What happened
On June 1, 2019, a CASA 1.131-E (registration D-EHDT) was leading a four-aircraft formation on a navigational flight from Hof-Paulen, Germany, to Cheb Airport, Czech Republic. During the pre-flight briefing, the flight leader was instructed to land on the grass runway 05/23, located south of the concrete runway 06/24.
During the final approach, the pilot maintained a higher speed and a higher altitude than usual, while flying with a slight left bank and a rightward drift to maintain visibility of the runway from the rear seat. The pilot mistakenly identified a freshly mown area used as a glider strip as the intended runway 23. The aircraft touched down on this unmapped surface, which was covered in thick rows of mown grass. Shortly after touchdown, the left main landing gear struck a deep depression in the ground. This impact caused the aircraft to bounce and veer left, where the landing gear and lower wing caught in a heavy furrow of mown grass. The sudden deceleration caused the aircraft to capsize onto its back. The pilot successfully shut off the fuel and ignition, and although the aircraft was irreparably damaged, the only injury was a minor abrasion to a passenger.
The investigation
The ÚZPLN investigation examined the pilot's qualifications, the aircraft's technical condition, and the state of the airfield. The investigation reviewed the flight leader's briefing instructions, which explicitly directed the group to use the grass runway 05/23. Investigators also analyzed the airfield's visual markings and documentation. It was established that while the grass runway 05/23 was properly marked, the visual markings for the concrete runway 06/24 and the glider strip did not comply with airport regulations. Furthermore, the glider strip was not published in the airport's official documentation at the time of the accident.