FlightGear gliders explained: check availability, install missing sailplanes, choose the best model, launch correctly and fly long distance.
FlightGear’s glider roster depends on the aircraft catalogue supplied for your installed release. Established choices include the Schleicher ASK-21, Schleicher ASW-20, SZD-9 Bocian and Colditz "Cock". Confirm each on the Launcher’s Aircraft screen: refresh the catalogue, search its designation, then check whether the result is installed, downloadable or absent.
Where can I confirm which FlightGear gliders are available?
The authoritative list for your installation is the FlightGear Launcher’s Aircraft screen or aircraft selector, not an old static roster.
- Start the correct FlightGear installation. If several releases are installed, confirm that the Launcher is connected to the release you intend to fly.
- Open the Aircraft catalogue. Disable any installed-only filter so downloadable packages are also displayed.
- Refresh or update the catalogue. The Launcher needs access to the catalogue associated with that FlightGear release.
- Search alternative names. Try
ASK-21,ASK21andSchleicher; repeat withASW-20/ASW20,SZD-9/Bocian, andColditz/Cock. - Read the package state. An installed model should be selectable, a catalogue model will offer a download or installation action, and no result means it is not offered through that configured catalogue. It may still exist as a compatible manual package.
Available does not necessarily mean bundled with the base simulator. Our explanation of included aircraft, catalogue downloads and additional FlightGear models covers that distinction, while our FlightGear fleet overview provides background on these established sailplanes.
What is the best FlightGear glider?
The ASK-21 is the best general training choice, the Bocian suits vintage training, and the ASW-20 is the best of these established models for long-distance and cross-country soaring. Choose the Colditz Cock only for its historical escape-glider scenario.
| Glider | Seating and controls | Best use | Main trade-offs |
|---|---|---|---|
| Schleicher ASK-21 | Two-seat trainer; no lift-changing flaps | First flights, circuits and aerotow practice | Stable, forgiving handling and a lower workload than the ASW-20, but less cross-country performance. Package revisions may differ in cockpit and launch-system depth. |
| SZD-9 Bocian | Classic two-seat trainer; non-flapped | Training with a vintage sailplane feel | More inertia and less clean performance than a modern glass-fibre sailplane. Do not assume both seats or every cockpit control are fully interactive in every package revision. |
| Schleicher ASW-20 | Single-seat; flaps and retractable landing gear | Fast cross-country and long-distance soaring | Better performance and energy retention, but flap scheduling, gear management and more responsive handling increase the workload. |
| Colditz "Cock" | Historical two-person escape-glider design | Recreating its unusual historical scenario | Not representative of a modern trainer or competition sailplane. Its value is historical; instrumentation, performance and scenario integration depend heavily on the package. |
Simulation depth is aircraft-package dependent. A convincing flight model does not guarantee a detailed cockpit, working second seat, tow hook, winch integration or complete documentation.
These are the best FlightGear aircraft specifically for gliding. Readers comparing powered trainers and other categories should use our broader guide to the best FlightGear aircraft for beginners.
How do I install a missing FlightGear glider?
Use the Launcher catalogue whenever the glider appears there; use a manual package only when it is compatible with your release and unavailable through the configured catalogue.
Installing from the Launcher catalogue
- Refresh the Aircraft catalogue and search by both designation and manufacturer.
- Select the correct result and use its download or installation action. Do not install a separate manual copy at the same time.
- Wait for the package to finish before selecting it. An interrupted download can leave an entry visible but unusable.
- Restart the Launcher if necessary. If the model does not become selectable, use the available rescan or refresh control; where no rescan is offered, close and reopen the Launcher.
- Check compatibility errors. A model that installs but opens with missing instruments, property errors or a failed flight model may target another FlightGear or data release.
Installing a manual aircraft package
- Confirm release compatibility first. Do not assume that a package made for an older FlightGear data set will work correctly merely because its folder is detected.
- Extract it into a dedicated add-on aircraft directory. Keeping manual aircraft outside the core programme and catalogue-managed folders makes updates and duplicate detection easier.
