Add AI traffic to Microsoft FS2004 (FS9): install World of AI or manual BGL packages, set density, and fix missing aircraft or schedules.
To add AI traffic to Microsoft Flight Simulator 2004 (FS2004/FS9), install an FS9-compatible package containing AI aircraft, liveries and a compiled traffic BGL. Put the aircraft in the simulator’s Aircraft folder, place the BGL in an active scenery folder, restart FS2004, then raise the airline or general-aviation traffic slider.
FS2004, FS9 and MFS2004 mean the same simulator
Microsoft Flight Simulator 2004: A Century of Flight is usually shortened to FS2004 or FS9, and is sometimes written as MFS2004 in searches. These names refer to the same simulator here.
Packages made only for FSX, Prepar3D, Microsoft Flight Simulator 2020 or Microsoft Flight Simulator 2024 are not drop-in replacements. Check that every aircraft model, installer and traffic file explicitly supports FS2004 or FS9.
What is the easiest way to add AI traffic?
The easiest method is a complete installer-based package containing the aircraft models, liveries and flight schedules.
| Method | Choose it when | Main consideration |
|---|---|---|
| World of AI-style package | You want ready-made airline traffic with minimal manual work | The installer and airline package may be separate, and the schedules reflect the period when the package was produced |
| Complete manually installed package | The download already includes aircraft and a compiled FS2004 traffic BGL | Follow its folder structure exactly and confirm that it is for FS9 |
| Traffic Tools and source plans | You want to create or alter routes, aircraft assignments and timings | Aircraft references must match the relevant title= entries exactly |
An aircraft model or repaint by itself cannot generate traffic. FS2004 also needs a compiled BGL containing routes, operating days, times and traffic-percentage thresholds.
Où puis-je trouver World of AI pour FS2004 ?
Vous pouvez rechercher d’anciens paquets World of AI et d’autres fichiers de trafic FS2004 dans notre bibliothèque de téléchargements gratuits pour simulateurs.
World of AI uses an installer together with individual airline package archives. Keep an airline archive intact if its instructions say the installer reads it directly, select FS2004 or FS9 as the target, and do not assume an FSX package will work in FS2004. These are legacy schedules and liveries rather than live airline timetables.
Install an FS2004 AI traffic package step by step
A complete package works only when both its aircraft and its compiled schedule reach the correct FS2004 installation.
- Locate the real FS2004 root folder. This is the folder containing
fs9.exe. If more than one copy is installed, confirm which one you actually launch. - Close FS2004 and make a backup. Preserve any same-named aircraft folders and traffic BGLs before replacing them. This makes it much easier to reverse duplicate or broken traffic later.
- Read the package instructions. Confirm that it supports FS2004/FS9 and determine whether the archive must be opened manually or passed intact to its own installer.
- Point the installer to the correct root. If automatic detection fails, browse to the folder containing
fs9.exe. Windows may block or redirect changes when FS2004 is underProgram Files; running a trusted legacy installer with administrator permission can prevent files being written to the wrong location. - Verify the AI aircraft folders. Each aircraft belongs directly under
Aircraft, with itsaircraft.cfg, AIR file, model and required textures inside that aircraft’s folder. Do not useSimObjects\Airplanes, which is an FSX-style location. Watch for an extra nested folder created during extraction. - Verify the traffic BGL.
Scenery\World\sceneryis the conventional location. A different location can work if it is inside a properscenerysubfolder registered and active in FS2004’s Scenery Library. - Enable AI traffic. Start FS2004, open its traffic settings and raise the airline or general-aviation density slider that applies to the package. Use 100 per cent temporarily while checking an installation.
- Test the right airport and time. Load a hub served by the installed airline and try several days and times. A valid schedule may have no flight at the airport when the flight is first loaded, and source schedules often use UTC/GMT rather than the local time a reader expects.
Manual installation and custom flight plans
Manual AI traffic needs three connected elements: an FS2004 aircraft variation, a source plan that identifies it correctly, and a compiled traffic BGL in an active scenery folder.
- Install the aircraft. Place the complete model under
Aircraftand open itsaircraft.cfg. - Find the exact aircraft title. Every usable variation has a
title=line in a[fltsim.x]section. The spelling, spaces and punctuation must be unique and must match the aircraft entry used by the traffic source files. - Check the Traffic Tools mapping. Traffic Tools normally maps an
AC#identifier to the aircraft title in its aircraft list; the flight-plan list then refers to that identifier. A mistake we see constantly is matching the folder name instead of thetitle=value. - Compile and install the BGL. The aircraft, airport and flight-plan text lists are source material only. They must be compiled into an FS2004 traffic BGL before the simulator can use them.
For route syntax, aircraft assignments and compilation, use our dedicated guide to building FS2004 AI flight plans.
Why does my FS2004 AI traffic not appear?
Missing FS2004 AI traffic is usually caused by a zero density setting, the wrong installation folder, an inactive or incompatible BGL, a schedule that is not operating at the selected time, or a mismatched aircraft title.
| Symptom | Likely cause and fix |
|---|---|
| No AI traffic anywhere | Raise both traffic sliders for testing, confirm the BGL is in an active scenery folder and restart FS2004. Check that the BGL was compiled for FS9 rather than another simulator. |
| Default traffic appears, but the new airline does not | Confirm that the package went into the same installation as fs9.exe. Test at a served airport on several days and times with density at 100 per cent. |
| The compiler reports a missing aircraft | Match the aircraft-list entry to the exact title= value in aircraft.cfg. The aircraft folder name is not the required reference. |
| Aircraft are invisible or untextured | The model or texture is missing, the folder is nested too deeply, or the aircraft is incompatible with FS2004. Reinstall the complete FS9 model rather than copying only a repaint. |
| A hub contains fewer aircraft than expected | Some plans may be excluded by their density thresholds. The airport may also lack enough parking positions of a suitable radius; parking codes can affect where available aircraft are placed. |
| The same flight or airline appears twice | Two active BGLs contain overlapping schedules. Disable the older schedule file instead of deleting an aircraft folder that other plans may share. |
Our focused checklist for viewing and diagnosing FS2004 traffic covers the remaining BGL, schedule, parking and aircraft-reference checks.
Does add-on AI traffic replace the default traffic?
Most FS2004 AI packages add their schedules alongside the simulator’s stock traffic rather than replacing it.
This can fill airport parking, mix traffic from different historical periods or create overlapping routes. Once the responsible BGL has been identified, close FS2004 and rename its .bgl extension to something such as .off; retaining the file makes the change reversible.
Do not remove AI aircraft at random while active schedules still reference them. If the stock plans are causing congestion or duplication, follow our safe procedure for identifying and disabling FS2004’s default traffic.
Choosing a practical AI traffic density
Use 100 per cent only to prove that a package works, then reduce the setting to balance airport activity, parking capacity and performance.
A starting range of roughly 30–50 per cent is sensible for many installations, but the useful value depends on the number of installed schedules and the airport being used. Large hubs create much more AI processing and ground congestion than regional fields.
The slider is a flight-plan filter, not a target airport occupancy. Each plan has its own activation threshold and still depends on its scheduled day, time and airport. Adjust airline and general-aviation traffic separately after confirming that both types appear correctly.