French investigators have determined that a Swiftair Boeing 737 freighter landed long at Montpellier in windshear conditions before overrunning and coming to rest with its nose partly submerged in water.
The aircraft, having carried out a VOR-DME approach to runway 12L at night in heavy rain, touched down 1,500m beyond the threshold – more than halfway down the 2,600m runway.
French investigation authority BEA states that the aircraft encountered windshear as it descended from 200ft to 100ft. Over the space of 4s the wind shifted from 350° to 70° and fell from 30kt to 8kt, replacing a substantial tailwind with a light headwind component.
The 737 had already been high on the approach, and the wind change increased airspeed and lift, but the consequences on flight parameters were “not detected” by the crew, says the inquiry.
It overflew the threshold at 100ft with a speed 34kt above the approach reference of 136kt, and began to flare.
