Occurrence
On 22 August 2018 at approximately 18:22 local time, a student pilot was performing a training flight on a SZD-30 Pirat glider, using a winch launch for exercise IV-6 (accuracy landing training). The student reported readiness for takeoff without ensuring the air brake lever was properly locked. During the initial climb phase, the air brakes opened. The supervising instructor repeatedly issued a radio command, "Pirat, close the brakes." The student did not respond. The winch operator, believing something dangerous was happening, released the towline. When the glider was at an altitude of about 50 meters, the towline released. The student pitched the glider forward, released the towline, and closed the air brakes. Shortly thereafter, the student began reducing the glider's pitch, creating a risk of excessive speed loss. The supervising instructor issued the command, "Pirat, lower the nose, release the stick," which was repeated by the flight director. The student complied and then landed straight ahead within the boundaries of the airfield. After the incident, the operation of the air brake lever lock was checked and no irregularities were found.
Causes
The incident had two identified causes: improper execution of the pre-start checklist by the student pilot, and unjustified release of the towline by the winch operator.
Preventive Actions
The investigating entity took several preventive measures. The situation was discussed during a refresher training for winch operators, emphasizing not to release the towline without a command from the flight director or supervising instructor. The student pilot completed check flights covering emergency situations during winch launch with towline release at low altitude (50 m and 30 m). The incident was also discussed during a safety conference organized by the Warsaw Aero Club.