What happened
On August 6, 2001, at 17:30, a pilot was conducting a banner towing flight along the coast near Sérignan. After releasing a banner near Cap d'Agde, the pilot began the return flight to the Sérignan ultralight base. During the final approach, the pilot attempted to correct a rightward drift by applying left stick input. At that moment, the control stick suddenly became loose, and the Ultralair Wheedhopper Europa 1 entered a right-hand turn.
In an attempt to maintain control of the aircraft, the pilot used the rudder pedals, but the loss of aileron effectiveness forced an emergency landing on a roadway. The aircraft struck the rear of a moving car before coming to rest on the side of the road. The accident resulted in one injury to the pilot and the destruction of the aircraft, while a vehicle sustained damage.
The investigation
Investigators examined the wreckage of the 34-NI to determine the cause of the control failure. The inspection revealed that the right-side aileron control cable had snapped, which rendered the aileron controls ineffective. The failure was traced to the cable rubbing against the sheath stop. The symmetrical left-side sheath stop showed similar wear patterns caused by the left aileron control cable.
Furthermore, the investigation looked into the maintenance history of the aircraft. The owner performed all maintenance personally and noted that the aircraft had flown approximately 200 hours since its last complete overhaul, though the total airframe hours since construction were unconfirmed. The aircraft had been used for banner towing every summer for roughly six years and had undergone repairs following an emergency water landing in July 2000.
Findings
- The primary cause of the accident was the rupture of the aileron control cable due to friction against the sheath stop.
- The physical configuration of the cables on this specific aircraft model facilitated progressive wear that went unnoticed.
- The owner's visual maintenance inspections were insufficient to detect the gradual degradation of the cables.