737 MAX Flight Crew Operations Manual
Flight Management, Navigation -
FMC Messages
MN-FLT-OH-201
11.60.17
FMC Entry Error Messages
These messages relate to incorrect scratchpad entries. FMC entry error messages:
• are shown in the CDU scratchpad
• illuminate the message light (MSG) of the CDU where the entry error
was made
• temporarily overwrite data in the scratchpad.
Use the CLR key or key in new data to remove the message. If the CLR key is
used to remove the message, the data previously entered is once again displayed.
If new data is keyed in over the message, the message and the data previously
entered are removed.
ENTRY ERROR
MESSAGE
CAUSE
CORRECTIVE ACTION
ALT CONSTRAINT
XXXXX (waypoint
identifier)
A flight plan
modification has caused
an altitude conflict with a
waypoint that has an
altitude constraint.
Clear the message and
revise the entry.
DATA BASE FULL
Entry attempted into a
supplemental or
temporary navigation
database category which
is full.
Go to the NAV DATA
pages and delete
unneeded waypoints,
navaids, or airports from
the appropriate database
and re–attempt entry.
DUPLICATE FLIGHT
PLAN ID
The entry attempted is a
duplicate of an existing
supplemental flight plan
name.
Clear the message and
select a unique flight
plan name.
INVALID DELETE
DEL key operation was
attempted for a data line
to which it was not
applicable.
Clear the message and
select the proper line
after the DEL key is
pressed.
INVALID ENTRY
Attempted data entry has
incorrect format, range,
etc. for the selected data
line. Entered RTA
waypoint is not in the
flight plan.
Clear the message and
scratchpad entry, and
repeat the entry with the
correct data.
March 1, 2021
