What happened
On June 17, 2013, a pilot was conducting a cross-country flight following a route from Białystok to Hajnówka and Suwałki. The flight involved a 300 km triangular course. During the flight, the glider was released from a tow plane at an altitude of approximately 500 meters within a thermal with a climb rate of about 1.5 m/s.
Upon reaching the area of Odrynki in the Narew River valley, the thermal conditions deteriorated. Due to the loss of lift, the pilot decided to perform an out-of-circuit landing in a recently mown field containing harvested hay. The approach was made into the wind, targeting the wider section of the field. During the landing roll, the pilot identified an obstacle that had not been visible during the initial inspection of the field: a wooden post measuring 8 cm x 8 cm and 1.2 meters in height. The pilot attempted to avoid the post by lifting the left aileron, but the wingtip struck the post, resulting in damage to the leading edge of the wing. The SZD-51-1 Junior came to a stop approximately 15 meters past the obstacle.
The investigation
The investigation focused on the circumstances surrounding the landing and the identification of obstacles within the chosen landing site. The inquiry established the sequence of events from the deterioration of thermal conditions to the impact with the wooden post.