Originally Posted by
fumje
Does this mean they broadcast radio waves to transmit the audio from the cockpit to the cabin?
Some searching around gives me the impression that is the case, but I'm having trouble imagining why it's not wired.
No; it's hard-wired. The output of the
#1VHF radio is routed by wire (when enabled) to the passenger entertainment system and comes up on "Channel 9" or "From the Flight Deck" in the legacy systems.
When the passenger entertainment systems were first removed from the A320 fleet and streaming entertainment installed, I asked a UA executive about the future of "From the Flight Deck." He explained they were exploring how to integrate the audio stream into the wireless system, but had no information on its progress nor confidence on it being feasible from both a technical and certification standpoint. That was many years ago, and I have had no update since then, so I can't even say if its still being considered for the future.