Method and device for aircraft, for avoiding collision with the terrain

A system for preventing collisions with a terrain comprising:

• a detecting unit configured for detecting risks of collision with the terrain after a predetermined forecasting delay, the risks of collision being located in a protection volume linked to an aircraft and located relative to the terrain being flown over by means of an onboard locating equipment item, the detecting unit being oriented in a direction in which the aircraft is moving and configured in such a way as to model a vertical terrain avoidance maneuver trajectory undertaken over the forecasting delay from the trajectory followed by the aircraft predicted from flight information delivered by flight equipment of the aircraft,
• a determining unit configured for determining, based on a trajectory followed by the aircraft, a possible limit point for success of the vertical terrain avoidance maneuver, said trajectory being predefined as a function of the type of the aircraft, and
• an indications unit configured for giving indications on azimuth clearance sectors, around the direction in which the aircraft is moving, suitable for of the vertical terrain avoidance maneuver, the indication unit linked to the aircraft and configured in such a way as to contain a limit point protection volume and, for different azimuths covered, trajectories of a compound maneuver beginning with change-of-heading maneuvers making it possible to reach an azimuth and continuing with the vertical terrain avoidance maneuver,
• an estimating unit configured for estimating a free-travel distance in each azimuth clearance sector on a straight distancing trajectory with constant gradient and over a distance corresponding to more than one minute of flight, the free-travel distance being free of potential conflicts with the terrain, and
• a signaling device configured for signaling azimuth clearance sectors and free-travel distances.