Accident Details
During a night takeoff, the aircraft experienced a catastrophic (uncontained) failure of the right engine. The aircraft subsequently rolled to the right and crashed. The right engine fan rotor disc separated from the hub, damaging the cowling. Some disc fragments became embedded in the fuselage but did not affect the flight controls.
Engine Failure
The fan failure originated from a low-grade fatigue crack on the high-time fan. This crack was not detected by the visual inspection procedures in use at the time. The drag created by the loss of thrust and the distorted cowling led to yaw and roll, resulting in loss of control of the aircraft.
Post-accident, the manufacturer improved manufacturing and inspection techniques. An Airworthiness Directive (AD 86-04-02) was issued on February 14, 1986, requiring fan removal from service according to an operating cycle schedule.
Probable Cause
The official findings identified three occurrences:
- Occurrence #1: loss of engine power (total) due to mechanical failure/malfunction during takeoff-initial climb. Findings: fatigue, total failure, and separation of the compressor assembly forward fan; insufficient standards/requirements by the manufacturer.
- Occurrence #2: loss of control in flight during takeoff-initial climb, with directional control not possible by the pilot.
- Occurrence #3: in-flight collision with terrain/water during uncontrolled descent.