Ready now · web session
Nashville · KBNA
Nashville Intl has a full web layout: run the airport from your browser, no download and no simulator required.
Early testing open · Microsoft Flight Simulator 2024 (2020 experimental)
Multiplayer air traffic control. One live airport, every position.
ATC Relay lets a group of people run the air traffic at one live airport together in Microsoft Flight Simulator. One person hosts the airport from their sim; everyone else takes a position either from a web browser or from their own simulator running ATC Relay Host, on the same live airport with the same positions and the same experience.
Ready now: start Nashville's web session, no download
Try the free demo — no account, no download
Open ATC Relay
Create a free account
Plan a day of traffic (free account)
Your tower. Their sim. One session. See where it stands
The demo: Nashville, 25 minutes, up to 3 a day from one network address.
Ready now · Nashville, KBNAA real capture of a Nashville web session. Start your own in one click, no account.
What it is
Controllers on the frequency, traffic in the sim.
The simulator host stays in charge of the airport and its AI traffic. Controllers see the same live airport, in a browser or from their own simulator running ATC Relay Host, and work it together, each from their own position, with clear ownership so two people never issue conflicting clearances.
- ATC Relay Host
- the desktop app that runs next to Microsoft Flight Simulator and opens a session.
- ATC Relay Scope
- the controller screen where you take a position.
- Web session
- the same airport run for you in your browser, with no simulator needed.
In the sim
ATC Relay Host
A desktop app that runs beside Microsoft Flight Simulator, loads the airport and its traffic, and opens a session for others to join.
In the browser
ATC Relay Scope
The controller screen in your browser. Pick a position, watch the live airport, and issue instructions through a structured panel.
Together
One live airport
Everyone in a session sees the same traffic and the same state, so a handoff between positions is a real handoff. A Ground controller in one city can hand off to a Tower controller on another continent — same live airport, same frequency, no region matching.
Who it is for
Flight simmers who want a busy, staffed airport.
Whether you like running a tower solo or want a group of friends covering delivery, ground and tower at a busy field, that is what this is built for. You do not need to be a real-world controller.
IllustrationDecorative artwork, not a screenshot from Microsoft Flight Simulator or ATC Relay.
The positions
Take a seat, keep it, hand it off.
Core positions are available in the early test build. Center is not offered yet.
DEL
Clearance delivery
Issue departure clearances: route, runway and squawk.
GND
Ground
Move aircraft between gates, taxiways and the runway hold-short lines.
TWR
Tower
Own the runways: line up, take off, land, and keep them clear.
RAMP
Ramp
Manage pushbacks and gate assignments.
APP
Approach
Sequence and vector arrivals toward the runway.
DEP
Departure
Climb departures out along their departure routes.
See the positions at work: real operating views from Fort Lauderdale
Your first 10 minutes
Start on Clearance Delivery: it is the first call every departure makes. A departure then moves through the seats in order: Delivery gives the clearance, Ramp pushes the aircraft back, Ground taxis it to the runway, Tower clears it for takeoff, and Departure climbs it out. Arrivals come back the other way: Approach sequences them, Tower lands them, Ground and Ramp bring them to the gate.
New to controlling? Read the first-session guide for both sequences on one page, or go straight to the rules and the Nashville procedures. Then take the demo and work one aircraft from clearance to takeoff.
Released airports
Pick your airport.
Nashville, Fort Lauderdale and Phoenix have full web sessions today: join from the browser, no simulator needed, or open one from your account once you are signed in. Baltimore/Washington is planned for a future web session.
Ready now · web session
Fort Lauderdale · KFLL
Fort Lauderdale-Hollywood Intl now has a full web layout: run the airport from your browser once you are signed in. See Delivery, Ramp, Ground, Tower and Departure at a real FLL operation too.
Ready now · web session
Phoenix · KPHX
Phoenix Sky Harbor Intl now has a full web layout: run the airport from your browser once you are signed in.
Coming soon
Baltimore/Washington · KBWI
Baltimore/Washington Intl is planned for a future web session and reference page. Nothing to open here yet.
How it works
Host it or join it.
Try it in the browser
No simulator needed. Try the 25-minute Nashville demo now, or sign in to run Nashville, Fort Lauderdale or Phoenix in your browser.
