Boeing 737-800 - Page 1509

737 Flight Crew Operations Manual
Flight Management, Navigation -
FMC Messages
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D6-27370-866-EGP 11.60.13
ALERTING MESSAGE CAUSE CORRECTIVE ACTION
UNABLE YYY KTS AT
XXXXX
(U10.7 and later)
Next waypoint speed
restriction (speed YYY,
at waypoint XXXXX)
cannot be met.
Modify flight plan as
required.
Clear the message.
UNABLE REQD NAV
PERF–RNP
(U10.3 and later)
FMC actual navigation
performance is not
sufficient for the
displayed RNP.
Refer to UNABLE
REQD NAV PERF -
RNP non-normal
checklist in the QRH.
Note: When on a
procedure or airway
without an RNP alerting
requirement, the FMC
Navigation Check
supplementary
procedure in SP11 can be
used to verify position.
VERIFY GW AND
FUEL
Fuel data becomes
invalid, PERF INIT fuel
value is replaced with
dashes. FMC uses last
valid fuel quantity for
performance predictions
until manual entry is
made.
Shows if 30 minutes
have elapsed since last
manual entry.
Does not show in descent
with Vref selected.
Enter fuel weight on
PERF INIT page 1/2.
Periodic update of fuel
weight is required to
keep gross weight value
current.
VERIFY POS:
FMC-FMC
(U10.7 and later)
Position information is
contradictory.
Refer to FMC
Navigation Check
Supplementary
Procedure.
VERIFY POS:
FMC-GPS
(U10.7 and later)
Position information is
contradictory.
Refer to FMC
Navigation Check
Supplementary
Procedure.
September 15, 2016