Incident Details
On June 6, 2005, at EPLS airport, a glider accident occurred during a training flight preparation for the European Gliding Championships. Weather conditions were good with wind from 250°–280° at 20–30 km/h. The pilot positioned the SZD-56-2 Diana 2 glider aligned with the wind on the edge of a mowed strip. The glider carried 150 liters of water ballast in the wings and 5.5 liters in the tail. The towing aircraft was a Jak-12M, using a 60-meter tow rope to minimize the slipstream effect on the glider's lateral balance during the ground run.
The takeoff began on runway 26. After the tow rope tightened, the tow plane dragged the glider approximately 20 meters away from other gliders, leaving about 40 meters of short grass ahead. The pilot set flaps to 5° and partially extended the airbrakes. At about 40 km/h, when lateral control improved, the pilot closed the airbrakes and began moving the flaps to 21°. At that moment, the left wing dropped and caught the taller grass. The pilot initially countered with aileron, but the glider deviated more than 20° according to witnesses, causing it to ground loop on the main gear with the tail wheel raised. The pilot released the towline, and the glider pivoted sharply over the left wing, breaking the tail, and came to rest inverted, 180° from the takeoff direction.
Aircraft and Crew
The glider was an SZD-56-2 Diana 2. The pilot was a 55-year-old male with a total glider flight time of 6,069 hours, including 6,009 hours and 20 minutes as pilot-in-command. On the Diana 2, he had 10 flights totaling 30 hours and 10 minutes. In 2005, he had flown 16 flights, 10 of them on the Diana 2. His license, medical certificate, and ratings were valid.
Cause
The investigation determined that the cause of the accident was the delayed release of the towline after the wing caught the grass. A contributing circumstance was the excessive grass height at the takeoff location.
Commentary
A test pilot who had previously flown the Diana 2 noted that for takeoff, the recommended flap setting is +14°, and that changing flap settings during the ground roll is not recommended due to the confined cockpit space.