What happened
On July 26, 2014, a GROB 103C Twin III, registration D-KAMX, was performing a solo flight at the Puimoisson airfield. The pilot, who had traveled from Germany the previous day and spent time reassembling the motor glider, intended to test the aircraft's performance before conducting future flights with passengers. After taking off from the unpired runway 26, the pilot flew for approximately twenty minutes in the vicinity of the airfield.
As the aircraft transitioned into the tailwind leg of the approach, witnesses observed the glider flying at a lower altitude than usual. Near the end of the tailwind leg, the aircraft suddenly entered a steep nose-down pitch of approximately 45 degrees, striking the ground and disappearing into the vegetation. The impact resulted in the death of the pilot and the destruction of the aircraft.
The investigation
Investigators analyzed flight data from the FLARM system, which established the aircraft's final trajectory. The last recorded point, located 115 meters from the impact site, showed the aircraft was at an altitude of 867 meters (approximately 120 meters above ground level) traveling at a speed of 110 km/h.
An examination of the wreckage revealed no mechanical anomalies that could account for the loss of control. Furthermore, there was no evidence that the pilot attempted to bail out of the aircraft. Medical examinations of the pilot, including a review of potential medication use, yielded no findings that would explain the accident. Meteorological conditions at the time included a 7-knot wind from 320°, CAVOK visibility, and moderate turbulence.
Findings
While the investigation could not definitively determine the cause of the loss of control, investigators noted that the pilot may have been experiencing fatigue following his travel from Germany and the physical labor of reassembling the glider. Additionally, the possibility of a sudden medical event during the late afternoon flight could not be ruled out.