Pilot Debrief

GRUMMAN AMERICAN AVN. CORP. AA-5A near Lakeview, OR — 2010-08-22

Final reportWPR10LA424
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Date
2010-08-22
Location
Lakeview, OR, USA
Airport
KLKV
Aircraft
GRUMMAN AMERICAN AVN. CORP. AA-5A
Registration
N26118
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Initial climb

Probable cause

A partial loss of engine power during the initial climb due to a stuck exhaust valve.

NTSB narrative

The pilot reported that the preflight run-up was uneventful. Shortly after takeoff, at approximately 150 feet above ground level, the engine suddenly dropped rpm; the pilot verified fuel quantity, and attempted to lean the engine. Despite the pilot’s efforts, the problem persisted, and he initiated a forced landing into a nearby field. During the landing roll, the airplane’s left wing struck a fence post, and its empennage collided with high sage brush. Examination of the engine by a certificated airframe and powerplant (A&P) mechanic revealed low compression within the number three cylinder. Further examination revealed that the exhaust valve was stuck in the full open position. The examination revealed no further anomalies with the cylinder assembly or engine.

Analysis

Primary failure mode
Engine power loss
First missed decision gate
Pilot could have aborted takeoff after engine rpm drop at 150 feet agl.

NTSB coding

Evidence available

  • 1 docket document
View NTSB final reportView NTSB docket

Docket documents1

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