What happened
On January 15, 2015, a Dassault Falcon 20, registration F-GYCA, was conducting a short private flight from Avignon Caumont to Cannes Mandelieu. During takeoff, the crew encountered an issue with the number 1 engine's N1 thrust, leading them to decide to proceed with the flight using manual regulation for that engine. During the flight, the crew also dealt with a recurring circuit breaker trip in the engine start control system.
During the approach to Cannes Mandelieu, the crew experienced significant confusion regarding navigation points and the active runway. Due to high workload and a failure to properly prepare for the specific arrival procedures at Cannes, the crew misidentified the approach path. While the controller had authorized an approach for runway 17, the crew was actually aligning with runway 35.
As the aircraft descended at a high rate of 2,20 and at an excessive speed of 250 knots, it approached another aircraft, a F-BXIF, which was departing on runway 17. The two aircraft came within approximately ten meters of each other at an altitude of 1,000 feet. The crew of the F-GYCA performed a high-bank right turn to avoid the collision after being alerted by the tower controller.
The investigation
The BEA investigation examined the flight's sequence of events, the technical status of the aircraft, and the performance of air traffic controllers. The investigation looked into the crew's preparation, specifically their failure to review the mandatory arrival briefing for Cannes Mandelieu. The investigators also analyzed the air traffic control environment, noting that the approach controller was in a training situation and that the transfer of communication between Nice approach and Cannes tower occurred late and outside of standard parameters.
Findings
- The crew's workload was significantly increased by the decision to operate with one engine in manual regulation and the need to manage engine-related electrical faults.
- A lack of flight preparation resulted in the crew being unaware of the specific approach requirements for Cannes Mandelieu and failing to realize they were approaching the wrong runway.
- The crew did not declare a degraded situation or notify controllers of their engine issues, which prevented controllers from adjusting guidance accordingly.
- The approach controller, acting in a training capacity, failed to impose a holding pattern (360-degree turn) despite recognizing the aircraft's excessive speed and unstable approach.
- The transfer of responsibility from the approach controller to the tower controller was performed too late, while the aircraft was already below the required transfer altitude.
- The aircraft's high descent rate triggered a terrain warning (MSAW), but the controller did not relay this warning to the crew.