Abstract: The invention relates to a method and a system for aircraft navigation along a predetermined airway, including an on-board navigation system supplying a positioning integrity of the aircraft during flight relative to said airway respecting an expected position precision performance level, and at least one on-board radio receiver on the aircraft suitable for communicating with at least one land-based radio beacon suitable for supplying a distance of the aircraft relative to said radio beacon. The system includes a module configured to obtain, from a current position of the aircraft and stored data, a tuple of radio beacons to be used, a module configured to obtain a distance measurement of the aircraft relative to each of the N radio beacons of said tuple, a module configured to compute an integrity position from distance measurements obtained by a predetermined computing method, and a module configured to use the computed integrity position as current integrity position.

Abstract: A method for manipulating aircraft flight plan segments is provided. A result of an avionics calculation, such as a flight plan sequencing, is selected from among a plurality of results determined by a plurality of systems executed in parallel and placed in competition, each system communicating to at least part of the other systems conditions to be satisfied by the result of a calculation, the method comprises the steps of a given system from among the plurality of systems shares its own calculation result with at least one other system only if its own calculation result satisfies the conditions received from at least one other system. Developments describe various modalities of negotiation and/or selection of the results, the switch to independent and/or the deactivation of a system, voting and/or weighting mechanisms. Software and system aspects are described.

Abstract: This method for determining an obstacle avoidance guidance law for an aircraft is implemented by a system for determining said guidance law. The aircraft comprises a collision avoidance system adapted to detect a collision risk with the obstacle and said determination system. This method comprises determining one or more set points from among flight path angle and speed set points, at least one set point depending on at least one vertical speed limit value, at least one set point comprising a vertical component in a vertical direction, each limit value being provided by the collision avoidance system following the detection of a collision risk with the obstacle; and computing the avoidance guidance law as a function of the determined set points. During the determination step, at least one determined set point comprises a longitudinal component in a longitudinal direction perpendicular to the vertical direction.

Abstract: A method for securing a ground speed used for guiding landing of an aircraft by determining a ground speed of the aircraft and determining a landing guidance instruction based on the determined ground speed. Next, estimate the vertical speed of the aircraft and limit, during guidance along a glide path having a descent angle, the determined ground speed as a function of the estimated vertical speed. The guidance instruction is based on the limited ground speed. Further, measure the height of the aircraft and compare it with a threshold height. If the measured height is greater than the threshold height, limit the ground speed as a function of acceleration measurements. If the measured height is below the threshold height, limiting the ground speed as a function of the estimated vertical speed and as a function of acceleration measurements of the aircraft taken once threshold height has been crossed.

Abstract: Guidance for an aircraft correcting a trajectory deviation due to wind computes a roll command during trajectory alignment according to imposed alignment passing through a determined point, via a current angular divergence between a line through the point and aircraft and direction of alignment and of a current estimated ground speed of the aircraft with respect to a frame of reference. The current estimated ground speed is computed via a current air speed and stored wind speed. The stored wind speed is obtained via at least one wind speed computed via a first value of a first speed equal to the speed of the said aircraft with respect to a frame of reference originating from a satellite navigation system and a second value of a second speed equal to the air speed. The first and second value are simultaneously accounted earlier than or at the instant at the alignment phase.

Abstract: The invention relates to flight control systems for aircraft, which have large control loops delivering load factor commands and which are applied to flight controls more suited to the following by the pilot of a longitudinal attitude deviation instruction than to the following of a load factor instructions. It consists of a small control loop generating a deviation indicator displayed by the flight director on the PFD screen, with a converter for converting a controlled load factor into a longitudinal attitude deviation instruction comprising a bandpass filter allowing the integration for the calculation of the longitudinal attitude deviation instruction value in the piloting frequency span only.

Abstract: The invention relates to flight control systems for aircraft, which have large control loops delivering load factor commands and which are applied to flight controls more suited to the following by the pilot of a longitudinal attitude deviation instruction than to the following of a load factor instructions. It consists of a small control loop generating a deviation indicator displayed by the flight director on the PFD screen, with a converter for converting a controlled load factor into a longitudinal attitude deviation instruction comprising a bandpass filter allowing the integration for the calculation of the longitudinal attitude deviation instruction value in the piloting frequency span only.