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I don’t understand why we’re using a voice based system to pass along a couple of structs worth of data for decades now. You want to get your approach clearanc

I don’t understand why we’re using a voice based system to pass along a couple of structs worth of data for decades now. You want to get your approach clearance or weather report? Just call up the ATC on busy line with bunch of people talking fast and over each other.

rudedogg 8d ago
Yeah, I listen/watch some flight radar youtube and it’s insane how many issues arise from the language barrier, which could be solved by just communicating via a text channel
- tjohns 8d ago
  CPDLC exists and is used. It has its limitations though - it doesn’t provide as much flexibility for pilot replies, pilots don’t always have a free hand to text with (especially in turbulence), and is generally slower and more clumsy than voice so is only suitable for routine, non-time-sensitive messages.
  - itopaloglu83 8d ago
    That sounds like a system that was bound to fail, because it was kept limited to a certain range of capabilities. One can easily imagine a system that broadcasts the weather and clearance, and even aircraft location data close to real-time, and provide great situational awareness to everyone involved. I don't think it's acceptable to put tens of thousands of people within a crowded airspace and not do everything in our power to keep things organized and secure.
    - tjohns 5d ago
      > That sounds like a system that was bound to fail, because it was kept limited to a certain range of capabilities. You're always going to be limited to a limited range of capabilities. You can't run a full web browser in every cockpit - you need a standardized interface that works across different vendors, across borders, and over a low-bandwidth radio link. And I don't think anybody considers CPDLC a failure. The goal was never to 100% replace voice communication. > One can easily imagine a system that broadcasts the weather That exists, it's called FIS-B. Everyone uses it. > and clearance Clearance isn't something that can just be broadcast. You need to have a conversation with the pilot to make sure the clearance is acceptable to them. The pilot needs the ability to reject the clearance and request amendments. > even aircraft location data close to real-time, and provide great situational awareness to everyone involved. This exists, it's called ADS-B. Everyone uses it.
labcomputer 8d ago
Maybe because literally the entire world is currently using that system, and sending machine-readable clearances to just some airplanes means that the non-equipped planes are denied situational awareness?
misswaterfairy 8d ago
Whilst voice clearances have been the norm since aviation really took flight, no pun intended, there's much more subtle but crucially important aspects about why this has remained: situational awareness by broadcast. The critically important aspect: approach clearances and weather reports for a specific aircraft are still useful and relevant to all nearby aircraft. Narrow-casting them to specific aircraft reduces situational awareness for all other nearby aircraft. The system is also tolerant of noise: digital communications can be lost entirely with some degradation in signal, analog voice communications can still be interpreted with a fair bit of noise present (see video below). The subtle aspect: multi-tasking by using more than one human sense - looking and hearing. People dealing with risky or dangerous situations absolutely should not be sucked into a screen for more than a minute or two to get critical information. This includes to more than one pilot where tasks are being managed and delegated. Most (if not all) controlled or 'aviator-coordinated' (CTAF) airports have a specific radio frequency to tune into to get weather information from an automated weather-to-voice system (e.g. https://youtu.be/HHbrlUPP-4k?t=339 https://youtu.be/HHbrlUPP-4k?t=339). Whilst it sounds clunky, aeronautical phraseology (https://en.wikipedia.org/wiki/Aeronautical_phraseology https://en.wikipedia.org/wiki/Aeronautical_phraseology) keeps communications detailed but brief and concise. Digital voice communications often completely degrade for several seconds with a few lost packets, combined with the brevity of aeronautical phrasing can mean critical information is missed. All of these 'old' systems add up to the cumulative safety (https://en.wikipedia.org/wiki/Swiss_cheese_model https://en.wikipedia.org/wiki/Swiss_cheese_model) and doctrine built by the aviation industry over many, many decades though sadly because a lot of them were written in the blood of others who perished.
- itopaloglu83 8d ago
  Well, as far as I remember, the Link 16 was invented around the 1970s where aircraft could share real-time data in a combat zone. The weather information can easily be transmitted every minute and it can be nicely visualized in the cockpit instead of being crammed into cryptic abbreviations and ancient codes. Similarly, we are aware of the precise aircraft location and it's intended course, I'm talking about commercial airlines here, so we already know where they're going and what the approach path will be etc. I find it hard to accept that we're collecting terabytes of telemetry from engines and all the other equipment on the aircraft, but we expect to communicate the weather and traffic information in verbal ways. There are so many good ways we can solve the underlying requirements, but I think it's all stuck on the cost of implementation and who's going to be making money from it.
Grombobulous 8d ago
Nearly hands-free for pilots operating controls (not all pilots have a copilot), simple and reliable technology available to planes and airports of all sizes, high amount of message flexibility, faster than typing or some other form of electronic message selection. Why do quarterbacks yell out code words to call plays? After all, it’s loud stadium and it’s only a couple structs worth of data!
- itopaloglu83 8d ago
  There is no need for pilots or anyone to type anything. Weather data can be published every minute and shown live as a full map over the screen, not as random abbreviations of wind and cloud coverage. And we already know where each aircraft is, and where they took off, and where they're headed. So practically speaking the radio talk can be limited to only the important communication and emergencies, while increasing the situational awareness by at least ten fold.
  - tjohns 5d ago
    > Weather data can be published every minute and shown live as a full map over the screen This already exists via FIS-B. > not as random abbreviations of wind and cloud coverage The abbreviations (METARs) are a feature, not a bug. There are numerical legal minimums for weather that determine whether a landing is legal or not. A graphical map doesn't tell you this. The METARs are condensed because they're easy for professional pilots to skim. (Back in the days of teletypes they also saved bandwidth, but that's just a historical note at this point.) Regardless, pilots already have access to both textual and graphical weather products in the cockpit. > And we already know where each aircraft is, and where they took off, and where they're headed. So practically speaking the radio talk can be limited to only the important communication and emergencies, while increasing the situational awareness by at least ten fold. As a pilot myself, I think you're vastly misunderstanding the nature of ATC communication. 90% of communication on the radio are time-sensitve, important things - mostly heading and altitude changes to avoid other traffic. Weather and clearances (when not relayed by ACARS, FIS-B, or CPDLC) are routinely handled on dedicated frequencies and aren't really causing meaningful frequency congestion.
ehe78qhe 8d ago
The military has switched their aircraft over to datalink for C2, but asking every civil aircraft to upgrade to the systems required is economically and legally infeasible.
fwlr 8d ago
The human auditory input channel is the modality already in use by pilots for other parts of this task - for example, copilots will verbally provide confirmation that the plane is capable of landing (flaps, gear). Aircraft safety engineering has done a lot of investigation into how humans process information and make decisions and they have found that putting two mandatory pieces of information for landing (is the ground ready for me, am I ready for the ground) in two separate modalities will inevitably mean that during high intensity moments such as landing a plane, only one modality is checked. You would absolutely get planes landing without clearance, or with clearance but without their gear down.

