Pilot Debrief

NAVAL AIRCRAFT FACTORY N3N-3 near Rialto, CA — 2008-10-26

Final reportWPR09LA025
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Date
2008-10-26
Location
Rialto, CA, USA
Airport
L67
Aircraft
NAVAL AIRCRAFT FACTORY N3N-3
Registration
N44848
Category
Airplane
Highest injury
None
Fatalities
0
Phase of flight
Initial climb

Probable cause

A total loss of engine power during initial climb due to an interruption in fuel flow through an improperly assembled carburetor.

NTSB narrative

The pilot performed a preflight inspection of the company airplane in preparation for a local area round-robin flight. After all systems appeared to function normally, the pilot took off and flew to his first intended landing site. Then, the pilot took off for the return flight. According to the pilot, during the ensuing takeoff, the "engine power output and acceleration were normal." However, upon climbing about 150 feet above the runway, "the engine smoothly lost power....The power loss felt like the throttle lever [was] being smoothly closed from takeoff power to idle. There was no engine roughness, vibration, or perceived reduced power output preceding the loss of power, and no backfiring or sputtering [was] associated with the power loss." The pilot made a forced landing in an open field ahead of the airplane. The airplane collided with vegetation during the landing rollout. A teardown examination of the airplane's carburetor was performed, and internal anomalies were found regarding its assembly. The main fuel jets were found too small for the engine application, and the mixture shaft was improperly keyed and/or out of alignment with its respective track. This anomaly likely resulted in unreliable mixture settings and an interruption of fuel flow to the engine.

Analysis

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

NTSB coding

Evidence available

  • 3 docket documents
View NTSB final reportView NTSB docket

Docket documents3

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