Accident Sequence
On the night of the accident, an airline transport pilot departed in a twin-engine, turbine-powered airplane on an air ambulance flight. The aircraft carried two medical crew members and a patient. The departure occurred in night visual meteorological conditions. A witness observed that during the initial climb, the airplane turned left approximately 30 degrees from the runway heading, then ceased climbing, made an abrupt bank to the left, and began to descend. The airplane subsequently struck a parking lot and burst into flames.
Maintenance History
In the two months leading up to the accident, pilots had notified maintenance personnel on three separate occasions that the left engine was not producing the same power as the right engine. In response, mechanics replaced the left engine's bleed valve three times, with the final replacement occurring three days before the accident. Additionally, approximately one month before the accident, the left engine's fuel control unit was replaced during troubleshooting of an oil leak.
Examination
Post-accident examination revealed that the right engine and propeller exhibited more pronounced rotational signatures than the left engine and propeller. This finding is consistent with the left engine not producing power or being at a low power setting at the time of impact. Furthermore, the abrupt left bank and descent observed by the witness align with a loss of left engine power during the initial climb. The extensive fire and impact damage to the airplane precluded determination of the specific reason for the loss of left engine power.