What happened
On December 11, 2015, a private Cessna Citation C550, registered M-AGGY, was performing a visual approach to the Oyonnax Arbent aerodrome in France. The flight, which originated from Saint-Brieuc Armor, was carrying a crew of two and four passengers.
During the approach to runway 22, the crew became preoccupied with the surrounding mountainous terrain. While the aircraft was descending, the flaps were inadvertently retracted. As the aircraft approached the threshold, the Enhanced Ground Proximity Warning System (EGPWS) triggered several terrain and 'too low flaps' alerts. Despite the high approach speed—estimated at approximately Vref + 30 knots—the crew did not initiate a go-around.
During the flare, the co-pilot deployed full flaps, which caused a decrease in the aircraft's pitch and further delayed touchdown. The aircraft touched down 306 meters past the threshold. Due to the excessive speed and late touchdown, the aircraft could not stop within the remaining runway length, resulting in a longitudinal excursion. The nose gear collapsed as the aircraft crossed an embankment 150 meters beyond the runway end, and the aircraft eventually came to a halt against a grove of trees. The aircraft sustained significant damage.
The investigation
The BEA examined the flight data recorder (FDR) and cockpit voice recorder (CVR) to reconstruct the final minutes of the flight. The investigation focused on the crew's performance, the aircraft configuration, and the environmental challenges of the Oyonnax Arbent aerodrome. Investigators analyzed the flight's preparation, noting that the destination had been changed from Annecy or Lyon to Oyonnax to better accommodate the passengers' meeting schedule. The investigation also reviewed the crew's task distribution and their response to the EGPWS warnings and the landing checklist.