Copyright D.P. Browne 2011
The Flight Management System (FMGS) is made up of two essential parts. The Flight Management (FM) part that computes the flight plan and flight plan predictions, and the Flight Guidance (FG) part that controls the aircraft flight path to achieve the flight plan.
FMCS Flight Guidance
The Flight Guidance pilot interfaces are the Flight Control Unit (FCU) and the Throttle levers. Together they allow the flight crew to select target speeds, altitudes etc and the auto flight mode in which to archive throes targets. The flight crew mat also use the FCU the engage the managed targets of the Flight Management part.
The Flight crew select Auto flight modes using the FCU. They may also select target values of speed, heading, altitude and V/S on the FCU
The Flight crew select Auto Thrust modes by positing the throttle levers in certain detent positions.
The Flight crew enter a flight plan into the FMGC by interfacing with the MCDU.
The flight crew may utilize the FMGS in one of two modes.
The aircraft may be guided to the FCU target values of SPD, V/S, HDG. In this case the guidance is referred to as “Selected”.
Alternatively, the pilot may use the FMGS to guide the aircraft along a pre defined route, both laterally and vertically. This mode of operation is referred to as “Managed”
At all times the Selected guidance from the FCU has priority over the managed guidance, and the FCU altitude value is the limiting altitude for system, which is normally set to the ATC cleared altitude.
Quick Reference index
Managed and Selected Modes
The pilot may utilize the FMGS in one of two modes.
The aircraft may be guided to the FCU target values of SPD, V/S, HDG. In this case the guidance is referred to as “Selected”.
Alternatively, the pilot may use the FMGS to guide the aircraft along a pre defined route, both laterally and vertically. This mode of operation is referred to as “Managed”
At all times the Selected guidance from the FCU has priority over the managed guidance.
Flight Management Guidance Computer (FMGC)
The FMGC is divided into 2 parts, the Flight Management (FM) part and the Flight Guidance (FG) part.
The FM part controls the following:
Navigation
Flight planning
Performance predictions
Route management
The FG part performs the following :
All the functions of the FM part of the FMGC are covered in the detail description of the MCDU.
