What happened
On June 4, 2014, an instructor and two pilots were conducting a flight for mountain rating renewal training. The flight originated from Grenoble-Le Versoud aerodrome, involving several takeoffs and landings on various altiports. During the takeoff roll on runway 02 at the Sollières-Sardières aerodrome, the right main gear wheel detached from the aircraft. This caused the Jodel D140, registration F-BOPT, to undergo a nose-over (cheval de bois) and come to a halt. The aircraft sustained heavy damage.
The investigation
The investigation focused on the mechanical state of the landing gear and recent maintenance activities. Investigators found that the retaining plug at the end of the right wheel axle was missing and could not be located. Additionally, on the left main gear, one of the two screws intended to secure the retaining plug was missing, while the other was present but unscrewed. The aircraft was not fitted with wheel fairing supports at the time of the accident.
Recent maintenance work had been performed ten hours prior to the accident. The aircraft had been equipped with skis for the winter season, which were removed by a maintenance technician who was new to the workshop and unfamiliar with this specific installation. Because the club had opted not to reinstall the wheel fairings, the ski-retaining plugs—which serve as bearings for the ski axle—remained in place. The removal of the skis was performed based on verbal instructions rather than a formal job card. The technician's post-maintenance check, which focused on taxi testing and braking effectiveness, did not include a specific inspection of the retaining plugs or their securing screws.
Findings
- The primary cause of the accident was the detachment of the right main wheel due to the absence of a post-maintenance inspection following the removal of the skis.
- The lack of a formal maintenance job card and specific procedures for verifying the tightness of the retaining plug screws contributed to the failure.
- The technician's lack of familiarity with the ski installation and the absence of a requirement to check the plugs during the pre-flight inspection further contributed to the event.