What happened
On August 12, 2005, a student pilot was conducting a solo cross-country flight in a Cessna RA F172N, registration HB-CCT, as part of a PPL training itinerary. The flight, which began at Altenrhein, included a planned stop at Yverdon-les-Bains.
Upon approaching Yverdon-les-Bains, the pilot established contact with the airfield information service and configured the aircraft for landing on runway 05. The landing initially involved a firm touchdown on the main gear followed by a slight bounce. As the nose wheel made contact with the pavement, the aircraft suddenly veered to the left. The aircraft exited the runway and traveled approximately 200 meters across the grass before striking a glider trailer with its left wing. The pilot, who was the sole occupant, sustained no injuries.
The investigation
Investigators examined the wreckage and the nose wheel assembly. While the wheel axle and bearings showed no signs of impact damage, the investigation revealed numerous fatigue cracks on the nose wheel rim. A segment of the right side of the rim had broken away, leading to a total failure of that section and a subsequent loss of pressure in the inner tube. This caused the tire to slip off the rim, resulting in the loss of directional control.
Furthermore, the investigation identified a significant maintenance discrepancy. The installed Goodyear rim was found to be non-compliant with the manufacturer's parts catalogue, which specifies only Cleveland or Mcauley rim types for this Cessna RA F172N model. The maintenance provider could not provide documentation justifying the use of this non-conforming part.
Findings
- The primary cause of the accident was the failure of the nose wheel rim due to fatigue.
- The installed nose wheel rim was not an approved part according to Cessna's technical documentation.
- The pilot, being a student with limited experience, was unable to manage the unexpected situation and likely did not apply corrective rudder or braking inputs.
- The aircraft's weight and center of gravity were within prescribed limits, and weather conditions were favorable.