4 ms·

It's broadcast in the clear, unencrypted. Just like all non-military aircraft comms.

lxgr 2y ago
> It's broadcast in the clear, unencrypted. But so were analog mobile phones and pagers, and in some countries, even receiving unencrypted voice ATC radio isn't legal.
- lazide 2y ago
  The whole point of ATC is that everyone in the area is able to figure out what is going on by listening in. What/how is making listening in on that illegal ok?
  - lxgr 2y ago
    Not sure about the details, but I suspect it's more a consequence of laws on telecommunication privacy from analog days being very generic than a specific intention to make ATC listening illegal. Opt-out vs. opt-in by frequency and/or purpose, essentially. That said, it's supposedly still being very much enforced against e.g. planespotters at airshows in some places – no idea what the point of that is.
    - lxgr 2y ago
      Baffling to get downvoted for a suspicion about the origins of the status quo, as if that were an endorsement of it.
      - lazide 2y ago
        Forget it up Jake, it’s Chinatown
  - tjohns 2y ago
    ACARS isn't ATC traffic. It's semi-private communications with airline company dispatch. Text-based ATC communications is done over a different system called CPDLC (FANS-1/A). That said, this is no different than listening to any other unencrypted, non-cellular radio traffic. Totally legal everywhere (except a few rare exceptions, like the UK). And as I mentioned in my other comment, in the US the ECPA specifically says you can listen to aeronautical radio traffic.
    - lxgr 2y ago
      > Totally legal everywhere (except a few rare exceptions, like the UK). And (after a cursory search) Spain, Portugal, Germany, Austria, maybe France... In other words, legal in some places, illegal in others. > Text-based ATC communications is done over a different system called CPDLC (FANS-1/A) ACARS is both an application and a (legacy) lower layer suite of protocols supporting it, but modern ACARS versions and CPDLC can use the same underlying digital channel, as far as I understand (i.e. VDL Mode 2). As a result, many of these tracking sites can capture both, as well as presumably "legacy/analog" ACARS.

lxgr 2y ago

> It's broadcast in the clear, unencrypted. But so were analog mobile phones and pagers, and in some countries, even receiving unencrypted voice ATC radio isn't legal.

lazide 2y ago
The whole point of ATC is that everyone in the area is able to figure out what is going on by listening in. What/how is making listening in on that illegal ok?
- lxgr 2y ago
  Not sure about the details, but I suspect it's more a consequence of laws on telecommunication privacy from analog days being very generic than a specific intention to make ATC listening illegal. Opt-out vs. opt-in by frequency and/or purpose, essentially. That said, it's supposedly still being very much enforced against e.g. planespotters at airshows in some places – no idea what the point of that is.
  - lxgr 2y ago
    Baffling to get downvoted for a suspicion about the origins of the status quo, as if that were an endorsement of it.
    - lazide 2y ago
      Forget it up Jake, it’s Chinatown
- tjohns 2y ago
  ACARS isn't ATC traffic. It's semi-private communications with airline company dispatch. Text-based ATC communications is done over a different system called CPDLC (FANS-1/A). That said, this is no different than listening to any other unencrypted, non-cellular radio traffic. Totally legal everywhere (except a few rare exceptions, like the UK). And as I mentioned in my other comment, in the US the ECPA specifically says you can listen to aeronautical radio traffic.
  - lxgr 2y ago
    > Totally legal everywhere (except a few rare exceptions, like the UK). And (after a cursory search) Spain, Portugal, Germany, Austria, maybe France... In other words, legal in some places, illegal in others. > Text-based ATC communications is done over a different system called CPDLC (FANS-1/A) ACARS is both an application and a (legacy) lower layer suite of protocols supporting it, but modern ACARS versions and CPDLC can use the same underlying digital channel, as far as I understand (i.e. VDL Mode 2). As a result, many of these tracking sites can capture both, as well as presumably "legacy/analog" ACARS.