737 MAX Flight Crew Operations Manual
Normal Procedures -
Amplified Procedures
MN-FLT-OH-201
NP.21.23
Advise any maintenance personnel using the FLT Interphone
that a test will be done on this communication channel.
Simultaneously push the Push-to-talk switch, the
EMERGENCY/Test selector (if installed) and the
RESET/TEST switch.
Verify oxygen flow sound is heard through the flight deck
speaker.
Push-to-talk switch - Release
TEST/RESET switch - Release
MASK/BOOM switch - BOOM
EMERGENCY/TEST selector - Push and Hold
As applicable: Regulator selector - Rotate to EMER
Continue to hold the TEST/RESET switch down and push the
EMERGENCY/TEST (if applicable) selector for 5 seconds.
Verify that the yellow cross shows continuously in the flow
indicator.
Verify that the crew oxygen pressure does not decrease more
than 100 PSI. If the oxygen cylinder valve is not in the full
open position, pressure can:
• Decrease rapidly, decrease more than 100 PSI or
increase slowly back to normal.
Release the TEST/RESET/ switch and the EMERGENCY/TEST
selector (if applicable). Verify that the yellow cross does not show
in the flow indicator.
Regulator selector (as installed) - Rotate to 100%
Normal/100% selector - 100%
Crew oxygen pressure - Check
Clock ............................................................................................. Set
TIME/DATE pushbutton (as installed) - UTC time
-700 and -800 Fleets Only
Display Select Panel ..................................................................... Set
MAIN PANEL DISPLAY UNITS selector ....................... NORM
LOWER DISPLAY UNIT selector ................................... NORM
TAKEOFF CONFIG light (as installed) ............. Verify extinguished
March 1, 2021
