Boeing 737-800 - Page 1501

737 Flight Crew Operations Manual
Flight Management, Navigation -
FMC Messages
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D6-27370-866-EGP 11.60.5
ALERTING MESSAGE CAUSE CORRECTIVE ACTION
FMC DISAGREE
(U10.8 and later)
During approach or on
the ground, monitored
parameters required for
dual FMC operation are
in disagreement. (Dual
FMC as installed)
Message will remain
displayed until the
condition has been
resolved. The FMC does
not check for mach and
indicated air speed
miscompares on the
ground.
Monitor FMCs closely.
Both FMCs remain
online. Limit approaches
to single FMC only. If
desired, revert to
SINGLE FMC
OPERATION in this
section.
FMC DISAGREE -
VERTICAL
(U10.8A and later)
A vertical deviation,
FMC Airspeed, or FMC
Mach value
disagreement between
the FMCs by more than
the allowed tolerance
occurs and long enough
that all attempts to
resynchronize failed
while the aircraft in a
path descent. Message
display is inhibited when
in the Approach Nav
environment. (dual FMC
as installed)
Do not move the FMC
source select switch.
Monitor crossing
altitudes to ensure
compliance.
FMC POS/RW
DISAGREE
(U10.7 and later)
Position information is
contradictory.
Refer to FMC
Navigation Check
Supplementary
Procedure.
September 15, 2016