737 MAX Flight Crew Operations Manual
Automatic Flight -
System Description
4.20.4
MN-FLT-OH-201
• the F/D has no landing flare capability. F/D command bars retract from
view at approximately 50 feet RA on an ILS approach.
1B785, 1J585 - 1J594
• During a Fail Operational autoland flare with FLARE engaged and
LAND 3 annunciated, F/D command bars center (as installed).
F/D commands are removed one second after activation of stick shaker for AFDS
modes that do not have minimum speed reversion. The F/D command bars (both
pitch and roll) return when airspeed increases to the top of the minimum maneuver
speed (amber) bar. Refer to the Minimum Speed Reversion in this section for
additional information.
Normally, FCC A drives the captain’s command bars and FCC B drives the first
officer’s command bars. With both F/D switches ON, the logic for both pilots’ F/D
modes is controlled by the master FCC, and both FMA displays show the same
mode status.
The master FCC is indicated by illumination of the respective master (MA) F/D
indicator light. The master FCC is determined as follows:
• with neither A/P engaged in CMD, the FCC for the first F/D turned on is
the master
• with one or both A/Ps engaged in CMD, the FCC for the first A/P in
CMD is the master FCC, regardless of which F/D is turned on first.
F/D modes are controlled directly from the respective FCC under certain
conditions. This independent F/D operation occurs when neither A/P is engaged
in CMD, both F/D switches are ON and one of the following mode conditions
exists:
• APP mode engaged with LOC and G/S captured
• GA mode engaged and below 400 feet RA
• TO mode engaged and below 400 feet RA.
For non-approach modes, if the pilot is flying manually but not following the
flight director guidance in the roll mode and then selects autopilot CMD
engagement, the autopilot will engage into the current flight director roll mode.
Independent F/D operation is indicated by illumination of both MA lights. When
independent operation terminates, the MA light extinguishes on the slaved side.
If a generator is lost during a F/D TO or GA, or while in dual F/D APP mode
below 800 feet, the FCC on the unaffected side positions the F/D command bars
on both attitude indicators. If the F/D MA light on the affected side had been
illuminated, it extinguishes upon electrical bus transfer.
March 1, 2021
