Accident Sequence
Witnesses reported that the aircraft performed a rolling takeoff and became airborne by the crossing runway, approximately 1,300 feet down the 6,600-foot runway. The aircraft then entered an approximate 40-degree nose-high climb and reached about 1,000 feet. Subsequently, it entered a steep left-hand banking turn. The nose dropped, and the aircraft rotated up to about four times before colliding with flat terrain adjacent to the departure end of the runway threshold.
Aircraft Examination
On-site documentation of the airframe found no evidence of flight control malfunction. An engine examination and teardown revealed that the gearbox section of the left engine experienced a high-cycle fatigue failure of the high-speed pinion journal bearing oil supply tube, which led to subsequent degradation of the high-speed pinion journal bearings. This failure resulted in a partial power loss to the left engine.
Pilot Experience
The pilot had recently purchased the aircraft and accumulated approximately 11 hours since the purchase. The pilot stated to personnel at the place of purchase that he had not received, nor did he need, recurrent training in this aircraft because he had several thousand hours in the aircraft. Flight logs provided by the family indicated that the pilot had accumulated about 551 hours in a Mitsubishi; however, the last time the pilot had flown this make and model was 14 years prior to the accident. Logbook entries showed that only a few hours of flight time had been accumulated in all aircraft during the approximately two years prior to the accident. Personnel who flew with the pilot in the make and model aircraft involved described the pilot as "proficiency lacking."
Performance Calculations
Normal takeoff calculations for the aircraft with flaps configured to 5 degrees indicated a ground run of 2,900 feet, a rotation speed of 106 KCAS, and a climb-out speed of 125 KCAS, with a maximum pitch attitude of 13 degrees. Performance calculations indicated that the aircraft was capable of lifting off where witnesses observed and climbing to 1,000 feet AGL by the end of the runway. To achieve this performance, the aircraft would have rotated at approximately 84 KCAS and climbed at an airspeed below Vmc (100 KCAS) and close to power-off stall speed (86 KCAS) with 5 degrees of flaps.
Emergency Procedures
The airplane's flight manual stated that in the event of an engine failure during takeoff climb with landing gear fully retracted, the emergency procedure is to maintain 140 KCAS, flaps at 5 degrees, the failed engine condition lever to EMERGENCY STOP, and the failed engine power lever to TAKEOFF. On-site documentation found the left side condition lever in the takeoff/land position and the power lever halfway between takeoff and flight idle.