Virtual Air Traffic Simulation Network

Virtual Air Traffic Simulation Network (VATSIM) is a nonprofit organization that operates an online flight-simulation network noted for its active membership and realism.[2][3][4][5] Users are able to fly aircraft as a pilot, or direct traffic as an air traffic controller in what has been described as a close approximation of real-life aviation procedures.[6][7][8][9]

Virtual Air Traffic Simulation Network
FormationJuly 2001
TypeNonprofit organization
PurposeProvide an online air traffic control and flying community for aviation enthusiasts
Region served
>800,000 (120,000 active in the last 6 months)
Tim Barber [1]
Main organ
Board of Governors


Communications between pilots and controllers are carried out using integrated VoIP or in-game text messages. Users are required to use custom software, designated as approved clients, in order to connect to the simulation.[10]

The main organs of the network consist of the Board of Governors,[11] three of whom are responsible for one of the three geographic regions—namely, the Europe, the Middle East and Africa region, the Asia-Pacific region, and the Americas region,[12] referred to as VATEMEA, VATAPAC and VATAMAS respectively. These regions are further subdivided into divisions, some of which further divide into virtual area control centers, and virtual air route traffic control centers. Operating procedures within each area reflect local standards.[13]

The network also has a volunteer team of supervisors[14] that help those who may need assistance in flying on the network and also help resolve reports of other fellow users breaking the VATSIM Code of Conduct.[15] Upon registering for the VATSIM network, new users have to undertake an entry-level test about basic piloting skills and about the rules of the network.[16] This was introduced on September 1, 2020, alongside a further restructuring of the pilot rating system to teach VATSIM users how to properly use the network and reduce the number of cases of pilots connecting without knowing what to do in busy airspace, causing disruption and frustration for some controllers.

Because the simulation adheres as closely as possible to real-life aviation procedures and radio phraseology, VATSIM can function as a training aid for student pilots lacking experience and private and commercial pilots looking to enhance their skills in radio communications.[17] Events in the simulation are not hard coded on the network but rather emerge through human interaction and error.[18] Consequently, the network has been described as bringing immersion to what was historically a solitary exercise[3] and credited with playing a key role in the commodification of flight-simulation software.[19][20]


Formation of VATSIMEdit

Spearheaded by Harvey Stein, the founding of VATSIM was announced on July 12, 2001, following the dissolution of the Simulated Air Traffic Controllers Organization (SATCO). This occurred after the founding of another network, IVAO,[21] which was more European-oriented, unlike SATCO, which was more American-oriented. The board drew up terms of agreement with Randy Whistler, the then President of SATCO, declaring VATSIM the official successor of SATCO.[22]

In 2020, VATSIM announced it had achieved 100,000 active users for the first time,[23] an increase of 20,000 users in two years.[24]

SquawkBox and ProControllerEdit

The advent of the Internet in the mid-1990s enabled users of modern flight simulators to fly together using multiplayer functionality. In 1997, SquawkBox[25] was created by Jason Grooms as an add-on for Microsoft Flight Simulator 95, enhancing the built-in multiplayer features to allow large numbers of players to connect to the game. ProController,[26] a radar-simulation program also developed by Jason Grooms, was created in the same year to connect virtual pilots with virtual controllers. The FSD Server was created by Marty Bochane to provide the signaling infrastructure and logic required to integrate ProController and Squawkbox, enabling users to fly in real-world weather conditions. ProController was retired as an approved ATC client on March 13, 2004.[27][28]

Screenshot of the ASRC (Advanced Simulated Radar Client) program that was used by ATC on VATSIM

The SquawkBox pilot client was retired for use on the network on April 1 2021,[29] due to its not being in active development,[30] which made it incompatible with fast position updates that are brought with VATSIM Velocity.

