Abstract: In an altitude and vertical speed indicator for aircraft, an altitude indicator includes a graduated scale vertically mobile past a fixed marker and a vertical speed indicator includes a pointer rotatable about the point of intersection of a straight line segment through the fixed marker and a straight line segment through the pointer and pointing towards the mobile scale. The angle defined by the fixed marker and the pointer is representative of the vertical speed value.

Abstract: A flight control system for an aircraft, particularly for a helicopter receives a number of items of information, especially the position of flight control members of said aircraft, and sends, depending on these items of information, control inputs to controls of the aircraft. The flight control system includes at least one sensor which measures values representative of the flight of the aircraft and computing means which generate, at least from these measured values and from the positions of flight control members, corrected control inputs which are sent to the controls and which enable control of the lateral speed of the aircraft with respect to the ground, without varying the course of the aircraft.

Abstract: A cyclic stick system for a helicopter or other aircraft includes memories for holding minimum and maximum speed values, a comparator for comparing an air speed V1 with the minimum and maximum speed values, a router for selecting either the air speed V1 or a quiescent speed, a subtracter for obtaining a difference between the output of the router and a reference speed, another router for selecting between the difference and a signal representing an orientation of the stick, and a switch for selecting times when the air speed V1 is to be stored as the reference speed. On the basis of the air speed V1 and under the control of the device for retrimming said cyclic stick, the system acts on the motorization of stick in order to confer on the helicopter apparent longitudinal static stability in terms of forces on the cyclic stick so that to accelerate (or decelerate) and maintain a new higher (or lower) speed.

Abstract: A cyclic stick system for a helicopter includes sensors for measuring at least one parameter representative of the current flight status of the helicopter. In response to the at least one parameter, the cyclic stick system either (1) continuously and automatically recenters the forces on the cyclic stick, thus canceling out the residual static forces, or (2) allows the pilot fully to feel the countering action of the elastic return device on the cyclic stick.

Abstract: A rudder bar system for a helicopter controlled in yaw by acting on the tail rotor or an equivalent device has a capability, as a function of the parameters representative of the current flight status of the helicopter, of either automatically continuously recentering the forces on the rudder bar, which cancels out the residual static forces and gives the pilot a tactile sensation close to that given by a friction-type rudder bar, or allowing the pilot fully to feel the countering action of an elastic return device such as a spring.