Pilot Debrief

Piper PA 12 near Willow, AK — 2018-11-02

Final reportANC19LA005
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Date
2018-11-02
Location
Willow, AK, USA
Airport
UUO
Aircraft
Piper PA 12
Registration
N3227M
Category
Airplane
Highest injury
Serious
Fatalities
0
Phase of flight
Initial climb

Probable cause

The loss of engine power shortly after takeoff for reasons that could not be determined based on the available information, which resulted in an emergency landing and collision with trees.

NTSB narrative

According to the pilot, during the initial climb on the personal flight, the engine backfired and then lost total power. He was unable to restore power, and during the subsequent off-airport forced landing, the airplane collided with a stand of trees, which resulted in substantial damage to the wings and fuselage. A mechanic/friend of the pilot stated that this was the first flight after engine maintenance, during which he and the pilot had been troubleshooting for excessive magneto drops and a cold cylinder. He added that they had just reinstalled the fine wire spark plugs after cleaning them. A postaccident examination of the airplane revealed that all spark plugs exhibited normal operational signatures with no defects or anomalies noted. Both magnetos produced spark at all terminals as designed. The impulse coupler inside the left magneto was fractured, but that did not preclude the magneto from sparking. Additionally, the wiring harness from the ignition switch to the magnetos was frayed and separated. However, it could not be determined if the separation occurred as a result of the accident. Thus, the reason(s) for the loss of engine power could not be determined.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted the flight after engine issues during initial climb.

NTSB coding

Evidence available

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

Docket documents3

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