rudedogg 8d ago

Yeah, I listen/watch some flight radar youtube and it’s insane how many issues arise from the language barrier, which could be solved by just communicating via a text channel

tjohns 8d ago
CPDLC exists and is used. It has its limitations though - it doesn’t provide as much flexibility for pilot replies, pilots don’t always have a free hand to text with (especially in turbulence), and is generally slower and more clumsy than voice so is only suitable for routine, non-time-sensitive messages.
- itopaloglu83 8d ago
  That sounds like a system that was bound to fail, because it was kept limited to a certain range of capabilities. One can easily imagine a system that broadcasts the weather and clearance, and even aircraft location data close to real-time, and provide great situational awareness to everyone involved. I don't think it's acceptable to put tens of thousands of people within a crowded airspace and not do everything in our power to keep things organized and secure.
  - tjohns 5d ago
    > That sounds like a system that was bound to fail, because it was kept limited to a certain range of capabilities. You're always going to be limited to a limited range of capabilities. You can't run a full web browser in every cockpit - you need a standardized interface that works across different vendors, across borders, and over a low-bandwidth radio link. And I don't think anybody considers CPDLC a failure. The goal was never to 100% replace voice communication. > One can easily imagine a system that broadcasts the weather That exists, it's called FIS-B. Everyone uses it. > and clearance Clearance isn't something that can just be broadcast. You need to have a conversation with the pilot to make sure the clearance is acceptable to them. The pilot needs the ability to reject the clearance and request amendments. > even aircraft location data close to real-time, and provide great situational awareness to everyone involved. This exists, it's called ADS-B. Everyone uses it.

labcomputer 8d ago

Maybe because literally the entire world is currently using that system, and sending machine-readable clearances to just some airplanes means that the non-equipped planes are denied situational awareness?

