Overview
On an uneventful flight from Lyon-Satolas Airport to Lorient-Lann-Bihoué Airport, the crew of a twin-engine aircraft contacted air traffic control and requested special clearance to cancel their IFR flight plan. The purpose was to conduct a visual circuit over the Bay of Quiberon to show the 'Norway' ship to passengers. While cruising under VFR mode in excellent weather conditions at an altitude of 2,000 feet, the aircraft collided with a private Cessna 177 Cardinal registered as F-GAJE and owned by the Aéro Club de Vannes. Following the collision, both aircraft entered an uncontrolled descent and crashed into the Bay of Quiberon approximately 1,500 meters from the ship and 10 kilometers off Quiberon. All 14 individuals on board the Beech 1900D, as well as the pilot of the Cessna 177, were killed.
Sequence of Events
The crew of the Beech 1900D changed their flight regime and trajectory to perform the visual circuit, placing the aircraft in an improvised and unusual flight situation for a public transport aircraft. The pilots of both aircraft were operating on different frequencies and were unaware of each other's presence. Their attention was focused on the ship 'Norway'. The cockpit organization and ergonomics of the Beech 1900D did not allow effective monitoring, particularly towards the outside of the turn. The Cessna 177's dead angles likely masked the Beech 1900D from its pilot as the aircraft approached each other. Additionally, the position of the sun may have hampered the pilot of the Cessna 177. The Cessna's transponder was off, preventing it from being viewed on ATC radar based in Lorient; consequently, air traffic control could not provide traffic information to the Beech 1900D crew.
Probable Cause
The collision was due to the absence of visual detection of the other aircraft by each of the two crews in uncontrolled Class G airspace, where collision avoidance relies exclusively on external vigilance (the 'See and Avoid' rule). The decision to change the flight regime and trajectory placed the crew of the Beech 1900D in an improvised and unusual flight situation with a public transport aircraft. Contributing factors included the pilots being on different frequencies and unaware of each other's presence, their attention focused on the ship, insufficient cockpit monitoring in the Beech 1900D, dead angles of the Cessna 177, the sun's position possibly hampering the Cessna pilot, and the Cessna's transponder being off, which precluded ATC from providing traffic information.