Text Based ATC Communications for GA

[kontiki]

I see NextGen text based provisions going into large 121 airplanes and I was wondering if there are any GA Cockpit - ATC text based communications systems out there? This was at one time called Controller Pilot Data Link Communications (CPDLC), I don't know if it changed into something else.

I personally believe better communications between the cockpit and ATC could improve safety. Missing routine radio messages seems common. If there was something out there, I might consider it when equipping for ADS-B out.

 

[Jim Logajan]

I personally believe better communications between the cockpit and ATC could improve safety. Missing routine radio messages seems common.

If loss of audio communications due to radio congestion or low signal strength is the problem to be solved, then the solution would be to change the underlying technology to something that can insure that audio gets through - the solution should not be to switch to text mode. Audio communications is well suited to piloting because you always get it regardless of your current mental or visual focus - text, not so much I think, because you have to visually scan for it.

Example: If 3 people all transmit at once, then using digital technology one can insure that they all hear each other without having to repeat themselves (the digital protocol hides all that work.) The receivers could be made to either emit the audio as if the 3 were all talking at the same time (which would be an improvement over the squeal that an analog radio might produce) or it could instead present each of the transmissions sequentially to the listener. Some transmissions will be heard a few seconds later than otherwise, but this would still be a big improvement over the analog case where some considerable time must elapse before the sender concludes the transmission didn't make it.

Other things are possible:

• Automatic acknowledgement of reception of a transmission by the intended receiver(s). Such acks could be conveyed to the sender by visual or audio means.
• Automatic addition of the sender's call sign, to be presented in whatever form the receiver prefers.
• With some added button pressing: automatic prepending of the intended receiver(s) e.g. unicast to ATC or broadcast to local traffic. The destination information could be digitally encoded, allowing the receiver (if the person so desires) to automatically silence any transmissions not broadcast or unicast to them.
• Automated encryption and authentication, where or if needed.

Audio communication using digital technologies are now well understood and in use today. But I don't expect aviation to shift from analog to digital within my lifetime. They'd regulate it to fiscal oblivion if it was pushed at all.