- Check the directory structure. The aircraft’s immediate model folder should contain one or more
*-set.xmlfiles. Avoid an accidental extra wrapper level such asAircraft/ModelName/ModelName/. - Add the parent directory to the aircraft search path. In the Launcher’s Add-ons or settings area, select the additional aircraft folder that contains the individual model folders. Command-line users can supply the same location through
--fg-aircraft=.... - Restart or rescan. Manual packages are commonly indexed when the Launcher starts. Reopen it if the aircraft list does not update immediately.
- Remove duplicate copies. Check every configured aircraft directory before troubleshooting. A frequent failure is an obsolete manual package taking precedence over a newer catalogue copy with the same aircraft identifier.
Our detailed FlightGear aircraft installation procedure covers package extraction and search-path setup in more depth. On case-sensitive systems, avoid changing package file or folder capitalisation because internal references may then fail.
How do I launch a glider in FlightGear?
An airborne start is the simplest test, while aerotows and winch launches require support from both the selected aircraft and the launch scenario.
| Launch method | What it requires | Practical use |
|---|---|---|
| Airborne start | A start position with adequate altitude and airspeed | Use this first to verify the flight model, controls and instruments. Starting near the stall with spoilers or gear extended can produce an immediate descent. |
| Aerotow | A working tow hook and release, tow rope, tow aircraft and compatible scenario | Keep the wings level, maintain position behind the towplane and release positively at the planned height. Opening the glider’s throttle will not substitute for a tow. |
| Winch launch | A working launch hook, winch subsystem and compatible scenario | Allow the glider to accelerate before establishing the climb. Release at the top or immediately if the cable or launch becomes unsafe. |
Before any launch, bind or verify these controls:
- Tow release: assign an accessible button and confirm that the package uses it.
- Spoilers or airbrakes: check the axis direction and make sure they close fully.
- Wheel brake: verify that it releases and is not being held by an inverted axis.
- Flaps: select the package’s take-off setting on a flapped sailplane such as the ASW-20.
- Trim: set a sensible take-off or near-neutral position rather than fighting a large pitch input immediately after launch.
- Landing gear: leave retractable gear down for a ground launch, then retract it once safely clear; fixed-gear gliders need no action.
Why does the glider remain stationary on the runway?
A conventional sailplane has no engine thrust, so remaining stationary is normal until an aerotow or winch is active. If the chosen aircraft or scenario does not implement either system, use an airborne start instead.
How do I fly long distance in FlightGear?
Long-distance soaring requires thermals, ridge lift, wave or another rising-air source; selecting a glider or a generic weather preset does not by itself create usable lift.
A sailplane is always descending relative to the surrounding air mass. It gains altitude only when the air rises faster than the aircraft’s sink rate. Without lift, the available distance is limited by starting height, glide performance, wind and the altitude reserved for landing.
- Choose the ASW-20 for cross-country work. Its performance makes it the strongest long-distance choice among the established gliders listed here, provided you are comfortable managing flaps and retractable gear.
- Test the aircraft before setting a route. Start airborne and confirm the variometer, airspeed indicator, trim, spoilers, flaps and gear. A control fault can resemble poor soaring conditions.
- Configure a specific lift source. For thermals, use an environment or soaring scenario that actually generates convective lift. For ridge soaring, arrange wind that blows towards and up the windward slope. Wave needs suitable terrain, airflow and an environment model or scenario that represents it.
- Plan a short first cross-country. Use a small triangle or out-and-return route with identifiable turn points, reachable landing areas and generous clearance above terrain.
- Climb before committing. Centre sustained positive lift using coordinated turns. Do not leave merely because the variometer briefly rises; establish that the average climb is strong enough to justify circling.
- Fly efficiently between lift sources. Retract spoilers and gear, use the appropriate flap range, avoid excessive control movement and account for headwind and sinking air. Do not copy a generic best-glide speed if the aircraft package supplies its own performance guidance.
- Keep a landing reserve. Remain within safe glide range of an airfield or suitable landing area and abandon the route early if lift weakens. A conservative final glide is more useful than arriving low with no options.
Why does my FlightGear glider keep descending?
First check airspeed, trim, spoilers, flap position and retractable gear. If the configuration is clean and the aircraft is flying normally, continued descent usually means the surrounding air is not rising strongly enough; clouds, hills or wind alone are not proof that the selected environment is producing usable lift.