What happened
On July 3, 2022, an SZD-9 bis Bocian 1E glider, registration SP-4082, was performing a training flight using a winch launch at the Rybnik-Gotartowice (EPRG) aerodrome. The flight was being conducted by an instructor and a student pilot, marking the 11th flight of this specific aircraft on that day.
The takeoff, climb, and release from the winch cable proceeded normally. However, while the crew was flying in a downwind position during the aerodrome circuit, the student pilot noticed a sudden blockage affecting both the elevator and the rudder. The instructor immediately took control of the aircraft and confirmed that while the movement of both surfaces was severely restricted, the ailerons remained fully functional.
The instructor declared an emergency via radio and continued the flight using minimal control inputs, successfully merging the third and fourth turns of the circuit. The aircraft landed safely at the aerodrome, and there were no injuries to the crew.
The investigation
Following the incident, the PKBWL examined the aircraft to determine the source of the control surface restriction. The inspection revealed that the trim plate for the elevator had become detached from its hinge sockets. Under the pressure of aerodynamic forces, this plate rotated onto the control linkage and subsequently became wedged between the elevator and the rudder. This physical obstruction was the direct cause of the significant reduction in the range of motion for both control surfaces.