First solo: pitch oscillation grows, ASK 13 stalls into houses
An ASK 13 was destroyed and a student pilot fatally injured during a first solo, with the glider striking a row of houses about 500 m north of the airfield (Germany). Training had begun 14 days earlier with 67 dual flights and about 9 h total. After a normal winch launch the student flew the downwind at low airspeed. A pitch oscillation between 61 and 91 km/h developed and amplified despite an instructor radio call to lower the nose. The glider pitched near-vertical, stalled, and rolled off a wing. Theoretical training was inadequate, abnormal flight states were not sufficiently practised, and a second instructor's solo approval was missing.
- First solo: winch launch from RWY 28: At 19:13:15 LT on 4 August 2012 a student began a winch launch from RWY 28 at Quakenbrück on his first solo; the cable released normally at about 329 m AGL in calm evening conditions.
- Insufficient training before solo: Training gaps preceded the solo: theory over the 14-day course fell short, spin exercises began before the practical foundation was set, and solo approval was given orally days earlier.
- Low downwind speed, oscillation begins: On downwind, ground speed dropped to an unusually low 61-76 km/h, well below normal cruise; a heading change suggested task saturation. FLARM data then show a pitch oscillation beginning.
- Oscillation amplifies (61–91 km/h): The oscillation grew, with sink rates reaching 5.5, then 9.2, then 7.8 m/s between about 240 m and 100 m AGL; the student's inputs reinforced rather than damped the pitching.
- Radio call; student overloaded: The instructor radioed to lower the nose below the horizon, but the overloaded student did not convert it into stabilising input. Hand injuries suggest he still gripped the stick at impact.
- Stall after vertical climb; hits houses: At low altitude the ASK 13 pitched near-vertical, stalled, and dropped over the left wing into a residential area north of the airfield, striking houses and coming to rest inverted.