ASRC and Roger WilcoEdit

Sometime in 2002,[31] ProController was slowly being phased out in favour of ASRC (Advanced Simulated Radar Client),[32][33] created by Mike Evans and David Hendleman, and was released to the public in early 2003. Alongside that, Roger Wilco (software) was used[34] to facilitate voice communications between pilots and ATC, with ATC denoting that voice communications were available with them with the callsign format XXXX_V_TWR, alongside putting their voice server IP and voice room name in their ATIS.[35][36] Later, however, Roger Wilco was phased out in favour of the Advanced Voice Client, which required VATSIM authentication to prevent any non-VATSIM users from logging into the voice servers.[citation needed]

The ASRC software was retired as an ATC client on April 1 2021,[29] due to its not being in active development, which will make it incompatible with fast position updates that will be brought with VATSIM Velocity.

Screenshot of the Virtual Radar Client (VRC) software used by some air traffic controllers on VATSIM

On March 27, 2005, an alternative add-on to FS2002/FS2004 and FSX called FSInn was approved for use on the VATSIM network alongside SquawkBox.[37]

The FSInn pilot client will be retired on April 1 2021,[29] due to it not being in active development,[38] which made it incompatible with fast position updates that will be brought with VATSIM Velocity.

VRC and EuroScopeEdit

On April 17, 2006, the VRC ATC client was approved for use on the VATSIM network.[39] Created by Ross Carlson, as of May 2020, the VRC client is still in use today[40] - mainly in the American and Oceanic regions, due to its easy setup, but comes with a lack of customisability.[citation needed]

On September 15, 2007, the EuroScope ATC client was approved for use on the VATSIM network.[41][42] Created by Gergely Csernak, the client is reported to be the most used ATC client on VATSIM,[43] due to its custom plugin support,[44] realistic radar screens, and automatic controller coordination. It is designed to integrate with other ATC clients like VRC, vSTARS, and vERAM,[45] however. It is generally used mostly in the Europe and Asia regions.[citation needed]

A screenshot of the EuroScope software utilising the TopSky plugin used by most air traffic controllers on VATSIM (not vatSys)

On January 14, 2012, the vSTARS ATC client was approved for use on the VATSIM network.[46] Also created by Ross Carlson, the client aims to replicate the real-world STARS system used in many US TRACON facilities.

On February 27, 2016, the vERAM ATC client was approved for use on the VATSIM network.[47] Also created by Ross Carlson, the client aims to replicate the real-world ERAM system used in many US ARTCC facilities.

On July 18, 2020, the vatSys ATC client was approved for use on the VATSIM network.[48] Created by Jake Saw, the client aimed to replicate the real-word TAAATS system used in Australia,[49] but is now modelled off the Eurocat/TopSky systems. It features an advanced profiling system which "means that the look and feel of the client can be adjusted with a simple few clicks".[50]

Audio for VATSIMEdit

From its inception, VATSIM employed a system consisting of voice 'rooms', in which, by using custom-written TeamSpeak 2 servers as a backbone, each virtual 'frequency' functioned similarly to a VoIP conference call, and a controller needed to 'open' each room in order for voice communications to be possible on the corresponding frequency.[51]

The new VATSIM logo as of July 23, 2020 (top) compared to the previous logo (bottom)

In October 2019, VATSIM had finished a complete overhaul of its voice system and called it Audio for VATSIM, a key feature of which is simulation of the entire VHF radio range, thus eliminating the need for voice rooms. The system realistically simulates signal degradation, audio quality, transceiver operation, frequency cross-coupling, and altitude effects.[52]

Microsoft partnershipEdit

On July 23, 2020, VATSIM, alongside announcing a complete overhaul of their branding, announced that they had entered into a partnership with Microsoft, to ensure that the desktop PC version of Microsoft Flight Simulator 2020 would be compatible with VATSIM upon launch.[53][54][55] However, VATSIM does not and likely never will support the Xbox version of Microsoft Flight Simulator 2020.[56]

VATSIM VelocityEdit

On March 13, 2021, VATSIM announced a closed-beta initiative to test low latency position updates on the network, named VATSIM Velocity.[57][58] With this update, position updates will be increased from 0.2Hz (5 seconds) by a factor of 5 to 5Hz (0.2 seconds) within a 10-mile range.

