What happened
On August 14, 2011, at approximately 14:05 UTC, an LS4 glider was performing a landing at the Wiener Neustadt (LOXN) airfield. The pilot had completed three flights that day and had performed a thorough pre-flight inspection, finding no technical issues with the aircraft.
During the landing sequence, approximately 150 meters above the ground, the pilot transitioned from a downwind to a crosswind leg. While on final approach for runway 18R, the aircraft remained above the desired approach angle despite the airbrakes being extended. In an attempt to manage the descent, the pilot retracted the airbrakes at a speed of approximately 90 km/h to initiate a side slip. During this maneuver, the aircraft progressively entered an accelerated flight state, moving from a right-wing-low to a left-wing-low attitude at an altitude of about 50 meters.
After recovering from the side slip, the pilot redeployed the airbrakes on the upper wing surface. However, at an altitude of roughly 10 meters, the glider tipped over onto its right wing. Although the pilot attempted to correct the roll with left aileron input, the right wing struck the ground. The aircraft subsequently underwent a yaw rotation and impacted the ground heavily on its main landing gear, causing significant damage to the fuselage and gear.
The investigation
The SUB investigation examined the flight sequence, the aircraft's condition, and the meteorological environment. The investigation reconstructed the flight path using witness statements and physical evidence from the wreckage. The investigators reviewed the pilot's licenses, medical certification, and flight experience, all of which were found to be valid and sufficient for the flight. The investigation also confirmed that the aircraft's weight and center of gravity were within permissible limits and that no mechanical failures or meteorological factors contributed to the accident.