Guide to understanding Pilot/ATC interaction better

How to make Expert Server sessions more enjoyable in Infinite Flight

Dear Infinite Flight Community,

My name is Sebastien as you can probably see it on the author field of this post. I am a 23 year old student passionnate about aviation. I’ve been playing IF on and off for quite a few years now but got more seriously into the game at the start of this year, especially focusing on the air traffic control part. I have been accepted a few weeks ago into the fabulous IFATC team as an ATC specialist and I probably have already controlled you somewhere :p

But enough about me as this post mostly concerns ideas and remarks I wanted to share to pilots and controllers concerning what reactions to follow when given a particular ATC instruction.

To be honest, I have been thinking of writing this post for some time now and I’m finally doing it now. The post is here to share you things that annoy us as controllers and can sometimes augment our stress and nervosity whilst controlling, especially in busy airspaces.

The way this post will work is: I will cover each topic with a bullet point going from the start of your flight to the end of it so it seems more natural. Then, I will recap general remarks that are most important to help us controlling in better conditions. Let us now start !

Additional comments: please note that most points assume there is an active controller for the given airfield. If it is not assumed, it will be explicitely written. Also, some bullet points are listed in more detail in the official IFATC manual which I will link at the end of this message.

Start of your journey: Ground frequency

Ground control
  • Callsign has to be double-checked: the use of “heavy” in the callsign should only be used for heavy aircraft, that is, long haul aircraft that have a fair amount of passengers and fuel on board. To be more precise, “heavy” should be used if the MTOW (Maximum Take-Off Weight) is at least 136 tonnes. As for “super”, it should only be used for a heavy 747 or an A380, but nothing else. Spawning at an airport with a cessna whose callsign is “Speedbird 723 heavy” is not a good way of proceeding.

  • No pushback request when not needed: as you may know, on airports there are stands and gates. However, only gates usually require pushback. So generally try to observe where you decide to spawn in, in order to see if a pushback request is needed. If not, you can simply start your engines and call for taxi whenever you’re ready.

  • Reasonable taxi speeds when possible: this generally means that most of the time, you should keep a correct taxi speed (around 20 knots) especially when there is a lot of surrounding traffic on the airfield. Typically, this means that you should not taxi at 30 knots ground speed when you are following an aircraft going at half your taxi speed.

  • Inbound aircraft have the priority: landing aircraft generally have the priority just like passengers getting off a bus have. This obviously means that you should give way to an eventual aircraft exiting the runway as he generally is taxiing faster than you are. If however, you are taxiing faster than him, please refer to the bullet point above.

  • "Give way" commands must be followed: when a controller gives you this command, it means that you have to be aware of the aircraft you would be taxiing into if you weren’t to listen. Look around you, there might be multiple aircraft taxiing one behind the other in which case, the give way command generally covers all of them. It is only once you are clear of surrounding traffic that you can continue your taxi. Keep in mind that aircraft on the right have priority on you.

  • Stay on ground frequency as long as needed: this generally means that if you are taxiing to the runway and have a lot of turns to do, aircraft to avoid and other similar situations, please stay on ground frequency until all conflict is avoided. Once you have a straight line to the runway and you know you will not cause anymore trouble, then you may change to tower frequency.

To recap, it is important that you look around you for any traffic. Do not purposely take the same taxiway as another aircraft which is taxiing the opposite way, of course when possible. Generally remember that your awareness helps the controllers a lot ;)

Onto Tower frequency

Tower commands
  • Correct understanding of departure command:

    • dep_requestrunwaydepartingstraight_outsend First in line for departure:
      If you are first for departure, the correct sequencing of commands to apply is the one given above. Please note that the runway and the direction of departure are simple examples.

    • dep_requestrunwaydepartingstraight_outin_sequence Ready behind another traffic:
      When you are not first in line for departure but you are however ready to depart, the use of in-sequence command is your friend. In some exceptions such as intersection departures, the sequence order may change so always be proactive when a controller gives you a take-off or line up and wait command.

    • If you are not ready to depart and there is a long line of aircraft behind you, try to find a waiting bay or another taxiway to taxi into until you are ready to go.

