Accident Sequence
The aircraft rolled to the right and crashed following a catastrophic uncontained failure of the right engine during takeoff for a night flight. The right engine fan rotor disc separated from the hub, causing damage to the cowling. Some disc fragments became embedded in the fuselage, but flight controls were not affected. The drag created by the loss of thrust and the distorted cowling resulted in yaw and roll, leading to loss of control.
Engine Failure Details
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 place at the time. The crack propagated, eventually leading to the uncontained failure.
Corrective Actions
Following the accident, the manufacturer improved both manufacturing and inspection techniques. Additionally, Airworthiness Directive (AD) 86-04-02 was issued on February 14, 1986, which mandated the removal of fans from service according to an operating cycle schedule.