AUDIO CONTROL

MICROPHONE SELECTOR BUTTONS

• Related communication channel is enabled for transmission and reception.

---

AUDIO CONTROL BUTTONS

• Related audio channel is enabled for reception.

• Automatically activated when a transmission channel is selected.

---

SATCOM CONTROL BUTTON

• Unavailable

---

PASSENGER ADDRESS CONTROL BUTTON

• Enables PA announcements. It deactivates the microphone selector button and in this case no radio transmission occurs since there is no VHF/HF/SATCOM microphone selection.

---

SERVICES INTERPHONE CONTROL BUTTON

• EMER: Enables communication with flight attendants during emergency situations. When selected a green bar flashes on the button. Once the flight attendant picks up the call the green bar flashes faster. Pressing the button again, the light becomes steady and the communication with the flight attendant is enabled. A triple HI/LO chime sounds.

• RAMP: Enables communication with ground personnel. For an incoming call, the ramp annunciator flashes and remains steady when active. Communication through the ramp interphone remains active unless PTT or PA PTT is activated, ramp resumes when PTT or PA PTT is released.

If you click on the RAMP button the MSFS ATC window will open so you can call ground services.

• CAB: Enables communication with flight attendants during normal situations. Works the same as EMER mode. Communication through the cabin interphone remains active unless PTT or PA PTT is activated, cabin resumes when PTT or PA PTT is released.

• RAMP and CAB can be selected at the same time.

---

MASTER VOLUME CONTROL KNOBS

• Allows adjustment of the most recently selected audio.

ID FILTER BUTTON

• Activates a filter that eliminates voice on VOR and ADF audio so the identification can be heard.

---

AUDIO SELECTION BUTTONS

• Enables the respective audio to be summed into the output on the cockpit speaker (SPKR), interphone (INPH), or headphone (HDPH).

---

ACP DISPLAY

• Displays the selected transmission channel and digital volume information.

---

AUTO/MASK MICROPHONE SWITCH

• AUTO (PUSH IN): allows audio communication via oxygen masks.

• MASK (PUSH OUT): activates oxygen masks microphone when auto mode fails.

• Oxygen mask stowage box doors must be closed and reset in order to enable hand or headset microphone booms after using the oxygen mask microphone.

---

BACKUP VOLUME CONTROL BUTTON/KNOB

• NORM (PUSH IN): normal operation mode.

• BKUP (PUSH OUT): restores VHF communication in case of digital audio system failure.

---

SELCAL ANNUNCIATOR BUTTON

• Unavailable