    • Please note that the “remaining in the pattern” command must only be used if you wish to do some pattern work around the airfield. In every other case, you will have to use the two commands listed above. The direction to give the controller is the one you will use to depart his airspace.

  • Awareness of expedite commands: it is important to be proactive all the time in case an expedite command is given to you. In that case, you must react quickly and help the controller managing the traffic as he would like to.

In general, try to always be proactive in order to respond quickly when a controller gives you the order to line up and wait or directly take-off. Also, if the controller tells you to expedite, you have to expedite.

Radar frequencies (Departure, Center and Approach)

1. Departure

Departure commands
  • Departure check-in:
    • check_in Way to check-in on radar frequencies (except for approach):
      If you have a flight plan (i.e. IFR flight), it is mandatory to call for “check-in” to the departure controller. This allows him to create radar contact. By default, continue as filed. It is the controllers job to give you additionnal vectoring if needed.

    • If you do not have a flight plan (for example you’re flying VFR), there are two scenarios:

      • vfr: No destination airport:
        Either you do not have a destination airport on your flight plan which implies you have to inform you are simply flying VFR.

      • flight_following Planned destination:
        Or, you do have a destination airport in which case you should simply ask for flight following to wherever you are planning to go to.

    • Please keep note that sometimes, the approach controller can also act as a departure controller when the active airspace is not really busy. In that case, simply act as if it was your normal departure frequency. If however the tower controller gives you a “Frequency Change Approved” command and there is approach, this means that the approach controller does not want to handle departures, so simply tune out of tower and do not tune into approach.

2. Center / Radar / FIRs

Center control
  • Check-in: the way to check-in to a center controller is exactly the same as you would do with the departure controller. Please refer to the above points.

  • Altitude change: please only use the “request altitude change” command when you are in-flight and would like to fly either a little lower or higher. It can also be used when you do not have a flight plan but never otherwise.

  • Initial descent: when you are ready to start descent, it is only to the center controller that you should ask to descend via your STAR (of course when you are flying IFR). Recall that in most cases, center covers all the airspace above 18’000ft. Passed this altitude, the center controller will switch you to approach unless approach is not active in which case it is possible that center guides you all the way to the approach you’ll want to perform.

3. Approach

Approach commands
  • Approach check-in:
    To tune into approach, “check-in” is not the way to go. You have to request for an approach (either ILS, GPS, Visual or vectors) to which the controller will respond to by confirming which approach you will fly. Keep in mind that you can change the approach type at anytime during the inbound process.
    • approachany_ils If you desire flying either an ILS, GPS or visual approach, you should use this command.
    • radar_vectors In the other case, there exists a fourth possible approach type which simply involves the controller giving you vectors to your destination.

Generally, remember that radar frequencies (which include departure, approach and center) are here to control you in-flight. If radar is not active, please do keep awareness of your surroundings in order to keep the airspace as clean as possible for when a controller comes back into service. Also, take note of your altitude and do not tune into a frequency that should not be controlling you at this point (for instance, you should not connect to DEP/APP frequencies when flying higher than 18’000ft approx.).

Last but not least: Local frequencies again

Local commands
  • Tower inbound call: When you call inbound to the tower controller, there are multiple solutions.

    • call_inboundsend Simple call inbound command:
      This command should only be used when you were given radar vectors by the approach controller and you have no specific flight plan filed. The tower controller will then give you a pattern entry, an eventual sequence and a clearance to land. Note that this is also the command to use at all times when approach is not active !

    • call_inboundon_the_ils Specific inbound command (can be ILS, Visual or GPS):
      This command should be used when one of the three common approaches is used. ILS or GPS require only a landing clearance whereas a visual approach requires sequencing. These commands should on the other hand only be used when approach is active !

    The first point above gives the only commands that should be used when reconnecting to tower at the near end of your flight. The “report position” should not be used in this case as it is redundant.

