FSX & FSX: Steam Edition Updated Thu, 02 Jul 2026 23:00:00 GMT 7 min read

Why is AI traffic not showing up in Microsoft Flight Simulator X (FSX) after installing WOAI or other traffic add-ons?

AI traffic in FSX can vanish because of sliders, install format, inactive flight plans, or airport parking conflicts. Here is how to fix it.

By Adam McEnroeFile Library Manager

In FSX, missing AI traffic after installing WOAI or similar packages is usually caused by one of four things: traffic density sliders set too low, flight plans installed in the wrong format or folder, testing at the wrong airport or time, or airport parking conflicts that leave nowhere for AI to spawn.

What usually stops AI traffic appearing in FSX?

Symptom	Most likely cause	What we would check first
No AI anywhere	Traffic sliders at zero, traffic files installed to the wrong place, or the add-on was installed into the wrong simulator	Set airline and GA traffic to 100% and verify the traffic .bgl files are in an active FSX scenery folder
AI appears at some airports but not others	Airport parking or AFCAD layout problem	Test at a stock major airport with default scenery
Only some airlines or aircraft are missing	Broken aircraft model, texture or `title=` entry mismatch	Check the AI aircraft folder and its `aircraft.cfg`
Default traffic disappeared after adding WOAI	Conflicting traffic file format or traffic file mix	Temporarily isolate the add-on traffic files and reinstall the package in FSX mode

First checks: the simple things that catch most people out

Set traffic density high for testing. In FSX, raise both Airline traffic density and General aviation traffic density to 100% temporarily. Some flight plans only appear above a certain percentage, so a low slider can make a perfectly good install look broken.
Test at the right airport and time. AI packages follow schedules. If you load into a quiet airport late at night, or on a day with little scheduled traffic, you may simply miss the flights. We usually test at a large stock airport on a weekday morning or afternoon.
Restart FSX after installing. FSX does not always pick up new traffic files cleanly while it is already running. Close the simulator fully, then relaunch and test again.
Use a stock airport first. If AI appears at a default airport but not at your custom scenery airport, the traffic system is working and the real problem is the airport layout, not WOAI itself.

Was WOAI installed into the correct FSX folder?

This is one of the biggest causes, especially on FSX: Steam Edition or on systems that have had more than one simulator installed.

Traffic add-ons need two things in the right place:

the traffic file, usually a .bgl, in an active scenery folder such as Scenery\World\Scenery or another enabled scenery area;
the AI aircraft folders in the simulator's SimObjects\Airplanes path, unless the package is set up to use another active SimObjects location.

If the installer points to the wrong simulator folder, FSX will never see the traffic. This is common when:

boxed FSX and FSX: Steam Edition have both been installed at some point;
an old installer still points to a previous path;
Windows permissions stop the installer writing where it should;
the package was installed into an FS2004 folder by mistake.

On FSX: Steam Edition the principle is the same, but the install path is often different from boxed FSX. If you have both versions on the machine, double-check which one the installer actually used.

Could the traffic file format be the problem?

Yes. Older AI packages were not always compiled in native FSX format. That does not always mean they will fail completely, but mixing traffic formats can cause confusing results in FSX, including traffic appearing inconsistently or one set of traffic suppressing another.

If a WOAI package gave you an option for FSX or FS2004 during installation, it needs to be installed for FSX. If you are not sure which option was used, reinstalling the package in FSX mode is often quicker than chasing the issue file by file.

A related clue is this: if your add-on traffic does not appear and your default FSX traffic also changes or disappears, you are probably dealing with a traffic file conflict rather than a bad density setting.

How do we check whether the flight plans are actually active?

AI traffic is schedule-driven. The package may be installed properly, but there may simply be no matching flight at the airport and time you chose.

We would check these points:

Airport choice: test at a known busy airport served by the airline in the package.
Time of day: many flights cluster in morning and evening banks.
Day of week: some schedules are not daily.
Traffic percentage: some plans require a minimum slider setting before they spawn.

If you are testing a regional airline package at a large international hub where it rarely parks, or you are loading at a dead time in the schedule, you can get a false negative very easily.

Why does AI show at one airport but not another?

That usually points to an AFCAD or parking problem. In FSX terms, the airport layout file controls gate sizes, parking types, airline codes and available spots. If the aircraft has nowhere suitable to park, it may never appear there at all, or it may arrive and immediately disappear.

Common airport-side causes are:

parking spots too small for the aircraft type;
no matching gate or ramp type;
airline parking codes that do not match the aircraft assignment;
a custom airport file that removed or replaced usable parking positions;
duplicate airport layout files fighting each other.

This is why testing at a stock airport matters. If the traffic shows there, the add-on is working. The airport scenery needs attention.

What if only some AI aircraft are missing?

If one airline package works and another does not, or if only a few aircraft fail to appear, the issue is often with the aircraft entries rather than the traffic engine itself.

We would look for:

a missing aircraft folder;
a broken or incomplete model or texture folder;
a mismatch between the aircraft name referenced by the flight plan and the title= line in aircraft.cfg;
a manual rename that broke the package after installation.

When this happens, FSX may still load the traffic file, but it cannot spawn the missing aircraft because the referenced AI model no longer matches what is installed.

A quick diagnostic order that usually finds the fault

Set both AI sliders to 100% and restart FSX.
Load a stock major airport with default scenery at a busy weekday time.
Confirm the add-on installed into the simulator you actually use, especially if you have FSX and FSX: Steam Edition on the same PC.
Check the traffic .bgl location. It must be in an active scenery area that FSX reads.
Check the AI aircraft folders in SimObjects\Airplanes and make sure the package files are present.
Temporarily isolate the suspect traffic files by moving only the relevant add-on traffic .bgl files out of the folder, testing, then restoring them one set at a time. Keep backups before you do this.
Reinstall the package in FSX mode if you suspect an FS2004-format or wrong-path install.
Test a default airport and your custom airport back to back. If only the custom airport fails, fix the airport layout or parking.

FSX and FSX: Steam Edition notes

The traffic system behaves broadly the same in both versions. The main difference is practical: installers and legacy AI packages are more likely to miss the correct path on Steam Edition, or to target boxed FSX if both have existed on the machine.

If you run Steam Edition, pay special attention to where the installer wrote the aircraft folders and traffic files. A correct package in the wrong folder looks exactly like a dead package inside the sim.

The short version

If no AI shows at all, start with the sliders, the install path and the traffic file location. If AI shows at stock airports but not custom ones, it is usually parking or AFCAD related. If only certain airlines are missing, check the aircraft folders and aircraft.cfg entries those flight plans depend on.