Auto Flight -Flight Management DSC 22-20

Question 1

Each FMGC computes its own aircraft position (FM position) from….?

Answer 1

A MIX IRS position and a computed Radio position, or

A GPS position

Question 2

What is the MIX IRS position?

Answer 2

The mean-weighted average position from the 3 IRS’s, as computed by each FMGC

Question 3

If one or more onside navaids fail, can each FMGC use offside navaids to compute the VOR/DME or DME/DME radio position?

Answer 3

Yes

Question 4

Does the FM position update at Take-off if GPS PRIMARY is active?

Answer 4

No, the update is inhibited

Question 5

What is required for a take-off update to occur?

Answer 5

Take off runway must be part of the flightplan, and

GPS PRIMARY must NOT be active

Question 6

The FMGS updates the FM position via the use of radio navaids or GPS, if available.
It can use 4 different navigation modes to make this update. In order of decreasing priority they are…?

Answer 6

IRS - GPS
IRS - DME/DME
IRS - VOR/DME
IRS only

Question 7

During ILS approaches the system performs a temporary lateral update via one of the following modes:

Answer 7

IRS - GPS/LOC
IRS - DME/DME/LOC
IRS - VOR/DME/LOC
IRS - LOC