History of the Flight
The pilot, who had recently purchased the sailplane, prepared for its first flight of the day at Temploux airfield (EBNM) on 18 May 2011. Runway 24 was in use. An aerotow was initiated with a Robin DR400/180R towplane. During the take-off roll, the pilot had to counter roll movements causing the left and right wings to alternately contact the ground. The oscillations became significant, and the pilot released the tow cable. The sailplane then rotated around the left wingtip, and the nose struck the ground, after which the aircraft fell back onto its tail, fracturing the tail boom. The pilot exited the glider uninjured.
Injuries to Persons
The pilot was not injured. No other persons were on board.
Damage to Aircraft
The glider sustained damage to the nose and tail boom.
Personnel Information
The pilot, aged 59, held a Glider Pilot Licence first issued on 4 June 1996, last issued on 10 March 2011, valid until 17 February 2013. He had ratings for aerotow and carrying passengers. His medical certificate was Class 2, valid until 10 March 2012. The pilot reported a total of 600 flight hours on various gliders, including the Schleicher Ka 6 (most recent), Jantar, LS1, and Astir. He flew approximately 30 hours per year. At the time of the accident, he had flown the SZD-55 for 6 flights totaling 6.5 hours.
Aircraft Information
The aircraft was a PZL-Bielsko SZD-55-1, serial number 551192045, built in 1988, registered D-5****. It had accumulated 1350 flight hours and 350 flight cycles. The glider is a Standard Class sailplane with a fiberglass fuselage and an elliptical wing. The flight manual includes directions for aerotowing, including an instruction to release the tow cable if the wingtip contacts the ground.
Meteorological Conditions
Wind was from 240 degrees at 6 knots. Visibility was more than 10 km, temperature 23°C, QNH 1017 hPa.
Aerodrome Information
Temploux airfield (EBNM) is located near Namur, Belgium. The grass runway (06/24) is 696 m long and 27 m wide, elevation 594 ft. The runway for Runway 24 has a slight upslope and is somewhat uneven.
Analysis
According to the investigation, the towing was assisted by a launching crew holding the left wingtip for the first few meters. When released, the left wingtip contacted the ground. The pilot applied right aileron and rudder, but the sailplane's response was slow, and tall grass caused a left yaw due to friction. At low airspeed, aileron effectiveness was minimal. The sailplane yawed 40° left of the towplane. The pilot then steered right, causing the right wingtip to contact the ground. He applied left aileron and rudder, and the glider turned left again, but the left wingtip struck the ground again. The pilot then released the tow cable at about 40 km/h. The glider rotated around the left wingtip, the nose impacted the ground, and the tail boom fractured. The flight manual prescribes releasing the tow cable as soon as the wingtip hits the ground.
Causes
The accident was caused by a delay in reaction time to release the tow cable further to the wing tip touching the ground.