Abstract: A mass memory stores a data base representing at least a substantial part of the terrestrial globe, in accordance with a grid configuration on several levels, said grid configuration being in particular more precise in the vicinity of an airport. Status indications are received representing the position of the aircraft with two horizontal components, and the altitude, and the velocity and acceleration vectors of the aircraft, as well as control indications coming from the flight deck. In accordance with the horizontal components of the position of the aircraft, a temporary local map is transferred into a fast access memory, on the basis of which map, an altitude envelope of the terrain is established in the zone where the aircraft is travelling. Anticollision processing make it possible to establish an alarm if the relation between a protection field and the altitude envelope meets a first condition which is defined at least partly by the control indications.

Abstract: A mass memory stores a data base representing at least a substantial part of the terrestrial globe, in accordance with a grid configuration on several levels, said grid configuration being in particular more precise in the vicinity of an airport. Status indications are received representing the position of the aircraft with two horizontal components, and the altitude, and the velocity and acceleration vectors of the aircraft, as well as control indications coming from the flight deck. In accordance with the horizontal components of the position of the aircraft, a temporary local map is transferred into a fast access memory, on the basis of which map, an altitude envelope of the terrain is established in the zone where the aircraft is travelling. Anticollision processing make it possible to establish an alarm if the relation between a protection field and the altitude envelope meets a first condition which is defined at least partly by the control indications.