System 22 Auto Flisht

Question 1

The Flight Management Guidance System (FMGS) contains the following units:

Answer 1

• Two Flight Management Guidance Computers (FMGC)
• Two Multipurpose Control and Display Units (MCDU) (third MCDU optional)
• One Flight Control Unit (FCU)
• Two Flight Augmentation Computers (FAC).

Question 2

What does the FAC control?

Answer 2

The FAC controls rudder, rudder trim and yaw damper inputs. It computes data for the flight envelope
and speed functions. The FAC also provides warning for low-energy and windshear detection if these
functions are installed.

Question 3

What modes can the FMGS operate in?

Answer 3

Dual mode (the normal mode)
- Independent mode. Each FMGC being controlled by its associated MCDU
- Single mode (using one FMGC only)
- Back–up navigation mode. (NEO)

Question 4

If the FMGS’s are in INDEPENDENT MODE, you can perform what and when?

Answer 4

CROSSLOAD when in PREFLIGHT or DONE phase

Question 5

What is the PROCEDURES IN FLIGHT when FMGS is in INDEPENDEN MODE?

Answer 5

DO NOT SWITCH the navigation databases.

MAKE the same entries on both MCDUs to have both AP/FDs similar orders.

Both FGs being valid, 2 APs may be engaged for CAT II or CAT III operations.

●In the event of a go-around and when the second AP is disconnected:
ENSURE that the FMGC in command has correct flight plan orders and an updated nav
database.

Airbus does not recommend pulling one FMGC circuit breaker to force the system to operate in
SINGLE mode

Question 6

How can you identify if the FMGS’s are operating in INDEPENDENT MODE?

Answer 6

The “INDEPENDENT OPERATION” message is displayed on both MCDU
scratchpads.
“IND” annunciator on top of the MCDU is lit (NEO)

Question 7

How can you see if the FMGS’s is in SINGLE MODE?

Answer 7

On the ND usually associated with the failed FM:
- If the NDs are not both in the same mode or range, the associated ND displays “MAP NOT AVAIL”
and “SET OFFSIDE RNG/MODE”.
- If the NDs are in the same mode and range, the associated ND displays the “OFFSIDE FM
CONTROL” amber message.

Question 8

What is the Procedure for SINGLE MODE?

Answer 8

If a transient failure triggers a single mode of operation:
DO NOT USE the MCDU(s) until the PLEASE WAIT message is suppressed.
SET both NDs on the same range and mode to display the same information from the operative
FMGC.
When convenient, RESET the failed FMGC.

Question 9

What does the BACK UP NAVIGATION MODE provide?

Answer 9

• Flight Planning
• Aircraft position using onside IRS, IRS3, or GPIRS position (if GPS  )
• F-PLN display on ND
• No AP/FD NAV mode
• Limited lateral revision
• F-PLN automatic sequencing.