Greetings all!
As some of you may have witnessed, just this Saturday, Zurich Airport (LSZH) encountered a pretty fun and unique ATC configuration during peak traffic, which included staffing the following 12 frequencies simultaneously:
| Position | Frequency | Controller |
|---|---|---|
| Zurich North Ground | 121.90 | @falcon.ccp |
| Zurich South Ground | 118.15 | @week |
| Zurich Tower (Rwy. 14) | 120.22 | @Tom |
| Zurich Tower (Rwy. 16/28) | 118.10 | @kadengg |
| Zurich Initial Approach (Rwy. 14) | 125.32 | @Vasu |
| Zurich Final Approach (Rwy. 14) | 118.00 | @anon33707117 |
| Zurich Initial Approach (Rwy. 28) | 135.22 | @Daksh_Jain |
| Zurich Final Approach (Rwy. 28) | 120.75 | @vipr |
| Zurich Departure | 125.95 | @Tom |
| Switzerland Center | 127.00 | @IFPHG-Enrico |
| Reims Center | 127.00 | @IFPHG-Enrico |
| Zurich ATIS | 125.72 | @falcon.ccp |
LSZH ATC Staffing as of ±1700Z 13/12/25 – credit to all other controllers not mentioned who were involved around this time. Some frequencies do not match their IRL counterparts.
This obviously led to some questions being asked among both IFATC controllers as well as pilots flying on the Expert Server at the time. For that reason, I wanted to make that topic to try explain how we arranged things so that other IFATC controllers can use this as a framework, as well as so that non-IFATC pilots can understand what we’re thinking with such an intense ATC frequency ‘split’. I’ll try explain it the best I can, but if anything is unclear, please feel free to ask below and we can explain – I hope to make this sort of arrangement as familiar to everyone as possible so we can open the door to more advanced staffing when required!
This, to my knowledge, was one of the most complex yet purposeful ATC staffing arrangements in the history of Infinite Flight. To accomplish this, each controller had to be sure of their role and work in close communication with all the other relevant controllers. The roles were generally set out as follows:
| Positions | Primary Role |
|---|---|
| Zurich North/South Ground | Manage all ground movements north/south of Runway 10/28, collaborate with tower controllers about runway crossings, taxi routings, and more. |
| Zurich Tower (Rwy. 14) | Manage all aircraft landing on (and exiting) Runway 14, which was the landing-only runway in use. |
| Zurich Tower (Rwy. 16/28) | Work with all departing aircraft on Runway 16, the primary landing runway, as well as all aircraft departing and landing on Runway 28. This includes timing both runways to work simultaneously as well as runway crossings on both runways. |
| Zurich Initial Approach(es) | Receive inbound aircraft from Center and sequence them into efficient and organised approach lines to be cleared by final approach. |
| Zurich Final Approach(es) | Receive aircraft from Initial Approach at a predetermined handoff point and ensure approach clearance and perfect spacing before handoff to tower. |
| Zurich Departure | Deconflict any outbound aircraft others, including assigning climb altitude restrictions until clear of conflict and handing to Center. |
| Switzerland & Reims Centers | Oversee all aircraft in their given boundary above FL180 and 50-60nm of Zurich. This includes holding patterns further from Zurich, ensuring correct spacing along STARs, and mitigating conflicts in the high flight levels. |
| Zurich ATIS | Communicating a massive amount of information from all the aforementioned controllers to pilots on matters such as who to contact, which procedures to file, and which runways to expect. Which, trust me, was a ginormous task. |
Local Frequency Arrangement Map
Sample Radar Frequency Arrangement Map
Note: This is a very basic model, the real model will reflect precise handoff points depending on controller preference and will include speed, altitude, and heading assignments and will be continually discussed. Also, departure’s work will include ensuring that the departing aircraft (purple) will be separated from any arriving aircraft at the conflict points – usually done in the form of pre-agreed altitudes that departing aircraft will fly until clear of arriving aircraft and will then be cleared to climb further.
The ATIS & How to Understand It
ICAO: LSZH
Landing Runways: 14 and 28, [ILS]
Departing Runways: 16 and 28
ATIS: Zurich airport, ATIS information ZULU, time 1703 ZULU, Wind Calm, Visibility 2, Temperature 4, Dew Point 3, QNH 1029. Remarks, no pattern work, no light aircraft accepted at this time, multiple frequencies in use, use of Departure and Arrival procedures recommended. Landing Runways 14 and 28, expect ILS approach, Departing Runways 16 and 28. Notams, event in progress, check forum for event information and expect delays. Recommended Departure Procedures, DEGE2S,DEGE2W,GERS2S,VEBI3W,WIL2Q,ZUE2R, Recommended Arrival Procedures, BLM2Z,DOPI1G,KELI2G,NEGR1A,RILA1A. Contact ground on 121.90 when on the North of the aiport, contact ground on 118.15 when on the South of the airport. Contact tower on 118.10 when on the North and East and South and West, contact approach on 125.32 when arriving from the West. Contact approach on 135.22 when arriving from the East. Advise on initial contact, you have information ZULU.
This was a slightly edited version of the ATIS we had active at the time. While a good majority of it is the same as you’d see at any controlled airport in Infinite Flight, the key differences start with the “Multiple Frequencies in Use” remark. This directs the pilot to check the multiple frequencies at the airport so they know who to contact. While we weren’t able to dictate exactly how the splits were occuring, this is how we tried to communicate it best.
Ground 118.15 – South & 121.90 North was used so aircraft on the ground could know who they should contact. While we couldn’t distinguish "north/south of Runway 10/28”, we figured it’d be quite likely understood, and anyone on the fringe could use their best judgement, and, in the worst case, be redirected by one ground to another. This didn’t cause many problems, and was usually the only point of confusion as the rest of the flight would be handoffs to tower on 118.10 for departure. In cases where a pilot tuned out of ground before they were handed off, the Tower 118.10 – All Directions indicated that all pilots should contact 118.10 if unsure, as they only aircraft using 120.22 would be handed off from Rwy. 14 Final Approach on 118.00.
The directions for approach in the ATIS actually aren’t required, as everyone should have contacted Center who would have manually handed them to the right approach frequency – but for those that may not have bene able to contact Center, we wanted to leave this as a backup option to minimise confusion.
Which Frequency Do I Contact Here?
In times of any confusion, you can always feel free to tune into a reasonable frequency, and you’ll be redirected if you made a wrong choice. On top of that, if you’re in active airspace, you’ll likely be made aware of it by a controller in the form of an “On guard” message to let you know which frequency you should be contacting. When there’s multiple ground frequencies, it will be notated in ATIS and you should use your best judgment about which listed frequency matches your position on the airfield. Considering this, in a time like the one in Zurich – the only initial ATC contact frequencies will usually be ground or center, so that should usually narrow things down. For a better explanation, and the procedure during ‘normal times’ – please see the ‘ATC Communication’ section of the Infinite Flight Flying Guide.
Hopefully this clears up some lingering confusion about how this was organised, as I’m sure it may have looked like chaos with all those frequencies open at once when in reality, it was rather orderly! This was all made possible by the great team on the day who showed what was possible, and what might just be the future of Infinite Flight’s ATC approach to busy hubs. Please feel free to PM me with any questions about how this was organised, and please see here if you want to join IFATC. Thanks for reading!