  • Reasonable approach speeds: if given no speed restrictions by the approach controller, you must still keep reasonable approach speeds especially if there is surrounding traffic. Namely:

    • maximum 220 knots on base turn

    • ideally 180 knots to a 6 mile final (or 160 knots to 4 miles if there is some traffic)

    • touchdown speed should be at around 120/130 knots for most aircraft out there.

  • When on ground: at this point, you have done all the big work. Congratulations ! Remember, just keep aware of surrounding traffic and this time, when you exit the runway, it is you that have the priority ;)

    Ask for a simple “taxi to parking”, check your surroundings, do not taxi through grass and it’s done.

General remarks

Here is a condenced sequence of information that is most important when piloting on the expert server:

  • No frequency change request all the time !

    • Please, I mean really, please do not ask for frequency change all the time. It is the controller that will hand you off when needed.
    • It is indeed evident that you should also not change frequency if the controller has not given you the permission to. Just be patient ;)
  • Tune out of each frequency:

    • When a controller gives you permission to leave his frequency but does not give you another frequency to tune into, simply tune out of the active frequency and go to “unicom” or “none” but avoid staying on the frequency where it is not needed.
    • If he hands you off to another frequency, click on it that’s all.
  • Awareness of surroundings !

    • Keep a solid awareness of surrounding traffic at ALL times. Remember that it hugely helps controllers if you also participate to avoid conflicts.
    • This is as much valid on ground as it is in the air !
  • Quick reactions to expedite commands !

    • Please follow all expedite commands when requested. These can be given either for takeoff, landing or in another particular scenario.
    • Note that expedite doesn’t mean that you should not respect the speed restrictions :)

That’s all from me folks. I hope you had the courage to arrive at this point. Please consider following all the advice above as it will help us control you better and permit us to have a better flying experience on the Expert Server. Remember, if you are unsure, you can still go on the training server to experience some more, it is here for that !

I would also like to take the opportunity to thank the numerous people that helped me in giving me advice on what to write in the post and how to write it. In particular, I would like to address my special thanks to @Chris_Hoss, @Antoine_Turrian, @Kedz, @RadarVectors_Mumbai, @Captain_Piotr, @MJMN, @Andy350, @MrJackT14, @Alexandre and many others. I unfortunately cannot tag all of you but you will surely recognise yourselves in the post ;).

Additionally, I would like to thank @Tyler_Shelton for giving me the opportunity to write this post without which I wouldn’t be writing this to you today. And finally, a big thank you to all the IFATC team for great times we spend together. You guys are awesome ❤️.

If you have any questions regarding the post above, do not hesitate to leave me a message and I will gladly respond to it when I can.

In the meantime, enjoy your flying, take care and stay safe !

Cheers from Switzerland,


  1. Official Infinite Flight ATC Manual → Introduction | Infinite Flight
  2. Official detailed Infinite Flight flying guide → Introduction | Infinite Flight

Nice job Sebastien!


Excellent job Sebastian!


I am AN IFGEP and I am intending to work as an IF pilot while practicing as an ATC?

Nice job there, hopefully it helps a few pilots out

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Great Guide! Nice Job!

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Great job Seb and thanks for putting in all the efforts! 💯👏

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Thanks for your ATC tutorial;)

Amazing job with this post! Greetings from Germany 🤗


Lovely job, and it’s been great seeing progression on this for the past few weeks!

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Very nice topic!

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imo it’s only used if an aircraft is about to lose separate with terrain or about to bust with another aircraft?

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Very Nice job Sebastian! Hope this can help all the new pilots and also make some concepts more clear for existing IFATC controllers. Thank You for taking out your time & your effort has transformed into a very beautiful topic!


For center, It can be used if aircraft is step climbing and is with in active airspace and want permission from center controller to confirm with the controller that altitude is being changed.


Not sure what you meant, but if you want any help with anything feel free to PM me.

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Amazing post Seb😉

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Spot on post Seb 💪🏼 this is something well worth the read 😉

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Hmm not exactly sure though. But here as the aircraft is supposedly over 18’000ft I guess terrain is not concerned here unless you’re overflying the Himalayas 😂

Nice topic Sebastián I like it. I wish pilots would follow it! Cheers

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ah yes ofcourse why I didnt think of that :P

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