Wilga tug crashes on a Puchacz aerotow after an aileron gust lock is left on

A towplane pilot was seriously injured when a PZL-104 Wilga crashed on an aerotow with an aileron gust lock left engaged; the towplane was destroyed and the glider crew unhurt. As the Wilga towed an SZD-50-3 Puchacz off the grass, it began to bank increasingly to the right after takeoff. The glider pilot released and landed the Puchacz, overrunning the runway end by about 50 m into a field, undamaged. The Wilga's right bank steepened and it descended into a hard impact, destroyed. Investigators found one of its two aileron gust locks at the parking spot and the other under the wreckage; the ailerons had been left locked.

1. Aerotow launch of a two-seat glider: A PZL-104 Wilga began an aerotow of an SZD-50-3 Puchacz two-seater from the grass at Schönebeck-Zackmünde; the ground run was normal.
2. Aileron gust lock left engaged: One of the Wilga's two aileron gust locks was still in place, leaving the ailerons locked and the pilot without roll control.
3. Tug banks right after lift-off: After the Wilga lifted off it began to bank increasingly to the right and could not be corrected.
4. Glider releases and lands: The glider pilot released the rope and landed the Puchacz, overrunning the runway end by about 50 m into a field, undamaged; the crew was unhurt.
5. Tug's bank steepens: With the glider gone, the Wilga's right bank steepened further and it entered a descent.
6. Tug crashes, pilot injured: The Wilga struck the ground hard and was destroyed; its pilot was seriously injured but freed himself. The aileron gust locks were found off the aircraft — the ailerons had been left locked.