Investigation Summary
The accident was initiated by the uncontained failure of the Progress D-18T Series 3 number 2 engine. Fragments of the fan disk were later recovered from a warehouse near the airport, indicating a high-energy disintegration. The resulting debris field acted like shrapnel, puncturing the fuselage and wings. This damage was particularly critical as it severed the wiring and hydraulic lines responsible for the aircraft's power supply and braking systems. The crew was forced to fly the massive aircraft with limited thrust control on the remaining engines and no ability to communicate with air traffic control. During the emergency gear extension attempt, one of the two sets of nosewheels failed to extend. Upon landing, the lack of spoilers, thrust reversers, and wheel brakes made a runway excursion inevitable. The situation was further complicated post-crash when the number 1 engine could not be shut down for three hours. The crew attempted to stop the engine using the standard 'Stop' lever and the fire handle, but both mechanical control cables—the low-pressure fuel cock and the emergency shut-off—had been severed by the engine debris.
Final Conclusions
The investigation by the Interstate Aviation Committee (IAC) concluded in August 2022. The final report confirmed that the uncontained failure was caused by a fatigue crack in the fan disk of the D-18T engine, which originated from a manufacturing defect. This failure led to a cascading system loss that stripped the crew of standard deceleration tools, including brakes and spoilers. The successful landing and survival of all 14 occupants, despite the loss of communications and primary stopping systems, is attributed to the crew's exceptional airmanship in managing a severely crippled heavy transport aircraft under emergency conditions.
Photographic Evidence (1)
Video Analysis
Antonov AN-124 Engine Failure and runway excursion in Novosibirsk! — Mentour Pilot analyzes the uncontained engine failure and subsequent emergency landing of Volga-Dnepr Flight 4066.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Systems & Failure Modes
Lotarev D-18T Engine
The number 2 engine suffered a catastrophic fan disk failure, sending high-velocity fragments into the airframe.
Braking System
Severed lines rendered the wheel brakes, spoilers, and thrust reversers inoperative during the emergency landing.
Electrical/Avionics
The debris strike caused a total failure of the power supply, cutting off radio and ADS-B communications.
Interesting Facts
- 01The aircraft was carrying 84 tons of automotive parts at the time of the accident.
- 02Debris from the engine created a 'through and through' hole in the upper fuselage.
- 03The nose landing gear failed to fully extend or collapsed upon impact with the soft ground past the runway.
- 04One of the four engines remained running for three hours post-crash because the control cables were severed.
- 05Two BREM-1 armored recovery vehicles were required to move the aircraft from the overrun area.
Safety Actions & Advisories
Fleet Grounding
Following the accident, Volga-Dnepr Airlines temporarily grounded its entire fleet of Antonov An-124 aircraft to conduct inspections of the D-18T engines.