Casualties unknown

1998-06-20: Zaklady/SZD-9 — Rudolstadt, DE

Rudolstadt, DE

On June 20, 1998, a Zaklady/SZD-9 was involved in an aviation accident near Rudolstadt, DE. Investigators recorded the probable cause as: Der Flugunfall ist darauf zurückzuführen, dass nach dem Abstellen des Schleppflugzeuges das angehängte Schleppseil über dem ausgelegten Windenschleppseil liegenblieb und dieser Zustand durch mangelhafte Koordination und Aufmerksamkeit bis zur Startfreigabe… This summary draws on records from the German Federal Bureau of Aircraft Accident Investigation (BFU).

Sourcesthe German Federal Bureau of Aircraft Accident Investigation (BFU)Primary reportUpdated 1785665765Data APIEditorial standards

On 20 June 1998, a glider crashed during winch launch at Rudolstadt after the towplane's rope was left lying over the winch cable, unnoticed. The student pilot was seriously injured, and the glider was destroyed.

Accident

On 20 June 1998, a glider accident occurred at Rudolstadt during a winch launch for a training flight. The glider, a Zaklady/SZD-9, was being used for an instructional flight. The student pilot suffered serious injuries, and the glider was destroyed.

Sequence of Events

During mixed flight operations involving both winch and aero towing, two winch cables were laid out on the runway after a previous aero tow start. A subsequent winch launch proceeded without incident. Following that, a Wilga towplane landed opposite the designated landing direction (landing on runway 07 instead of 25) with its tow rope attached. After landing, the towplane rolled left across the winch tow area to reach a parking position, overrunning the winch cable laid out for the next winch launch. The attached tow rope was left lying on top of the winch cable. This situation went unnoticed.

The student pilot was briefed for the last winch launch of the day by the flight instructor. The instructor checked the glider, which was flown single-seat although it was a two-seat type, coupled the tow rope, and held the wing during the start. The instructor signaled launch readiness to the launch director.

During the launch, witnesses heard an unusual sound shortly after takeoff and saw the tow rope from the towplane being pulled up by the winch cable. As the tow rope reached the glider's landing gear area and became entangled, the rope tightened and pulled the towplane off course. Simultaneously, the glider, in its initial climb, was pitched into a steep descent and struck the ground at approximately 45° angle.

Investigation

Examination of the glider revealed no technical defects; it was properly certified for operation. The investigation confirmed witness accounts. The contact between the tow rope end and the glider's landing gear beam resulted in a very firm knot, effectively pulling the glider to the ground from low altitude during the initial climb.

Conclusions

The investigation concluded that the accident occurred because, after the towplane was parked, its tow rope remained lying over the winch cable, and this condition went unnoticed due to poor coordination and attention until the glider launch was released. During the launch, the fast retraction of the winch cable caused the overlying tow rope to slide toward the glider. At only a few meters above the ground, the rope end contacted the glider's landing gear, became entangled, and abruptly terminated the climb.

Probable cause

Der Flugunfall ist darauf zurückzuführen, dass nach dem Abstellen des Schleppflugzeuges das angehängte Schleppseil über dem ausgelegten Windenschleppseil liegenblieb und dieser Zustand durch mangelhafte Koordination und Aufmerksamkeit bis zur Startfreigabe des Segelflugstarts unbemerkt blieb.