What happened
On August 19, 2017, at 01:16 UTC, an Air France Airbus A340-313, registration F-GLZO, was performing a commercial flight from Bogotá El Dorado Airport to Paris Charles de Gaulle. Due to high altitude and temperature conditions at Bogotá, the aircraft's takeoff weight was restricted to ensure safety margins.
During the takeoff roll on runway 13R, the aircraft experienced a rapid change in wind conditions. As the aircraft approached rotation speed (VR) of 138 kt, the wind shifted from an 11 kt headwind to a 12 kt tailwind. Simultaneously, a downward vertical wind component of approximately 4 kt developed. Six seconds after liftoff, the aircraft's flight management system detected windshear, triggering a red "WINDSHEAR" warning and an audible alert. The aircraft's airspeed dropped to 128 kt, which was 13 kt below the minimum selectable speed (VLS). The high angle of attack triggered the "Alpha Prot" protection mode. Despite the encounter, the crew maintained TOGA power, and the aircraft successfully climbed, passing the runway threshold at 58 ft and eventually recovering airspeed.