What happened
On August 20, 2023, at the EPJG aerodrome, a training flight was being conducted using a winch launch method as part of a basic glider training program. The flight, involving an instructor and a student, was intended to practice emergency procedures, specifically simulating a loss of tow tension at altitudes below 50 meters. The takeoff of the SZD-50-3 Puchacz, registration SP-3155, proceeded normally.
At an altitude of approximately 20 meters AGL, the instructor released the winch cable. During the transition from the climb to a glide, the crew transitioned too abruptly into the gliding phase. Simultaneously, the winch operator ceased tension and began braking the drum. Due to the rapid change in flight attitude, the glider caught up to the trailing cable, causing the cable to strike and drape over the left wing. The crew continued the landing straight ahead, and the aircraft landed without further incident. Upon inspection, the crew found the cable still resting on the wing, with minor damage noted on the leading and trailing edges of the wing and the surface of the left horizontal stabilizer.
The investigation
The investigation focused on the sequence of events following the cable release and the physical configuration of the winch cable assembly. The investigation examined the distance between the cable's drogue parachute and the attachment ring, as well as the behavior of the cable during the braking process.
Findings
- The primary cause of the incident was the too abrupt reaction of the crew following the cable release, specifically the rapid acceleration of the glider into a glide, which caused the aircraft to overtake the winch cable.
- The size of the drogue parachute on the winch cable may have caused the cable to descend too slowly after release.
- The distance between the drogue parachute and the cable attachment ring was only 8 meters, which was insufficient for the circumstances.