Patent ID: 7493197

Claim:
A method for evaluating and signaling the lateral margins of maneuver on either side of a trajectory scheduled in the flight plan of an aircraft furnished with a locating device and with a cartographic device formulating, on the basis of a topographic database onboard or accessible from onboard, an envelope of the terrain overflown comprising the steps of: generation, on the basis of a position of the aircraft traveling along the trajectory scheduled in the flight plan, of two adjoining lateral protection envelopes, right and left extending one to the right and the other to the left of a navigation band centered on the trajectory scheduled in the flight plan and of width Wn taking account of the uncertainties of location of the aircraft, of the inaccuracy of the envelope of the terrain overflown delivered by the cartographic device and of a lateral tolerance accepted in the tracking of the trajectory scheduled in the flight plan, the right lateral protection envelope delimiting a sufficient volume to allow the aircraft to perform at least one half-revolution, flat, to the right, during a turn with imposed radius R, the left lateral protection envelope also delimiting a sufficient volume to allow the aircraft to perform at least one half-revolution, flat, to the left, during a turn with imposed radius, and detection of the intrusions of the envelope of the terrain overflown into the right and left lateral protection envelopes, and signaling of the passages of the trajectory scheduled in the flight plan with reduced margins of lateral maneuver on the right and/or on the left corresponding to intrusions of the envelope of the terrain overflown into one or the other of the right or left lateral protection envelope; wherein the longitudinal and lateral dimensions of the right and left lateral protection envelopes are dependent on the imposed turning radius R and the positions, with respect to the aircraft, of the points of the ground traces of the turns with the imposed radius R corresponding, for the aircraft, to a vanishing of its speed component perpendicular to the course scheduled in its flight plan.