What happened
On March 30, 2008, at approximately 12:40 PM, a privately operated Kitfox IV-1200, registration HB-YFZ, was performing a takeoff from Birrfeld airfield. During the initial climb, at an altitude of roughly 80 meters, the engine lost power. The pilot attempted to execute a sharp left-hand turn to reach a nearby glider airstrip, but the aircraft's rate of descent was too high. The aircraft subsequently struck the ground, causing the landing gear to collapse and the airframe to sustain heavy damage. The pilot sustained one serious injury during the impact.
The investigation
Investigators examined the wreckage and the engine components. While the engine was tested on a stand and showed no mechanical malfunctions, it was observed that the engine continued to run for approximately 30 seconds after the fuel supply was cut, which aligned with the timing of the accident. A critical finding was discovered regarding the fuel system: the fuel valve located beneath the instrument panel was mislabeled. The label marked "OFF" had shifted 90 degrees, covering the "ON" position, which created a highly misleading indicator for the pilot.
Findings
- The engine failure was caused by a lack of fuel supply.
- The fuel supply was interrupted due to the unintentional closure of the fuel valve.
- The mislabeled fuel valve presented a significant technical defect that likely led the pilot to close the valve during pre-flight preparations.
- The pilot's decision to perform a steep, tight turning maneuver at low altitude following the engine failure contributed to the loss of control and the subsequent ground impact.