Accident Sequence
The pilot began a loop maneuver from an altitude of approximately 50 feet above ground level. The aircraft failed to recover before impacting the water.
Inspection and Maintenance
The airplane had last undergone an annual inspection 2.01 hours prior to the accident. Since that inspection, the aircraft had been flown on three separate flights, none of which involved acrobatic maneuvers. The left wing aft hinge attach hardware was not in place at the time of the accident; however, investigators could not determine when the hardware had separated. The annual inspection checklist requires that this hardware be inspected for condition and security.
Mechanical Findings
A tension overload failure of the left aileron up cable was observed near the wing root area. The engine was started and found to operate normally during post-accident testing.
Weight and Balance
Weight and balance calculations indicated that the airplane was over its maximum gross weight at the time of takeoff and at the accident.
Regulatory Compliance
Federal Aviation Regulations specify that aerobatic maneuvers must be performed such that the completion occurs at an altitude of at least 1,500 feet above ground level. The accident maneuver was initiated well below this threshold.