Pilot Debrief

GRUMMAN ACFT ENG COR G-164A near La Salle, CO — 2012-08-01

Final reportCEN12LA513
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Date
2012-08-01
Location
La Salle, CO, USA
Airport
NONE
Aircraft
GRUMMAN ACFT ENG COR G-164A
Registration
N9822
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Initial climb

Probable cause

The loss of engine power due to the detached distributor rotor.

NTSB narrative

The pilot stated that shortly after takeoff for the aerial application flight, the airplane’s engine ”popped and banged.” The pilot decided to jettison the airplane’s load and return to land at the departure airport. However, while returning to the airport, the engine began to surge repeatedly between full power and a total loss of power, and the pilot decided to land in a nearby alfalfa field, where the airplane nosed over during the forced landing. Examination of the engine revealed that a screw that secured the distributor rotor to the brass gear had come out, which resulted in the detached rotor moving loosely inside the magneto. Internal damage to the rotor and magneto was consistent with the rotor rubbing inside of the magneto. This distributor rotor separation and subsequent movement most likely resulted in the rough running engine and the subsequent loss of engine power.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted takeoff after hearing engine issues.

NTSB coding

Evidence available

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

Docket documents7

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