VATSIM announced that the long-awaited update would be released on January 31, 2022 at 22:00 UTC.[59] There will be major changes to the client, including the retirement of xSquawkbox (which is not compatible anymore with the new technology being implemented). On rollout, Velocity has no effects on present ATC Clients (such as Euroscope, VRC, VATSys, and vERAM).


Considered the largest online flight simulation network in the world,[2] VATSIM has attracted mainstream media attention.[6][21][4][60] Commentators have praised VATSIM for its realism and quality,[61] describing the network as giving flight simulation an interest and depth it would otherwise lack[62] and lauding its friendly atmosphere.[60][19]

Coverage, although mostly positive, has focused on what is perceived to be the peculiar nature of a hobby so complex that it can closely approximate work and cost thousands of dollars.[4][63] The experience has been described as more strict, for both air traffic controllers and pilots, than some participants might like.[8]

Membership and trainingEdit

VATSIM has over 110,000 active users as of 2021.[64] Joining is free, and there are no usage fees associated with connecting to the network.[65]

Pilots must successfully complete a new user orientation program, including a simple exam that helps reinforce the material about basic piloting skills and the rules of the network as of September 1, 2020.[16] They may also undertake optional training to learn how to fly certain procedures on the network. Pilots may also transfer their real world license into a VATSIM rating as many real world Pilots fly on the VATSIM network.

The current pilot ratings are:

  • P0 - Basic VATSIM User (awarded after completion of the New User Orientation Program)
  • P1 - Private Pilot License (PPL)
  • P2 - Instrument Rating (IR)
  • P3 - Commercial Multi-Engine Licence (CMEL)
  • P4 - Airline Transport License (ATPL)

Pilots are able to file their own flight plans either through their flight plan dialog in their pilot client or "pre-filing" by using the myVATSIM ICAO flight planning form, also used by flight planning sites and flight tracking tools such as projectFLY, SimBrief, SimToolkitPro, and Volanta.

Pilots can pre-file an ICAO flight plan before connecting to the network using the myVATSIM portal.

Air Traffic Controllers are required to undertake mandatory training before they are permitted to direct traffic.[66][6][67] The Global Ratings Policy[68] defines the requirements for each ATC rating, preceding local division restrictions. The ratings are as follows:

  • S1 - Tower Trainee - no particular competencies, can only control up to Tower (TWR) level as per division restrictions
  • S2 - Tower Controller - validated to control Delivery (DEL), Ground (GND) and Tower (TWR) facilities except procedural tower (subject to training)
  • S3 - TMA Controller - validated to control all facilities up to Approach (APP/DEP) level
  • C1 - Enroute Controller - validated to control all available facilities, including Center (CTR)
  • C3 - Senior Controller - a special rating awarded to users at the discretion of their local region/division for seniority/recognition
During the 2002 Operation OpenSky event, total online members reached 798 concurrent connections. The "dots" in the screenshot represent aircraft with their routes shown as lines.


The network creates and sponsors regular events to encourage interaction between pilots and controllers, during which traffic can approximate real-life levels.[19]


Worldflight Australia is an annual virtual round-the-world charity event that has been run continuously since 2001, where 11 teams from different countries[69] in their own fixed-base aircraft simulators fly to over 40 destinations around the world on VATSIM to raise money for the Australian Royal Flying Doctor Service.[70] VATSIM air traffic controllers provide service throughout this event. In 2006, fifteen enthusiasts conducted a 130-hour flight in a full-sized Boeing 747-400 simulator, for which Qantas provided food.[63]

Cross the PondEdit

The VATSIM stand at the International Flight Simulator Conference in Blackpool, July 2005

