What happened
On August 2, 2018, a Rolladen Schneider LS4 glider, registration F-CADT, departed from the Chambéry Challes–les-Eaux airfield via winch launch for a local recreational flight. The pilot began climbing over the terrain east of the airfield before heading north.
At approximately 15:20, the aircraft was tracked passing south of Lake Annecy at an altitude of roughly 2,100 meters. Shortly thereafter, the aircraft's position was lost from the Glidernet tracking system for fifteen minutes. The final recorded position was approximately 21 kilometers northeast of the last known point, at an altitude of 2,130 meters. The wreckage was eventually located eight kilometers south of the last track, on a mountainside at an altitude of 1,800 meters. The impact resulted in one fatality and the destruction of the aircraft.
The investigation
The investigation focused on the wreckage, meteorological conditions, and the pilot's medical history. Examination of the F-CADT wreckage revealed that the fuselage and tail section were intact, while the wings were slightly deformed and the cockpit was destroyed. The nature of the damage indicated the aircraft struck the ground at a significant angle, likely a combination of a nose-down attitude and the slope of the terrain, with the wings hitting the surface flat. Investigators confirmed that all flight controls were functional prior to impact.
Meteorological conditions at the time involved partly cloudy skies, good visibility, and moderate turbulence caused by thermal convection and terrain-induced winds.
Medical examinations and an autopsy of the pilot revealed an ongoing myocardial infarction (heart attack). The pilot also had several cardiovascular risk factors, including obesity and a history of smoking. Notably, the pilot had experienced a fainting spell with loss of consciousness approximately one month prior to the accident, an incident that was not reported to medical authorities or flight instructors.
Findings
While the investigation could not definitively prove the exact cause, the evidence points toward a medical emergency occurring during flight. The autopsy confirmed a developing heart attack, and the pilot's history of a recent syncopal episode suggests a potential loss of consciousness.
Contributing factors included the physiological strain of flying at altitudes between 1,500 and 3,000 meters, where reduced oxygen partial pressure increases cardiac workload. The pilot may have underestimated the severity of his underlying coronary condition or failed to report his recent medical episode to avoid losing his medical certification.
Safety action
Following the investigation, the aeronautical medical authority and the Société Francophone de Médecine Aérospatiale (Soframas) have engaged in discussions to promote awareness of regulation MED.A.020, which requires pilots to report any health changes that could affect flight safety. The medical authority plans to implement a specific acknowledgment form for pilots to sign during medical examinations to ensure they understand their obligation to report such changes.