Patent ID: 9617012
Date: 2017-04-11
CPC Classifications: B64D,G01C,G05D

Claim:
1. A method of automatic protection of an aircraft against a risk of collision with the ground, comprising the steps: implementing on the aircraft at least one protection function, said protection function preventing the aircraft from flying under a given height with respect to the ground, said protection function being capable of being activated and deactivated, automatically and repetitively, during a landing on a landing strip, at least when the protection function is activated, performing the following successive steps: determining a plurality of data including the current values of parameters related to the flight of the aircraft, namely at least the current position of the aircraft and a current heading deviation of the aircraft with respect to the landing strip, as well as at least one target point; calculating, from some of these data, a current longitudinal distance, this current longitudinal distance being defined in the horizontal plane and being necessary and sufficient for bringing the aircraft into a position for deactivating the protection function; and checking whether at least the following first condition is met: in which: XAC illustrates a longitudinal coordinate of the current position of the aircraft, this longitudinal coordinate having a negative value and being defined along a longitudinal axis of the landing strip in the horizontal plane, with respect to a reference point; sign represents the sign; D4 is the current longitudinal distance, Δχ is the current heading deviation of the aircraft with respect to the landing strip; and XTGT is a longitudinal coordinate of a target position dependent on said target point, said method including an additional step comprising deactivating the protection function if at least said first condition is met.