Accident Overview
On 1 August 2009 at approximately 13:20 local time, a SZD-30 Pirat glider (registration SP-2680) operated by Aeroklub Warszawski was involved in an accident during a landing in unprepared terrain. The accident occurred about 6 km northeast of Warsaw-Babice Airport (EPBC). The pilot, a 37-year-old male with a glider pilot license, was not injured.
Aircraft and Pilot Information
The glider, manufactured by S.Z. Delta-Bielsko in 1973 (serial number B-571), had a total flight time of 2078 hours 45 minutes. It held a valid Certificate of Airworthiness and Radio License. The pilot had accumulated 88 hours 31 minutes total glider flight time, with 38 hours 4 minutes on the SZD-30 Pirat type.
Sequence of Events
The pilot departed on a thermal and soaring training flight at 13:03. The tow was uneventful, and release occurred at approximately 700 meters altitude. After losing thermal lift and observing a steady sink rate of 3 m/s, the pilot decided to land in an open field. He flew a circuit and began the approach. On final at about 150 meters, the pilot extended the air brakes. Noticing tall vegetation, he leveled off and retracted the brakes. However, the speed was too high, and seeing approaching thickets, he re-extended the brakes. He was late in retracting them before contact with the tall vegetation, and the right air brake lower plate struck the vegetation.
Damage
The glider sustained damage including bending of the right air brake lower plate, cracks in the center section near the right air brake box, and a crack in the upper fuselage skin between main frames near the center section attachment.
Causes
The investigation identified two causes: 1. Landing in an unprepared field that did not provide a safe landing run due to tall and uneven vegetation. 2. Improper execution of the flare phase, including premature retraction of air brakes, subsequent re-extension, and delayed retraction, leading to contact between the air brake lower plate and vegetation.
Contributing Circumstance
A tactical decision to release from tow too early and failure to return to the airport after losing thermal lift was noted as a contributing circumstance.