FMS

Question 1

FMS

Answer 1

3d flight management system that calculates a 4d flight trajectory

Question 2

CDU

Answer 2

control display unit

1 for captain 1 for FO, sometimes a third

Question 3

FMC

Answer 3

flight management computer
2, one for each CDU, connected as a backup up to other CDU
X-talk bus- connects both FMC so they can communicate

Question 4

Duel mode

Answer 4

normal operation
each CDU connected to its own FMC
FMCs communicate via x-talk bus
info entered on either side will update eon both

Question 5

single mode

Answer 5

one FMC failed
both CDUs on one FMC
info can still be entered on either side
may be limitations on AP usage and EFIS
NAV displays may need the same mode and range set

Question 6

independent mode

Answer 6

X-talk bus failed
FMCs cant communicate
entering on CDU1 only FMC1 would receive it
need to enter information on both sides separately

Question 7

FMS inputs

Answer 7

pilot
clock
database
GPS
IRS
ADC
configuration
fuel 
air ground logic switch
FWS
CDU
NAV radios

Question 8

FMS outputs

Answer 8

autopilot
auto thrust
HUD
EFIS

Question 9

navigation database

Answer 9

SID's- standard instrument approaches 
STAR's- standard arrivals 
airways 
way points 
airports 
approaches 
runways 
company routes 

valid over 28 day period

Question 10

ways to enter way points

Answer 10

lat and long
Wpt name
nav aid ident
ICAO airport code

Question 11

performance data base

Answer 11

fuel parameters 
drag parameters 
engine parameters
speeds 
one engine inoperative data

it can account for engine failure
can not account for non-standard configuration

Question 12

FMS position calculation

Answer 12

mixes various sources of position to find most likely position
sources:
-VOR,DME , localiser on some
- GPS
-IRS

priority of sources
GPS>DME>VOR>IRS

Question 13

initialising the fms

Answer 13

1) who am I? IDENT- aircraft type/ engine type
2) where am I? pos init- position info
3) where am I going? route- route info
4) how do I get there? performance

Question 14

FMS functions: LEGS page

Answer 14

waypoints
tracks
distances
predicted speed
predicted altitude 
speed constraints
altitude constraints

Question 15

FMS functions:LNAV

Answer 15

lateral navigation

connects auto pilot and FMS
FMS tells AP to fly: headings & bank angles to achieve flight planned route

Question 16

FMS functions: VNAV

Answer 16

vertical navigation

FMS gives AP: speed target or vertical speed target 
vertical profile calculated using: 
barometric alt 
ZFW
fuel quantity 
cost index

Question 17

FMS functions: X-trk

Answer 17

works out perpendicular distance from flight planned route

route will be a great circle

Question 18

FMS 1 says 0 X-trk error
FMS 2 says 4R error
what can you say?

Answer 18

at least one is wrong

Question 19

FMS functions: lateral offset

Answer 19

allows pilot to fly a constant lateral offset left or right of route
may be used to avoid collisions if mistake was made that you were on same FL as others in other direction

Question 20

FMS functions: RTA

Answer 20

required time of arrival
pilot enters desired time of arrival at a waypoint or destination
FMS then calculates CAS/Mach no. that will achieve it

Question 21

FMS functions: temperature corrections

Answer 21

not all FMS’s can do this

non-precision approach check heights can be corrected at very low temps automatically

Question 22

FMS functions: approaches

Answer 22

FSM's approved to fly non precision approaches:
VOR
loc only
RNAV 
NDB

Question 23

FMS functions: fuel prediction

Answer 23

predicts fuel remains at each waypoint and destination
uses wind entered at each waypoint OR current wind extrapolated over the remaining flight

AIDS FUEL MANAGEMENT

CANNOT use for FUEL PLANNING

Question 24

dead reckoning mode

Answer 24

back up position mode

if normal position sources are lost the FMS provides position guess with speed distance time calc

Question 25

Boeing fuel philosophy

Answer 25

calculated fuel- calc how much has been used by each engine. subtracts from starting
totaliser fuel- fuel measured in each tank then added to get total
calculated should = totaliser

Question 26

Airbus fuel philosophy

Answer 26

totaliser fuel- measured in each tank then added for a total
used fuel- keeps track of how much each engine has used
PILOT then deducts used from starting to compare to the totaliser