FCU SELECTIONS: CLEARANCE, TARGET AND MODE
FCU selections provide the immediate targets and mode requests used while the flight plan is being flown. Keep them tied to the current clearance and the intended vertical and lateral strategy. An entered target and the mode using it are different parts of the guidance state. [21, PDF pp. 51-64]
In the normal push/pull arrangement, pushing the applicable knob requests managed guidance and pulling requests the corresponding selected operation. For a cleared heading, set the target, request the selected mode and check the FMA and turn. The same discipline applies when handing guidance back to a managed path. [21, PDF pp. 51-64]
The selected altitude continues to limit the authority given to the guidance. A lower flight-plan constraint farther along the route does not remove an uncleared FCU level. During descent in particular, keep the clearance, selected altitude, active mode and resulting path in agreement before making another intervention. [21, PDF pp. 51-64]
Original Fenix FCU/EFIS detail. ALT 10000 is selected; SPD/HDG windows are dashed. The far-left speed knob is outside this source view. [1, Source illustration]