737 MAX Flight Crew Operations Manual
Automatic Flight -
System Description
MN-FLT-OH-201
4.20.3
1B785, 1J585 - 1J594
• activating either pilot’s control wheel trim switch (except with LAND 3
or LAND 2 annunciated)
• moving either STAB TRIM PRI or the STAB TRIM B/U cutout switch
to the CUTOUT position
• for a column and/or wheel force override of a single or dual channel
CMD engaged autopilot, in approach or non-approach phase of flight.
The AFDS will maintain the active pitch and roll modes with flight
director guidance.
• either left or right IRS system failure or FAULT light illuminated
• loss of electrical power or a sensor input which prevents proper
operation of the engaged A/P and mode
• loss of respective hydraulic system pressure.
Note:
Loss of the system A engine-driven hydraulic pump, and a heavy demand
on system A, may cause A/P A to disengage.
1B785, 1J585 - 1J594
Note:
During a LAND 3, LAND 3 fail-operational, or LAND 2 fail-passive
landing with LAND 3 or LAND 2 annunciated, pressing TO/GA switch
after touchdown or activating the manual electric trim will be ignored by
both autopilot channels, both flight directors, and the autothrottle system.
This ensures that inadvertent press of the TO/GA switch does not affect
rollout.
AFS Failures
Power interruption or loss may cause disengagement of the AFDS and/or A/T.
Re–engagement is possible after power is restored.
Dual channel A/P operation is possible only when two generators are powering the
busses.
Two independent radio altimeters provide radio altitude to the respective FCCs.
With a radio altimeter inoperative, the autopilot will disengage two seconds after
LOC and GS capture.
Flight Director Display
Turning a F/D switch ON displays command bars on the respective pilot’s attitude
indicator if command pitch and roll modes are engaged. If command pitch and roll
modes are not engaged, the F/D command bars do not appear. The F/Ds can be
operated with or without the A/P and A/T. F/D command modes can be used with
an A/P engaged in CWS.
F/D commands operate in the same command modes as the A/P except:
• the takeoff mode is a F/D only mode
• dual F/D guidance is available for single engine operation
March 1, 2021
