Incident Overview
A pilot was maneuvering at a low altitude in conditions of high humidity when the engine lost power. According to the Federal Aviation Administration (FAA), the pilot reported using carburetor heat prior to the maneuver. Following the power loss, the airplane entered a spin; the pilot regained control but not in time to avoid impacting water.
Aircraft Examination
Examination of the aircraft did not disclose evidence of mechanical malfunction. The carburetor heat box was found to be damaged, but the heat appeared to be on.
Weather Conditions
According to the carburetor icing chart, the temperature and dewpoint were in the area of "moderate icing – cruise power or serious icing – glide power."
Conclusion
The investigation did not identify a mechanical cause for the power loss. The presence of carburetor icing conditions and the pilot's use of carburetor heat were noted.