I fly Microsoft Flight Simulator
Host an airport from your sim, or join one and take a position from your own sim. Made for MSFS 2024; MSFS 2020 is experimental. Free early-test build, free account.
Join with a session code
Already have a code from a host? Look up the room, see who is on which position, then open the live radar.
1
Host a session
Start ATC Relay Host next to Microsoft Flight Simulator, choose the airport, schedule, runways and positions, run the start-up checklist, and start the session.
2
Join a session
Use the session code, follow the short before-you-join steps, and open the controller page in ATC Relay Scope with your Navisphere Studios account. Prefer your own simulator? Run ATC Relay Host beside Microsoft Flight Simulator and take a position from there: it is the same live airport and the same experience as the browser. Have a session code? Enter it here.
Example codeABC123However the host started the session — from the simulator or the browser — everyone joins with this same six-character code.
3
Claim a position
Pick delivery, ground or tower and start controlling. The host keeps the final say over the session.
Early testing
Join the early test
IllustrationDecorative artwork, not a screenshot from Microsoft Flight Simulator or ATC Relay.
Early testing is open for Microsoft Flight Simulator 2024; MSFS 2020 works experimentally. ATC Relay Host, early test build 0.9.0-dev54, is free to download with a free Navisphere Studios account. It is a test build, not a final release: expect changes and rough edges, and tell us what you find.
Create a free account to download
Sign in
Download Setup (11.5 MB) Download the zip (11.4 MB) Setup guide
We do not host or bundle Microsoft's SDK or SimConnect files; Setup can copy them from your MSFS 2024 SDK (recommended) or your MSFS 2020 SDK, and the setup guide links to Microsoft's own documentation. No pass is needed to host, join or play a session with the simulator. Trouble connecting? Troubleshooting and connection check.
+
Or play in the browser, no simulator
Real captureThe ATC Relay web session at KBNA, Tower position — not a mockup.
A web session runs the same airport for you in the browser, without Microsoft Flight Simulator, with a start time you choose. It is open to signed-in players at Nashville (KBNA), Fort Lauderdale (KFLL) and Phoenix (KPHX). Weather is the airport’s live METAR, fetched when the session starts — not a player choice. Start one from the Create screen in ATC Relay Scope.
Available now
Plan a day of traffic.
The flight scheduler builds a busy day at KFLL, KBNA, KBWI or KPHX from a real airline timetable, lets you add flights of your own and assign airlines to gates, and exports the files ATC Relay Host loads. It needs a free account: sign in first, then it runs in your browser and a Save button keeps your files in your account and lets you share them.
Timetable data: US DOT on-time statistics and the FAA aircraft registry. It covers domestic US airlines only, so add international and cargo flights yourself.
Free demo
Try it free for 25 minutes.
A free demo at Nashville (KBNA) is open: 25 minutes, no account needed. When the time is up you can sign in or create an account and continue the same session, or start a fresh one.
Honest status
Where ATC Relay stands today.
Early testing. The early test build is open to Microsoft Flight Simulator 2024 players. MSFS 2020 is experimental: it can work, but we have tested it less, so expect rough edges. It is not a final release, and there is no public release date.
- Flight scheduler and gate files: available now, free, in your browser.
- Sim host and browser controller: working, in early testing.
- Controlling from your own simulator with ATC Relay Host: in early testing, on the same live airport as the browser.
- Play without the simulator: open to signed-in players at Nashville (KBNA), Fort Lauderdale (KFLL) and Phoenix (KPHX); a free 25-minute demo at KBNA needs no account.
- Passes and the Supporter badge: available now. A pass is a one-time payment that adds optional web access for a set time. It never renews. The Supporter badge is permanent. Free sessions keep working with or without a pass.
- Payment: by card through Stripe. We never see or keep your card number. Tax is added at checkout where it applies. Refunds are covered in the ATC Relay Terms.
What's new
- — Clearer path to the free demo. The hero now leads with one button, plus a look at the Nashville web session right underneath it.
- — New artwork in “Who it is for.” A fresh illustration now leads that section.
Airport layouts in web sessions contain information from OpenStreetMap, made available under the Open Database License (ODbL) 1.0. © OpenStreetMap contributors. See openstreetmap.org/copyright and the ODbL 1.0; the layout files are on the open data page. Contains FAA NASR data (cycle 2026-09-03). Not FAA-endorsed. Not for navigation.