FMS Flashcards
Fundamentally, what is an FMS
A multi-purpose performance and navigation computer
What are the 4 main things it provides
- Flight planning and Nav info
- Performance Calculations and Optimisation
- Long term guidance targets
- Information displays on Electronic Flight Instrument System (EFIS)
How many databases does the FMC normally consistent of and what are they
4 NAV PERFORMANCE Magnetic Variation Pilot stored elements
How does the FMS NAV system determine position
GPS
IRS
ground based nav aids
When the FMS determines aircraft position, does it use a singular source or more than one. If more than one, whats it called
More than 1. Hybrid
On the pc21 what nav mode does the FMS prioritise, and how many sources are used
GPS (average of 2 gps positions)
Dme/ dme
Vor/dme
Irs
Dead reckoning
What is the definition of RNP
Aircraft nav accuracy must be able to calculate within 95% of actual position
What are the 2 functions common to all FMS
Auto nav
Flightpath management
What provides an interface between FMS and aircrew
CDU
What are the 3 main functions of the PC21 FMS
Area nav
Backup tuning
Backup volume control
Are the 2 FMS in the PC21 identical
Yes
When is the EXEC Annunciator illuminated
When the user is prompted to execute/ accept the modification to the active route
How many LSKs are on the FMS
12
How is the brightness adjusted on the FMS
INT LIGHT panel, display rotary DISPLAYS control
Do the FMS operate individually or in tandem
Tandem
The FMS recieves data from what sources
- GLSSU 1 & 2
- 2 X VOR/ILS recievers
- TACAN (DME Data)
- ADC
- IRS
- PFD (reversionary SFD air data)
Where is the primary display of FMS data
HSI, in map mode of PFD
What poweres both FMS
Batt bus
Does the FMS have to be manually turned on when external power is supplied
No, its auto
What 3 phases of flight does the FMS compute and monitor.
Enroute
Departure & arrival
Approach
What are the RNP values for the 3 stages of flight (terminal, enroute, approach)
Terminal = 1.0NM Enroute = 2.0NM Approach = 0.3NM
Up to how many DME stations can be used to triangulate position in DME/DME
6
What would be shown on the FMS if:
- Pilot action is required
- loss of functionality
- Degraded mode of operation
Yellow system alert message
What colour are maintenance messages
White
Upon powering up of the FMS what page is shown
IDENT
What would cause an Amber “FMS FAIL” on the MFD with aural tone
FMS has failed
FMS data isnt correct
FMS is off
What does route discontinuity mean
FMS doesnt know how to proceed between 2 waypoints
