Overview
Witnesses reported that the airplane conducted maneuvers described as aerobatic prior to impact. A photograph taken shortly before the accident shows the aircraft in an inverted attitude. The airplane is not approved for aerobatic maneuvers.
Recovery
The fuselage, engine, propeller, and one wing were recovered from 90 feet of water for inspection by Federal Aviation Administration (FAA) inspectors.
Inspection
Records indicate that the airplane had recently undergone structural repairs to its steel tubing structure. Those repaired areas, along with the remainder of the structure and the wing and wing-strut attachment points, were examined by FAA inspectors and an NTSB investigator. No evidence of pre-impact structural failure was found.
Conclusion
The investigation determined that the airplane experienced no pre-impact structural failure. The specific cause of the accident remains unstated in the available information.