Flight Management System (FMS) Flashcards
What are the primary purposes of the FMS?
Automatic flight, navigation, performance optimization, fuel monitoring.
What are the components of the FMS?
Autothrottle, AFDS (Autopilot Flight Director System), IRS x 3, MCP, 2 x FMCs, 2 x CDUs, and EFIS.
How are CDUs connected?
Parallel, so information entered in one is presented in the other.
Where can data be entered on the FMC?
Where boxes or dashes exist. Boxes represent mandatory information, dashes are filled in if information is known
How many databases does the FMC have?
2 databases, performance and navigation
Explain the differences between performance and navigation databases…
performance = anything to do with aircraft flying e.g. altitudes, speeds, temps, landing and takeoff performance etc... navigation = position, and airport/waypoint information (e.g. lat/long, frequencies etc...)
What is the update cycle for the navigation database?
28 days
How many sets of navigation data are stored in the FMC?
2, one is the current data, the other is the data that is yet to be current
How long does IRS alignment take?
10 minutes
What is required data for the CDU to be ready for flight?
dep/dest airport, route, ZFW, FL, cost index
Which FMC is the master and which FMC is the slave?
Left (captain’s) is master, Right is slave
What are conditional waypoints?
Waypoints not defined by a geographic position, but by an event. E.g. PF9 departure, at departure end of runway turn right 215.
How are conditional waypoints indicted on the CDU?
Put in brackets as opposed to just plain letters/numbers
How does the aircraft FMC select which sector entry to do for a holding pattern?
Based on aircraft TRACK
What is the preferred combination for an IRS position update?
DME/DME, or VOR/DME
Can NDBs be used for position updating?
Lol no
To operate outside of radio coverage, what navigation systems are required?
Dual FMC, Dual CDU, 3 x IRS. You can operate with a single FMC and CDU with 3xIRS if within radio coverage and auto-update is on.
Explain: Operation Outside Database Area
all waypoints must be entered with lat/long, FMC won’t update position, and EHSI won’t display navaids, waypoints or airports not entered on the route.
Explain the Stanby Navigation system:
Has two independent systems, provides lateral navigation only, the CDUs now act independently, there is no stored information, therefore waypoints must be entered with lat/long.
How is a route flown in the stanby navigation mode?
AFDR HDG select mode
In stanby mode, is position relative to true or magnetic north?
Magnetic north only for PRESENT position, otherwise represented as TRUE.
