Fix FlightGear sound not working by checking mixer routing, output devices, OpenAL, aircraft files and FGData with clear symptom-based steps.
FlightGear sound usually fails because audio is muted in the simulator or operating-system mixer, the wrong output device was active when FlightGear started, OpenAL could not initialise, or one aircraft has broken sound files. Check volumes and routing, restart FlightGear, test a bundled aircraft, then inspect the log for audio or missing-file errors.
How do I restore sound in FlightGear?
- Establish whether anything should be audible. Load a bundled aircraft and start with its engine running if that option is available. Check both cockpit and external views. A cold-and-dark aircraft may be almost silent, so it is a poor test unless you know its start-up procedure.
- Check FlightGear's sound controls. Open the sound or audio controls exposed by your FlightGear build. Make sure sound is enabled, mute is off, and the master, engine and effects levels are above zero. Saved launcher profiles can preserve a muted setting.
- Inspect the operating-system mixer while FlightGear is running. On Windows, check both the volume and per-application output assignment in Volume Mixer. On macOS or Linux, confirm that the FlightGear audio stream is not muted and is routed to the intended speakers or headset. A system alert playing correctly does not prove that FlightGear uses the same output.
- Restart after selecting the output device. OpenAL often opens an audio device when FlightGear starts and may not follow a later switch from speakers to USB, HDMI or Bluetooth audio. Quit FlightGear completely, connect the device, make it the system default, and launch again. For Bluetooth headsets, select the normal stereo playback endpoint rather than a hands-free call profile.
- Remove sound-disabling launch options. Check launcher profiles and additional command-line arguments for
--disable-sound. Remove it;--enable-soundcan be used temporarily to confirm that sound has not been disabled by a saved option. - Read the log. Use the launcher log, console view or a terminal launch and search for references to OpenAL, audio devices, sound configuration files, or missing
.wavfiles. The first relevant error is usually more useful than later warnings caused by the same failure.
Use the symptom to choose the next fix
| Symptom | Likely cause | Best next action |
|---|---|---|
| Every aircraft is silent | Mute, output routing, disabled sound or OpenAL failure | Check the mixer, restart with the correct device, then inspect the log |
| Only one add-on aircraft is silent | Missing, incompatible or incorrectly installed aircraft sound files | Test a bundled aircraft and reinstall only the affected aircraft |
| Sound stopped after connecting a headset or monitor | OpenAL is still attached to the old endpoint | Set the new default output and restart FlightGear |
| Engine sound works but radio audio does not | Aircraft audio-panel controls, tuning or an unpowered radio | Check the aircraft's avionics and radio volume controls |
| Sound crackles when performance collapses | Audio underruns caused by heavy simulator load or a problematic device mode | Reduce the load temporarily and test a standard stereo output |
Why is only one aircraft or audio channel silent?
If a bundled aircraft produces sound, FlightGear's global audio system is working. Aircraft packages contain their own sound definitions and samples, so an incomplete extraction, a version mismatch, incorrect path capitalisation on a case-sensitive file system, or files left over from an older release can silence one model.
Install a clean copy of the affected aircraft into a fresh folder rather than merging it over the old one. Preserve its internal directory structure and use a package intended for your FlightGear generation. Testing with bundled content is the quickest way to separate simulator faults from add-on faults; this is also part of our wider advice for diagnosing free PC flight simulators.
If engine and environmental sounds work but navigation identifiers or other radio audio do not, do not reinstall OpenAL. Confirm that the avionics are powered, the station is receivable and correctly tuned, and the relevant audio-panel switch and volume control are enabled. Some aircraft model these controls individually.
What do OpenAL and missing-file errors mean?
An OpenAL device or initialisation error means FlightGear could not create an audio stream; a missing-file error points instead to FlightGear data or an aircraft package. Treat them as different faults.
- OpenAL or device errors: select a conventional default stereo output, close applications taking exclusive control of it, and restart FlightGear. If the error remains, repair or reinstall FlightGear and its audio dependency from the same installer or package source. On Linux, avoid mixing a FlightGear binary from one packaging system with libraries from another.
- Missing sound XML or audio samples: repair the affected aircraft if only that model fails. If bundled aircraft also report missing files, repair the base FlightGear data package.
- Permission errors: make sure FlightGear can read its installation and aircraft directories. Do not run the simulator permanently as an administrator to hide a bad installation location or ownership problem.
- Errors after moving data folders: verify that any custom FlightGear data-root setting points to the complete matching base-data package, not an aircraft or scenery subfolder. The executable and base data must belong to compatible releases.
Do not download a loose audio DLL or copy sound files between unrelated aircraft as a shortcut. That can replace one clear error with a harder library or configuration mismatch.
When should I reset FlightGear or reinstall it?
Reset FlightGear's user preferences only after checking volume, routing, launch arguments and logs. Back up and rename the per-user settings file or directory so FlightGear creates clean preferences on the next launch. This may remove saved launcher choices and control assignments, but it should not require deleting scenery or aircraft.
Reinstall the smallest component implicated by the test: one aircraft for an aircraft-only failure, base data for missing bundled sounds, or FlightGear and its packaged audio components for persistent OpenAL initialisation errors. If sound is one part of a broader installation problem, use our general FlightGear first-flight troubleshooting checks before replacing the whole setup.