Comment by wolverine876 | Hacker News Reader

Comment by wolverine876 | Hacker News Reader

Why are ATC instructions given verbally over sometimes staticy channels using the always error-prone communication tech, human speech? Why not digital?

The ATC operator chooses a command from a UI: 'JAL 123' > 'Runway 34R' > 'Clear for landing'.

Everything cascades automatically from there: ATC's on-screen maps and info, airport lights, commands to all relevant planes (including 'Runway 34R' > 'Hold short').

Transmission to planes could be digital. Given the relatively few possible commands, we're talking very little bandwidth, plenty of room to ensure error correction, redundancy, etc. - and perfectly accurate reception.

All planes would show the exact command on a screen, their maps etc would update, and they could play locally generated audio of the command.

I know nothing about aviation. (I do know that entirely rebuilding matured, critical systems for the new technology is rarely a good idea - the trick is to start with one small subsystem, work out the bugs, mature it, and grow from there.)

For standard situations, text clearances might really be safer: Pilots usually just acknowledge, and augmentation systems could help warn them if they don't conform with a certain clearance.

But having a broadcast channel accessible (for listening and talking) to all aircraft and ATC can increase situational awareness for everybody. Just look at the near-miss of Air Canada 759 [1] for an example of where it might have contributed to saving hundreds of lives:

[1] https://en.wikipedia.org/wiki/Air_Canada_Flight_759

While ATC controllers might be able to issue urgency text messages quickly enough on a keyboard, pilots literally have their hands full flying the airplane. Voice is their only feedback channel, and if it falls out of use, outages might go unnoticed for critical seconds.

> But having a broadcast channel accessible (for listening and talking) to all aircraft and ATC can increase situational awareness for everybody.

OK, so send all messages to all aircraft (or to whatever the appropriate subset is).

> pilots literally have their hands full flying the airplane. Voice is their only feedback channel

Interesting. I wonder if the error rate of voice recognition exceeds the error rate of bad channels.

Sure, you could emulate the broadcast channel.

You'd have to read out all of these prompts and acknowledgements though, since pilots also will have their eyes on many instruments other than just datalink.

Definitely doable using text-to-speech, but that way you lose the original intonation (Did the speaker sound confused? Hesitant? Was it a different voice than before?) – and what did you gain?

> you lose the original intonation (Did the speaker sound confused? Hesitant? Was it a different voice than before?) – and what did you gain?

Good point about intonation. You gain almost perfect signal-to-noise, an error-free cascade of instructions to all (if that's needed), and immediate synchronized updates of all systems.

Maybe that's not as significant a problem as it seems from the outside. As I said, I'm in IT not aviation. Thanks for answering my questions!

I think you are swapping one issue for another. A clearance that is a button push has far less meaning and protection than standard verbal phraseology. During the critical phase of flight, attention is needed on the aircraft performance and position using the working auditory memory we can minimise distracting messages and popups close to the ground.

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