FCU - Flight Control Unit

Selection and Management

On this FCU, the speed, heading and altitude buttons can be pushed or pulled. To push a button, press the left mouse button. To pull, use the right mouse button.

When you push one of these buttons, you use the SELECTED mode of the FCU. This is the "standard" mode, where the autopilot will follow the instruction entered as a value displayed on the FCU panel.

When you pull a button, you use the MANAGED mode. It means the FMGC will automatically take control of the autopilot to provide it the right value of speed, heading or alititude in order to follow the flight plan programmed in the FMGC. When a speed, heading or altitude is managed, no value is displayed on the FCU panel, "----" appears instead.

| As you can see on this example, the speed and altitude are managed, the pilot does not have to think about the right value of speed and altitude, the FMGC handles it. Heading is selected with a value of 76°, which means the aircraft will follow this heading.

FCU features

| Autopilot Activation The autopilot is engaged pressing the AP1 button. It can not be engaged when the aircraft is on the ground. A secondary autopilot is available to provide redundacy during critic phases of the flight. In these Airbus panels, the secondary autopilot must be used for automatic landing only, as this is the most dangerous part of the flight. The secondary autopilot is engaged by pressing the AP2 button on the FCU panel.
| Speed and Auto-Throttle Speed and Mach mode are armed using the same button. To choose between Speed (in knots) and Mach, press the Speed Selector button. Auto-Throttle can be armed and disarmed using the A/THR button. If you arm the auto-throttle, nothing will happen until you arm the speed or mach mode. Conversely, if you arm the speed or mach mode, it will automatically arm the auto-throttle if it is not already armed.
| Heading / Course mode Heading and Nav (or Course) modes are designed to be set and activated using the same button. To choose between heading and course setting, press the Heading/Course selector. When the HDG or NAV mode is activated, a dot highlights next to the selected heading or course display.
| Wing Leveler Pressing the LVL button will keep your wings leveled.
| Altitude mode This mode is activated with the ALT mode button. The interesting feature here is that you can select your target altitude by increasing or decreasing the altitude by increments of 100 or 1000 feet. This is very useful when you want to select your cruise altitude (33000 feet for example), because it is much faster with 1000 feet increments. When the ALT mode is activated, a dot highlights next to the selected altitude display. When the aircraft altitude is close to the programmed altitude (within 800 feet), the dot flashes until the target altitude is reached.
| Vertical Speed When ALT mode is engaged, you can select your vertical speed (in feet per minute). You can also press this button to level off at the current altitude.
| LOC and APPR modes LOC mode activation will make the aircraft follow the actual localizer. APPR mode will do the same, and will also manage the altitude to follow the glideslope. This is very useful for automatic landings.

Autoland

The autopilot pilot is now equiped with an automatic landing capability. The autoland is automatically engaged when the aircraft is below the decision height (displayed on the Flight Mode ANunciator of the PFD).
In order to make it work, te following conditions must be fulfilled:

- AP1 must be activated.
- The APPR mode must be engaged on the FCU panel, and the aircraft must be positioned on the approach path (localizer and glideslope). Obviously, this will only work if AP1 is active.
- Auto-throttle must be armed
- Auto-Brake must be set (LOW, MED or MAX, as you wish)
- AP2 must me activated for high redundancy.

If one of this condition becomes false, the autoland is aborted.
If all these conditions remain true during the final aprroach, you will hear a beep and an AUTOLAND message appears on the E/WD. At this time, you can let the iarcraft land by its own... When the aircraft will be close to the ground, the throttle will be set to IDLE. As soon as the aircraft touches the ground, the spoilers will be deployed if they were armed (recommended), and reverse thrust will be engaged and brake power will be applied until the aircraft decelerates to 60 knots. Then thrust will come back to IDLE, and auto-brake will keep braking until the aircraft comes to a complete stop. At this time, all autopilots and auto-throttle will be disarmed, and the control of the aircraft comes back to the pilot.

If the AUTOLAND is engaged and you wish to abort it, you can easily abort it by switching AP1 or AP2 OFF or by disarming auto-throttle. As soon as AUTOLAND is aborted, it will not be available again until the aircraft has landed.

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