Cross the Pond is a biannual event during which pilots complete transatlantic flights across "The Pond" between Europe and Northern America. The event alternates between westbound and eastbound every 6 months. Certain airports are selected a few months prior for which pilots can book slots to fly for,[71] and VATSIM air traffic controllers provide full service for each of these airports throughout the event. The event is meticulously planned and coordinated by all major VATSIM staff members,[72] to make sure that pilots enjoy their service. During the Spring 2020 event, VATSIM surpassed its record for most pilots connected to the network with 3,111.[73]

Regional eventsEdit

In addition to the global/international events that VATSIM sponsors and advertises, regional events can be found daily throughout the network. These events can range from small in size, including only a few airports or facilities, to very large in size, spanning across multiple regions and facilities. Although they don't typically attract record-breaking traffic, these events have been known to draw enough pilots to simulate (and even surpass) real-world operations at the selected facilities.

See alsoEdit


  1. ^ "Time for a Change - General Discussion - VATSIM Community".
  2. ^ a b Van West, Jeff; Kevin Lane-Cummings (2007). Microsoft Flight Simulator X for Pilots. John Wiley and Sons. pp. 672–685. ISBN 978-0-7645-8822-8. VATSIM is the largest network, with more than 110,000 registered members
  3. ^ a b Stewart, Laverne (December 5, 2009). "Flight Simulation". The Daily Gleaner. Retrieved March 24, 2011.
  4. ^ a b c Rheinberger, Joel (November 28, 2008). "Flight simulator takes off in Lauderdale". 936 ABC Hobart. Retrieved March 24, 2011.
  5. ^ Radcliffe, Doug; Andy Mahood (2003). Microsoft Flight Simulator 2004: A Century of Flight (Official Strategy Guide). John Wiley & Sons. p. 188. ISBN 0-7821-4237-0.
  6. ^ a b c Sanders, Peter (May 18, 2006). "In Imaginary Skies, Would-Be Controllers Guide Pretend Pilots". Wall Street Journal. Retrieved April 29, 2008.
  7. ^ Castronova, Edward (2005). Synthetic Worlds: The Business and Culture of Online Games. University of Chicago Press. p. 158. ISBN 0-226-09626-2.
  8. ^ a b Wallace, Lane (October 1, 2006). "Microsoft Unveils Mission-Capable Flight Sim X". Flying. p. 45. Retrieved April 15, 2009. Systems like VATSIM are apparently very strict experiences, however, with standards for training and currency that can be more intense and involved than some pilots want to undertake.
  9. ^ D'Alessandro, Nic (November 15, 2007). Transference of PC based simulation to aviation training: issues in learning (PDF) (Technical report). InSite Solutions (Tas.) Pty Ltd. Retrieved July 16, 2022.
  10. ^ "Approved Software". Retrieved July 16, 2022.
  11. ^ "Board of Governors". Retrieved July 16, 2022.
  12. ^ "Regions". Retrieved July 16, 2022.
  13. ^ Galvin, John (March 2003). "Always a Dull Moment". Wired. Retrieved April 14, 2008.
  14. ^ "What is a VATSIM Supervisor? | VATSIM Inc. Support". Retrieved July 16, 2022.
  15. ^ "Code Of Conduct". Retrieved July 16, 2022.
  16. ^ a b "Restructuring of the Pilot Rating System". VATSIM Community. Retrieved May 1, 2020.
  17. ^ Maharg, Paul (2007). Transforming Legal Education. Ashgate Publishing. p. 165. ISBN 978-0-7546-4970-0.
