So as Ben has mentioned, I’ve been working on giving X-Plane a new ATC system. To be clear, the task was not to add features or fix bugs with the existing system, it was to write a whole new one…from the ground up. Why? Because our goal is to lay the foundation for a system that can grow over time; a system that we can easily expand and add features to. So what does this mean? It means that starting with the initial release of v10, the ATC system will grow incrementally until we feel it suits the needs of most of our users. It will never be a replacement for VATSIM however!

There’s only so much that can be done with artificial intelligence and since starting this project I’ve learned that humans make decisions in ways that are really really difficult to quantify, so lines have to be drawn somewhere. If you want that human factor, that’s what VATSIM’s for. The goal for our ATC is to make it as realistic as possible within the confines of what’s reasonable. It also needs to cater to a wide range of users. Some who are real pilots and do not deviate from ATC commands at all while others are new to aviation and may make some mistakes (even some dangerous ones). In real life making some mistakes will get you killed or at least earn you a phone call to the FAA…in here, the controller may grumble that you’re not listening and encourage you to follow directions again. I know that some of you are thinking “Why not just add levels of realism that the user can pick from a menu” and we may just do that for some things in the future, but for now I can’t stress enough that the goal is to be reasonable and flexible in our system design so that we can grow the system over time…all while keeping it fun for all types of users.

Enough blabber, time for some pretty pictures. The shot below is a picture of X-Plane with the North American ARTCC/FIR boundaries turned on. This is just for development purposes but it’s kind of neat to see the boundaries overlayed on the planet. As you fly from one center to the next, you’ll get handoffs from facility to facility.

And the shot below is what happens when I turn on the boundaries of towered airports. Any airport in the apt.dat file that has some combination of Delivery/Ground/Tower specified in it will be given a living control tower.

This only covers a tiny bit about the ATC system which is quite complex even in its infancy but I’ll do my best to keep the posts coming so that you can learn more about what it’s capable of.

I don’t have time to go into great detail about subsystems just yet (that’ll be covered in other posts) but I’ll leave you with a juicy detail….See those dots in the first image in the ZBW (Boston) ARTCC’s boundary? That’s a custom ATC pack (similar to a custom scenery pack) that I created that perfectly replicates Boston (KBOS) and Bradley (KBDL) TRACON airspace. Yeap, that means you can customize the system how you want it. More on what that means in the future….

About Chris Serio

Chris is an electrical engineer and commercial pilot who got roped into software development by Ben because misery loves company.

11 comments on “The world is under control…

  1. Hi Chris-

    Funny you should showcase the ZBW ARTCC! I too have been construction my own simulation of air traffic control. The structure of ZBW is quite complex, especially when considering individual sector SOPs and LOAs. It looks like you’re off to a great start 🙂 Please feel free to contact us with any questions 🙂

  2. Fantastic news Chris. Can’t wait for more updates, as I’m curious at how easy it will be for us to edit airspace data and whether we need to specify such details as SIDS and STARS, if so, how easy it will be.

    One of our blog followers has just asked “PLEASE add real speech to the Linux version. I miss that in 9.x! Otherwise it’s an awesome sim and I’m looking forward to 10 coming out.”


    1. Airspace data will be very very easy to edit. There will be config files that allow you to generate lat/lon pairs to create 3D airspace prisms so you can build complicated airspace layers.

      SIDS/STARS are definitely on our “radar” for features but they will not likely make the first release. As I said, this is a new beginning and like the scenery system, it will take time to grow…but grow it will.

      Speech will no longer be a robotic text-to-speech. We have a new system in place that will also be highly customizable so if you want to you can hear a New York accent at KJFK and a southern accent in KATL. More details on this at a later date.

      1. Awesome, sounds and looks like very realistic ATC, 100x better than the current version. Constantly hearing United Heavy for no reason and the same loop of 20 bites or whatever it is annoying. Let alone the un precise and hard approach instructions. Can’t wait.

  3. A menu option to display those ARTCC/FIR boundaries while in flight would be pretty cool, and useful for VATSIM flying as well.

    Ditto *any* type of airspace boundary display. Flying through semi-transparent, upside-down wedding cakes of controlled space–even cooler.

  4. I was interested in Simons comment as all my routes are very intergrated into the current SID/STARS, but as you mentioned this should be customiable to make the two fit together, am I correct on this?
    I think the whole approach in putting the basics in place and then allowing the xplane community in contributing to the system is very clever, there won’t look at lot at first, but that will change and fill very quickly, and gives the system a lot of flexibility, I think this is why Xplane is far better than other sims, a lot more fun too.
    You can’t but get excited by it all.

    1. In the first release, there will be no custom routings. In subsequent updates we are certainly planning on giving the system the capability to make SIDS/STARS and custom routings.

      1. Something that would be useful is the ability to give the radios to a virtual copilot so the user could concentrate on flying.

  5. Hi Chris,

    Thank you for these updates on the ATC. I posted the following a the Org sometime ago and wanted to share my ideas with you. Maybe you can find something useful here:

    “After playing/building the X-plane world for closer to 2 years, I have a suggestion. This may be a bit complex, but I know you like a challenge.

    I made the total switch from MS to X-Plane because of the scenery. Occasionally I will bring-up MS for curiosity, but the graphics are so terrible that I just can’t stay with it. Now here is the point…I used to think that their ATC was impressive, and it was to a beginner. But lately I’ve been adding recorded LiveATC .wavs (~30 min.) to the areas where I am doing XTraffic and the realism is so satisfying. If there was a way to integrate the LiveATC recordings with the ATC your programmer is setting up, that would have to seem (and sound)more real. And, with the advent of voice activation/detection, a pilot (me) could actually wait for a silent spot in the recorded LiveATC and then, just like the real pilots, contact the tower on approach/pushback/taxi/takeoff through a real headset, and get the proper return command. This way you would get realistic interaction between the pilot and the virtual ATC, while still hearing the real(recorded)thing in between times.

    So there are 3 things going on here:

    1. recorded or live LiveATC, (which would just be paused while the other two are working)
    2. The pilot talking through his headset;
    3. X-plane ATC responding with the correct reply/command.

    I know this is far more complicated than what your single programmer can probably handle, but it may be something to think about for the future.

    The drawback is that not all cities are covered by LiveATC. Well, many are and if the program exists for one it will work for others that may come online later.

    The other HUGE pro is that using a headset/voice activation system would eliminate all the distraction (which isn’t real)with answering ATC choices with the mouse, like MS does.

    And, last but not least, PLEASE get rid of Microsoft Sam! Get some real voices in there, and many different ones to choose from; or that change from time to time like in real life. I have recorded quite a few clips of and whenever I fly I always use them with Harbor Flyer’s fantastic FSChatterLive utility found here: //forums.x-plan…&showfile=10160

    which allows you to dial-in the correct tower freq. and also set the range.

    Keep up the great work and thanks for giving us a great product to look forward to!”

    Thanks for your time and consideration, and for all your effort in bringing us a much more satisfiable ATC. 🙂


  6. hi Cris, very interesting, a very common problem in areas outside the United States, for example in some South American countries, when you are flying online (VATSIM IVAO) is the absence of air traffic controllers. You could create any automated (generic) system to organize the air traffic online and make their communications? this would be great to fly with people online without depending on a person who wishes to exercise the role of air controller

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