How do I set up and join multiplayer flights in FSX?

To set up and join multiplayer flights in FSX, first match the host’s edition and connection method: Steam sessions for FSX: Steam Edition, or LAN/direct IP for boxed FSX, whose GameSpy service is defunct. Allow FSX through the firewall, select the session, then choose your aircraft, role and starting position.

Which FSX multiplayer method should you use?

The correct connection method depends on your FSX edition, where the host is located and whether you want built-in multiplayer or organised air traffic control.

Our breakdown of FSX internet, LAN and offline multiplayer methods explains what each connection type can and cannot do. If the group means structured online flying rather than a private FSX session, follow the separate FSX-to-VATSIM setup for vPilot, voice and flight plans.

Can Steam Edition join boxed FSX sessions?

Steam Edition and boxed FSX cannot find each other through their normal internet session browsers. Steam Edition uses Steam matchmaking, while the old boxed version’s GameSpy browser no longer works.

LAN or direct-connection compatibility can depend on the installed build and session configuration, so we recommend that every participant use the same edition and update level. Do not organise a flight around mixed editions unless the host has confirmed that exact setup works.

Set up FSX before joining

A few checks before connecting prevent most missing-session, aircraft and spawn-position problems.

1. Confirm the edition and connection method. Ask whether the host is using FSX: Steam Edition, boxed FSX on a LAN or boxed FSX through direct IP. Obtain the session name, password and host IP address where applicable.
2. Match the expected FSX build. Boxed users should have the service pack or Acceleration configuration requested by the host. Steam participants should let Steam finish updating FSX before connecting.
3. Set your multiplayer identity. Enter a recognisable player name or callsign on the Multiplayer screen. Configure and test your push-to-talk control before joining if the session uses FSX voice.
4. Permit FSX through the firewall. Allow fsx.exe and, for Steam Edition, Steam on the appropriate Windows network profile. Do not permanently disable the firewall.
5. Agree on the route and parking positions. Do not place every pilot on the same runway or gate. Each participant should prepare the route independently; you can create and load the shared route with FSX’s built-in Flight Planner.

How do I join multiplayer in FSX: Steam Edition?

FSX: Steam Edition joins internet flights through the Steam session browser.

1. Start Steam in online mode and launch FSX: Steam Edition from the Steam client.
2. Open Multiplayer from the FSX opening screen and select the Steam internet option.
3. Refresh the session list and check that filters are not hiding full, private or password-protected sessions.
4. Select the host’s session, choose Join and enter its password if requested. Private sessions may require an invitation from the host.
5. Choose your role and aircraft. Pilot is the normal choice; observer or tower-controller roles appear only when the session and edition support them.
6. Select a starting location agreed with the group, preferably a separate parking stand rather than the active runway, then enter the session.

The host may lock weather, time, realism options, aircraft changes or starting locations. Those restrictions are session rules, not faults in your FSX installation.

How do I join a boxed FSX multiplayer flight?

Boxed FSX should use LAN discovery on the same network or a direct IP connection over the internet because GameSpy login and session browsing are obsolete.

1. Open Multiplayer and enter your player name.
2. Choose Local Network or LAN when the host is on the same router, then search for available sessions.
3. Use Connect Directly for a remote boxed-FSX host and enter the public IP address supplied by that host.
4. Select the session, enter its password and choose your aircraft and starting position.
5. Join and remain clear of other aircraft until everyone has finished loading.

A direct internet host normally needs a reachable public IPv4 address and correctly configured router and firewall rules. Carrier-grade NAT can prevent inbound hosting even when every FSX setting appears correct.

Do all players need the same aircraft and scenery?

Everyone can often connect without identical add-ons, but FSX does not transfer aircraft, liveries or scenery between computers.

• Aircraft: Pilots without another participant’s add-on model may see a substitute aircraft or an incorrect visual model. Use a stock FSX aircraft, or ensure everyone has the agreed multiplayer model installed.
• Scenery: Each computer renders its own local scenery. Different airport layouts can place one pilot on a building, grass or a taxiway that does not line up for somebody else.
• Flight plans: Do not assume a route loaded on one computer is loaded for everyone. Distribute the same .PLN file or have each pilot create the identical route.
• Weather and time: A host can impose these settings, but participants should still confirm the planned departure time and conditions.

Why can’t I find or join the FSX session?

Missing FSX sessions are usually caused by the wrong edition or connection method, an offline Steam client, restrictive filters, firewall rules, NAT or a full/private host session.

• No Steam sessions appear: Confirm Steam is online, refresh the list, clear restrictive filters and verify that the host is also using FSX: Steam Edition.
• The boxed GameSpy login fails: Stop trying to repair the account or password; the service is defunct. Use LAN or direct IP instead.
• Direct connection fails: Recheck the host’s public IP address. The host may need router configuration, and carrier-grade NAT may require a different hosting arrangement.
• You connect but cannot see the group: Confirm that everyone selected the same session, airport and nearby parking positions. An absent add-on aircraft may also appear as a substitute model.
• Voice does not work: Select the correct Windows recording device before launching FSX, verify the push-to-talk assignment and check that voice is enabled for the session.
• You disconnect while loading: Try a stock aircraft and default airport first. Complex add-ons, version mismatches and long scenery-loading pauses are common causes.

If the session remains invisible or reports a connection error, work through our specific fixes for FSX firewalls, NAT, ports, edition mismatches and add-on conflicts.