What happened
On September 2, 1961, a Pilatus Porter HB-FAZ, operated by Air-Alpes, was conducting an experimental flight to survey potential mountain landing platforms in the Mont Blanc massif. The aircraft, equipped with skis for glacier operations, had departed from Chambéry-Aero-Club earlier that morning. After performing several landings on the Tour Glacier, the crew proceeded to the Dôme du Goûter.
Upon arriving at the Dôme du Goûter at approximately 08:40, the crew waited for local cloud cover to dissipate. After about ten minutes of idling the engine, the pilot attempted a takeoff along the slope, aiming for a path between two crevasses. During the takeoff roll, the aircraft failed to gain sufficient airspeed to lift off the snow. The aircraft struck the edges of two crevasses before impacting the ground on its belly. While the aircraft sustained approximately 80% damage, the two crew members escaped through the emergency exits with only minor contusions and superficial injuries.
The investigation
Due to the extreme terrain, investigators were unable to access the wreckage directly. The site was only reachable via an Alouette helicopter dispatched by the High Mountain Gendarmerie. The investigation relied on statements from the crew and findings from the specialized gendarmerie unit that reached the site shortly after the accident. The aircraft was being used by Air-Alpes as a temporary replacement while they awaited the delivery of a Turbo Porter.
Findings
- The aircraft failed to achieve sufficient lift to clear the terrain.
- A reduction in engine power is the suspected primary cause of the failed takeoff.
- The aircraft's path was interrupted by the edges of two crevasses located roughly 150 meters apart.