Learn how live traffic feeds place real-world flights in simulators, why aircraft are delayed or missing, and how native traffic differs from injectors.
Live traffic in flight simulators takes real-world aircraft position and flight data from an online feed, converts each tracked flight into a simulated aircraft, then updates its displayed position and movement. It is an approximation, not a perfect radar picture: feed delay, coverage gaps, model matching and simulator limits all affect what appears.
In general-purpose civilian flight simulators, live describes the source of the traffic data. It does not mean every aircraft is shown instantly or follows the exact taxi route, runway clearance and flight path used by its real-world counterpart.
How is a real flight turned into simulator traffic?
A live-traffic system collects flight reports, matches them to available aircraft models and injects moving objects into the simulator.
- Collect the flight data: A provider supplies information such as callsign, aircraft type, position, altitude, heading, groundspeed and destination. These reports may combine ADS-B with other surveillance or operational sources, and some fields may be missing or filtered.
- Match an aircraft model: The simulator or injector searches its available library for the reported ICAO aircraft type and airline. If it cannot find an exact match, it may substitute a generic airliner, the wrong variant or a default livery.
- Create and update the aircraft: The traffic engine places an AI object in the simulator and interpolates between successive position reports. Interpolation produces smooth movement, while a large gap or bad report can cause a sudden turn, jump or disappearance.
- Handle local behaviour: Depending on the system, the aircraft either follows the reported track closely or hands parts of the flight to the simulator's AI logic. Taxiing, runway selection, landing and parking are often inferred because a position feed does not contain every ATC instruction.
The simulator is therefore reconstructing a flight from periodic reports. It is not connected to the real aircraft's controls, flight-management computer or cockpit instruments.
Is live traffic the same as AI traffic or multiplayer?
No. Live traffic, offline AI traffic and multiplayer can all place aircraft around you, but their data sources and control methods are different.
| Traffic type | Source | Who controls the aircraft? | Typical limitation |
|---|---|---|---|
| Live real-world traffic | Online flight-position feed | The simulator or an injector interprets the reports | Delay, missing coverage and model substitutions |
| Offline AI traffic | Schedules, flight plans or generated activity | The simulator's AI engine | Does not represent actual flights in progress |
| Multiplayer traffic | Other connected simmers | Each human pilot | Aircraft may not follow real-world routes or procedures |
The terminology can be confusing because live aircraft are usually created as AI objects inside the simulator. As a result, a setting labelled AI traffic may still affect real-world live traffic. An external traffic injector is a delivery method rather than a separate traffic category; it can inject live data, scheduled traffic or both.
Microsoft Flight Simulator also displays human-controlled aircraft separately from real-world traffic. Our explanation of how MSFS separates multiplayer pilots from other traffic covers the visibility and grouping options involved.
Why does live traffic not match real-world flight tracking?
Live traffic seldom matches another tracking display aircraft-for-aircraft because each service processes, filters and updates its data differently.
- Feed latency: Position reports must be received, processed and sent to the simulator. The aircraft shown in the sim may therefore trail its real position.
- Uneven coverage: Tracking can be sparse over oceans, remote areas and some airport surfaces. An aircraft may appear after take-off or vanish before reaching its stand.
- Filtering and licensing: A provider may suppress particular aircraft, regions or data fields for privacy, security or commercial reasons.
- Interpolation errors: The traffic engine must estimate movement between reports. Delayed or contradictory reports can produce circling, sliding or abrupt altitude changes.
- Incomplete intent data: A feed may know a flight's destination without knowing its assigned runway, taxi clearance or latest amended route. The simulator must fill those gaps.
- Object and range limits: Simulators restrict how many traffic objects they process or display. Distant aircraft and excess ground traffic may be removed first.
- Model matching: A Boeing or Airbus type can be tracked correctly but displayed with the wrong model or livery when the required asset is unavailable.
Should I use built-in live traffic or an injector?
Use built-in traffic for simpler setup and tighter simulator integration; choose an injector when accurate model matching, liveries and traffic controls matter more than convenience.
| Option | Best reason to choose it | Main trade-off |
|---|---|---|
| Built-in live traffic | Minimal setup and generally better integration with native systems | Limited control over feed processing, models and liveries |
| External traffic injector | Can offer broader fleets, better matching and more traffic options | Requires compatible models, background software and a working data connection |
Microsoft Flight Simulator 2020 and 2024 provide native online traffic options. FSX, Prepar3D and X-Plane installations commonly obtain real-world traffic through an add-on, although their built-in AI systems can still generate scheduled or flight-plan traffic.
A mistake we see constantly is running native live traffic and an external injector together. Unless the injector's documentation explicitly says the two can coexist, this causes duplicate aircraft, competing model assignments and unnecessary processor load.
Why is live traffic missing, duplicated or stuttering?
Missing or unstable live traffic usually comes from the wrong traffic mode, two active sources, an unavailable online service or simulator performance limits.
- Confirm the selected traffic mode: Make sure real-world online traffic is enabled rather than offline AI or multiplayer-only traffic. Names differ between simulators and versions.
- Use one traffic source: Disable the native feed before starting an injector unless the add-on specifically requires it.
- Check online connectivity: Verify that the simulator is signed in, its online data services are enabled and any injector can reach its data provider. Firewall or account problems may affect an injector without affecting the simulator itself.
- Check time requirements: A true live feed normally represents real-world operations, while some injectors replay schedules according to simulator time. A large clock or date mismatch can produce unexpected results in systems that combine both.
- Verify model availability: Missing models usually cause substitutions, but a failed or incomplete model library can prevent an injector from creating aircraft at all.
- Reduce traffic limits: Lower ground-aircraft density, traffic range or the number of generated objects. Testing at a busy airport is useful, but maximum density is not a realistic target.
- Allow for service outages: If settings have not changed and all live aircraft disappear at once, the upstream feed may be unavailable. Repeatedly reinstalling models will not fix a server-side problem.
For Microsoft Flight Simulator, our MSFS live-traffic troubleshooting checks narrow down online-service, data-mode and feed problems without confusing them with multiplayer.
Traffic also consumes CPU time to calculate movement and GPU resources to draw aircraft, lights and liveries. Around large airports, reducing traffic quantity or model complexity can help more than lowering an unrelated scenery setting; see the traffic settings that recover frame rate in MSFS for platform-specific guidance.
Does live traffic follow simulator ATC?
Sometimes, but the level of ATC integration depends on how the traffic was created and what the simulator exposes to external injectors.
Native traffic is more likely to be recognised and sequenced by built-in ATC. Injected aircraft may be fully registered as AI traffic, partly visible to ATC or treated as visual objects only. Even when integration works, simulator ATC creates its own clearances; the real aircraft's voice instructions and runway assignment are not normally part of the live position feed.
This explains why a tracked aircraft can approach the expected airport but use a different runway, go around unexpectedly or conflict with another traffic source. Our guide to how simulator ATC identifies and sequences aircraft explains the distinction between built-in controllers and human-operated online networks.