202-450-0800 Page 9June 2022 PMA450C Pilot Guide
Mono headsets in Stereo Installation
Not recommended, because the benefit of IntelliAudio® is lost. However, if
desired, the PMA450C can be installed monaurally by using the LEFT audio
connections only (left side contains Fail-Safe audio).
Do NOT short left and right together.
Intercom Modes (8)
The ICS button cycles through the frequently used intercom modes, from
left to right, then right to left as: ISO, ALL, CRW and CRW, ALL, ISO.
The green indicator shows which mode is currently active.
ISO (Pilot Isolate): The pilot is isolated from the intercom and connected
only to the aircraft radio system. Pilot will hear the aircraft radio recep-
tion (and sidetone during radio transmissions). Copilot and passengers
can talk together but neither will hear aircraft radio receptions or pilot
transmissions. The pilot can hear music if desired.
ALL Everybody hears the aircraft radio and intercom. Crew and passengers
will hear selected Music. During any radio or intercom communications,
the music automatically mutes, and increases gradually back to the orig-
inal level when it is quiet. The music muting can be triggered by radio
only, radio and intercom, or nothing, for a “Karaoke” mode.
CRW : Pilot and copilot can talk to each other and have exclusive
access to the aircraft radios. They may
also listen to Music sources. Passen-
gers can continue to communicate
with themselves without interrupting
the crew and may listen to music as
configured.
Alternate Intercom and Copilot as Passenger (CPX) Modes
What if the folks in back do not want
to listen to the radio chatter, but want
to converse with the pilot and copilot
positions? That is where our Alternate
Intercom Mode comes in handy. This
mode allows intercom conversations between crew and passengers, without
affecting the crew’s radio communications. The passengers do not hear the
aircraft radio audio, and passengers microphones are blocked from the crew
while the radio is active. Passengers can still talk to each other while the
crew is listening to the radio.
To activate the Alternate Intercom Mode, press RADIO-ICS→ Intercom:
to switch between Standard, Alternate modes and CP Pax modes.