Accident Sequence
The medical transport flight was cleared by air traffic control for an instrument approach and instructed to switch to the advisory frequency, which the pilot acknowledged. After crossing the initial approach fix on the RNAV approach, the aircraft began a gradual descent toward the intermediate fix. Before reaching that fix, the aircraft entered a right turn and initiated a rapid descent, losing approximately 2,575 ft of altitude in 14 seconds. Radar contact was subsequently lost.
Witness Report and Discovery
A witness at the destination airport, scheduled to meet the aircraft, observed the pilot-controlled runway lights illuminate. When the aircraft failed to arrive, she contacted the company to inquire about the overdue flight. The following day, debris was found floating on the ocean surface. About 48 days later, after an extensive underwater search, the heavily fragmented wreckage was located on the ocean floor at a depth of approximately 500 ft.
Postaccident Examination
Examination of the engines revealed contact signatures consistent with power at the time of impact, with no evidence of mechanical malfunctions or failures that would have precluded normal operation. Examination of the airframe revealed an approximately 10° asymmetric flap condition. However, significant impact damage to the flap actuator flex drive cables and actuators indicated that these measurements were likely not a reliable source of preimpact flap settings. Additionally, it was considered unlikely that a 10° asymmetric flap condition would result in a loss of control.
The aircraft was equipped with five seats and five restraints. Of the three restraints recovered, none were buckled. The unbuckled restraints could suggest an emergency requiring crewmembers to move about the cabin, but the reason could not be confirmed.
Investigation Limitations
While the known circumstances are consistent with a loss of control event, factual information was limited. The wreckage was not recovered in its entirety. The cockpit voice recorder (CVR) did not contain the accident flight, no non-volatile memory was recovered from the aircraft, and no autopsy or toxicology of the pilot could be performed. Therefore, the reason for the loss of control could not be determined.