What happened
On September 2, 2022, a pilot prepared an SZD-51-1 Junior glider, registration SP-3472, for flight operations at the Krywlany aerodrome (EPBK). At approximately 13:30, the pilot initiated a winch launch. During the takeoff roll, the aircraft unexpectedly rotated at an insufficient airspeed.
In an attempt to manage the sudden movement, the pilot applied significant forward elevator input. This caused the main wheel to strike the ground and bounce. In an effort to counteract the resulting bouncing motion, the pilot applied further forward pressure, which caused the aircraft to strike the ground with the front of the fuselage, followed by an impact with the tail. The cockpit canopy detached during the sequence, and the fuselage and tail sustained multiple cracks.
Despite the impact, the pilot regained control of the aircraft, stabilized the airspeed, and performed a landing from an altitude of approximately 6 to 8 meters, deviating about 20 degrees from the original launch axis. The pilot sustained a minor injury to a finger while exiting the cockpit. The glider sustained serious damage.
The investigation
The PKBWL examined the sequence of events, the pilot's control inputs, and the configuration of the aircraft prior to the launch. The investigation focused on the cause of the premature rotation and the subsequent pilot responses during the takeoff roll.
Findings
- The primary cause of the accident was pilot error in flight technique, specifically the failure to maintain longitudinal balance and the improper correction of the aircraft's bouncing motion during the initial phase of the winch launch.
- Contributing factors included the possibility that the trim was incorrectly set to a "tail-heavy" position prior to takeoff, or that the trim moved to such a position spontaneously during the takeoff roll.
- The pilot's limited flight experience was also a contributing factor.