737 MAX Flight Crew Operations Manual
Airplane General, Emergency
Equipment, Doors, Windows -
Systems Description
MN-FLT-OH-201
1.40.15
Flight Crew Oxygen System
The flight crew oxygen system uses quick-donning, diluter-demand
masks/regulators located at each crew station. Oxygen is supplied by a single
cylinder. Oxygen pressure is displayed on the Oxygen Pressure indicator located
on the aft overhead panel when the battery switch is ON. Oxygen flow is
controlled through an in-line, pressure-reducing regulator to supply low-pressure
oxygen to the regulator on the mask. System pressure may be as high as 1850 psi.
Oxygen flow is controlled by a regulator that is mounted on the oxygen mask. The
regulator may be adjusted to supply NORMAL, 100% or EMERGENCY oxygen
by rotating the regulator selector.
Flight Crew Oxygen Mask Usage
Donning Instructions
To don the oxygen mask accomplish the following:
• Grasp the regulator with the hand nearest the stowage box.
• Pull upward to expose the entire regulator and mask assembly.
• Squeeze the inflation lever while pulling the mask across in front of
you, toward the center of the airplane (to ensure ample hose extension)
and while rolling the mask face-up.
• Lean slightly toward the center of the airplane and place your face into
the mask so the chin contacts the lower part of the mask first, then roll
the top of the mask toward your forehead so the harness goes over and
behind your head.
• Release the inflation lever so the harness holds the mask in place.
March 1, 2021
