What happened
On May 2, 2015, a Schempp-Hirth Nimbus-3/24,5 glider departed from the Wahlstedt airfield (EDHW) via aero-tow for a cross-country flight. At approximately 15:17, other glider pilots in the vicinity of Bad Münder am Deister/Bakede observed the aircraft in an unusual, steeply upward flight attitude. The witnesses then saw the aircraft enter a steep spiral dive at an altitude of approximately 1,200 m AMSL. During this maneuver, a portion of the wing detached from the glider, with visible ballast water leaking from the remaining wing structure. Shortly thereafter, the aircraft disappeared from view.
Witnesses on the ground reported hearing a whistling sound followed by a loud bang as the wing component separated, and a final impact sound as the glider struck the ground. The aircraft crashed at a steep angle into a forested area, resulting in the destruction of the aircraft and the death of the pilot.
The investigation
The BFU investigation focused on the wreckage and the sequence of structural failure. The aircraft was found in a cockpit-down position. The main wreckage occupied an area of roughly 20 m by 4 m, with the cockpit area destroyed up to the wing spar. The investigation identified that the wing spar had suffered multiple breaks and delamination along its entire length.
Debris from the wing skin was scattered within a 15-meter radius of the main wreckage, and further fragments of the wing skin were found approximately 1 km away. Additionally, nearly undamaged wingtips and a detached portion of a flap were located about 800 m northeast of the main impact site. While several flight recorders were believed to be on board, the recovered data carriers were too heavily damaged to be read. Medical examinations and toxicological reports confirmed no evidence of drugs, alcohol, or organic medical conditions that would have impaired the pilot's ability to fly.