What happened
On May 19, 2013, a Standard Cirrus glider, registration OK-3267, was performing a winch launch at Jičín airport. During the initial climb, approximately 2 to 5 meters above the ground, the pilot experienced a perceived drop in winch tension and feared the cable might overshoot the aircraft. To prevent a potential mishap, the pilot executed an emergency release from the cable and landed the aircraft on an open area ahead of the launch path.
The glider came to a stop approximately 500 meters from the launch point. As the aircraft settled, the pilot observed the trailing cable with its drogue parachute falling toward the glider. The cable subsequently became entangled with the aircraft's horizontal stabilizer. The tension from the cable, being pulled back toward the winch, caused the glider to rotate around its tail, resulting in structural damage to the horizontal stabilizer and minor damage to the lower fuselage. There were no injuries to the pilot during the event.
The investigation
The ÚZPLN investigation examined the actions of both the pilot and the winch operator. The winch operator, who had performed approximately twenty successful launches that day, testified that the winch itself was functioning correctly. However, after the glider released from the cable, the operator believed the cable was positioned in front of the glider and continued to reel it in. The operator only ceased winding when they observed the glider rotating due to the cable snagging the tail.
Technical inspections of the Standard Cirrus confirmed the damage to the tail surfaces, while the K-4 winch was found to be in good working order with no defects identified.
Findings
- The pilot was fully qualified and the aircraft was airworthy.
- The pilot's decision to release the cable was likely prompted by a momentary change in flight controls during the transition phase, which created a false sensation of losing tension.
- The glider's movement allowed it to effectively "outrun" the cable during the landing roll.
- The primary cause of the accident was the winch operator's incorrect assessment of the cable's position, which led to continued reeling after the glider had disconnected, ultimately causing the cable to snag the tail surfaces.