What happened
On July 16, 2010, a 3Xtrim aircraft was participating in a National Microlight Team training session at the Włocławek airport (EPWK). The training session, which began at 12:30 local time, focused on precision landing techniques on an asphalt surface without the use of brakes. The flight maneuvers involved performing right-hand circuits following a procedure for immediate takeoff after landing.
During the pre-flight inspection and the first four takeoff and landing cycles, the pilot reported no abnormalities regarding the aircraft's structural appearance or flight characteristics. During the fifth landing, which occurred at approximately 80 km/h, the pilot heard a dull thud and experienced spontaneous braking despite not applying the brakes. The aircraft came to a halt approximately 80 meters from the touchdown point.
Upon exiting the aircraft, the pilot and navigator discovered fuel leaking from the tank, which contained approximately 20 liters of fuel at the time. After the leak ceased, the aircraft was moved to the grass area of the airfield. The pilot notified the manufacturer's chief engineer and the aircraft owner, and the aircraft was subsequently transported to Bielsko-Biała for repairs.
The investigation
The PKBWL investigation was unable to perform a physical inspection of the aircraft at the site of the occurrence. This was due to the fact that the report was submitted five days after the event and the aircraft had already been removed from the location. Furthermore, the investigation committee did not receive an assessment regarding the cause of the structural damage from the operator, owner, or manufacturer.