communications

The oxygen microphone is active when:

The left oxygen mask compartment door is opened — An oxygen mask microphone is enabled and the boom microphone is disabled when the oxygen mask left stowage door is open. [Ref: Chapter 5 — Communications — 5.20.1]

When the SERVICE INTERPHONE switch is turned ON, what systems are connected?

The service and flight interphone systems — The FCOM describes the triggering logic as “The cargo interphone and upper deck interphone systems can be connected to the flight interphone with the Cargo Interphone switch.” Those are the conditions that lead to The service and flight interphone systems. [Ref: FCOM 5.30.1]

What occurs when the GROUND SERVICE CALL switch is pushed?

A horn sounds for three seconds in the nose wheel well — The FCOM describes the triggering logic as “Pushing the Ground Call switch on the call panel sounds a three second horn in the nose wheel well.” Those are the conditions that lead to A horn sounds for three seconds in the nose wheel well. [Ref: FCOM 5.30.1]

An illuminated CARGO call light indicates:

A call has been received from the main deck cargo area — The FCOM describes the triggering logic as “flight interphone system • personnel address (PA) system • cargo interphone • upper deck interphone system • cargo intercom (main.” Those are the conditions that lead to A call has been received from the main deck cargo area. [Ref: FCOM 5.30.1]

When does the cockpit voice recorder ERASE switch operate?

On the ground with AC power ON and the parking brake set; push and hold ERASE for three seconds [Ref: FCOM Chapter 5 — Flight Management, Navigation - FMC Cruise (NG FMC)]

In ICA/ICD, the captain's audio panel is inoperative. What can be done?

Select VHF-L DIRECT on the CAPT Audio System panel on the overhead panel [Ref: FCOM Chapter 5 — Flight Management, Navigation - FMC Cruise (NG FMC)]

What option does the first officer have if the right audio panel has failed?

Switch the OBS Audio Panel System to F/O [Ref: FCOM 5.20.1]

What does the CALL light on the left HF selector mean?

A SELCAL call has been received — CALL Lights — Illuminated (white) - with aural chime, indicates a call on: … SELCAL (VHF or HF) [Ref: Chapter 5 — Communications — 5.10.2]

What stations can be connected through the flight interphone system?

Flight deck crewmembers, and the flight deck with ground crew through the flight interphone jack on the nose landing gear [Ref: FCOM 5.30.1]

The left radio tuning panel has failed. Can the left HF sensitivity still be adjusted?

Yes — HF sensitivity adjustment is not affected by radio tuning panel failure or by the OFF switch (ICB; not ICA) [Ref: FCOM Chapter 5 — Flight Management, Navigation - FMC Cruise (NG FMC)]

The OFFSIDE TUNING light is illuminated on the audio panel. What is one possible risk?

Inadvertently changing the other person's frequency — The FCOM describes the triggering logic as “Highlight Audio Control Panel 1 Transmitter Select Switches Push – • MIC light illuminates • MIC light for any other.” Those are the conditions that lead to Inadvertently changing the other person's frequency. [Ref: FCOM Chapter 5 — Flight Management, Navigation - FMC Cruise (NG FMC)]

All engines and the APU are shut down and no GPU is available. Can you still contact ATC if needed?

Yes — on battery power only, VHF-L and RTP-L remain operative [Ref: FCOM Chapter 5 — Flight Management, Navigation - FMC Cruise (NG FMC)]

How many radios or systems can be selected for transmission on one audio panel at a time?

Only one can be selected at a time for each crew station [Ref: FCOM 5.10.1]

What must the captain do to clear the CALL light on the center VHF transmitter switch?

Select the respective transmitter selector — Resets when respective transmitter select switch pushed or; when already pushed, by pressing a MIC/INTERPHONE switch. [Ref: Chapter 5 — Communications — 5.10.2]

The flight deck can communicate with the cabin interphone without using the interphone handset. True or False?

True [Ref: FCOM 5.10.1]

What occurs when the cockpit voice recorder TEST button is pushed?

Push and hold for five seconds to test all four CVR channels, one per second; the test passes with the needle in the green band or the green light illuminated [Ref: FCOM Chapter 5 — Flight Management, Navigation - FMC Cruise (NG FMC)]

On the audio control panel, VHF-L is deselected by mistake but its associated MIC light remains illuminated. What happens?

Audio for VHF-L remains on — The FCOM describes the triggering logic as “by pushing the desired audio control panel transmitter select switch and then selecting one of the following: • the MIC.” Those are the conditions that lead to Audio for VHF-L remains on. [Ref: FCOM 5.20.1]

The audio panel and volume are set correctly and HOT MIC is ON, yet you are unable to transmit. What may have happened?

The left oxygen mask compartment door may be partially open, activating the service-phone switch [Ref: FCOM Chapter 5 — Flight Management, Navigation - FMC Cruise (NG FMC)]