5. Communications

Question 1

Radio Tuning Panel OFF Switch

Answer 1

Disconnects the panel from the communication radios

Question 2

Offside Tuning Light

Answer 2

• The radio normally associated with this panel is being tuned by another Radio Tuning Panel or,
• The Radio Tuning Panel is being used to tune a radio not normally associated with this radio tuning panel

Question 3

VHF Test Switch

Answer 3

• Removes automatic squelch feature, permitting reception of background noise, testing receiver operation,
• Improves reception of weak signals

Question 4

AM Switch and Light

Answer 4

• Illuminates: HF AM is in use,
• Distinguished: HF USB in use,
• USB: Upper Side Band

Question 5

Keyline Timer

Answer 5

• Limits VHF transmission to approximately 35s,
• After 25-30s after any PTT selected, transceiver maken an aural tone in the headset,
• Tone continues for 5s and after it stops RF transmission stops,
• Then radio is set to receive mode automatically,
• Radio remains in receive mode until PTT is released and selected again

Question 6

Service INTERPHONE Handset Jack

Answer 6

• Positioned above the PA Hand Mike Jack,
• Used to directly communicate on SERVICE INTERPHONE,
• Bypasses ACP

Question 7

Voice Recorder ERASE Switch

Answer 7

To erase:
- Push 2s,
- Operates only on the ground and,
- Parking Brake Set

Question 8

Voice Recorder TEST Switch

Answer 8

To test:
- Push for 5s,
- Status light flashes once,
- A tone may be heard through headset

Question 9

Voice Recorder Switch AUTO

Answer 9

Powers CVR from first engine start until 5 minutes after last engine shutdown

Question 10

Master Call Lights in Cabin

Answer 10

• Pink: Flight Deck or other Flight Attendant Station is calling,
• Blue: A Passenger seat call switch activated,
• Amber: A Lavatory call switch is activated

Question 11

Call RESET Switch

Answer 11

• Extinguishes both pink master call lights,
• Cancels call,
• Disconnect headset from PA system

Question 12

Audio Warnings

Answer 12

• GPWS, Altitude Alert, Traffic Collision and PWS alerts,
• Heard through the speakers and headsets at preset volumes,
• They cannot be controlled or turned off

Question 13

Mutes Speakers

Answer 13

• Muted for CPT and F/Os PTT microphone operation,
• Not muted for Oxygen Mask microphone operation

Question 14

Oxygen Mask Microphone

Answer 14

• For some airplanes it’s enabled and boom mic disabled when left oxygen mask door is open,
• It’s disabled and the boom mic enabled when left oxygen mask door closed and RESET/TEST switch is pushed

Question 15

Normal Audio System Operation

Answer 15

• Located in a common Remote Electronics Unit in the E/E compartment,
• They function independently

Question 16

Degraded Audio System Operation

Answer 16

• If the Remote Electronics Unit or ACP fails, the ACP cannot control the Remote Electronics Unit,
• Audio system can be switched to a Degraded mode by the ALT-NORM switch,
• In ALT mode, the ACP at that station is inoperative and crew member can only communicate on one radio,
• Transmitter selector of the usable radio illuminates,
• Only usable radio heard at a preset volume through the headset,
• Speaker is not functional on that station,
• Flight and Service interphones cannot be used,
• Hand mic is not usable,
• Mask and Boom mics and MASK-BOOM switch works normally,
• Altitude Alert, GPWS and Windshear alerts are heard

Question 17

Degraded Audio System Default Radios

Answer 17

• CPT: VHF-1,
• F/O: VHF-2,
• Observer: VHF-1

Question 18

VHF Communications Antennas

Answer 18

• VHF-1: Upper Fuselage,
• VHF-2/3: Lower Fuselage

Question 19

CVR

Answer 19

• Uses 4 independent channels (Flight Deck Area Conversations, others ACP output audio and transmissions),
• Records audio for last 120 minutes,
• Equipped with Locator Beacon operable for 90 days

Question 20

ACARS

Answer 20

ARINC Communications Addressing and Reporting System

Question 21

CPDLC

Answer 21

Controller-Pilot Data Link Communications

Question 22

SATCOM

Answer 22

• Some aircrafts has it,
• Provides only datalink communication,
• CDU connects to SDU,
• ACARS management unit connects with SDU to send and receive data signals