737 MAX Flight Crew Operations Manual
Flight Management, Navigation
Chapter 11
Flight Management System Description
Section 30
MN-FLT-OH-201
11.30.1
30 Flight Management System Description
Flight Management System Description
File Highlight
Introduction
The flight management system (FMS) aids the flight crew in managing automatic
navigation, in–flight performance optimization, fuel monitoring, and flight deck
displays. Automatic flight functions manage the airplane lateral flight path
(LNAV) and vertical flight path (VNAV). The displays include a map for airplane
orientation and command markers (bugs) on the airspeed and N1 indicators to
assist in flying efficient profiles.
The flight crew enters the desired route and flight data into the CDUs. The FMS
then uses its navigation database, airplane position and supporting system data to
calculate commands for manual or automatic flight path control.
The FMS can automatically tune the navigation radios and determine LNAV
courses. The FMS navigation database provides the necessary data to fly routes,
SIDs, STARs, holding patterns, and procedure turns. Lateral offsets from the
programmed route can be calculated and commanded.
For vertical navigation, computations include items such as fuel burn data,
optimum speeds, and recommended altitudes. Cruise altitudes and crossing
altitude restrictions are used to compute VNAV commands. When operating in the
Required Time of Arrival (RTA) mode, the computations include required speeds,
takeoff times, and enroute progress information.
Flight Management Computer (FMC)
The basis of the flight management system is the flight management computer.
Since the term FMC is universally understood, it is used here for standardization
and simplification.
The FMC uses flight crew–entered flight plan information, airplane systems data,
and data from the FMC navigation database to calculate airplane present position,
and pitch, roll, and thrust commands required to fly an optimum flight profile. The
FMC sends these commands to the autothrottle, autopilot, and flight director. Map
and route information are sent to DUs. The EFIS control panels are used to select
the desired information for the navigation displays. The mode control panel is
used to select the autothrottle, autopilot, and flight director operating modes.
Refer to the following chapters for operation of these other systems:
• Chapter 4, Automatic Flight
• Chapter 10, Flight Instruments, Displays.
March 1, 2021