Understanding the Multiplayer Landscape in Flight Simulation

Multiplayer flight simulation has evolved from niche peer-to-peer connections into a robust ecosystem spanning dedicated servers, third-party networks like VATSIM and IVAO, and built-in features within platforms such as Microsoft Flight Simulator (2020 and 2024), X‑Plane 12, and Prepar3D v6. When you introduce multiple aircraft add‑ons, the goal is to create a shared visual and functional experience where every participant sees the correct aircraft model, livery, and performance characteristics. This requires careful pre‑flight planning, consistent add‑on installations, and a clear understanding of how each simulator handles model matching.

Prerequisites for Multiplayer Flights with Add‑Ons

Before you configure any settings, verify that every pilot in your group has the following baseline setup:

  • Simulator version parity – All participants must run the same simulator version (e.g., MSFS 1.37.19.0, X‑Plane 12.1.2). Minor patch differences can cause connectivity or model display issues.
  • Installed and activated third‑party aircraft – Each add‑on must be installed exactly as instructed by its developer. Many add‑ons require activation via a product manager (e.g., Orbx Central, Aerosoft One, X‑Organizer).
  • Multiplayer/online mode enabled – Within the simulator’s settings, turn on multiplayer or online services. For MSFS, this is enabled by default via Xbox Live; for X‑Plane, you need to enable multiplayer via the “Network” settings or use an external plugin such as Swift or x‑SquawkBox.
  • Stable internet connection – Wired connections are strongly recommended. Latency below 100 ms and consistent upload speeds of at least 5 Mbps help maintain synchronization.

Selecting and Installing Multiple Aircraft Add‑Ons

The first challenge is ensuring that all participants own and install the exact same add‑on versions. Developers frequently update their products for compatibility and bug fixes; using mismatched versions will often result in the simulator displaying a default placeholder model instead of the custom aircraft.

Choosing Your Fleet

When flying as a group, decide on a common set of aircraft that everyone will use. While it is possible to have some pilots flying a PMDG 737‑800, others in an Aerosoft CRJ, and the rest in an iniBuilds A310, each participant must own every add‑on flown by the group – or accept that they will see a substitute aircraft (the “model matching” fallback). For the best experience, limit your fleet to two or three models per session, and ensure everyone installs the same versions.

Installing from Official Sources

Purchase add‑ons from reputable vendors only: the MSFS Marketplace, X‑Plane.org Store, FlightSim.to, or developer websites. Follow these steps precisely:

  1. Download the installer – Always use the latest file available. Some products use a web‑based installer (e.g., PMDG Operations Center, Fenix A320 Configurator).
  2. Run the installer as Administrator – This ensures file permissions allow the add‑on to write to the simulator’s Community folder (MSFS) or Custom Scenery folder (X‑Plane).
  3. Activate via the product manager – Many high‑fidelity add‑ons require online activation. Verify your product key remains valid after any major simulator update.
  4. Test the aircraft offline – Before any multiplayer session, load each add‑on at a generic gate or ramp. Check that panels, sounds, and flight dynamics load correctly.

Keeping Add‑Ons Updated

Stalled or corrupted installations are a common cause of model‑matching failures. Use automatic update tools where available (e.g., the Fenix Sim updater, PMDG Operations Center, X‑Plane add‑on manager). On the day of your multiplayer flight, schedule a 15‑minute “update check” call with your group so everyone can patch simultaneously.

Configuring Multiplayer Settings for Different Simulators

Each simulator handles multiplayer connectivity differently. Below are the specific setup steps for the three most popular platforms.

Microsoft Flight Simulator (2020/2024)

MSFS uses a server‑based lobby system integrated with your Xbox Live or Microsoft account.

  • In the main menu, go to World Map and select the Multiplayer tab (the two‑person icon).
  • Choose “Create a Group” or join an existing group via an invitation sent through the in‑game overlay or Xbox party system.
  • Once in a group, all members see each other’s aircraft. However, if someone does not own a particular add‑on, MSFS will replace that model with the closest default aircraft (e.g., a Cessna 172 replaces an aftermarket Cessna 172 mod).
  • Important: To ensure model matching, every group member must have the exact same add‑on installed and activated. The “Allow substitutes” setting in the Multiplayer menu can be toggled, but disabling it will hide missing aircraft instead of showing a substitute.

