Pilot Debrief

MAULE M-4-220C near Fredericksburg, PA — 2013-06-01

Final reportERA13LA268
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Date
2013-06-01
Location
Fredericksburg, PA, USA
Airport
9N7
Aircraft
MAULE M-4-220C
Registration
N40337
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Initial climb

Probable cause

A total loss of engine power due to the fatigue failure of the No. 4 cylinder piston pin.

NTSB narrative

The pilot reported that, while the airplane was in cruise flight, the engine began to vibrate and lose power. The pilot shut down the engine and performed a forced landing to a field. During the landing roll, the airplane nosed over and was substantially damaged. Examination of the engine revealed that the No. 4 cylinder head was partially separated and that the No. 4 piston pin was fractured. The piston pin fractured due to fatigue that had initiated at the pin's outer diameter, and the fracture corresponded to the location of the pin bearing separation from the connecting rod. The bearing fracture surface was obliterated. It is likely that pin and bearing wear altered the stress distribution and precipitated the failure. A review of maintenance records revealed that the 41-year-old engine had been operated for about 1,400 total hours since new and about 50 flight hours since its most recent annual inspection, which was performed about 1 year before the accident. In addition, the No. 4 cylinder was overhauled about 23 years and 560 flight hours before the accident. It was also removed, reconditioned, and reinstalled about 4 years and 165 flight hours before the accident.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted takeoff upon engine vibration and smoke.

NTSB coding

Evidence available

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

Docket documents10

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