Pilot Debrief

MOONEY M20J near El Reno, OK — 2013-06-25

Final reportCEN13LA370
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Date
2013-06-25
Location
El Reno, OK, USA
Airport
RQO
Aircraft
MOONEY M20J
Registration
N205MC
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Climb

Probable cause

A loss of engine power, which resulted from the failure of the magneto assembly for reasons that could not be determined during postaccident examinations.

NTSB narrative

The pilot stated that the engine abruptly lost power while he was practicing instrument approaches under visual flight rules. His efforts to restore engine power were unsuccessful. The pilot subsequently executed a forced landing to the center median of a roadway. A postaccident examination revealed that the dual magneto assembly was not functioning properly. Although the magneto drive shaft operated during engine crankshaft rotation, the magneto points did not open as required. A teardown examination revealed that the magneto components were worn. In addition, the threaded inserts had lifted out of the mounting block. The magneto assembly was inspected less than 1 flight hour before the accident during an engine propeller strike inspection, and the magneto block, points, and cam were replaced at that time. The accident flight was the second flight since the inspection and maintenance work had been performed. Although the magneto points might have been misaligned due to the threaded insert lifting out of the mounting block, it is unlikely that such a discrepancy would have resulted in a loss of magneto function within such a short timeframe. The magneto failure caused the loss of engine power; however, the cause of the magneto failure could not be determined.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Conduct thorough preflight inspection of engine components before flight.

NTSB coding

Evidence available

  • 4 docket documents
View NTSB final reportView NTSB docket

Docket documents4

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