737 MAX Flight Crew Operations Manual
Flight Management, Navigation -
FMC Messages
MN-FLT-OH-201
11.60.9
ALERTING MESSAGE
CAUSE
CORRECTIVE ACTION
NAV INVALID–TUNE
XXXXX (navaid
identifier)
FMC is unable to
auto–tune or receive the
navaid for a RNAV or
VOR approach
procedure.
Cross–check radios and
manually tune the
desired navaid.
NO VNAV AFTER
XXXXX,
The descent path is
monitored independent
of path construction for
the following scenarios:
A) - an “at”, “at or
above”, “at or below” or
“window” constraint is
violated
B) - a navigation data
base gradient (vertical
angle) is violated
If a violation is detected
and not resolved, VNAV
will disconnect after the
point of the violation.
The alerting message is
displayed one minute
prior to the violation.
After sequencing
waypoint XXXXX,
VNAV INVALID -
PERF logic applies:
Pilot should reenter the
CI using either the
previous CI displayed or
enter a new CI.
Reengage VNAV when
change has been
EXECuted.
OAT DISAGREE -
DELETED
A check of entered OAT
versus sensed OAT
occurs after first engine
start. A difference of +/-
6 degrees Celsius
between the OAT value
on the N1 LIMIT /
TAKEOFF REF page
and the engine
temperature sensors.
Enter updated/corrected
OAT on the N1 LIMITS
page.
March 1, 2021
