What happened
During an instrument approach, the pilot of a medical transport flight received clearance from air traffic control to proceed with the RNAV approach and was instructed to switch to an advisory frequency. After passing the initial approach fix, the aircraft type began a steady descent while traveling northeast toward the intermediate fix. Prior to reaching that fix, the plane entered a right turn and underwent a rapid descent, dropping approximately 2,575 feet within a 14-second window. At this point, radar contact with the aircraft was lost.
A witness at the destination airport, who was expecting the flight, noted that the pilot-controlled runway lights were activated. When the aircraft failed to arrive as scheduled, the witness notified the company. The following day, debris was spotted floating on the ocean surface. Following an extensive search, the fragmented wreckage was discovered on the seabed at a depth of roughly 500 feet approximately 48 days later.
Findings
Investigations into the engines showed no mechanical failures or malfunctions that would have prevented normal operation; signatures indicated the engines were producing power at the moment of impact. While an examination of the airframe suggested a 10-degree asymmetric flap condition, significant damage to the flap actuators and flex drive cables made it impossible to confirm the exact flap settings prior to the crash. Investigators noted that such an asymmetry was unlikely to cause a loss of control.
Of the five seats and restraints on board, only three restraints were recovered, and none were found buckled. While unbuckled restraints can sometimes indicate an in-flight emergency, the cause could not be verified. Ultimately, the loss of control could not be definitively attributed to a specific cause because the wreckage was incomplete, the CVR did not contain the relevant flight data, no non-volatile memory was retrieved, and no toxicology or autopsy was available for the pilot. The 0 fatalities and 0 injuries cannot be fully contextualized due to the lack of recovered occupants, though the aircraft was lost with its crew.
Note: The source does not provide a specific registration, but the investigation focused on the medical transport flight's descent.