What happened
On 16 October 2019, a Cessna 172 S, registered F-OKDV, crashed near the Plaine des Sables on Reunion Island during a local flight. The aircraft had departed from Saint-Pierre aerodrome with the pilot and three passengers, intending to fly over the Piton de la Fournaise volcano.
During the flight, the aircraft followed the Langevin River ravine, gaining altitude as it progressed. Analysis of onboard video and passenger photographs indicates that the aircraft was climbing through the ravine, likely utilizing dynamic uplifts created by the local wind conditions. However, as the aircraft approached the Cassé de la Plaine des Sables, it was flying at a low altitude, specifically less than 300 feet above the terrain. Shortly after crossing this area, the aircraft entered a right bank and collided with the ground. The impact was violent, leaving the wreckage upside down on the volcanic plateau. The accident resulted in three fatalities (the pilot and two passengers) and one serious injury.
The investigation
The BEA examined the wreckage, engine components, and various digital records, including onboard video and passenger photos. Investigators analyzed the engine's power unit and found that it was delivering power at the moment of impact. While an insulation defect was found in one ignition wire and a twisted needle was noted in the fuel manifold, spectral analysis of the onboard video soundtrack suggested that engine speed remained stable until the very end of the flight, effectively ruling out a sudden engine malfunction as the cause of the crash.
Meteorological data and witness statements from hikers were also reviewed. The investigation established that the region was experiencing moderate trade winds, which were known to create significant turbulence, including downdraughts, in the area of the Langevin ravine and the plateau cliffs.
Findings
- The primary cause of the collision was the low flight altitude, which left the pilot with insufficient margin to recover from maneuvers or environmental disturbances.
- The flight continued through a highly turbulent environment, where the aircraft's climb performance was limited by the altitude and the presence of potential downdrafts.
- The aircraft's right-hand bank prior to impact suggests a loss of control during the turn, though the specific trigger for the maneuver could not be definitively determined.