Incident Summary
On 18 August 2016, at approximately 18:50 local time, a training flight involving multiple gliders was conducted at Radawiec airfield (EPLR) using winch launches. A student pilot embarked on his fifth solo flight of the day in a SZD-9 Bis Bocian 1E glider (registration SP-3103), owned and operated by Aeroklub Lubelski. The previous four solo flights, part of Exercise 8 Task 1 (solo flights), had been completed without incident.
Sequence of Events
During the fifth flight, the student misjudged the traffic pattern, resulting in insufficient altitude after the fourth turn while aligning with the final approach path. Despite the low altitude, the student deployed the air brakes. The supervising instructor issued a radio command to retract the air brakes. The student complied with a slight delay. While flying over trees on the approach to Runway 21, the glider's left wing struck a protruding branch. The impact caused the glider to bank slightly to the left, but did not result in a loss of airspeed or a change in direction. The glider subsequently touched down safely and completed its landing roll just beyond the threshold of Runway 21.
Damage
As a result of the collision, the leading edge of the outboard section of the left wing was damaged.
Probable Cause
The investigation identified two causes: (1) the student pilot's improper planning of the traffic pattern, and (2) the supervising instructor's delayed response to the student's error.
Preventive Actions
A debriefing was conducted with the flying personnel, during which the incident was discussed and measures to prevent similar occurrences in the future were established. No safety recommendations were issued.
Commission's Comment
The commission noted that, particularly during initial solo flights, the supervising instructor should continuously observe the glider with the student pilot on board to provide timely radio guidance if necessary.