What happened
On the evening of July 28, 2001, an amateur-built Aircampeur J3 (registration F-PBGT) was performing a local flight from Andernos aerodrome under calm weather conditions. During the takeoff roll, the left main wheel detached from the aircraft and remained on the runway.
Lacking radio communication, the pilot alerted emergency services by performing a low-altitude pass and wing rocking maneuvers. To mitigate the risk of fire, the pilot continued the flight to burn off as much fuel as possible before returning to the airfield. The pilot attempted a landing using only the right main wheel, attempting to prevent the left side from contacting the ground. However, as the aircraft decelerated, it entered a ground loop and eventually came to rest on its wing.
There were two persons on board; the pilot and one passenger survived the incident without injury.
The investigation
The investigation focused on the structural failure of the landing gear. Examination of the left main gear revealed that the wheel axle had fractured. Notably, the break occurred inside the sleeve rather than at the exit point, where mechanical stress is typically highest. This pattern suggested a pre-existing metallurgical defect within the component.
Investigators determined that the axle was not an aviation-grade part, but rather a component sourced from a motorcycle. While the pilot had performed a visual inspection of the landing gear within the month preceding the accident, the internal nature of the defect meant the flaw was not detectable through standard visual maintenance.
Findings
- The primary cause of the accident was the use of a non-aviation-grade motorcycle part as a wheel axle.
- A metallurgical defect within the repurposed part facilitated the structural failure of the axle during takeoff.
- The failure of the left main gear led to the loss of control and the subsequent ground loop.