3B-19. FMS-800 FLIGHT MANAGEMENT SYSTEM.
(1) System Overview. The FMS-800 flight
management system provides global autonomous
guidance using GPS navigation. This FMS guidance
may be used to fly published airways, direct routing,
TACAN emulation procedures, and published non-
precision or autonomous GPS approaches, as well as
various mission patterns.
The FMS-800 permits pre-flight loading of 40
complete mission plans using a data cartridge. It also
permits the crew to generate or modify mission plans
on the aircraft, using a global International Civil
Aviation Organization (ICAO) data base of waypoints
and automatic flight plan calculations.
The FMS-800 also provides simplified crew
control of the communication radios.
The C-12 installation utilizes a single
Control Display Unit (CDU).
This section contains the basic procedures to
operate the FMS-800 flight management system. The
paragraphs are organized as follows, with each
paragraph providing the procedures necessary to use
that corresponding function.
(2) System Architecture. Figure 3B-16
shows a simplified diagram of the FMS-800 system.
The CDU provides access to all system functions for a
single crew member. It also provides user interface
between the FMS-800 and MIL-STD -1553B and non-
1553B aircraft systems.
The data cartridge is used to load mission data
and to act as an in-flight library of ICAO waypoints. It
also loads the current worldwide magnetic variation
tables automatically upon power-up and can be used
to load or store GPS almanac data to reduce GPS cold
start time following installation of a GPS receiver.
A lithium battery is installed in the CDU to
reduce the initialization time.
The MIL-STD-1553B multiplexed serial digital
data bus is the primary means of control and data
Transferal within the FMS-800. This bus has the
1. Dual data paths (buses) between
each remote terminal and the bus
2. No operator actions required for
initialization or any other aspect of
normal bus controller operation.
The CDU operates on the MIL-STD -1553B data
bus as a Bus Controller (BC). The CDU that is
functioning as bus controller performs all navigation
and guidance computations, builds all page displays,
communicates with all external equipment and
performs all other computations required to support
b. CDU Operations.
(1) General Operation Concepts. CDU data
alphanumeric keypad, arrow keys, function keys, and
eight line select keys, Figure 3B-17. The CDU display
has 8 lines of 22 characters each. Lines 1, 3, 5, and 7,
are data lines with a line select key on both the right
and left of the field. Line 2 is reserved for page title
and line 6 is reserved as an annunciation line. Line 4
is an unreserved data line and line 8 is the scratchpad
for holding all keypad entries. See Table 3B-8 for the
descriptions of the CDUs function and application
The character set displayed in Figure 3B-17
does not represent the actual view on the