What happened
During a nighttime visual approach from the south, the aircraft was flying over the ocean toward the airport. While transitioning navigation inputs from a VOR to the ILS for runway 10, the pilot lost the DME signal from a VOR situated on a hill north of the localizer course. This loss of distance information led the pilot to believe the aircraft was significantly closer to the airport and the island than its actual position.
In an effort to maintain clearance from nearby terrain while searching for visual contact with the airport, the pilot allowed the aircraft to descend. This resulted in the aircraft impacting the sea approximately 3 miles southwest of the airport. The pilot reported that all engines, flight controls, and aircraft systems were functioning normally at the time of the accident. No FAA flight plan had been filed for this scheduled commuter operation.
Findings
Investigations revealed that the pilot had been operating this specific route for five days but lacked prior experience in the local area. Furthermore, the operator had not been subject to FAA Operations inspector surveillance in the Caribbean since its service commencement in December 1996. The primary factor in the accident was the pilot's incorrect perception of the aircraft's distance from the destination due to the loss of DME data.