White lines on FS2004 airport surfaces usually mean texture seams, conflicting scenery or overlapping polygons. Diagnose the cause and fix it safely.
White lines on FS2004 airport surfaces are usually texture seams, damaged or mismatched runway/taxiway textures, or overlapping airport polygons. If the lines flicker as the view moves, suspect duplicate scenery; if they stay fixed in a tiled pattern, suspect textures or graphics filtering. Back up files before replacing anything.
What causes white lines on FS2004 airport surfaces?
The pattern and behaviour of the lines usually identify the fault.
| What you see | Likely cause | First check |
|---|---|---|
| Crisp lines following a runway or taxiway | Normal painted airport markings | Check whether they follow centreline, edge or threshold positions |
| Thin, stationary seams or a repeating grid | Faulty replacement textures, poor mipmaps or texture filtering | Test an unmodified default airport |
| Lines confined to one add-on airport | Local scenery textures or conflicting airport files | Disable that airport's scenery layer |
| Lines that flicker or shimmer as the view moves | Two surfaces occupying almost the same position, known as z-fighting | Look for duplicate airport or AFCAD files |
| Bright strips around the airport boundary | Conflicting ground polygons, exclusions or airport elevation | Temporarily disable nearby scenery packages |
How do I remove the white surface lines?
Isolate whether the problem is airport-specific, texture-wide or graphics-related before changing any files.
- Compare several airports. Load one unmodified default airport and one affected airport. If every airport shows the same seams, concentrate on the main FS2004 texture installation or graphics settings. A fault at only one location normally belongs to that airport's add-on scenery.
- Disable the affected scenery layer. Untick the add-on in FS2004's Scenery Library, close the simulator and restart it. If the lines disappear, examine that package and any other scenery covering the same airport. Disabling a layer will not undo textures that were copied directly into FS2004's main
Texturefolder. - Check for duplicate airport files. Keep the airport file supplied with the visual scenery and temporarily move older alternatives outside every active scenery folder. File names often contain the ICAO code, but this is not guaranteed. Our guidance on finding conflicting airport and AFCAD files explains how to isolate them without deleting the originals.
- Restore a complete matching texture set. If the problem began after installing replacement ground textures, restore the backup made before installation. Do not mix selected files from several texture packs: mismatched bitmaps and mipmaps can create visible joins. Follow our checks for installing and troubleshooting FS2004 ground textures if the package also changed terrain or airport surfaces.
- Reset graphics overrides for testing. Set the graphics-driver profile to application-controlled settings, then compare FS2004's filtering, mip-mapping and anti-aliasing options one change at a time. Restart FS2004 and use the same viewpoint after each change. If filtering merely hides the seams, the underlying custom texture probably has poor edge padding or mipmaps.
- Repair damaged default textures last. If the fault appears at default airports with all add-on scenery disabled, restore the original texture files from a known clean backup or repair the FS2004 installation. Preserve the existing folders first because add-ons may have placed shared files there.
A replacement package such as this FS2004 runway, taxiway and tarmac texture set can replace defective airport-surface textures, but it will not cure overlapping scenery. Install another texture set only after making a recoverable backup.
Why do the white lines flicker when the view moves?
Flickering white lines usually indicate z-fighting rather than a damaged texture. FS2004 is trying to draw two runway, apron or ground surfaces at nearly the same height, and the visible surface changes with camera position and distance.
This commonly happens when an add-on airport is active alongside an older AFCAD, an AI-traffic package's airport file or another scenery package for the same location. Disable one candidate at a time and restart the simulator. Do not delete or alter FS2004's stock scenery files merely because they cover the same area; a properly built add-on handles the necessary exclusions itself.
Are white runway and taxiway lines normal?
Some white airport markings are intentional. Runway centrelines, runway edges and threshold markings are normally white, while taxiway centrelines are generally yellow. Add-on airports may also include white stand or apron markings.
A rendering fault is more likely when a line cuts randomly across several surfaces, repeats at regular tile intervals, outlines every texture square or changes as the viewpoint moves.
Should I edit the AFCAD or replace the textures?
Edit the AFCAD only when the defect follows incorrect airport geometry and duplicate files have already been ruled out. AFCAD can change runways, taxiways, aprons and facility data, but it cannot repair a damaged bitmap or every custom ground polygon compiled into a scenery BGL.
If the layout itself is wrong, use the safe AFCAD airport-layout editing procedure and retain an untouched copy of the original file. For repeated seams across many airports, repair the texture installation or graphics configuration instead.
- Do not install several airport texture packs over one another while diagnosing the fault.
- Do not remove core scenery BGL files to fix a problem confined to one add-on.
- Do not judge a scenery-library change until FS2004 has been closed and restarted.