In addition to the annunciations and scratchpad
messages listed in Table 3B-9, the FMS-800 will
provide the additional alerts listed in Table 3B-11 to
inform the flight crew of various flight conditions.
These alerts may appear either on electronic flight
instrument displays or on annunciator light displays.
c. Power Control.
(1) FMS -800 System Power. All FMS-800
units operate from 28 Vdc aircraft essential bus power.
Power is provided through a 5-ampere CB placarded
FMSI on the right side circuit breaker panel.
Subsystems. Using the CDU, the crew can control the
power on/off state of the avionic subsystems managed
by the FMS-800. Whenever a unit is powered off, the
CDU shows dashes for the data normally supplied by
that unit. Attempts by the flight crew to control that
subsystem is inhibited and results in a POWER
message in the scratchpad.
(3) CDU Power Control Procedures. On
Index 1 page, pressing the POWER line select key
displays the Master Power page. Refer to Figure
3B-20 and Table 3B-12. This page permits on/off
control of individual communication or navigation
radios. It also provides a RADIO MASTER selection
which turns the controlled radio on or off.
Table 3B-11. Additional Alerts
TYPE OF ALERT
Within waypoint alert prior to waypoint sequence when in EN ROUTE and
OCEANIC sensitivity modes. Ten seconds prior to waypoint sequence
when in TERMINAL and APPROACH sensitivity modes.
FMS in Terminal Mode.
FMS in Transition or Approach Mode.
GPS RAIM function detects error (RAIM Warn).
Parallel offset has been applied to the active flight plan.
CDU MSG Alert Light
The MSG Alert column in this table lists which annunciations are
accompanied by a message alert.
No INPUT (with a blank
A bus terminal has taken control of the MIL-STD -1553 bus, but is not
responding as a bus controller. Activate the bus -split switch to split
operations and isolate the faulty device on the 1553 bus.
CDU has experienced a catastrophic failure of the CDU chip or a flash
memory fault and should not be used for navigation because navigation
data may be corrupted and extremely unreliable. Switch to backup
navigation means immediately.
A power reset of the CDU may restore full operation if the
failure was caused by the CDUs misreading its terminal
address during cyclic power fluctuations. If this occurs,
cross check all navigation data until you are ensured that the
primary FMS-800 system is operating properly.