Casualties unknown

1990-01-31: Mooney M20-K (N1149G) — David M. Morrison — Gibsonia, PA

Gibsonia, PA, US

On January 31, 1990, a Mooney M20-K (registration N1149G) operated by David M. Morrison was involved in an aviation accident near Gibsonia, PA. Investigators recorded the probable cause as: The failure of the camshaft drive gear and crankshaft cluster teeth, which resulted in a loss of engine power during flight. 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

A pilot experienced a sudden power loss and executed a forced landing in an open field, resulting in substantial damage to the airframe after striking steel rods on the ground.

What happened

The pilot was operating the aircraft when it experienced an unexpected loss of engine power. Unable to maintain altitude or reach a suitable airport, the pilot initiated a forced landing procedure. The aircraft touched down in an open field. During the impact with the ground, the airframe sustained substantial damage after striking steel rods located within the landing area.

The investigation

Following the accident, investigators examined the engine components to determine the root cause of the power failure. The engine was removed and disassembled for a detailed inspection. Examination of the internal mechanisms revealed significant mechanical failures. Specifically, the camshaft drive gear was found to have a chunk missing, consisting of three teeth. Additionally, the crankshaft cluster, which meshes with the camshaft drive gear, was discovered to have seven teeth stripped off at their base.

Findings

The investigation identified mechanical failure of the engine as the primary factor leading to the accident. The substantial damage to the airframe was a direct result of the forced landing in an unprepared area containing obstacles. The specific mechanical defects observed in the camshaft drive gear and the crankshaft cluster indicate a catastrophic internal engine failure that resulted in total power loss during flight.

Safety message

Regular maintenance inspections are critical for detecting early signs of gear wear or damage before they lead to in-flight failures. Pilots must remain vigilant regarding engine performance parameters and be prepared to execute emergency landing procedures if power is lost.

Probable cause

The failure of the camshaft drive gear and crankshaft cluster teeth, which resulted in a loss of engine power during flight.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X22495. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.