This October 2008 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
Aircraft: Naval Aircraft Factory N3N-3. Injuries: None. Location: Rialto, Calif. Aircraft damage: Substantial.
What reportedly happened: 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, he took off and flew to his first intended landing site. He landed, then took off for the return flight. According to the pilot, the takeoff was normal until approximately 150 feet above the runway when the engine lost power. The pilot made a forced landing in an open field.
The post-accident investigation included a teardown examination of the airplane’s carburetor. It was determined that the main fuel jets were 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.
Probable cause: A total loss of engine power during initial climb due to an interruption in fuel flow through an improperly assembled carburetor.
For more information: NTSB.gov