Air France flight AF3682 was on ILS final approach to runway 08 at Cayenne-Rochambeau aerodrome, the airplane encountered windshear and sank suddenly at a height of a hundred feet. A “SINK RATE” warning sounded.
The Co-pilot, at the controls, pulled back on the control column, then reduced thrust to land. The Captain increased thrust and took over the controls.
The airplane touched down on its left main landing gear thirty metres before the runway threshold, bounced and landed about five hundred metres further on.
The incident was caused by encountering windshear at a low height, associated with a squall, which surprised the crew. In the course of the approach, the crew did not identify the risk of encountering such a phenomenon and no information was transmitted to them about this point. They thus had not envisaged any specific strategy.
Air France flight AF3682 speed dropped below approach speed to reach Vapp – 6 kt. The airplane began to sink.
Close to the ground, the crew, whose attention was concentrated on the exterior in this phase and was disturbed by the deterioration of visibility due to the rain shower, did not notice the rapid variations in speed revealing that airplane was sinking.
The following factors contributed to the event: the absence of exact instructions given to transport public flight crews for performing approaches in stormy conditions; the limits on the capacity of the autothrust system to maintain airplane speed in the conditions encountered.