777 AIRCRAFT MAINTENANCE MANUAL
PAS -SDM, ANS, AND SPEAKER INSTALLATION
EFFECTIVITY BEJ ALL 23-31-00
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D633W101-BEJ Jan 05/2002
PAS -FLIGHT INTERPHONE ANNOUNCEMENT -OPERATION
General
The audio control panel (ACP) lets the flight crew make priority 1 announcements.
Control and Indications
Push the PA receiver switch to listen to PA audio. The green PA receiver light above the receiver volume control comes on when the PA receive is on.
Push the PA transmitter select switch to make a priority 1 announcement. The white MIC light comes on. Push the MIC/ interphone switch to connect the microphone to the PA/CI controller.
Priority 1 announcements go to all passenger address areas.
EFFECTIVITY BEJ ALL 23-31-00
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D633W101-BEJ Sep 05/2002
PAS -FLIGHT INTERPHONE ANNOUNCEMENT -OPERATION
EFFECTIVITY BEJ ALL 23-31-00
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D633W101-BEJ Jan 05/2002
PAS -DIRECT ACCESS FUNCTIONAL DESCRIPTION
General
Flight attendants normally make PA announcements through the cabin interphone system (CIS) (priority 2B). If the CIS has a failure, attendants can make direct access announcements (priority 2A). Direct access announcements go around the CIS.
CIS Announcements
When an attendant selects a passenger address dial code, the CIS circuits in the zone management unit (ZMU) send digital audio to the PA/CI controller. The cabin interphone controller (CIC) sends the audio to the passenger address controller (PAC) in the PA/CI controller.
Direct Access
Two of the cabin attendant handsets (CAHs) have the direct access function. They are at door 1 left and door 3 left. Only one direct access handset may connect to a ZMU. The handset at door 1 left connects to ZMU 1. The handset at door 3 left connects to ZMU 3. There is no direct access handset connected to ZMU 2.
A momentary DIRECT ACCESS switch is on the front of the CAH cradle. When you push the switch, 28v dc goes though the contacts to the relay in the zone management unit (ZMU). The relay energizes. The 28v dc goes through the reset line and latches the relay in the energized position.
When the relay energizes, the CAH microphone audio and PTT signals go around the CIS circuits. In each ZMU, the direct access mic and PTT signals from the CAH mix with the signals from the previous ZMU. The direct access outputs from ZMU 1 connect directly to the PAC in the PA/CI controller.
When the CAH goes back in the cradle, it opens the CAH on hook switch. When the CAH on hook switch opens, this deenergizes the direct access relay.
EFFECTIVITY BEJ ALL 23-31-00
Page 34
D633W101-BEJ Sep 05/2002
PAS -DIRECT ACCESS FUNCTIONAL DESCRIPTION
EFFECTIVITY BEJ ALL 23-31-00
Page 35
D633W101-BEJ Jan 05/2002
PAS -DIRECT ACCESS AND CABIN INTERPHONE ANNOUNCEMENT -OPERATION
General
You use cabin attendant handsets (CAHs) for both direct access and cabin interphone announcements.
Cabin Interphone
Flight attendants normally use the cabin interphone system (CIS) to make PA announcements (priority 2B). They can use any CAH to make a CIS announcement.
CIS announcements go to selected PA areas or all areas. To select a PA area, dial the code. These are typical PA dial codes:
*
Area 1 -41
*
Area 2 -42
*
Area 3 -43
*
Area 4 -44
*
Area 5 -45
*
Area 6 -46
*
All areas -40
*
Priority all areas -47.
To make a CIS announcement, dial the code for the area and push the PTT. To end the announcement, either push the RESET button or put the handset back in the cradle.
Direct Access
Flight attendants use CAHs at doors 1 left and 3 left to make direct access announcements (priority 2A).
The direct access CAH cradle has a PA switch. To make a direct access announcement, push the PA switch. Then push and hold the PTT. This connects the CAH microphone to the PA/CI controller.
Direct access announcements go to all PA areas.
To end the direct access announcement, put the handset back in the cradle.
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