737 MAX Flight Crew Operations Manual
Flight Controls -
Controls and Indicators
MN-FLT-OH-201
9.10.3
7
ALTERNATE FLAPS Master Switch
OFF (guarded position) – normal operating position.
ARM – closes TE flap bypass valve, activates standby pump, and arms the
ALTERNATE FLAPS position switch.
8
ALTERNATE FLAPS Position Switch
Functions only when the ALTERNATE FLAPS master switch is in ARM.
UP –
• electrically retracts TE flaps
• LE devices remain extended and cannot be retracted by the alternate
flaps system.
OFF – normal operating position.
DOWN (spring loaded to OFF) –
• (momentary) fully extends LE devices using standby hydraulic pressure
• (hold) electrically extends TE flaps until released.
9
Feel Differential Pressure (FEEL DIFF PRESS) Light
Armed when the TE flaps are up or down.
Illuminated (amber) -
• indicates excessive differential pressure in the elevator feel computer
Note:
Excessive differential pressure can be caused by erroneous activation of
the Elevator Feel Shift module.
10
Speed Trim Failure (SPEED TRIM FAIL) Light
Illuminated (amber) –
• indicates failure of the Speed Trim System (Speed Trim function or
MCAS function). If one function fails, the other function is inhibited.
• indicates failure of a single FCC channel when MASTER CAUTION
recall is activated and light extinguishes when Master Caution System is
reset.
11
Mach Trim Failure (MACH TRIM FAIL) Light
Illuminated (amber) –
• indicates failure of the mach trim system
• indicates failure of a single FCC channel when MASTER CAUTION
light recall is activated and light extinguishes when master caution
system is reset.
March 1, 2021
