737 MAX Flight Crew Operations Manual
Flight Controls -
System Description
MN-FLT-OH-201
9.20.19
Landing Attitude Modifier
The Landing Attitude Modifier (LAM) system performs two functions. The first
LAM function applies when the flaps are in the 30 or 40 position. To maintain
acceptable nose landing gear contact margin, LAM symmetrically deploys flight
spoilers on approach to reduce lift and force the airplane to use a higher angle of
attack. The amount of spoiler deflection depends on the approach speed.
Deflection begins at approximately 10 knots above VREF.
The second LAM function applies when flaps are positions 15 through 30 and the
thrust levers are near idle. This function also symmetrically deploys flight
spoilers, in order to generate additional drag.
Emergency Descent Speedbrakes
In order to minimize exposure time of passengers and crew to high cabin altitude,
an Emergency Descent Speedbrakes (EDS) function is included. EDS is armed
when the airplane is above 30,000 feet and the cabin altitude warning is active.
Moving the speedbrake lever activates the function. When activated, the EDS
raises the speedbrakes to a higher than normal position when the speedbrake lever
is in the flight detent. EDS is deactivated when the spoilers are stowed, or when
the cabin altitude warning is no longer active.
Ground Operation
During landing, the auto speed brake system operates when these conditions
occur:
• SPEED BRAKE lever is in the ARMED position
• SPEED BRAKE ARMED light is illuminated
• radio altitude is less than 6 feet
• landing gear strut compresses on touchdown
Note:
Wheel spinup or compression of any landing gear strut enables the
flight spoilers to deploy. Compression of both main landing gear
struts enables the ground spoilers to deploy.
• both thrust levers are retarded to IDLE
• main landing gear wheels spin up (more than 60 kts)
The SPEED BRAKE lever automatically moves to the UP position and the
spoilers deploy.
If a wheel spin-up signal is not detected, when the air/ground system senses
ground mode (any gear strut compresses) the SPEED BRAKE lever moves to the
UP position and flight spoiler panels deploy automatically.
March 1, 2021
