737 MAX Flight Crew Operations Manual
Supplementary Procedures -
Air Systems
SP.2.2
MN-FLT-OH-201
APU BLEED air switch ........................................................... ON
APU supplies left pack and external air source supplies right
pack.
# Air Conditioning from an External Air Conditioning Unit
(ACU)
Before connecting ground conditioned air:
PACK switches..................................................................................OFF
Packs can be damaged if they are operated while ground conditioned
air is connected.
After disconnecting ground conditioned air:
PACK switches........................................................................ As needed
# Isolated Pack Operation during Engine Start
To improve cabin air quality between starting the first and second engine:
CAUTION: Moving engine BLEED air switches while a starter is
engaged can damage the starter.
Engine No. 2 .....................................................................................Start
After engine No. 2 stabilized:
ISOLATION VALVE switch. ................................................ CLOSE
Right PACK switch. ................................................................ AUTO
Duct pressure. ..................................................................... Stabilized
Engine No. 1. ....................................................................................Start
After engine No. 1 stabilized:
ISOLATION VALVE switch.................................................... AUTO
Pressurization System Manual Mode Test
PACK switches..................................................................................OFF
Pressurization mode selector ...........................................................MAN
AUTO FAIL and ALTN lights – extinguished.
MANUAL light – illuminated.
March 1, 2021
