What happened
On May 22, 2016, a pilot performing a winch launch at EPEL aerodrome experienced unexpected control difficulties during a planned thermal flight. Following a successful takeoff, the pilot noted significant resistance when attempting to move the elevator. Additionally, the pilot was unable to reduce the aircraft's speed below 100 km/h, despite adjusting the trim.
At an altitude of approximately 380 meters, the pilot executed a gentle 180-degree right turn to return to the airfield and performed a landing on runway 100. Upon touchdown, the resistance in the elevator controls ceased. The SZD-50-3 Puchacz sustained no damage during the landing and was subsequently moved to a hangar.
The investigation
An inspection of the glider following the incident revealed that the elevator's range of motion had been restricted. The investigation established that the buckle of the fifth-point safety harness (the crotch strap used during aerobatic flight) in the rear cockpit had become partially lodged in the control stick compartment. This buckle had moved into the area of the control stick mechanism, physically blocking the stick's movement.
Findings
- The primary cause of the control restriction was the improper positioning of the fifth-point harness buckle, which obstructed the control stick.
- The buckle was not properly secured to its designated attachment point on the seat pan, as is required when the harness is not in use.
- The pre-flight inspection was performed insufficiently, which resulted in the pilot failing to notice that the harness buckle was unsecured and incorrectly positioned.