Accident Overview
A Mitsubishi MU-2 aircraft experienced an abnormal left engine start, noted by the crew and maintenance personnel. Following start, the pilot taxied to runway 10 for an instrument flight rules departure. Due to the taxiway not reaching the runway end, another aircraft waited on the taxiway about 2,967 feet from the runway's end. The pilot of this other aircraft observed smoke from the left engine of the MU-2 and reported it on the unicom frequency. The MU-2 continued and initiated takeoff, rotating approximately 200 to 250 yards east of the observer's position.
Takeoff and Maneuvers
The aircraft climbed to about 300-400 feet above field level, then turned left toward higher terrain. After the turn, two witnesses described the aircraft entering a VMC roll. Subsequently, the aircraft crashed and burned. Post-crash examination of the airframe found no preimpact mechanical failures.
Engine Examination
A teardown of the left engine revealed a turbine bearing (part number 3101092-1) had been misaligned and began to fail, damaging the second and third turbine stages. The airport elevation was 6,597 feet. The computed takeoff roll was 1,620 feet, and the computed accelerate-stop distance was 3,100 feet. The landing gear selector was found in the down position.
Probable Cause
The official probable cause findings are:
- Occurrence #1: Loss of engine power (partial) - mechanical failure/malfunction. Findings: (c) turbine assembly, shaft bearing - failure, partial; (c) maintenance, installation - improper - other maintenance personnel.
- Occurrence #2: Loss of control - in flight. Findings: (f) weather condition - high density altitude; (f) aborted takeoff - not performed - pilot in command; (c) gear retraction - not performed - pilot in command; (c) airspeed (VMC) - not maintained - pilot in command.
- Occurrence #3: In flight collision with terrain/water. Findings: Terrain condition - mountainous/hilly.
The aircraft was destroyed, and all six occupants were killed.