What happened
Around midday, the pilot/owner of a Skyhopper arrived at the Smiths Falls airport to perform maintenance on the aircraft. Shortly after 13:00 EDT, the aircraft was observed taxiing past a hangar, though no takeoff was witnessed by bystanders. Approximately one hour later, a witness reported hearing an unusual noise followed by the engine sputtering. Upon looking up, the witness saw the right wing had detached from the aircraft, causing it to descend uncontrollably. The aircraft struck the ground less than a mile from the witness, resulting in one fatality.
At the time of the accident, weather conditions were characterized by daylight and good visual meteorological conditions with light winds.
The investigation
The investigation focused on the structural integrity of the Skyhopper's wing and the history of the aircraft. The aircraft was an amateur-built, single-place, low-wing design with a wooden, fabric-covered wing construction. Records indicated the aircraft had been operated for 756 hours since its 1962 completion.
Investigators examined the fractured wing surfaces and the wing tip. They found that the design strength and construction of the wing were otherwise adequate, with no evidence of wood deterioration. However, a fresh scrape was identified on the underside of the right wing tip, consistent with recent contact with an asphalt or concrete surface, such as during a ground loop or a sharp swerve.
Findings
- The aircraft's right wing spars had been weakened by a recent impact.
- The scrape on the wing tip was recent enough that there was no debris in the mark and no evidence of rubbing on the fracture surfaces, suggesting the damage occurred during a very recent operation.
- The right wing spars failed under normal flight loads due to the structural damage caused by the recent wing tip scrape, leading to the separation of the wing in flight.