What happened
On July 11, 2018, a KR-03 and Topaz ultralight aircraft, registration SP-SGEO, was performing training flights at Rzeszów-Jasionka Airport (EPRZ). The flight crew, consisting of a student pilot and an instructor, was conducting training maneuvers involving touch-and-go landings.
During one such maneuver, the student pilot landed on runway 09. Following the landing, the instructor instructed the student to continue the takeoff roll. As the instructor applied back pressure on the control stick to initiate the climb, the upper part of the control stick handle snapped. This failure immediately severed the pilot's ability to transmit longitudinal and lateral control forces through the handle.
As a result, the aircraft lost directional control and began oscillating violently from wing to wing. The aircraft struck the runway surface multiple times, causing damage to the wingtips, the horizontal stabilizer, and the fuselage. The impact also damaged runway lighting equipment. The crew managed to bring the aircraft to a stop on the taxiway without sustaining any injuries.
The investigation
The PKBWL examined the structural integrity of the control stick and performed strength tests. The investigation focused on the mechanism of the handle failure and the ergonomic design of the cockpit. The commission analyzed the physical properties of the handle, noting that it was constructed from a composite material with a hollow interior, held together by screws and adhesive.
Investigators also reviewed the aircraft's flight manual, noting discrepancies in minimum speed data, and evaluated the manufacturer's claim that the failure might have been caused by a hard landing. However, flight data showed no significant vertical acceleration spikes during the preceding landing that would account for such a structural failure.