737 MAX Flight Crew Operations Manual
Supplementary Procedures -
Adverse Weather
SP.16.24
MN-FLT-OH-201
If bleed air is needed to maintain tolerable flight deck and cabin
temperatures, use APU bleed air rather than engine bleed air during the
taxi in. Limit APU bleed air use as much as possible to reduce sand and
dust ingestion.
If APU bleed air will be used and the APU is not operating:
APU switch .................................................... START
PM
Note:
Run the APU for one full minute before using it as a bleed
air source.
Engine BLEED air switches ...............................OFF
PM
APU BLEED air switch ....................................... ON
PM
Taxi-In
Do the following, conditions permitting, to minimize sand and dust
ingestion by the engines and to improve visibility during the taxi-in:
• Use all engines and taxi at low speed. Limit ground speed to 10
knots and maintain thrust below 40% N1 whenever possible.
• Maintain a greater than normal separation from other aircraft while
taxiing and avoid the ingestion of another engine’s wake.
• Avoid engine overhang of unprepared surfaces.
• In the event of a crosswind during 180° turns, turn away from the
wind if possible to minimize sand and dust ingestion.
• Whenever possible, avoid situations that would require the airplane
to be brought to a complete stop.
• Avoid excessive braking. The presence of sand or dust will increase
brake wear.
Secure Procedure
Do the normal Secure Procedure with the following modifications:
CAUTION: Do not leave the interior unattended with a pack
operating and all doors closed. With the main outflow
valve closed, an unscheduled pressurization of the
airplane may occur.
PACK switches................................................... Verify OFF
F/O
Pressurization mode selector ....................................... MAN
F/O
Outflow VALVE switch ...........................................CLOSE
F/O
Position the outflow valve fully closed to inhibit the intake
of sand or dust.
March 1, 2021
