What happened
On July 11, 2010, a student pilot was performing a winch-assisted launch training flight at the EPBC aerodrome. The flight was intended to be a solo launch in an SZD-51 Junior glider. The weather conditions were favorable, with light winds and temperatures below 27°C.
Following a pre-flight briefing by an instructor, the student pilot initiated the launch. While the glider initially achieved lift and entered a gentle climb, the flight path leveled off at an altitude of approximately 30 to 40 meters instead of transitioning into a steep climb. Observing the flat flight path, the winch operator initially increased tension, but subsequently cut the power entirely when the climb did not improve. This caused the winch cable to slacken, triggering the deployment of the cable'obstructing parachute.
As the glider outpaced the slackening cable, the line was thrown across the left wing near the fuselage junction. Upon receiving the command to release, the student pilot disconnected the cable. However, the cable remained entangled with the left wing tip, causing the glider to descend erratically and drift left of the runway centerline. The aircraft performed a hard landing on the main wheel without a proper flare, bounced, and subsequently spun 180 degrees to the left. The impact resulted in structural damage, including cracks in the fuselage and heat damage to the laminate where the cable had rubbed.
The investigation
The PKBWL investigation examined the flight sequence, the winch operation, and the student pilot's actions. The investigation reviewed the student pilot's training records, noting she had completed 40 flights earlier that year and was qualified to fly Puchacz and Bocian gliders. The investigation also analyzed the physical damage to the SZD-51 Junior, specifically the cable marks on the wing-fuselage junction.
Findings
- The primary cause of the accident was an insufficiently steep initial climb phase, which led the winch operator to terminate the tension.
- The student pilot's release of the cable was delayed after the loss of tension, which allowed the cable to drape over the left wing.
- The aircraft underwent a high-speed descent and landing without a proper flare.
- It is possible that insufficient initial winch tension caused the airspeed to drop to 80 km/h, prompting the pilot to lower the nose and preventing the transition to a steep climb.