What happened
On May 21, 2013, at approximately 13:32 local time, a Glasflügel 303 Mosquito glider performed a winch launch from runway 28 at the Beilngries airfield. According to witness accounts, the initial takeoff proceeded normally. However, during the initial climb, the aircraft failed to gain altitude and touched down again approximately 50 meters after the first liftoff. Following this second contact, the aircraft climbed again, entering a very steep ascent.
At an altitude of approximately 20 meters, the aircraft rolled over the left wing. The glider then struck the airfield terrain nearly vertically about 250 meters from the takeoff point. The impact resulted in the death of the pilot and the total destruction of the aircraft. The crash also caused damage to the airfield grounds.
The investigation
The BFU investigation examined the aircraft, the pilot's credentials, and the flight sequence. The pilot held a valid license for winch and aero-tow launches, with approximately 86 total flight hours. However, his experience was limited, with only 27 flight hours recorded in the two years preceding the accident. This specific flight was his first winch launch in the Glasflügel 303 Mosquito, having only flown the model three times in an aero-tow capacity two years prior.
The investigation of the wreckage revealed that the cockpit had been destroyed and separated from the wings. The tailplane remained largely intact but was separated from the fuselage at the tailplane boom. While the left wing remained largely intact, the right wing's leading edge was compressed and the spar was broken near the aileron. No technical defects were found in the aircraft's systems or structure.
Findings
- The primary cause of the accident was that the glider entered an overstressed flight condition during the winch launch, leading to a stall and subsequent roll.
- The pilot likely applied excessive elevator input to avoid the unplanned touchdown after the initial liftoff, which induced a steep climb.
- The steep angle of climb led to an aerodynamic stall at a very low altitude.
- Contributing factors included the pilot's limited overall flight experience and his lack of experience specifically with this aircraft type.