French investigators have determined that a Bombardier CRJ700 arriving at Lorient airport touched down halfway along a wet runway before overrunning.
The twinjet was being operated by French regional carrier Brit Air on a domestic service from Paris Orly and had been cleared for an instrument landing system approach to Lorient's runway 25.
French investigation authority BEA states that the crew had been informed about poor weather conditions, including crosswinds from the left gusting to 26kt (48km/h).
Visibility was also reduced to 2,000-3,000m, while the runway surface was wet with standing water following a downpour. Preceding aircraft had experienced control difficulties and hydroplaning.
BEA says the crew, concerned about the possibility of windshear, performed the approach with 30˚ flaps at a speed of about 150kt, disengaging the autopilot at 500ft (152m). The approach was made in darkness.
Runway 25 is just over 2,400m (7,870ft) long and had an available landing distance of 2,230m. But French investigation authority BEA says the CRJ700 touched down with its main gear about 1,100m from the runway end.
It overran the runway and struck the localiser antenna with its left wing before coming to a halt in the grass about 200m from the threshold of the opposite-direction runway 07.
BEA says there were 53 passengers and four crew members on board the jet (F-GRZE) at the time of the 16 October accident, and an evacuation was conducted through the front door and left-side overwing exits.
Brit Air operates as a subsidiary of Air France and has a regional jet fleet that includes the larger CRJ1000.