Flight Management

Also from: FM

Four main functions:

• navigation
• flight planning (lateral and vertical)
• prediction and optimisation of performance
• management of the displays (MCDU, ND, PFD)

Position

Each FMGC computes its own aircraft position (FM position).

• MIX IRS position: computed from 3 IRSs
• GPS position: called GPIRS (mix IRS/GPS position), uses GPS data
• Radio position: computed using onside navaids

GPIRS position combines GPS 1 with IRS 1, GPS 2 with IRS 2, and GPS 1 with IRS 3. A bias vector is calculated from the MIX IRS position to the radio or GPIRS position, and used if the FMGC loses its radio or GPIRS position.

Accuracy:

• EPE [Estimated Position Error] ≤ RNP [Required Navigation Performance] : HIGH
• EPE > RNP: LOW

Managed speed profile

TO	V2+10
CLB	ECON CLB
CRZ	ECON CRZ
DES	ECON DES
APP	VAPP

Navaids

Each FMGC can tune (automatically or manually):

• 1 VOR
• 5 DMEs
• 1 ADF - if the from or to waypoint is an NDB, or if required in an approach
• 1 ILS

Cost index

CI = 0	minimum fuel consumption / maximum range
CI = 999	minimum time

Failures

If an FM fails, the onside MCDU and ND displays are lost; the MCDU reverts to the MENU page and the ND displays MAP NOT AVAIL. After switching, the remaining FM will drive both sides.

Categories: Airbus A330 | Auto Flight | Automatic Flight System | FMGC

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