What happened
On September 30, 2000, a Zaklady SZD-30 "Pirat" glider was performing a winch launch for a private flight at the Schönebeck-Zackmünde airfield. During the takeoff roll, the aircraft's skid (tail hook) inadvertently picked up a second winch cable that had not been sufficiently separated from the primary towline.
As the glider climbed, the flight instructor noticed the trailing cable and alerted the winch operator via radio, requesting that the second line be cut. Once the aircraft reached an altitude of approximately 250–300 meters, the winch operator reduced power to idle and severed the extra cable. Despite instructions from the instructor to maintain speed and perform a landing across the runway, the pilot—unaware of the entanglement—maneuvered the aircraft into a left-hand turn.
As the glider flew over airfield buildings, the trailing 27-meter section of the second cable became snagged on a concrete post of a nearby fence. This sudden tension abruptly decelerated the aircraft at an altitude of only about 30 meters. The glider struck the ground with its skid and landing gear, resulting in the fatal injury of the pilot, who passed away eleven days later. The aircraft was destroyed.
The investigation
The BFU investigation focused on the mechanical state of the aircraft's skid and the procedures used during the winch launch. Investigators examined the skid and found that a rivet was missing, which had allowed the second cable to become wedged between the metal components.
Witness statements from the flight leader, instructor, and winch operator were used to reconstruct the position of the cables. The investigation also reviewed the safety regulations (SBO) of the German Aero Club, which at the time required a 15-meter separation between the active towline and unused cables to prevent such an occurrence.
Findings
- The primary cause was the insufficient separation of the two winch cables during the takeoff roll, which allowed the aircraft to run over the second line.
- A pre-existing damage to the aircraft's skid (a missing rivet) enabled the cable to become trapped.
- The pilot was not clearly or timely informed of the entanglement, leading to a flight path that crossed non-obstacle-free terrain.
- The trailing cable became snagged on a fence post, causing the sudden impact.
- While the flight instructor attempted to manage the situation, the decision to continue the climb rather than aborting immediately contributed to the aircraft entering a path where the cable could snag.