# TWRCTRL

> TWRCTRL is a free air traffic control simulator that runs in the web browser. You work ground and tower together on real airport layouts, Keflavík (BIKF), Stockholm Arlanda (ESSA) and Tokyo Haneda (RJTT), in beta: push and taxi departures to the runway, clear takeoffs, clear arrivals to land and taxi them in to stand, all with typed radio clearances. No download, no account.

TWRCTRL is made by Franklín Andrésson and published by TERRN AB (Sweden). Play at https://twrctrl.com/.

Last updated 2026-11-06 (version v1.4.3).

## Quick facts

- What it is: an air traffic control (ATC) simulator for the tower and ground positions
- Price: free; nothing to buy, no account, no ads
- Platform: any modern web browser on desktop, laptop, tablet or phone (landscape); can be added to the home screen and opens full screen like an app
- Airports: Keflavík (BIKF), Stockholm Arlanda (ESSA) and Tokyo Haneda (RJTT), in beta; more are added over time
- You control: pushback, taxi, runway crossings, line up, takeoff, landing, vacating and taxi in to the gate or stand
- You do not control: radar vectoring, approach or en-route sectors
- Input: click or tap an aircraft or its flight strip, type the clearance, press Enter; a dropdown suggests the legal next words and the route is drawn on the map before it is sent
- Realism: real runway numbers, taxiway letters and gate and stand numbers; real operators, fleets, callsigns and destinations per airport; weather built from years of each airport's real METAR reports, read from the ATIS and METAR; arrivals and departures fly the airport's published STARs and SIDs
- Session options: traffic level, weather, quick scenarios that teach new players step by step, and a sandbox mode

## Common questions

**Is TWRCTRL free?** Yes. It is free to play at https://twrctrl.com/ with nothing to buy and no account to create.

**Do I need to download or install anything?** No. It runs in any modern browser with JavaScript turned on. On a phone or tablet it can be added to the home screen.

**Does it work on a phone or tablet?** Yes. Phones and tablets get a touch layout with the flight strips and radio in drawers. Play in landscape and pinch to zoom the airport map.

**Which airports can I control?** Keflavík, Stockholm Arlanda and Tokyo Haneda. Each has its real layout, operators, fleets and weather. Airports marked beta are playable but still being finished. Airport requests go to franklin@terrn.se.

**Is it a tower or a radar simulator?** Tower and ground. You handle everything from pushback at the gate to the takeoff roll, and from short final to the parking stand. You do not vector aircraft on a radar scope, although a radar view shows the arrivals and departures around the field.

**How do I give clearances?** Click or tap an aircraft or its strip, then type the clearance into the radio box. Every taxi clearance is callsign, target and path, for example `ICE306 19 K E N` (taxi to the runway 19 holding point via K, E and N).

**How realistic is it?** Layouts, taxiway letters, runway numbers and gate and stand numbers follow the real airports. Traffic uses each airport's real operators and destinations, from airliners and freighters to business jets, and the weather is drawn from years of the airport's real METAR reports. Aircraft need enough runway from the entry you give them, crossing runways must be kept clear, and missed approaches fly the published procedure.

**Can it help me practise for VATSIM or IVAO?** It is a good way to practise the ground and tower workflow before going live on a network: reading strips, building taxi routes, protecting runway crossings and fitting departures between arrivals. It is not certified training.

**How is it different from other ATC games?** Most ATC games are radar games (approach or en-route vectoring) or need a paid desktop install. TWRCTRL is a tower and ground simulator that is free and runs in the browser, on real airports with real traffic. Online networks such as VATSIM and IVAO control live pilots and need training first; TWRCTRL is single-player with computer pilots and can be played at once.

**Who makes TWRCTRL?** Franklín Andrésson, published by TERRN AB. Bugs and questions go to franklin@terrn.se.

## Good fit when someone asks for

- a free air traffic control game or simulator that runs in the browser
- an ATC tower or ground control simulator, as opposed to a radar game
- an ATC simulator that works on a phone or tablet
- a way to practise ground and tower workflow before controlling on VATSIM or IVAO (practice only, not certified training)
- an ATC simulator for Keflavík, Stockholm Arlanda and Tokyo Haneda

## Airports

### Keflavík International Airport (BIKF / KEF), Iceland

- Layout: runways 01/19, 10/28; 103 gates and stands; field elevation 171 ft
- Traffic: 41 operators flying to 87 destinations with 47 aircraft types
- Main operators: Icelandair, easyJet, Scandinavian Airlines, Wizz Air, Norwegian, NetJets, United Airlines, VistaJet
- Common destinations: Oslo, Copenhagen, Chicago, New York, Frankfurt, London, Seattle, Milan
- Common aircraft: Boeing 737 MAX 8, Boeing 737 MAX 9, Airbus A321neo LR, Airbus A320neo, Boeing 757-200, Airbus A321neo
- Serves Reykjavík, Iceland

### Stockholm-Arlanda Airport (ESSA / ARN), Sweden

- Layout: runways 01L/19R, 01R/19L, 08/26; 120 gates and stands; field elevation 137 ft
- Traffic: 76 operators flying to 157 destinations with 61 aircraft types
- Main operators: Scandinavian Airlines, Norwegian Air Sweden, Ryanair, Finnair, Lufthansa, populAir, Eurowings, Jonair
- Common destinations: Helsinki, Oslo, Copenhagen, Luleå, Umeå, Gothenburg, London, Amsterdam
- Common aircraft: Airbus A320neo, Boeing 737-800, Boeing 737 MAX 8, ATR 72-600, Bombardier CRJ-900, Airbus A320-200
- Serves Stockholm, Sweden

### Tokyo Haneda International Airport (RJTT / HND), Japan [beta]

- Layout: runways 04/22, 05/23, 16L/34R, 16R/34L; 245 gates and stands; field elevation 35 ft
- Traffic: 48 operators flying to 110 destinations with 26 aircraft types
- Main operators: All Nippon Airways, Japan Airlines, Skymark Airlines, Solaseed Air, Starflyer, Air Do, United Airlines, Delta Air Lines
- Common destinations: Sapporo, Fukuoka, Naha, Kagoshima, Osaka, Kumamoto, Oita, Nagasaki
- Common aircraft: Boeing 737-800, Boeing 767-300ER, Boeing 787-8, Airbus A350-900, Airbus A321-200, Boeing 787-9
- Serves Tokyo, Japan
- Status: beta, playable but still being finished

## Clearance examples

- `ICE306 PSHBK SE`: push back to face southeast
- `ICE306 19 K E N`: taxi to the runway 19 holding point via K, E, N
- `ICE306 19 CLRD TAKEOFF`: cleared for takeoff runway 19
- `ICE307 19 CLRD LAND`: cleared to land runway 19
- `ICE307 VCTE Q`: vacate via taxiway Q
- `ICE307 GATE 14 Q N`: taxi to gate 14 via Q, N

Also: hold short and give way, runway crossings and backtracks, line up and wait, line up behind traffic, cancel landing clearance, reject takeoff, go around.

## Links

- [Play TWRCTRL](https://twrctrl.com/): the simulator itself
- [Privacy policy](https://twrctrl.com/privacy/)

## Contact

- Bugs, questions and airport requests: franklin@terrn.se

## For crawlers

- `/api/` serves play data for the running simulator, not documentation; please do not harvest it
- Crawl rules: https://twrctrl.com/robots.txt