2
$\begingroup$

Can a pilot transmit and receive information at the same time? Or can he either transmit or receive but not at the same time?

I thought communication channels were half-duplex because this reduced the chance of the information by trasmitter (say the ATC) being overlapped by information from the receiver (the pilot) in case he possibily accidentaly pressed the PTT button. Is that a right assumption or not?

$\endgroup$
  • $\begingroup$ They are half-duplex because all parties share the same frequency. Only one party can transmit at any time. Full duplex would require two frequencies. Can you edit your question to clarify if you don't understand this aspect of communication. $\endgroup$ – Transistor Jun 17 '18 at 9:33
  • $\begingroup$ That is very clear, thanks. So the reason behind the channels being half-duplex lies in the fact that it would be necessary the use of two frequencies for the two parties to transmit and receive at same time. But was it the intention of non being able to transmit and receive at the same time wanted from the start because (as I said) that would potentially create confused situations? Or is that just a plain technical limitation as having two frequencies assigned per aircraft is just non convenient? $\endgroup$ – aviation_geek Jun 17 '18 at 9:41
  • $\begingroup$ Full duplex would require two frequencies and therefore third parties would have to monitor both frequencies simultaneously in order to hear both sides of the conversation. Half-duplex operation on a single frequency is inherently 'open-channel' - everybody can hear everything transmitted by anybody else on that frequency. That's the way it's always been done in aviation and in many other fields. $\endgroup$ – Fiddlesticks Jun 17 '18 at 10:41
  • $\begingroup$ Full duplex isn't unheard of though in aviation, there are some frequencies that are transmit only or receive only (like listening for an FSS over a VOR and transmitting on a separate frequency). $\endgroup$ – Ron Beyer Jun 17 '18 at 16:15
  • $\begingroup$ @Fiddlesticks You should go ahead and make your comment an answer. They're trying to cut down on "answers in comments." $\endgroup$ – TomMcW Jun 17 '18 at 16:47
1
$\begingroup$

They are half-duplex because all parties share the same frequency. Only one party can transmit at any time.

Full duplex would require two frequencies and therefore third parties would have to monitor both frequencies simultaneously in order to hear both sides of the conversation. Half-duplex operation on a single frequency is inherently 'open-channel' - everybody can hear everything transmitted by anybody else on that frequency. That's the way it's always been done in aviation and in many other fields.

(Answer taken from comments by https://aviation.stackexchange.com/users/13124/transistor and https://aviation.stackexchange.com/users/15152/fiddlesticks)

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.