Piper PA46 N777PG accident near Burns, Oregon

Probable cause

The total loss of engine power for reasons that could not be determined because postaccident examination revealed no evidence of an anomaly that would have precluded normal operation. Contributing to the accident was a preexisting landing gear anomaly that prevented the landing gear from completely extending after flight at high altitude in cold weather during landing.

NTSB analysis

The private pilot reported that, about 90 minutes after takeoff and about 19,000 ft, the engine of the high-performance pressurized airplane lost total power. Although the loss of power happened at high altitude, for the next 11 minutes, the pilot did not perform any troubleshooting steps, which were limited in scope and would not have taken long to complete, and instead diverted directly to an airport.

After arriving at the diversion airport with altitude remaining, the pilot performed a circling descent maneuver over the runway. During the landing approach, he moved the landing gear selection lever to the "down" position, but the gear did not extend, so the pilot chose to land the airplane on snow adjacent to the runway. Just before touchdown, the main landing gear extended, but the nose landing gear remained retracted. Upon touchdown, the airplane's nose dug into the snow. The airplane then abruptly stopped, sustaining substantial damage to the forward fuselage and both wings.

Examination of the engine and landing gear did not reveal any anomalies that would have precluded normal operation, and the engine performed normally during a subsequent test run. Given the engine ran normally during the test run, it is possible that, if the pilot had attempted to troubleshoot the problem, engine power could have been restored. The reason for the loss of engine power could not be determined. According to the owner, there was a previously undiagnosed landing gear problem that, on two previous occasions, had resulted in the delayed deployment of the landing gear after flying at high altitudes in cold weather. Given the airplane was flying at high altitude in cold weather when the event occurred, a reoccurrence of the landing gear anomaly could not be ruled out.

Text from the NTSB. Open the NTSB docket for WPR16LA060 for the full record.