What happened
On June 6, 2008, a Schempp-Hirth Discus 2b glider was performing a winch launch from the Hoya airfield. The pilot, intending to conduct a long-distance flight, attempted the takeoff without the assistance of a wing walker or a launch director. Because no other personnel were present at the takeoff site at the time, the pilot used a 50 cm high folding bench to support the right wing tip.
Immediately after liftoff, the aircraft began to yaw to the right around its longitudinal axis. Due to the low altitude, the glider entered a roll, stalled, and struck the ground approximately 100 meters from the takeoff point in an inverted position. The impact caused the fuselage to break and the cockpit canopy to shatter. The pilot sustained serious injuries, and the aircraft was destroyed.
The investigation
The BFU investigation examined the takeoff configuration, the aircraft's technical condition, and the meteorological environment. The investigation established that the pilot was highly experienced, with over 2,300 total flight hours and 940 hours on this specific model. No technical defects were found in the glider or the winch mechanism.
Investigators also noted that while the pilot had intended to fly with 50 liters of water ballast, no water was observed leaking from the wreckage, and witnesses did not see the aircraft being ballasted. Meteorological data confirmed gusty side winds from the east/northeast at approximately 10–12 knots during the event.
Findings
- The primary cause of the accident was that the glider entered a climb attitude that fell below the stall speed, leading to a loss of lift and a roll over the right wing.
- The absence of a wing walker meant the right wing was resting on a makeshift support (a folding bench) rather than being held level. This prevented the pilot from achieving a horizontal wing position.
- The investigation concluded that the right wing likely made contact with the ground during the takeoff roll. This contact was exacerbated by the unmanicured, tall grass located near the takeoff site, which created asymmetric drag and induced a strong yawing motion.
- The use of a single-sided support made the aircraft inherently unbalanced and difficult to control during the critical transition from the ground to flight, especially when contending with gusty side winds.