What happened
On September 8, 1972, at approximately 17:55 CEST, a Champion 7 GCB (registration HB-UAV) departed from the Schänis airfield to perform a glider tow operation. Following the release of the glider and the disposal of the tow rope, the pilot attempted to land on the dry, paved runway 17. The aircraft touched down in a three-point position approximately 190 meters from the start of the runway and rolled straight for about 60 meters.
At that point, the aircraft suddenly veered to the left. Despite the pilot applying full right rudder and engaging the right wheel brake, the aircraft drifted off the runway. The aircraft traveled in a wide arc to the left, crossed the taxiway leading to the hangar, and struck a Blanik glider (registration HB-833) that was parked near the hangar. During the collision, the rotating propeller of the HB-UAV struck the right wing of the parked glider at approximately 18:05.
There were no injuries to the pilot. The Champion 7 GCB sustained light damage, while the Blanik glider suffered heavy damage.
The investigation
The investigation confirmed that the pilot held a valid private pilot license and was authorized to perform glider towing. At the time of the accident, the pilot had a total flight time of 152 hours and 40 minutes, though experience specifically on this aircraft type was limited to only 50 minutes. There was no evidence of health impairment or pilot error related to medical fitness.
The aircraft was found to be airworthy and properly registered. Investigators found no evidence of pre-existing mechanical failures, specifically regarding the braking or control systems. The aircraft's weight at the time of the accident was 628 kg, well within the maximum allowable limit of 750 kg, and the center of gravity was within the permitted range.
Findings
- The primary cause of the collision was the aircraft veering off the paved runway during the landing roll.
- The Champion 7 GCB model possesses an inherent tendency to veer during landings on hard surfaces.
- This tendency was exacerbated by the aircraft's center of gravity being positioned far forward, which reduced the load on the tailwheel and diminished its directional stability.
- The pilot's limited flight experience on this specific aircraft type may have contributed to the difficulty in maintaining directional control during the excursion.