Incident Overview
Following an engine oil change, the operator's practice was to conduct a test flight before releasing the aircraft for student use. The pilot, a flight instructor, reported that the engine start, taxi, and run-up were normal. The engine operated smoothly during the initial climb, but at approximately 300 feet above ground level (agl) during the takeoff climb, the engine abruptly quit. Power was regained momentarily, then lost again.
Forced Landing
Unable to sustain flight, the pilot attempted to return to the departure runway but landed short in a marsh area. At the accident site, the propeller did not appear to have been rotating at the moment of impact.
Post-Accident Examination
Investigators noted fuel in both wing tanks, and fuel samples from the sumps showed no contamination. Emergency responders had instructed the pilot to turn the fuel selector to the 'off' position; the fuel pump functioned audibly. The engine contained clean oil, rotated freely, and exhibited good compression. After recovery, the cowling was removed, and a thorough examination of the engine revealed no anomalies. The propeller was replaced, and the carburetor heat box was removed because it was damaged.
Engine Run Test
Following the replacement of the propeller and removal of the damaged carburetor heat box, the engine was started promptly. It ran normally during the run-up and delivered full power. No further issues were encountered.
The source does not specify a probable cause for the power loss.