Add correct airline callsigns to FSX AI aircraft by editing aircraft.cfg, installing missing voicepack entries and fixing silent or wrong ATC names.
To add correct airline callsigns to AI aircraft in FSX or FSX: Steam Edition, edit each repaint’s atc_airline= value in aircraft.cfg so it matches an FSX voicepack callsign. If that callsign is absent, import it with EditVoicepack X, update the voicepack, restart FSX, and test the scheduled AI flight.
How do I change an AI aircraft’s airline callsign?
The change has two parts: assigning the correct callsign to the AI repaint and ensuring FSX has recordings for that callsign.
- Close FSX and make backups. Copy the aircraft’s
aircraft.cfgbefore editing it. Back up the active voicepack before applying any voice modification. - Locate the AI aircraft variation. Open the aircraft’s folder under
SimObjects\Airplanes, then openaircraft.cfgin a plain-text editor. If the installation layout is unfamiliar, our guide to locating and installing FSX aircraft files explains where these folders belong. - Edit the correct
[fltsim.x]section. Find the variation used by the traffic plan and change itsatc_airline=line. Each repaint can have a different value, so do not alter another airline’s section accidentally. - Use the operational callsign. Enter the spoken callsign recognised by the voicepack, not automatically the airline name or ICAO code. British Airways, for example, uses Speedbird rather than BAW. Copy the exact callsign label and spacing specified by EditVoicepack or the callsign package.
- Add a missing voice entry. An arbitrary value after
atc_airline=does not create speech because FSX uses recorded voice fragments rather than unrestricted text-to-speech. Import the supplied callsign modification into EditVoicepack X and apply its voicepack update. Our Southern callsign package and configuration example demonstrates the full process, while the Air China Cargo callsign import example shows the same method for another operator. - Restart the simulator. Reloading or restarting FSX ensures that both the edited aircraft configuration and updated voicepack are read again.
A typical entry is simply atc_airline=CALLSIGN, with CALLSIGN replaced by the voicepack’s recognised value. Do not add quotation marks unless the supplied documentation explicitly requires them.
Which settings control the callsign and flight number?
For scheduled AI traffic, atc_airline= supplies the spoken airline prefix, while the traffic flight plan normally supplies the flight number.
| Setting | Purpose | Common mistake |
|---|---|---|
atc_airline= | Chooses the recorded airline callsign | Entering an ICAO code or company name that the voicepack does not recognise |
atc_flight_number= | Provides a flight number in some aircraft and free-flight contexts | Expecting it to override a scheduled AI flight number stored in the traffic plan |
atc_id= | Provides a registration or tail identifier | Changing it when the airline callsign is the actual problem |
atc_heavy=1 | Adds the Heavy designation where applicable | Enabling it for aircraft or operations that should not use Heavy |
title= | Identifies the exact aircraft variation used by compiled AI traffic | Editing a repaint that the traffic file does not reference |
If the airline name is right but the number, route or schedule is wrong, changing aircraft.cfg is not the complete fix. See our explanation of how aircraft titles and AI flight plans work together.
Why does FSX still use the wrong or no callsign?
FSX usually retains the wrong callsign because the edited repaint is not the one referenced by the traffic file, or because the requested phrase is missing from the active voicepack.
- Wrong
[fltsim.x]entry: compare itstitle=value with the aircraft title assigned to the AI traffic plan. - Unrecognised callsign: verify that the value after
atc_airline=exactly matches an installed voicepack entry. Similar spelling is not enough. - Voicepack not updated: importing a modification into EditVoicepack X is only part of the job; the revised voicepack must also be applied to the intended FSX installation.
- Different simulator language: a callsign modification may target a particular voicepack language. It will not necessarily appear in another language’s ATC recordings.
- File was not saved: installations under a protected Windows folder may block direct edits. Save with suitable permissions, then reopen
aircraft.cfgto confirm the change remained. - FSX was left running: restart the simulator or reload the flight after changing aircraft configuration or voice files.
Do I need to rebuild the AI traffic file?
No rebuild is normally required when only atc_airline= changes and the repaint’s title= remains identical. Recompile the traffic plan only if you change its aircraft assignment, flight number, route or schedule.
How can I test the new AI callsign?
Load an airport and time where the edited AI flight is scheduled, enable enough airline traffic for it to spawn, and monitor the relevant ground or tower frequency. Check the ATC text as well as the audio: the text confirms which aircraft and flight number FSX has loaded, while the audio confirms that the voicepack entry works.
If the text shows the old airline, the wrong aircraft variation is being used. If the text is correct but the spoken airline is omitted or broken, inspect the voicepack installation and the exact atc_airline= spelling.