Learn what FSX [fltsim.x] aircraft.cfg entries control, how fields map to folders, and why a livery may not appear in the aircraft menu.
In FSX and FSX: Steam Edition, each [fltsim.x] section defines one selectable variation of an aircraft—usually a livery. It tells FSX which shared flight-model file, model, panel and sound to load, which texture folder to use, and what name and ATC details to show. It does not contain the aircraft's performance data.
How [fltsim.x] works
The x is a placeholder for a number, not something entered literally. Sections normally begin with [fltsim.0], followed by [fltsim.1], [fltsim.2] and so on, with one section for each variation shown in FSX's aircraft selection menu.
Several entries can share the same AIR file, exterior model, cockpit, panel and sounds while using different texture folders. They can also select distinct model variants, such as versions with different equipment or external geometry. A worked repaint configuration example shows how these values fit together in a complete block.
Key fields in an FSX [fltsim.x] section
The most important fields identify the variation, connect it to the aircraft's files and determine how FSX lists it.
| Field | What it controls |
|---|---|
title= | The variation's internal identity. It should be unique across all installed aircraft because FSX, saved flights and AI references can use it. |
sim= | The base name of the .air file in that aircraft folder, written without the extension. |
model= | The exterior and virtual-cockpit model folder. A blank value uses model; model=winglet uses model.winglet. |
panel= | The panel folder or panel alias. Blank normally means panel; a suffix selects a folder such as panel.wide. |
sound= | The sound folder or sound alias, following the same suffix convention. |
texture= | The texture-folder suffix. For example, texture=Blue points to texture.Blue, while a blank value points to texture. |
ui_manufacturer=, ui_type=, ui_variation= | The manufacturer, aircraft type and variation name displayed in the aircraft menu. Other ui_ fields provide filter and creator information. |
atc_id=, atc_airline=, atc_flight_number= | The registration, callsign and flight number used where supported by FSX ATC. |
kb_checklists=, kb_reference=, description= | Checklist, reference and descriptive information associated with that variation. |
A common mistake is entering the whole folder name in a suffix field. If the folder is named texture.Red, use texture=Red, not texture=texture.Red. The same rule applies to model, panel and sound.
How do I add a new [fltsim.x] entry safely?
Add a new entry by copying a compatible existing variation, assigning the next continuous section number and changing only the values required by the new repaint or model variant.
- Close FSX and back up the file. Use our aircraft.cfg location and safe-editing instructions if you are unsure which file to edit or Windows blocks the save.
- Copy the closest matching entry. For a repaint, choose an entry using the same model, panel, sound and AIR file rather than copying configuration from an unrelated aircraft.
- Keep the numbering continuous. If the existing sections end at
[fltsim.2], use[fltsim.3]. Correct duplicate numbers or gaps before adding further entries. - Create a unique title. Change
title=even if the visibleui_variation=name is already different. - Match the texture suffix. Confirm that
texture=Bluehas a correspondingtexture.Bluefolder in the same aircraft directory. - Save the exact filename. It must remain
aircraft.cfg, notaircraft.cfg.txt. Restart FSX so it rebuilds the aircraft list.
For the folder-copying and repaint steps surrounding this edit, follow our manual FSX livery installation procedure.
Why doesn't the new variation appear in FSX?
A variation that is completely absent usually has a numbering, identity, file-reference or aircraft-menu problem rather than a texture problem.
- Show all variations is disabled: enable the option in the aircraft selection window and clear any manufacturer, aircraft-type or publisher filters.
- The section number is wrong: check for duplicate numbers, a missing number or a header accidentally left as
[fltsim.x]. - The title is duplicated: every
title=value should be unique, including across separate aircraft folders. - The AIR file reference is invalid: the value after
sim=must match the relevant.airfilename without its extension. - The section syntax is damaged: both square brackets are required, and the new block must not have been pasted into another configuration section.
- The wrong file was edited: duplicate installations and similarly named aircraft folders make this easy to do, particularly with the boxed and Steam editions installed together.
- The edit was not loaded: close and restart FSX after saving, then check that Windows did not create a text file or redirect the edited copy elsewhere.
What if the variation appears but its textures are missing?
An aircraft that appears in the menu but is white, black, transparent or partly unpainted normally has a texture-file problem. Check that the texture= suffix matches the folder exactly and that the repaint contains the files required by the selected model= variant.
Some aircraft use a texture.cfg fallback file to obtain shared cockpit, reflection or detail textures from another folder. A missing or incorrect fallback can therefore break only part of the aircraft while the main livery textures still load.
Does [fltsim.x] change the aircraft's flight model?
The section does not directly define thrust, drag, weight or handling, but sim= selects the AIR file used by that variation. Most repaint entries retain the original sim= value, so changing title=, texture= or the menu labels has no effect on performance.
Flight characteristics are primarily controlled by the aircraft's AIR file and the performance-related sections elsewhere in aircraft.cfg. The [fltsim.x] block is chiefly a variation selector that joins those shared components to a specific appearance and menu entry.