Pilot Debrief

CESSNA 172 near Pleasant Valley, NY — 2020-12-27

Final reportERA21LA091
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Date
2020-12-27
Location
Pleasant Valley, NY, USA
Airport
44N
Aircraft
CESSNA 172
Registration
N8311X
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Approach

Probable cause

A total loss of engine power due to failure of the magnetos, which were not overhauled in accordance with the manufacturer’s time specifications.

NTSB narrative

The student pilot was practicing takeoffs and landings when the engine sputtered and lost all power while on final approach. The student pilot tried to restart the engine to no avail and subsequently made a forced landing in a wooded area. The airplane came to rest inverted in swampy terrain amongst trees. The magnetos were removed from the engine during the postaccident examination, and they failed to produce sparks when tested. Further examination of the magnetos revealed extensive corrosion present on the coil laminations between the coil and magnet. It is likely the rotor was unable to transmit electricity to the coil and therefore the magneto was unable to produce a spark. The magneto manufacturer maintenance manual and overhaul manual states the magneto time in service allowance is the time before overhaul for the engine or 12 years. The magnetos had not been overhauled and were 14 and 23 years old. No other engine anomalies were identified that would have prevented normal operation.

Analysis

Primary failure mode
Mechanical failure
First missed decision gate
Pilot could have aborted the flight after engine malfunction was announced.

NTSB coding

Evidence available

  • Photos
  • 8 docket documents
View NTSB final reportView NTSB docket

Docket documents8

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