Communications - Interphone
The Interphone Communication System includes the:
The interphone systems allow the flight crew to communicate with the flight attendants, ground personnel and maintenance technicians. The Passenger Address (PA) system allows flight attendants or the flight crew to make announcements in the passenger cabin.
The Flight Interphone, Service interphone, Cabin interphone and PA systems are normally operated through the Audio Control Panel in conjunction with the Pilot Call Panel (PCP).
Flight Interphone System
The Flight Interphone System (FIS) permits intercommunications between flight deck crew members and, on the ground, with ground personnel.
The system is used by the following methods:
- Pressing the INT (Interphone) position of a control wheel mic/interphone switch to transmit.
- Selecting INT (Interphone) transmitter select switch on the ACP and pushing a PTT switch.
Ground personnel are able to communicate on the FIS through a jack located on the APU Ground Control Panel mounted on the nose wheel strut.
The pilots are alerted to an incoming call from the ground crew by the following methods:
- An aural chime sounds on the flight deck.
- The GND CALL light on the PCP illuminates.
- As installed - The EICAS message •GROUND CALL is displayed.
The pilot should press the GND CALL switch/light on the PCP to respond to the call. Any of the PTT switches may be used to communicate.
The flight crew initiates a call to ground personnel by pushing the GND CALL switch on the PCP. A horn in the nose wheel well activates as long as the switch is pushed.
Cabin Interphone System
The Cabin Interphone System (CIS) provides voice communications between the flight deck and the flight attendant stations. Flight deck crew members communicate on the CIS either using their ACP and the PCP. The flight crew may use the boom microphones, oxygen mask microphones, or - as installed - hand microphones to transmit.
The flight attendants communicate between flight attendant stations or with the cockpit using any of the handsets in the cabin. The system is a party line in that anyone who picks up a handset is automatically connected to the system.
A call can be placed by selecting the CABIN transmitter select switch on an audio control panel, selecting the appropriate (FWD, MID, AFT or ALERT) station on the PCP, and pressing the PTT switch to speak when the call is answered.
When the call is answered, it may be heard on the flight deck speaker or on the headset.
(SB changes B-2852 - As installed, EICAS communication messages)
The ALERT function calls all other interior stations simultaneously. The ALERT is initiated by pressing the ALERT switch on the PCP which will illuminate the call lights and sound the chime at all interior stations except for the originating station. Alert calls automatically override other cabin interphone calls.
Calls to the flight deck can be answered by selecting CABIN on the Audio Control Panel and transmitting using the interphone (INT) switch on the control wheel, or any other PTT switch.
As installed
Calls to the flight deck can be answered by selecting FLT INT on the pilots call panel and transmitting using the interphone (INT) switch on the control wheel.
If CIS power is lost, the attendant handsets will automatically be connected to the Passenger Address (PA) system. Pushing the Push-To-Talk switch then allows PA announcements.
Service Interphone System
The Service Interphone System consists of additional internal and external jacks connected to the Flight/Cabin Interphone System for use by maintenance personnel. To reduce external noise in the flight/cabin interphone system, the Service Interphone Switch can be left OFF during normal flight operations. This disconnects the microphone jacks at all exterior (unpressurised) service interphone stations except the jack on the nose wheel strut. This switch does not affect the interior flight/Cabin interphone stations.
Call System
The call system allows the cockpit crew, flight attendants and ground personnel to indicate that interphone is desired. The cockpit crew can initiate calls through the Pilots Call Panel or (as installed) through the Pilots Handset. Attention is called through call lights and chimes.
Ground personnel are able to call the cockpit using a switch on the APU Ground Control Panel. Cockpit crew can call ground personnel through the Pilots Call Panel which activates a horn in the nose wheel well.
The capability for any interior station to call all other interior stations simultaneously is provided through an alert function on each cabin handset and the Pilots Call Panel. In addition to illuminating all cabin station call lights, the alert function activates the cabin HI/LO chimes three times.
