Casualties unknown

1990-12-09: DE Havilland DHC-6-100 (N121PM) — One Papa Mike Corp. — Perris Valley, CA

Perris Valley, CA, US

On December 9, 1990, a DE Havilland DHC-6-100 (registration N121PM) operated by One Papa Mike Corp. was involved in an aviation accident near Perris Valley, CA. Investigators recorded the probable cause as: A LOSS OF POWER ON THE LEFT ENGINE DUE TO A FATIGUE FAILURE OF A COMPRESSOR TURBINE BLADE LEADING TO FURTHER COMPRESSOR BLADE DAMAGE; A WORN POWER TURBINE GOVERNOR THROTTLE CAM ASSEMBLY WHICH LED TO LOSS OF POWER ON THE RIGHT ENGINE; AND INADEQUATE… 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

After lift-off at about 100 ft and 85 kts, the left engine lost power due to a fatigue-fractured compressor turbine blade, causing yaw and roll. The pilot aborted, landed in a field, and struck a fence and trees.

Event Summary

After lift-off from an unspecified runway, at approximately 100 feet above ground level and 85 knots, the left engine decelerated. The airplane began to yaw and roll left. The pilot in command (PIC) aborted the takeoff, turned left, and executed a landing on a flat level field. During the landing rollout, the airplane struck a fence, followed by trees.

Engine Examination Findings

Following the event, examination of the left engine revealed that the loss of power was attributed to a fatigue fracture of a compressor turbine blade, which led to subsequent blade fractures.

The right engine was also examined. It was found to have advanced wear on the throttle cam assembly of the power turbine governor. In a test cell, the right engine could achieve only approximately 28% of takeoff power. The cam lobe wear had progressed over an extended period of time. The right engine propeller governor had been replaced on November 18, 1990, followed by a test run.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001212X24764. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.