737 MAX Flight Crew Operations Manual
Automatic Flight -
System Description
MN-FLT-OH-201
4.20.9
With CWS engaged, the A/P maneuvers the airplane in response to control
pressures applied by either pilot. The control pressure is similar to that required
for manual flight. When control pressure is released, the A/P holds existing
attitude.
If aileron pressure is released with 6 degrees or less bank, the A/P rolls the wings
level and holds existing heading. This heading hold feature with bank less than 6
degrees is inhibited when any of the following conditions exists:
• below 1,500 feet RA with the landing gear down
• after F/D VOR capture with TAS 250 knots or less
• after F/D LOC capture in the APP mode.
Pitch CWS with a CMD Engage Switch Selected
The pitch axis engages in CWS while the roll axis is in CMD when:
• a command pitch mode has not been selected or was deselected
• selecting CMD while not following a large deviation in the pitch flight
director command.
CWS P is annunciated on the FMAs while this mode is engaged. Command pitch
modes can then be selected.
When approaching a selected altitude in CWS P with a CMD engage switch
selected, CWS P changes to ALT ACQ. When at the selected altitude, ALT HOLD
engages.
Roll CWS with a CMD Engage Switch Selected
The roll axis engages in CWS while the pitch axis is in CMD when:
• a command roll mode has not been selected or was deselected
• flying beyond FMS end of route or into a route discontinuity.
CWS R is annunciated on the FMAs while this mode is engaged.
CWS R with a CMD engage switch illuminated can be used to capture a selected
radio course while the VOR/LOC or APP mode is armed. Upon intercepting the
radial or localizer, the F/D and A/P annunciations change from CWS R to
VOR/LOC engaged, and the A/P tracks the selected course.
Autothrottle System
The A/T system provides automatic thrust control from the start of takeoff through
climb, cruise, descent, approach and go–around or landing. In normal operation,
the FMC provides the A/T system with N1 limit values.
The A/T moves the thrust levers with a separate servo motor on each thrust lever.
Following manual positioning, the A/T may reposition the thrust levers to comply
with computed thrust requirements except while in the THR HLD and ARM
modes.
March 1, 2021
