Casualties unknown

1999-12-12: Mooney M20-M (N270BB) — Missoula, MT

Missoula, MT, US

On December 12, 1999, a Mooney M20-M (registration N270BB) was involved in an aviation accident near Missoula, MT. Investigators recorded the probable cause as: Total loss of engine power while cruising, which led to an emergency descent and subsequent collision with mountainous 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 1781061362Data APIEditorial standards

An airplane lost all engine power while cruising at 25,000 feet. The pilot attempted an emergency descent toward an alternate airport but collided with mountainous terrain, destroying the aircraft.

What happened

The incident occurred while the aircraft was operating at flight level 250, which corresponds to an altitude of 25,000 feet. During this cruise phase, the airplane experienced a sudden and total loss of engine power. With propulsion no longer available, the pilot initiated an emergency descent to regain control and seek a safe landing area.

The descent was directed toward a designated alternate airport. However, during this critical maneuver, the aircraft collided with mountainous terrain. The impact resulted in the complete destruction of the airframe. No survivors were reported from the wreckage.

The investigation

Following the accident, investigators conducted a thorough post-accident examination and testing of the airframe, engine, and all associated components. The goal was to determine if any mechanical issues contributed to the power loss.

The technical analysis revealed no evidence of a preexisting mechanical malfunction or failure within the examined systems. This finding suggests that the engine failure was not caused by a known defect in the hardware prior to the event.

Findings

The primary factor leading to the accident was the total loss of engine power at high altitude. The inability to maintain flight resulted in an uncontrolled descent into terrain. The investigation confirmed that mechanical failure was not a contributing factor based on physical evidence.

Probable cause

Total loss of engine power while cruising, which led to an emergency descent and subsequent collision with mountainous terrain.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X20318. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.