External link: For detailed MSFS multiplayer troubleshooting, refer to the official Microsoft Flight Simulator Multiplayer FAQ.

X‑Plane 12

X‑Plane’s built‑in multiplayer is more basic. You will typically use third‑party tools for a full experience.

  • Enable “Allow multiplayer” in Settings → Network.
  • Set a static IP address or use a virtual LAN tool such as ZeroTier or Hamachi to create a direct connection between PCs.
  • Each pilot must forward UDP ports if using a direct IP connection (default: 49000–49010).
  • For a simpler experience, use the free Swift plugin, which bridges X‑Plane with the VATSIM or IVAO networks. Swift handles model matching via your aircraft library, but it still requires all participants to own the same add‑ons.

Prepar3D v6

Prepar3D’s multiplayer is built around hosted sessions.

  • Go to Multiplayer → Host a Session. Set a session name and password.
  • Choose the “Locked” session type to prevent random users from joining.
  • Share the session name and password with your group.
  • Use an external voice‑comms tool; Prepar3D lacks built‑in voice.

Model matching in Prepar3D relies on SimObjects and the appropriate aircraft.cfg entries. If a missing add‑on is encountered, Prepar3D will use a generic substitute unless you disable substitution in the session options.

Model Matching: The Core Challenge

Model matching – the process of replacing missing aircraft with the correct visual model – is where most multiplayer add‑on issues arise. Here’s how to handle it on each platform:

On MSFS

MSFS uses a built‑in model matching database that maps ICAO codes and livery names to installed aircraft. If a pilot does not have the add‑on, the sim shows a default aircraft of the same type (e.g., a Boeing 737‑800 for the PMDG 737‑800). This substitution is acceptable for most group flights, but it breaks immersion. For perfect visual consistency, insist that every pilot owns and installs the identical add‑on version.

On X‑Plane and Prepar3D

Model matching is handled by the third‑party plugin in use (e.g., Swift, xPilot, vPilot). These tools scan your aircraft folder and create a “library” file that maps ICAO codes to installed liveries. To ensure everyone sees your PMDG 737, for example, every participant must have that PMDG product installed. If someone does not, the plugin will pick the first available matching aircraft from their library – often a default 737‑200 or a generic tube.

Tip: On VATSIM/IVAO, it is common practice to fly only default aircraft or widely owned add‑ons. For private groups, create a shared Google Drive or Dropbox folder containing a “livery pack” of the aircraft you all plan to fly. Many texture repainters offer free liveries for common fleet types (A320, B737, B77W).

Server Selection and Session Coordination

You have three main options for hosting your multiplayer session:

  1. Built‑in simulator servers – Easiest for small groups (2–16 players). No port forwarding required. Works well for MSFS and Prepar3D.
  2. Third‑party virtual airlines (VATSIM, IVAO, PilotEdge) – Offer structured ATC, but you must abide by network rules. Suitable for groups that want realism and ATC coverage. Note: these networks generally prohibit pure fun‑flying with multiple simultaneous aircraft add‑ons unless you are on an “Uncontrolled” frequency.
  3. Dedicated hosted server (e.g., using the FSLabs Server, JoinFS, or a custom LAN) – Gives you full control. JoinFS (free) works across MSFS, Prepar3D, and X‑Plane simultaneously, but setup is more involved.

Whichever method you choose, agree on the following before launch:

  • Departure airport and runway – Use a freeware airport or default scenery.
  • Flight plan and route – Share a .pln file or an image of the route.
  • Spawn offsets – To avoid collisions, use the simulator’s “start on runway” option and have each pilot enter a different spawn time offset (e.g., 30‑second intervals).

Starting Your Multiplayer Flight: Step‑by‑Step

  1. Launch simulation – Each pilot starts their simulator and connects to the shared server or group session.
  2. Select aircraft – Choose the agreed‑upon add‑on from the aircraft selection screen. Verify that the livery matches the rest of the group (if desired).
  3. Position at departure – Use the “World Map” or “Location” menu to set the spawn point. For group flights on the same runway, assign parking spots or use gate starts.
  4. Perform a connectivity check – While at the gate, ask each pilot to state the aircraft type and livery they see for you. If someone sees a default replacement, reinstall or verify add‑on versions.
  5. Taxi and departure – Use voice comms to coordinate pushback, taxi, and takeoff timing. Stagger departures by 30–60 seconds to prevent visual glitches or collisions.
  6. During flight – Use your chosen voice tool (Discord is the universal standard). Avoid sudden speed/altitude changes that may cause desync.

