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View Full Version : Why no CAT technology for airband radio?


ChickenHouse
6th Mar 2021, 09:53
A friend of mine is a decent HAM and now started to learn to fly. When we had a discussion on airfield operations he asked a question I never thought about it:

Why lack usual airband transceiver CAT capability?

During the conversation I learned that almost all HAM radios now come with CAT interface and most of the operator don't use the physical radio controls, but a computer and headset. If I understand correct, the only thing you need is a sound card to get audio in and out, some switch to do PTT and a way to tell the radio which frequency to go. That neither sounds rocket science, nor expensive. So, what is your opinion, why don't they spend the sub-£ circuit to give us a full control USB connection to a (handheld?) airband radio?

Uplinker
6th Mar 2021, 10:07
I assume CAT in this context is computer aided transmissions, or something?

I think it is desirable from an operational point of view to have physical knobs and controls on the radios - think about smoke in the cockpit for example.

On Airbus we can remotely control any radio from any Audio Control Panel e.g. 'post' frequencies to other radios. On some other aircraft types, e.g. Dash 8; Comm radios can be preloaded with, I think it was eight frequencies for easy selection. But they all have actual knobs and controls.

I would like to know when they will introduce digital audio modulation of HF radio. That would vastly improve that service.

ChickenHouse
6th Mar 2021, 10:12
CAT is Computer Aided Transceiver. Yes, physical knobs do have advantages, but the whole world did jump on the 'Digital Religion' train already. You can always use knobs, they don't have to use physical connection, as in many other applications, where you do have knobs driving a computer driving the function.

ScepticalOptomist
6th Mar 2021, 11:33
One word - costs.

Certification costs to fix something that isn’t broken.

If you think VHF sucks, you should see what the latest and greatest aircraft have in terms of a HF rig!

Peter Fanelli
6th Mar 2021, 13:26
Up until the time I quit flying 25 years ago a pilot flying light aircraft could climb into any aircraft and it didn't matter what brand avionics it was fitted with the pilot could operate them because they all operated the same way. Secondly having a physical knob is a huge plus when flying in turbulence.

ChickenHouse
6th Mar 2021, 14:41
Yes, all granted.

But - we need future, not tales on the ocean when we were protozoon ...

Vessbot
6th Mar 2021, 15:41
I think I can figure out what you're describing, but not completely sure. But it seems that at least one quality is that the tuning unit is separate from the physical radio itself... and this is already the case in modern airliners. The radio itself is in a rack in the belly of the plane, while the box in the cockpit just displays the frequency and has a knob to tune a new one. Is there anything more to it?

GlobalNav
6th Mar 2021, 16:37
From a certification perspective, and from a operational perspective, one would need to prove the reliability of frequency selection. Communications, and communication with who you intend to communicate with is safety critical. Who are you listening to? What alerts, warnings or instructions might you be missing, because you are no longer tuned to the frequency you thought you were?

dixi188
6th Mar 2021, 17:35
" Alexa, tune com 1 to 118.65"
:)

ATC Watcher
6th Mar 2021, 18:49
If we are to believe the future plans , data link will make all this redundant , the next frequency will be automatically uploaded by ATC , and you just have to accept , the D/L will then send a message back that you have gone to the next frequency and another that will make your call sign pop up on a screen. You can even skip the Good morning and Good bye. You can even select the language you want the box to display.. No need to speak anymore... wonderful future :rolleyes:

Denti
6th Mar 2021, 20:38
It already works that way in some sectors. And equipped airplanes, which is a bit more scarce. And that is fine, but for something where immediate action is required, there is still the fallback to voice.

Roj approved
7th Mar 2021, 00:33
ATC Watcher

The 787 has this capability for both VHF and HF, very useful when busy airwaves or the controller "forgot" to transfer you.

ATC Watcher
8th Mar 2021, 09:17
Did not know they were so advanced, you mean no tuning of frequencies needed anymore , just accepting the D/L messages automatically tunes in the right frequency ?
Is that on all 787s or only recent ones with a specific avionic suite ?

Roj approved
8th Mar 2021, 11:08
I flew the 787-8 between 2013 and 2018, and it was a thing. Not sure of the “newness” of the avionics suite.

Check Airman
8th Mar 2021, 18:08
" Alexa, tune com 1 to 118.65"
:)

“Ok, setting speed to 118 knots- Mach point 65”

GlobalNav
8th Mar 2021, 18:59
What wasn't "Alexa" (and Siri) named "Murphy"?

ex-EGLL
8th Mar 2021, 21:18
“Ok, setting speed to 118 knots- Mach point 65”
Perfect!!!

Dan Dare
9th Mar 2021, 13:04
787s may have magic auto tuned radios, but they forgot to do the basic voice modulation - so many of them have the crappiest radios on the airport and you can almost know the aircraft type just from the carrier wave noise of their radios.