Three radio management panels (RMP), two on the center pedestal and one on the overhead panel, and three audio control panels (ACP), each located next to an RMP, control radio communications. The RMPs also provide a backup for radio nav aid tuning.
Each RMP can tune any communication radio. Usually, however, RMP1 is dedicated to VHF1, RMP2 to VHF2 and RMP3 to VHF3 or HF. A white SEL light illuminates when a radio that is not dedicated to an RMP is selected. Note that the standby frequency is specific to the RMP, not the radio currently being tuned.
The ACPs incorporate SELCAL and interphone call alerts. When any of these calls occurs, a buzzer sounds and the relevant transmit button flashes amber. The RESET button is used to silence these alerts. The VOICE key supresses a nav aid's ident so that voice transmissions can be heard more clearly.
A CALLS panel situated in the left lower corner of the overhead panel.The MECH button illuminates a light on the external power panel and sounds an external horn. Pressing either the FWD or AFT buttons causes a high/low chime in the cabin and a "CAPTAIN CALL" message to appear at the selected cabin station. The ALL button does the same, except the message appears at all cabin stations. Activation of the emergency call system, either initiated by the flight crew by pressing the EMER button or initiated by the cabin crew, causes the CALL light in the EMER button to flash amber and the ON light to flash white. If the call is to the cabin, three high/low chimes sound in the cabin. If it is from the cabin, three long buzzers sound on the flight deck.
The CVR, when activated, records the last two hours of communications and aural warnings from the cockpit. It is controlled from the RCDR panel. In AUTO mode, it runs for five minutes after power is applied to the aircraft, then automatically shuts down. It then restarts after first engine start and continues running until five minutes after the last engine has been shut down. Pushing the GND CTL pushbutton manually powers the CVR on the ground. The CVR ERASE and CVR TEST buttons are inhibited unless GND CTL is ON, the aircraft is on the ground and the parking brake is set. Pushing the CVR ERASE button for two seconds erases the CVR recording. Pushing the CVR TEST button sounds a tone through the loudspeakers if the CVR is serviceable.
The system monitors the communication radios and will produce an ECAM warning if there is continuous transmission.
A switch on the overhead panel allows for deselection of a failed ACP and its replacement by ACP3.