What happened
On May 6, 2011, at approximately 12:15 UTC, a winch launch accident occurred at Krnov airport. The aircraft, an Alexander Schleicher ASW 19B with registration PH-565, was being launched via a winch system. During the takeoff roll and initial climb, approximately 10 to 15 meters above the ground, witnesses and the tow plane pilot observed the glider oscillating rapidly in altitude.
Recognizing a loss of longitudinal control, the glider pilot elected to release the winch cable to terminate the launch. However, due to the lack of elevator control, the glider entered a high angle of attack, followed by a rapid loss of airspeed and a subsequent stall/spin. The aircraft struck the ground, impacting first with the right wing and then the nose. The pilot sustained one minor injury during the impact. The aircraft suffered significant damage, including a broken left wing, a fractured fuselage near the cockpit, and damage to the tail section.
The investigation
The ÚZPLN investigation focused on the mechanical state of the aircraft and the assembly process. The pilot had personally assembled the glider from its transport trolley prior to the flight. Investigators examined the control system and discovered that the elevator control rod was not connected to the elevator via the quick-release mechanism.
Technical inspection of the quick-release joint, which uses a spring-loaded sleeve, showed no defects in the hardware itself. However, evidence of paint abrasion on the elevator surface indicated that the unattached rod had been physically striking the elevator during flight. The investigation confirmed that the pilot had failed to ensure the connection was properly secured during the post-assembly checks.