What happened
On December 31, 2015, an Airbus Helicopters AS350B3e, registration F-HOLD, was engaged in aerial work operations near the Maïdo escarpment in Réunion. The mission involved transporting cargo between the Mafate La Nouvelle helisurface and the Maïdo parking area.
Earlier that morning, the pilot had completed seven successful rotations, dropping an assistant at the Maïdo parking lot to facilitate cargo loading. After returning to Mafate La Nouvelle to refuel, the pilot notified the assistant via radio that only two additional rotations would be performed due to deteriorating weather conditions. Following the final cargo delivery, the pilot attempted to fly back to the Maïdo parking area to pick up the assistant and prevent them from having to descend the mountain on foot. During this final approach, the aircraft entered cloud cover and struck the terrain. The wreckage was located 20 meters below the ridge of the Maïdo escarpment.
The investigation
The investigation examined the wreckage and flight data recorders. Analysis of the engine showed it was delivering power at the moment of impact, and no anomalies were found in the flight controls or mechanical systems. Data from the DECU and EDR confirmed the engine functioned normally until the end of the flight.
Witnesses on the ground, including hikers, observed the helicopter flying toward the Maïdo ridge. They noted the aircraft entered the clouds, emerged briefly during a left turn, and then entered the clouds a third time before a loud impact was heard. The witnesses also noted the aircraft was traveling at a significant speed.
Weather conditions at the site were characterized by broken clouds, rain, and an unstable western weather pattern. While the average wind was 6 knots, gusts reached up to 31 knots. The cloud base was low and intermittently touching the terrain.
Findings
- The pilot, an experienced professional with approximately 14,000 flight hours, attempted to complete the final leg of the mission despite worsening visibility.
- The pilot likely attempted to navigate along the north face of the cliff to avoid the clouds, leveraging local geographic knowledge.
- The primary cause of the accident was the pilot's decision to continue the flight toward the Maïdo parking area, which led to entering cloud cover and the subsequent loss of visual references relative to the terrain.