What happened
On June 17, 2013, a PS-28 Cruiser, registration OK-PSA, was conducting flight testing to verify its certification specifications for the CS-LSA category. The testing program, managed by Czech Sport Aircraft a.s., involved performing intentional spins to ensure safe recovery procedures for pilot training.
During the second flight of the day, the pilot initiated a left spin at approximately 10,331 ft. Following two rotations, the pilot attempted a standard recovery using rudder and elevator inputs. However, the aircraft failed to respond to these standard procedures. In an attempt to break the rotation, the pilot increased engine power, which likely transitioned the aircraft into a flat spin. During this phase, the engine subsequently failed, with data showing a sharp drop in engine RPM, fuel pressure, and oil pressure.
Despite further uncoordinated control inputs and the deployment of an anti-spin parachute, the rotation could not be arrested. The pilot eventually exited the aircraft via parachute at approximately 3,000 ft. The aircraft continued its uncontrolled descent, ultimately impacting a garden in the Mařatice district of Uherské Hradiště. The aircraft sustained heavy damage, but no injuries were reported on the ground.
The investigation
The ÚZPLN investigation examined the flight data recorder (FDR), engine monitoring systems (EMS), and electronic flight instrument system (EFIS) parameters. The investigators reviewed the aircraft's configuration, including recent structural changes to the fuel tanks designed to prevent fuel sloshing during high-G maneuvers. The investigation also analyzed the pilot's flight maneuvers, the effectiveness of the anti-spin parachute, and the circumstances surrounding the engine failure during the flat spin.