What happened
On November 11, 2010, a Piper PA 28-161 (registration F-GIBQ) departed from Cannes Mandelieu airport carrying the pilot and two passengers. The flight plan involved following the coastal transit south of Nice before returning via the NA waypoint. At approximately 12:00 local time, the pilot reached the NA waypoint at 1,800 ft and notified Nice Information of his intention to fly toward the communes of Saint-Jeannet, Vence, and Tourrettes-sur-Loup.
Shortly after, the pilot requested a deviation toward the Caire sector, north of Tourrettes-sur-Loup, before returning to the original route. While navigating a valley in the Caire sector, the aircraft struck trees at an altitude of approximately 2,670 ft. The impact caused the aircraft to catch fire, resulting in three fatalities and the total destruction of the aircraft.
The investigation
The investigation focused on the flight path and the aircraft's performance capabilities. Radar data indicated that when the aircraft entered the valley, it was at an altitude of 1,944 ft. By the final recorded point, 67 seconds later, the aircraft had climbed to 2,644 ft. Witnesses on the ground, including friends of the occupants, observed the aircraft flying in a climbing direction into the valley before striking trees and bursting into flames.
Examination of the wreckage revealed no mechanical failures. Analysis of the propeller indicated that the engine was producing power at the moment of impact. While the aircraft's takeoff mass was estimated to be 5 kg above the maximum allowable takeoff weight, fuel consumption during the flight meant the aircraft was likely within weight limits at the time of the accident. However, calculations showed that the average vertical climb rate achieved within the valley exceeded the performance limits specified in the aircraft's flight manual for those specific atmospheric conditions and weight.
Findings
- The primary cause of the accident was the unplanned deviation into terrain that exceeded the aircraft's climb performance capabilities.
- The pilot likely attempted to fly into the valley to greet a group of friends, choosing an entry altitude that did not allow for a safe exit from the ascending terrain.
- The aircraft's climb performance was insufficient to clear the rising terrain of the valley floor.