  18. ^ McCracken, Grant (May 16, 2006). "How virtual worlds discovered dynamism". Intersection of Anthropology and Economics. Archived from the original on August 31, 2009. Retrieved July 14, 2008.
  19. ^ a b c Regis, Ed (January 1, 2009). "Welcome to Cyberairspace". Air & Space Magazine. Retrieved March 28, 2011.
  20. ^ Takeda, K.; Newman, S.J.; Kenny, J.; Zyskowski, M (2008). "Convergence: commodity flight simulation and the future". Aeronautical Journal. California: University of California. 112 (1136): 599–607. doi:10.1017/S0001924000002566. S2CID 58712971. Retrieved May 7, 2009.
  21. ^ a b Terdiman, Daniel (December 16, 2006). "Into the wild blue virtual yonder". CNET Retrieved April 29, 2008. It formed in 2001 when internal politics in a precursor network, SATCO, caused a rupture that resulted in two rival networks: VatSim ... and IVAO
  22. ^ "2001, Meeting 1 |" (PDF). Retrieved July 16, 2022.
  23. ^ "An Incredible Milestone for VATSIM - Announcements & Important Notices - VATSIM Community". VATSIM Community. Retrieved July 16, 2022.
  24. ^ "VATSIM Achieves membership milestone - Announcements & Important Notices - VATSIM Community". VATSIM Community. Retrieved July 16, 2022.
  25. ^ "SquawkBox". Retrieved May 1, 2020.
  26. ^ "VATSIM gets it together" (PDF). AOPA Magazine. November 19, 2001. Retrieved May 3, 2020.
  27. ^ "Approved Software". December 10, 2003. Archived from the original on December 10, 2003. Retrieved March 14, 2021.
  28. ^ "Approved Software". April 3, 2004. Archived from the original on April 3, 2004. Retrieved May 4, 2020.
  29. ^ a b c "Preparing for VATSIM Velocity - Retirement of Legacy Clients |". VATSIM Community. Retrieved July 16, 2022.
  30. ^ DeYoung, Joel. "SquawkBox News Blog". Retrieved February 13, 2021.
  31. ^ "Introduction". Retrieved May 3, 2020.
  32. ^ "Advanced Simulated Radar Client (ASRC)". Retrieved May 4, 2020.
  33. ^ "ASRC video". YouTube. November 24, 2007. Retrieved May 4, 2020.
  34. ^ "ProController - Observer's guide". Retrieved May 3, 2020.
  35. ^ "ProController - Observer's guide". Retrieved May 3, 2020.
  36. ^ "Useful information". Retrieved May 3, 2020.
  37. ^ "2005, Quarter 1 |" (PDF). Retrieved July 16, 2022.
  38. ^ Desfosse, Don. "FSInn vs. vPilot". VATSIM Community. Retrieved February 13, 2021.
  39. ^ "2006, Quarter 2 |" (PDF). Retrieved July 16, 2022.
  40. ^ "VRC - Virtual Radar Client for VATSIM Controllers". Retrieved May 3, 2020.
  41. ^ csernak. "v2.9 – EuroScope". Retrieved May 4, 2020.
  42. ^ " - NOTAMS". September 25, 2007. Archived from the original on September 25, 2007. Retrieved May 4, 2020.
  43. ^ "Software |".
  44. ^ "Plug-Ins – EuroScope". Retrieved May 4, 2020.
  45. ^ "Interaction with VRC/ASRC/vERAM/vSTARS – EuroScope". Retrieved May 4, 2020.
  46. ^ "2012, Quarter 1 |" (PDF). Retrieved July 16, 2022.
  47. ^ "vERAM Launched". VATSIM Community. Retrieved May 4, 2020.
  48. ^ "2020, Quarter 2 |" (PDF). Retrieved July 16, 2022.
  49. ^ "2020, Quarter 3 |" (PDF). Retrieved July 16, 2022.
  50. ^ Saw, Jake. "vatSys". Retrieved February 23, 2021.
  51. ^ "Audio for VATSIM launch date announced - Announcements & Important Notices - VATSIM Community". VATSIM Community. Retrieved July 16, 2022.
  52. ^ The AFV Team. "Audio for VATSIM User Guide" (PDF). Retrieved October 19, 2019.
  53. ^ "A Big Day for VATSIM!". VATSIM Community. Retrieved July 27, 2020.
