What happened
On June 28, 2023, a Pilatus PC-6/B2-H4, registration EC-LQH, was performing a skydiving flight at Příbram Airport (LKPM) after dropping nine parachutists from 14,000 feet. Following the jump, the pilot initiated a steep descent to prepare for landing on the unpaved runway 24R.
During the landing roll on the grass strip, the aircraft encountered a crosswind component of approximately 8.5 knots. As the aircraft decelerated, it began to veer to the right. This swerving motion caused the aircraft to tilt sharply to the left, lifting the right main landing gear. During this sudden roll, the external tip of the left wing's static balance struck the grassy surface, resulting in the outer portion of the left wing being torn from its mounting. The aircraft eventually came to a stop on the right edge of the grass strip. The pilot was uninjured.
The investigation
The ÚZPLN investigation focused on the sequence of events leading to the loss of directional control. Investigators examined the aircraft's tailwheel steering system and the pilot's pre-flight actions. The investigation established that while the pilot had moved the tailwheel steering lever to the "LOCK" position during the pre-takeoff checklist, the tailwheel itself had not yet physically aligned with the aircraft's longitudinal axis. Consequently, the mechanical locking of the steering mechanism was not fully achieved.
Furthermore, the investigation noted that the aircraft's right skydiving door remained open during the descent, which may have contributed to the aircraft's instability. Video footage from the airport confirmed the rapid leftward roll and the subsequent impact of the wing tip with the ground.