Troubleshooting Common Multiplayer Add‑On Issues

Missing Aircraft / Default Substitution

Symptom: You see a Cessna 172 instead of your friend’s 737‑800. Resolution: Confirm that all pilots have the same add‑on installed and activated. Check that the add‑on is not a “flavor” variant (e.g., the PMDG 737‑700 vs 737‑800). Use the “verify files” function in the respective product manager. On VATSIM, update your model matching library via vPilot/Swift.

Desync of Flight Parameters

Symptom: Your friend appears to be at FL350 while you see them at FL300. Resolution: This is usually a network issue. Ensure all pilots have a stable ping (under 150 ms). Avoid using Wi‑Fi if possible. Some add‑ons with custom flight models can desync if they override simulator data; try switching to a default flight model temporarily to isolate the problem.

Sound or Panel Malfunctions After Multiplayer

Symptom: After a multiplayer session, the add‑on’s sounds or displays behave oddly. Resolution: This is often caused by mismatched add‑on versions. Run the updater again. If the issue persists, delete the add‑on’s cache files (e.g., %AppData%\PMDG\PMDG 737 NGXu\Cache) and reload.

Performance Drops When Multiple Add‑Ons Are Loaded

Multiplayer with complex add‑ons can strain your CPU and GPU. To optimize:

  • Set global texture resolution to High (not Ultra) for the session.
  • Reduce traffic density and aircraft detail distance in multiplayer settings.
  • Close unnecessary background applications (especially browsers with many tabs).
  • Use a frame‑rate limiter to 30 fps – smoother than fluctuating 40–60 fps.

Tips for a Successful Multiplayer Experience with Add‑Ons

  • Test the setup with a short flight first – Fly a 20‑minute hop between two airports before attempting a 5‑hour long‑haul. This exposes compatibility issues quickly.
  • Keep aircraft types consistent if possible – When everyone flies the same type (e.g., all fly the Fenix A320), model matching is guaranteed. Mixing types increases the chance of substitution for those who don’t own every add‑on.
  • Share clear instructions – Create a checklist document with exact add‑on names, versions, and installation paths. This avoids confusion on flight night.
  • Use a reliable voice communication tool – Discord is the gold standard because it supports screen sharing, text channels, and push‑to‑talk. Alternatives include TeamSpeak (lightweight) and Mumble (low latency).
  • Coordinate the flight plan beforehand – Share SimBrief flight plans, charts, and company routes via a common channel. This reduces workload during the flight.
  • Designate a flight leader – One pilot decides the departure time, rate of climb, and cruise altitude. This prevents the group from splitting up.

Advanced: Using External Network Services for Larger Fleets

If your group grows beyond 10–15 pilots, the built‑in multiplayer systems may struggle. Consider migrating to a dedicated network:

  • VATSIM – Free, offers ATC, but requires strict adherence to pilot and model matching rules. All pilots must file a flight plan. Useful for realistic ops with add‑ons.
  • IVAO – Similar to VATSIM but with slightly different model matching libraries. Both networks publish community‑maintained lists of recommended add‑ons.
  • PilotEdge – Paid service focused on real ATC from Los Angeles to Seattle. Ideal for groups that want ATC practice with complex add‑ons.
  • JoinFS – Free, supports cross‑simulator multiplayer (MSFS, X‑Plane, Prepar3D). However, it requires a host PC with a publicly accessible IP and good upload speed.

For more details on VATSIM model matching, see the official vPilot model matching documentation.

Conclusion

Setting up multiplayer flights with multiple aircraft add‑ons is entirely achievable with careful planning and communication. The keys to success are ensuring every pilot has the same add‑on versions, selecting a compatible multiplayer method for your simulator, and testing the configuration before the main event. By following the steps outlined above – from installation and model matching to server selection and troubleshooting – you and your friends can enjoy seamless, visually consistent group flights with your favourite third‑party aircraft. Whether you’re flying a PMDG 737, a Fenix A320, or a mix of both, the reward is a shared virtual cockpit experience that feels as close to real as possible. Happy flying!