds) at the time of takeoff.
- 02The engine failure was uncontained, meaning debris exited the engine casing.
- 03The turbine blade degradation was linked to overheating that was undetectable by the crew's instruments.
- 04The captain and flight engineer were among the eight survivors of the crash.
Safety Actions & Advisories
Instrumentation Improvements
The investigation highlighted the need for improved engine instrumentation to detect turbine overheating that is not visible to the crew or indicated by standard gauges.
Known Controversies & Unanswered Questions
Overload Contribution
Reference ↗While the investigation noted the aircraft was overloaded by 193 kg, there is debate regarding whether this minor excess (less than 1% of MTOW) significantly impacted the crew's ability to maintain altitude on a single engine compared to the catastrophic damage caused by the uncontained failure and subsequent cable strike.