- Flight management system
It is considered to be composed of three major components: FMC (Flight Management Computer), AFS (Auto Flight System), and
NavigationSystem including IRS (Inertial Reference System) and GPS.
Electronic Flight Instrument System) is not an FMS component, though it is an important interface between FMS and pilots.
FMC is taken as the core of FMS, which works as a head of the whole system. Its primary function is to:
* Give out real-time lateral
navigationinformation by showing the route programmed by the pilots, as well as other pertinent information from the database, such as standard departure and arrival procedures. This information combined with the location of the aircraft creates a moving map display.
* Calculate performance data and predicted vertical profile. Based on weight of the aircraft, Cost Index and Cruise Altitude, preferably with predicted wind, FMC calculate a most fuel efficient vertical path that AFS would follow if AFS is engaged and both of
VNAVand LNAVare engaged.
Flight Management Computer
A Flight Management Computer is a
computercarried on an aircraftto integrate the functions of navigation and performance management. It is composed of 2 kinds of database: Navigation and Performance of a certain aircraft. The FMC is the heart of the modern aeroplane's electronic systems, and gathers information from other subsystems.
The Flight Management Computer is located in the
cockpitbetween the pilots' seats, beneath the main panel. It's composed of one or more displays with keypads.
The computer features a persistent read-only internal memory containing data for
airports, approach and departure procedures, airways, holding patterns, and other information. The FMC can also control the chosen ATS route, most data coming from the aircraft sensors, the pilot's inputs, weatherconditions, etc.
Auto Flight System
AFS is the super system of all the systems that enable an aircraft to fly. FMS is the operating system of the AFS.
If FMC is taken as the "head" of the system who does the calculation and gives out command, AFS is the system who accomplishes it. AFS is composed of AFDS (A/P-
Autopilot-F/D-(Flight Director) and A/T( Autothrottle) if the aircraft is equipped with A/T. It is the one who flies the airplane with one hand on the control wheel (when A/P is engaged), and the other hand on the throttle (when A/T is engaged). Only when the mode LNAV and VNAV, or LNAV, or VNAV is engaged, AFS would totally or partly follow the flight path FMC commands.
The Navigation System is mainly composed of IRS (Inertial Reference System) or AHRS (Attitude Heading and Reference System) and GPS (Global Positioning System), as well as existing physical
navaids such as VOR-DME. The IRS or AHRS provides raw information that is crucial to flight, such as attitude and heading. The Navigation System sends navigation information to the FMC to calculate, to the AFS to control the aircraft, and to the EFIS system to display.
EFIS, as a display system displays flight information including command from FMC and real-time information such as attitude, heading, position, planned route and flight track, etc. It is composed of EADI (Electronic Attitude Display Indicator) and EHSI (Electronic Horizontal Situation Indicator), or on some aircraft PFD (Primary Flight Display) and ND (Navigation Display). Either displays lateral or vertical flight information.
* [http://www.cmcelectronics.ca CMC Electronics]
* [http://www.honeywell.com/sites/aero/Flight_Management_Systems.htm Honeywell]
* [http://www.lhsystems.com/topic3/topic33/index.htm Lufthansa Systems]
* [http://www.rockwellcollins.com/products/cs/br/avionics-systems/flight_management/index.html Rockwell Collins]
* [http://www.thalesgroup.com/aerospace/ Thales Aerospace]
* [http://www.uasc.com/ Universal Avionics]
* [http://www.smiths-aerospace.com Smiths Aerospace]
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