  54. ^ Bolding, Jonathan (July 25, 2020). "Flight Simulator teases a partnership with online flight network VATSIM". PC Gamer. Retrieved July 27, 2020.
  55. ^ "VATSIM on Twitter: "We're excited to announce that we have partnered with our friends over at @MSFSofficial to ensure day one support of the new Microsoft Flight Simulator on the VATSIM Network!"". VATSIM Forums.
  56. ^ "VATSIM Statement on Xbox Compatibility". VATSIM Community. Retrieved July 27, 2020.
  57. ^ "VATSIM Announces Velocity |". VATSIM Community. Retrieved July 16, 2022.
  58. ^ We Feel The Need..., retrieved March 13, 2021
  59. ^ "VATSIM Announces Velocity Release Date and Rollout Plan". VATSIM Community. Retrieved July 16, 2022.
  60. ^ a b "Gaming News". PC Gamer. GP Publications. 15 (4–13). 2008. Retrieved March 28, 2011.
  61. ^ Kimbrough, Steven O.; D. J. Wu (2004). Formal Modelling In Electronic Commerce. Birkhäuser. p. 17. ISBN 3-540-21431-3. There now exists a vibrant community organized around VATSIM, as well as remarkably complex and robust software supporting these activities.
  62. ^ Maharg, Paul (2007). Transforming legal education: learning and teaching the law in the early twenty-first century. Ashgate Publishing, Ltd. p. 346. ISBN 978-0-7546-4970-0.
  63. ^ a b Galvin, Nick (June 6, 2006). "Cockpit capers". Sydney Morning Herald. Retrieved January 14, 2009.
  64. ^ "About VATSIM?". Retrieved July 16, 2022.
  65. ^ Orr, Josh (May 2, 2006). "Teen earns wings for his first solo flight". Sarasota Herald Tribune. Archived from the original on January 11, 2009. Retrieved July 14, 2008.
  66. ^ "Becoming a Controller". Retrieved July 16, 2022.
  67. ^ Margulius, David (May 26, 2006). "Tech jobs take stress to whole new levels". InfoWorld. Retrieved April 29, 2008. so realistic that some commercial airlines are starting to use it to train [their] pilots...
  68. ^ "Global Ratings Policy". Retrieved July 16, 2022.
  69. ^ "Worldflight | VATSIM Charity Event". Retrieved May 1, 2020.
  70. ^ "Worldflight Australia". Worldflight Australia Website. Retrieved January 14, 2009.
  71. ^ @vatsim (March 18, 2020). "Cross The Pond is closing in with lighting speed, and we are so excited! We are pleased to announce that booking for this year's biggest event will open March 21st at 1200z! As usual bookings open in bulks, details about specific airports below." (Tweet). Retrieved July 16, 2022 – via Twitter.
  72. ^ @vatsimctp (April 3, 2020). "Guess what time it is?" (Tweet). Retrieved July 16, 2022 – via Twitter.
  73. ^ @vatsim (April 5, 2020). "The numbers are in! Thank you to everyone who have flown or controlled tonight, and a special thanks to all the wonderful people who have worked hard for months to host this amazing event! We are pleased to share our new connection record with you. Thank you for flying with us!" (Tweet). Retrieved July 16, 2022 – via Twitter.

External linksEdit

  • Official website – Includes links to region and division-specific websites.
  • SimAware – Official live flight tracking map & statistics for VATSIM traffic.
  • VAT-Spy – A widely used flight tracking tool & statistic viewer for VATSIM. Data can be updated here.
  • VATTASTIC – An unofficial flight tracking map for VATSIM traffic with statistics.
  • vataware – Detailed statistics & live flight tracking for VATSIM traffic.
  • Worldflight Group – Worldflight Group official website.