What happened
On July 14, 2008, a Humbert-Tétras ultralight, registration 17-QH, departed La Rochelle for Marennes. While cruising at approximately 1,500 feet over the sea, the aircraft suddenly banked sharply to the right and entered a rapid descent. Witnesses observed the aircraft enter a left-hand spin before heading toward the coastline. The aircraft flew at a very low altitude over the coastal road and ultimately struck the surface of the water approximately 20 meters from the shore. The impact was severe, resulting in one fatality (the pilot) and the total destruction of the aircraft.
The investigation
The investigation focused on the aircraft's mechanical condition, the pilot's medical history, and the flight trajectory. Technical examinations of the Rotax 912 ULS-FR engine and the propeller showed no mechanical failures; while the engine was producing low power at the moment of impact, the internal components were in good condition. The aircraft's GPS data confirmed the flight path observed by witnesses.
Medical analysis via autopsy revealed that the pilot had suffered a cardiac event. Specifically, findings showed coronary artery disease and localized changes in the heart muscle consistent with myocardial ischemia. Investigators also noted that the pilot had reported feeling unusually fatigued to a friend the day before the flight. Furthermore, the investigation examined the aircraft's emergency parachute system, noting that while the pilot had likely initiated the deployment procedure—evidenced by the magnetos being switched to the 'OFF' position—he was unable to complete the process.
Findings
- The primary cause of the accident was the pilot's loss of control due to a cardiac event.
- The pilot's failure to account for unusual fatigue experienced prior to the flight acted as a contributing factor.
- There were no mechanical or structural failures identified in the aircraft or engine that could explain the sudden change in flight path.