Pilot Debrief

AIR TRACTOR INC AT-301 near Ralls, TX — 2012-08-29

Final reportCEN12LA589
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Date
2012-08-29
Location
Ralls, TX, USA
Aircraft
AIR TRACTOR INC AT-301
Registration
N23960
Category
Airplane
Highest injury
Minor
Fatalities
0
Phase of flight
Climb

Probable cause

The total loss of engine power due to a fatigue failure of the rocker arm journal casting of the rocker arm cap.

NTSB narrative

The pilot reported that, while conducting aerial application operations, the engine sputtered and then experienced a complete loss of power. During the forced landing, the airplane nosed over and then came to rest inverted. A postaccident examination of the engine revealed a fatigue failure of the rocker arm journal casting of the rocker arm cap, which resulted in the complete separation of the rocker arm and failure of the exhaust valve.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have checked engine condition before flight to prevent power loss.

NTSB coding

Evidence available

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

Docket documents4

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