B737 Audio Control Panel

ACP
P8 AFT ELECTRONICS

Transmitter Selector (MIC SELECTOR) Switches

  • Illuminated: Indicates the related switch is active.
  • Push:
    • Selects the related communication system for subsequent transmission.
    • Only one switch may be selected at a time; pushing a second switch deselects the first switch.
    • Reception is possible over the selected system regardless of whether the related receiver switch is on.

Receiver Switches

  • Illuminated (white): Indicates the related switch is active.
  • Rotate: Adjusts volume.
  • Push:
    • Allows reception of the related communication system or navigation receiver.
    • Multiple switches may be selected.
    • Push again: Deselects the related system or receiver.

Push-to-Talk Switch

  • RADIO (Radio-Transmit): Keys the oxygen mask or boom microphone for transmission as selected by the transmitter selector.
  • INT (Interphone): Keys the oxygen mask or boom microphone for direct transmission over the flight interphone, bypassing the transmitter selector.

Filter Switch

  • V (Voice): Receives NAV and ADF voice audio.
  • B (Both): Receives NAV and ADF voice and range audio.
  • R (Range): Receives NAV and ADF station identifier range (code) audio.

CALL Light

  • Illuminated (white):
    • Accompanied by a chime, indicates a call received by SELCAL, ACARS (if installed), ground crew (INT), SATCOM (if installed), or flight crew (CABIN).
    • Resets when the transmitter is selected and the microphone is keyed.
    • PA does not have a CALL indication.

Ground Crew Call Light

  • Illuminated: Indicates a call to the flight deck initiated by ground crew using the Pilot Call Switch at the external power receptacle.
    • Light extinguishes when the ground crew releases the switch.
    • Accompanied by a single high-tone chime.

Speaker (SPKR) Switch

  • Illuminated (white): Indicates the SPKR switch is active.
  • Push: Adds or removes communication audio from the flight deck speaker.
  • Rotate: Controls the communication audio volume in the flight deck speaker.

Cabin Call Light

  • Illuminated: Indicates a call to the flight deck by an attendant.
    • Accompanied by a single high-tone chime.

Alternate-Normal (ALT-NORM) Switch

  • NORM (Normal): The ACP operates normally.
  • ALT (Alternate): The ACP operates in degraded mode.

SAT Switch

Push – Terminates the SATCOM call connection.