WPR18LA121 · Airborne Windsports PTY Ltd XT-912-L

The owner lent the weight-shift-control aircraft to the pilot for a local flight. During that flight, the pilot noted that the aircraft's handling characteristics were different than other weight-shift-control aircraft he had flown, and that it was not as responsive to his control inputs. He asked the mechanic who had performed the most recent condition inspection whether these characteristics were normal, and the mechanic stated that it was typical for the aircraft make. On the day of the accident, the pilot again borrowed the aircraft for an early morning flight in light wind conditions. He noted during takeoff that the aircraft's roll tendency was more pronounced, and he completed a traffic pattern followed by a low pass over the runway. He again climbed the aircraft to pattern altitude and after leveling off, noticed that the roll tendency had become worse and he had limited control of the aircraft. On final approach, the aircraft's stability further decreased, and the aircraft entered a spiraling descent to ground contact. The aircraft's wing was replaced about two years before the accident and the required 5-hour flight testing period of the carriage and wing combination had not been completed. Examination of the aircraft revealed that the right outboard leading edge had fractured. The mechanic that examined the wreckage stated that the fracture surfaces and surrounding fabric indicated that the fracture occurred inflight, with the fractured edge of the tube rubbing the cloth to failure. He stated that this type of fracture in the leading edge was known to occur in this make and model, usually due to improper ground handling. Although review of maintenance records revealed no indication of previous damage to the wing assembly, the circumstances of the accident are consistent with a failure of the leading-edge structure, which subsequently resulted in an inflight loss of control.

Verbatim NTSB analysis and probable cause from the NTSB dataset