What happened
The pilot reported that he had reduced engine power in order to perform a low pass over an area that might serve as a future landing site. While executing this maneuver, the pilot reapplied power to the engine. At that moment, the engine failed to respond to the throttle input. This lack of power resulted in a hard landing on a gravel bar.
After the aircraft came to rest and was recovered from the immediate impact, the engine started up again. It continued to run without any obvious mechanical issues or further irregularities.
The investigation
An examination of the incident focused on the sudden loss of power during the low pass. Despite the hard landing, the subsequent normal operation of the engine after recovery complicated the diagnosis. Investigators looked for mechanical failures that could explain the unresponsiveness.
Findings
The primary finding was the unexplained nature of the power loss. The engine functioned normally before and after the event. No specific mechanical fault or external factor was identified as the reason for the power loss during the critical phase of the maneuver.