A witness saw the amateur-built airplane flying parallel to a beach and thought that the engine sounded unusual. He did not observe anything else abnormal about the flight. Examination of the airplane revealed that it had impacted the water in a landing attitude, with the wings level. The impact separated the upper cabin, propeller and engine gearbox. The engine remained partially attached by it mounts. After recovery, the airplane and engine showed no evidence of precrash mechanical failure or malfunction. Autopsy and toxicology findings indicated that the pilot had severe coronary artery disease, an enlarged and thickened heart, and poorly controlled diabetes. There were no indications that the pilot was aware of these medical conditions and the relevance of the conditions to the accident could not be determined.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows: Controlled flight into water for undetermined reasons.