737 MAX Flight Crew Operations Manual
Communications -
Controls and Indicators
MN-FLT-OH-201
5.10.5
1
Transmitter Selector (MIC SELECTOR) Switches
Illuminated – related switch is active
Push –
• selects related communication system for subsequent transmission
• only one switch may be selected at a time; pushing a second switch
deselects first switch
• reception possible over selected system regardless of whether related
receiver switch is on.
2
Receiver Switches
Illuminated (white) – related switch is active
Rotate – adjusts volume
Push –
• allows reception of related communication system or navigation
receiver
• multiple switches may be selected
Push again – deselects related system or receiver.
1B785, 1B786
3
Push–to–Talk Switch
(spring–loaded (R/T) / manually latch (I/C) to neutral position)
R/T (radio–transmit) – keys oxygen mask or boom microphone for transmission
as selected by transmitter selector.
I/C (Intercom) – keys oxygen mask or boom microphone for direct transmission
over flight interphone and bypasses transmitter selector.
1B401, 1B402, 1B801 - 1J594
3
Push–to–Talk Switch
(Radio-Interphone switch latched in the Interphone position)
RADIO (radio–transmit) – keys oxygen mask or boom microphone for
transmission as selected by transmitter selector.
INT (Interphone) – keys oxygen mask or boom microphone for direct
transmission over flight interphone and bypasses transmitter selector.
1B401, 1B402, 1B801 - 1J594
4
Filter Switch
V (Voice) – receive NAV and ADF voice audio.
B (Both) – receive NAV and ADF voice and range audio.
R (Range) – receive NAV and ADF station identifier range (code) audio.
1B785, 1B786
4
MASK–BOOM Switch
MASK – selects oxygen mask microphone for transmissions.
BOOM – selects boom microphone for transmissions.
October 26, 2021
