737 MAX Flight Crew Operations Manual
Flight Management, Navigation -
Flight Management Computer
MN-FLT-OH-201
11.32.3
Takeoff Derate
Fixed derates can be selected on the N1 LIMIT page. Performance data for these
derates is provided in the Airplane Flight Manual (AFM).
With derated takeoff selected, the thrust setting parameter is considered a
limitation for takeoff; therefore, thrust levers should not be advanced further
except in an emergency. A further thrust increase following an engine failure
could result in a loss of directional control while on the ground. Use the takeoff
speeds supplied by the FMC or specified in Chapter PI, Performance-Inflight, for
the selected derate condition.
Derated takeoff rating can be further reduced by assumed temperature.
Use the takeoff speeds specified in Chapter PI, Performance–Inflight, for the
selected derate or variable takeoff rating condition.
Assumed Temperature Thrust Reduction Takeoff
A takeoff thrust less than the full rated thrust may be achieved by using an
assumed temperature that is higher than the actual temperature. The desired thrust
level is obtained through entry of a SEL TEMP value on the N1 LIMIT page or
TAKEOFF REF page 2. Use approved sources for selecting the assumed
temperature.
The maximum thrust reduction authorized is 25 percent below any certified rating.
Do not use assumed temperature reduced thrust if conditions exist that affect
braking, such as slush, snow, or ice on the runway, or if potential windshear
conditions exist.
When the assumed temperature method is used with full rate, the reduced thrust
setting is not considered a limitation. If conditions are encountered where
additional thrust is desired, the crew can manually apply full thrust.
Takeoff Bump Thrust
1B801 - 1B806
(as installed)
Takeoff bump thrust may be used to meet extra thrust requirements for takeoff at
certain airports. Takeoff bump thrust provides thrust above normal maximum
takeoff thrust. The takeoff thrust bump setting may be selected on the N1 LIMIT
page. If takeoff thrust bump is selected, assumed temperature reduced thrust is not
available.
Bump thrust is available for takeoff thrust, and is the applied thrust rating for
Go-around thrust. Thrust bump is not applied to max continuous or climb thrust
ratings.
March 1, 2021