What happened
During the startup process, a maintenance supervisor and two pilots identified that the left engine of the Mitsubishi MU-2 was not responding as expected. Following the engine start, the pilot taxied toward runway 10 for an IFR departure. While waiting on a taxiway near the runway threshold, another pilot observed smoke emitting from the aircraft's left engine and broadcasted a warning over the unicom frequency.
The Mitsubishi MU-2 proceeded to take off, rotating approximately 200 to 250 yards east of the observing aircraft. Shortly after reaching an altitude of between 300 and 400 feet, the plane initiated a left turn toward higher terrain. During this maneuver, witnesses observed the aircraft enter a VMC roll before it impacted the ground and caught fire. The accident resulted in six fatalities and the total destruction of the airframe.
Findings
Post-accident investigations determined that there were no mechanical failures present on the airframe prior to impact. However, a teardown of the left engine identified that a turbine bearing (pn 3101092-1) had been improperly installed. This misalignment caused the bearing to fail, which subsequently damaged the second and third stages of the turbine section.
Several contributing factors were noted during the investigation, including high density altitude at the airport elevation of 6,597 feet. The pilot's decision not to abort the takeoff despite the engine issues, combined with a failure to maintain airspeed and an inability to maintain control during the turn, led to the loss of control. Additionally, the landing gear remained in the down position throughout the event.