Limitation by full call sign

[kusterjs]

Hi,

Next to that I've another question, is it possible to add squawks that are limited to a certain callsign. So instead of a squawk range for a specific airport: EBBR:7101:7127 to EBBR_TWR:7101:7127?

Kind regards,

Jan Willem Oomes
Navigation Director Belux vACC

[kusterjs]

This is currently not possible. Would you mind sharing the scenario in which such a differentiation might be used?

[JanWillemOomes]

These squawk ranges are used in our CTRs and TMA's (and therefore assigned specifically by the respective TWR or APP controller).

Ideally it would be that for example range 6301 to to 6313 can only be assigned by EBBR TWR, since this squawk is only used in the CTR of EBBR. If EBBR TWR is offline, this squawk range cannot be used, even if EBBR TWR is covered by a station above.

[kusterjs]

Assuming there are stations below TWR, like GND and DEL, should they use these ranges as well?

You are also saying that the squawk ranges used would be different for the same flight depending on the controller (type)?

[JanWillemOomes]

Ideally DEL and GND should assign these codes (as that would be coordinated IRL with tower), but if this would be too hard then that would be no problem. Once this traffic is leaving the CTR or TMA they will switch back to squawk 2000 or 7000, waiting to be assigned another squawk code, either by FIS or by another APP or TWR controller.

For example a flight from EBOS to EBLG, would be assigned 6344 by EBOS TWR, then once leaving the CTR would squawk 2000. Gets assigned squawk 0041 by FIS, then when entering the EBBR CTR squawk 6301, then back to FIS with squawk 2000 where he gets another squawk 0041 (or 0042, etc), then finally with EBLG TWR squawk 6330.

[kusterjs]

But in case there is no EBBR TWR, but just an EBBR APP, he would be assigned a different squawk, but while transiting the EBBR CTR?

I'm also confused by your initial request referring to call signs / stations, but now you're referring to geographical limits. This points rather to a use of the geographical definitions. But I'm assuming you are relating to IFR flights!? I've not seen IFR flights requiring to switch codes that often. Is this really how it works?

[JanWillemOomes]

In case only EBBR APP is online, flights transiting the CTR would be assigned the squawk range reserved to EBBR APP (being 4450-4457). So no EBBR TWR squawks will be assigned if EBBR TWR is offline.

In practise IRL and I think it’s fine to limit this on VATSIM, these flights would only be VFR flights.

I believe the domestic range for IFR traffic that can be assigned by all stations is 5102-5173.

[kusterjs]

Ok, so we are talking about VFR flights, correct? What about VFR flights to a destination outside Belgium? What code would they get when crossing EBBR CTR with TWR?
Considering RL, what would even be a scenario that a APP code is used? You mentioned codes 0041+ being used by FIS, which is probably mostly covered by an APP/CTR station on VATSIM, right? How to differentiate if an APP code from the list or a "normal" FIS code is assigned?

[JanWillemOomes]

Yes let’s remain with VFR flights.

So when crossing a CTR or TMA that is not staffed (only by a top down position) a squawk from the range of the top down position shall be used. As you can see, every unit ACC-APP-TWR have their own individual ranges. If traffic crosses a CTR without APP or TWR being online, an ACC range shall be used.

IRL the TMA squawks would be used for traffic crossing through the TMA, or for traffic doing operations in the TMA such as aerial photographing, VOR/ILS calibration, etc.

In theory FIS shouldn’t be given by the APP controllers, since it’s not part of their AOR. If so, it would be fine to assign them a TMA squawk instead of a FIS squawk.

Therefore:

TWR ranges only to be used by TWR
APP ranges only to be used by APP
ACC range only to be used by ACC
And FIS range only to be used by FIS and ACC. But if coupling this makes it 100000x harder then it’s fine to leave the FIS squawks with FIS only.

I hope you understand what I mean now haha 😅

[kusterjs]

I think I have the full picture now. I suggest to implement those squawk ranges in your ese file and assign squawks for this kind of traffic with the default EuroScope function. Because squawks based on the station is exactly how the ESE file definitions work.

[JanWillemOomes]

Okay, thanks. Will do that then. Will open a (hopefully final haha) pull request with some final amendments to the dat files soon.