What happened
On February 28, 2011, at 13:40, a Schempp-Hirth Arcus T, registration D-KTSP, departed from the unpaved runway 28 at Vinon aerodrome via aero-tow. Following release in the southwest, the pilot was unable to locate rising air and decided to orbit the airfield. At an altitude of approximately 300 meters, the pilot attempted to start the retractable auxiliary engine located behind the cockpit, but the engine failed to start. The pilot then activated the electric retraction mechanism and prepared for a landing at the aerodrome.
The aircraft approached the unpaved runway 28 on a left-hand downwind leg at a low altitude. During the final turn, the aircraft drifted beyond the runway centerline. In an attempt to correct the flight path, the pilot applied significant bank angle, causing the left wing and the fuselage to strike the ground. The glider continued to slide laterally across the ground, crossing an earthen embankment before coming to a stop. At the time of the accident, winds were blowing from the southeast at approximately 10 knots.
The investigation
The investigation focused on the configuration of the aircraft and the pilot's decision-making process. Examination of the wreckage revealed that the auxiliary engine had not actually been retracted. Although the pilot believed the retraction mechanism had functioned, they had failed to visually verify the engine's position. The investigation also noted that the auxiliary engine had not been operated for four months prior to the accident. Because this specific model lacks an electric starter, the engine relies on relative wind for ignition during flight.
Findings
- The primary cause of the accident was the failure to verify that the engine was fully retracted, which resulted in additional aerodynamic drag that increased the aircraft's descent rate.
- The pilot's focus on landing on runway 28 prevented them from considering alternative runways, such as runway 10 or 02, which might have been more suitable given the wind conditions and descent rate.
- The southeast wind pushed the aircraft toward the runway during the downwind leg of the approach.