ROLL, YAW AND SIDESTICK PRIORITY
Normal-law lateral control interprets sidestick roll input through a roll-rate demand and coordinates the relevant surfaces. Bank-hold and return tendencies change across the law’s operating regions. Rudder functions include yaw damping, turn coordination and trim, with the appropriate computer and hydraulic dependencies. The sidestick therefore influences yaw indirectly through coordinated flight as well as commanding roll. None of this removes the need to monitor sideslip, track and the actual flight path, particularly during asymmetric thrust or degraded references. [73, PDF pp. 14–18, 24–26] [87, PDF p. 61]
Sidesticks are not mechanically linked to one another. The reference describes simultaneous-input and priority logic, with associated visual/aural indications. One pilot’s control does not simply push the other handle to match, and dual input should not be treated as a conventional shared control column. The priority controls establish which input is accepted under their defined logic. Their short/held/latched details belong to the applicable source standard; an arbitrary remembered duration is not supplied here as a universal Fenix command. [73, PDF pp. 36–41]
A sideslip target associated with asymmetric-thrust conditions is not the same thing as the geometric centre of a slip indication in every phase. The reference distinguishes the target used for efficient asymmetric flight. Interpret it with the engine state, flight phase and actual control law. Pedal input also serves a different role on the ground, where nosewheel steering may be coupled within its authority. Keep airborne yaw control, ground steering and the hardware axis mapping identifiable so an apparent rudder effect is attributed to the correct function. [73, PDF pp. 17–18, 26] [90, Rudder/tiller/PED DISC configuration]
The loss of a FAC, an inertial reference or hydraulic users can change different parts of this picture. A roll-direct relationship in a degraded law does not establish that every yaw function is retained, and a working rudder does not establish normal characteristic-speed calculation or turn coordination. For a useful system assessment, state which demand law is active, which surfaces respond and which augmentation/indications remain. That is more precise than describing the aircraft as broadly fly-by-wire or manual after a failure. [73, PDF pp. 27–33] [87, PDF pp. 62–64]