misswaterfairy 8d ago

Whilst voice clearances have been the norm since aviation really took flight, no pun intended, there's much more subtle but crucially important aspects about why this has remained: situational awareness by broadcast. The critically important aspect: approach clearances and weather reports for a specific aircraft are still useful and relevant to all nearby aircraft. Narrow-casting them to specific aircraft reduces situational awareness for all other nearby aircraft. The system is also tolerant of noise: digital communications can be lost entirely with some degradation in signal, analog voice communications can still be interpreted with a fair bit of noise present (see video below). The subtle aspect: multi-tasking by using more than one human sense - looking and hearing. People dealing with risky or dangerous situations absolutely should not be sucked into a screen for more than a minute or two to get critical information. This includes to more than one pilot where tasks are being managed and delegated. Most (if not all) controlled or 'aviator-coordinated' (CTAF) airports have a specific radio frequency to tune into to get weather information from an automated weather-to-voice system (e.g. https://youtu.be/HHbrlUPP-4k?t=339 https://youtu.be/HHbrlUPP-4k?t=339). Whilst it sounds clunky, aeronautical phraseology (https://en.wikipedia.org/wiki/Aeronautical_phraseology https://en.wikipedia.org/wiki/Aeronautical_phraseology) keeps communications detailed but brief and concise. Digital voice communications often completely degrade for several seconds with a few lost packets, combined with the brevity of aeronautical phrasing can mean critical information is missed. All of these 'old' systems add up to the cumulative safety (https://en.wikipedia.org/wiki/Swiss_cheese_model https://en.wikipedia.org/wiki/Swiss_cheese_model) and doctrine built by the aviation industry over many, many decades though sadly because a lot of them were written in the blood of others who perished.

itopaloglu83 8d ago
Well, as far as I remember, the Link 16 was invented around the 1970s where aircraft could share real-time data in a combat zone. The weather information can easily be transmitted every minute and it can be nicely visualized in the cockpit instead of being crammed into cryptic abbreviations and ancient codes. Similarly, we are aware of the precise aircraft location and it's intended course, I'm talking about commercial airlines here, so we already know where they're going and what the approach path will be etc. I find it hard to accept that we're collecting terabytes of telemetry from engines and all the other equipment on the aircraft, but we expect to communicate the weather and traffic information in verbal ways. There are so many good ways we can solve the underlying requirements, but I think it's all stuck on the cost of implementation and who's going to be making money from it.

Grombobulous 8d ago

Nearly hands-free for pilots operating controls (not all pilots have a copilot), simple and reliable technology available to planes and airports of all sizes, high amount of message flexibility, faster than typing or some other form of electronic message selection. Why do quarterbacks yell out code words to call plays? After all, it’s loud stadium and it’s only a couple structs worth of data!

itopaloglu83 8d ago
There is no need for pilots or anyone to type anything. Weather data can be published every minute and shown live as a full map over the screen, not as random abbreviations of wind and cloud coverage. And we already know where each aircraft is, and where they took off, and where they're headed. So practically speaking the radio talk can be limited to only the important communication and emergencies, while increasing the situational awareness by at least ten fold.
- tjohns 5d ago
  > Weather data can be published every minute and shown live as a full map over the screen This already exists via FIS-B. > not as random abbreviations of wind and cloud coverage The abbreviations (METARs) are a feature, not a bug. There are numerical legal minimums for weather that determine whether a landing is legal or not. A graphical map doesn't tell you this. The METARs are condensed because they're easy for professional pilots to skim. (Back in the days of teletypes they also saved bandwidth, but that's just a historical note at this point.) Regardless, pilots already have access to both textual and graphical weather products in the cockpit. > And we already know where each aircraft is, and where they took off, and where they're headed. So practically speaking the radio talk can be limited to only the important communication and emergencies, while increasing the situational awareness by at least ten fold. As a pilot myself, I think you're vastly misunderstanding the nature of ATC communication. 90% of communication on the radio are time-sensitve, important things - mostly heading and altitude changes to avoid other traffic. Weather and clearances (when not relayed by ACARS, FIS-B, or CPDLC) are routinely handled on dedicated frequencies and aren't really causing meaningful frequency congestion.

ehe78qhe 8d ago

The military has switched their aircraft over to datalink for C2, but asking every civil aircraft to upgrade to the systems required is economically and legally infeasible.

fwlr 8d ago

The human auditory input channel is the modality already in use by pilots for other parts of this task - for example, copilots will verbally provide confirmation that the plane is capable of landing (flaps, gear). Aircraft safety engineering has done a lot of investigation into how humans process information and make decisions and they have found that putting two mandatory pieces of information for landing (is the ground ready for me, am I ready for the ground) in two separate modalities will inevitably mean that during high intensity moments such as landing a plane, only one modality is checked. You would absolutely get planes landing without clearance, or with clearance but without their gear down.