Incident Overview
On an overcast night with no moon or ground reference lights, a flight was planned across a 22-mile channel between islands. The aircraft disappeared from radar and was not located after extensive searches. Radar data allowed reconstruction of the three-dimensional flight path. In the final 60 seconds, the aircraft decelerated from 170 to 95 knots, climbed 500 feet, and turned left 190° before vanishing from radar.
Investigation Findings
Flight tests demonstrated that the observed maneuvers were consistent with a loss of power in the left engine, without compensatory action by the pilot. The operator's training program did not include night or instrument flight conditions. The pilot's last documented instrument flight was 15 months earlier during a checkride. The pilot had flown only sporadic night flights and was on his thirteenth hour of duty at the time.
Aftermath
The wreckage and all eight occupants were never recovered. However, it is believed that the aircraft crashed approximately 13 miles northwest of Maunaloa, on Molokai Island.
Probable Cause
The official probable cause was documented as three occurrences: (1) Loss of engine power during cruise—undetermined cause; (2) Loss of control in flight due to dark night, pilot not maintaining aircraft control, spatial disorientation, failure to maintain VMC airspeed, pilot fatigue, lack of recent instrument time, inadequate training by operator management, and inadvertent stall/spin; (3) In-flight collision with terrain/water during uncontrolled descent.