Casualties unknown

Partial Engine Power Loss Leads to Mountain Impact (N73771)

Nome, AK, US

On February 9, 1989, a Cessna 207 (registration N73771) was involved in an aviation accident near Nome, AK. Investigators recorded the probable cause as: The partial loss of engine power due to a foreign object obstructing the low pressure check valve plunger in the fuel pump, which resulted in the aircraft impacting terrain. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

During cruise flight, the pilot experienced two instances of partial engine power loss. Although power was regained both times, the aircraft struck a snow-covered mountainside before the descent could be arrested.

What happened

The airplane transport pilot reported that during cruise flight, he encountered a partial loss of engine power on two separate occasions within a span of approximately three minutes. He managed to restore full engine power both times; however, during the second instance, the aircraft impacted a snow-covered mountainside before the descent could be stopped.

The investigation

A teardown and analysis of the engine fuel pump revealed an eighth-inch long thread-like metal sliver lodged under the low pressure check valve plunger. This obstruction likely contributed to the intermittent power loss experienced by the pilot during flight.

Probable cause

The partial loss of engine power due to a foreign object obstructing the low pressure check valve plunger in the fuel pump, which resulted in the aircraft impacting terrain.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001213X27677. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.