Enable the FlightGear HUD with the correct h key, understand its speed and flight cues, and fix missing, red, faint or misaligned overlays.
To enable FlightGear’s generic HUD, click inside the simulator window, choose a forward view and press lower-case h without Shift. Press h again to hide it. The overlay places speed, altitude, heading and attitude cues over the view; an aircraft’s modelled cockpit HUD is separate and may need power, avionics and brightness controls.
How do I turn the FlightGear HUD on?
The standard FlightGear HUD toggle is the lower-case h key.
- Select a forward-facing view. Start in the normal pilot or cockpit view so the symbology is easy to recognise.
- Give FlightGear keyboard focus. Click inside the main simulator window and close any dialogue, console or text field that might capture keystrokes.
- Press lower-case
h. Do not hold Shift. The generic HUD should appear over the rendered scene. - Press
hagain to hide it. This command is a simple on/off toggle; repeatedly pressing it can make it appear that nothing changed. - Check the aircraft instruments. Confirm that the displayed speed, altitude and attitude agree with the panel before relying on the overlay.
FlightGear keyboard commands are case-sensitive. Capital H is commonly assigned to a different HUD-related action, while custom configurations can replace either binding. If lower-case h does nothing, use our guide to checking FlightGear’s default keys and remapping a command.
What is a flight simulator HUD overlay?
A HUD, or head-up display, presents flight information in the pilot’s forward view; an overlay is information drawn over the simulator picture rather than on a conventional panel instrument.
FlightGear’s generic overlay is a simulator aid rather than a physical system installed in the selected aircraft. Its exact layout, labels and available symbols can vary with the HUD style, aircraft integration and configuration.
| HUD element | What it means | How to use it |
|---|---|---|
| Horizon and pitch ladder | Pitch and bank attitude relative to the horizon | Use small, smooth corrections to establish level flight, a climb or a descent. |
| Heading scale | Aircraft heading or another directional reference, depending on the layout | Monitor turns and roll out on the required heading. |
| Speed display | Airspeed or another labelled speed value in the configured units | Check the label and units rather than assuming an unlabelled figure is groundspeed. |
| Altitude and vertical information | Altitude plus climb or descent information when provided | Use both together to anticipate a level-off instead of chasing the altitude figure. |
| Flight-path marker | The direction in which the aircraft is moving when this symbol is available | Remember that it shows the flight path, which is not always where the nose is pointing. |
How should I read the speed HUD?
The speed display should be read alongside attitude and altitude, not treated as a target in isolation.
During take-off or approach, make pitch and power changes gradually and cross-check the panel airspeed indicator. Display styles can use different units or data sources, so confirm whether the value is labelled as knots, another unit, airspeed or groundspeed before using it for aircraft limits.
What is the difference between the generic HUD and a cockpit HUD?
The generic HUD belongs to FlightGear itself, while a modelled cockpit HUD belongs to the aircraft and follows that aircraft’s systems.
| Display | How it is enabled | Typical requirements |
|---|---|---|
| Generic FlightGear HUD | Normally toggled with lower-case h | Keyboard focus, the correct binding and a usable view |
| Modelled aircraft HUD | Operated through controls supplied with that aircraft | Electrical power, avionics, display mode, brightness and the correct pilot eye position may be required |
Pressing h does not necessarily power the built-in HUD in a fighter or other HUD-equipped cockpit. Conversely, the generic overlay may remain available while the aircraft is cold and dark. A mistake we see constantly is troubleshooting aircraft electrics when the pilot actually wanted FlightGear’s generic display—or pressing h when the problem is an unpowered aircraft instrument.
Here, cockpit means an aircraft flight deck. Entertainment searches for the Cockpit web series, including a “hot scene”, are unrelated to FlightGear HUD controls.
Why does the FlightGear HUD not work?
Most cases where the HUD does not work are caused by lost keyboard focus, the wrong letter case, a changed binding, an unsuitable view or confusion between the generic overlay and an aircraft-specific display.
- Identify the display you want. Use
hfor the generic FlightGear overlay; use the cockpit controls for a modelled aircraft HUD. - Click the main simulation view. An open dialogue, property window, console or text box may be receiving the key instead.
- Press
hwithout Shift. Check that Caps Lock, Shift or a keyboard remapping utility is not producing a different command. - Verify the binding. Custom keyboard files and user changes can override the default HUD toggle.
- Reset the view. Return to the intended pilot position and undo an extreme zoom or viewpoint offset.
- Test an included aircraft. If the generic HUD works there but not in one add-on aircraft, the fault is probably specific to that aircraft’s configuration or systems.
A short forum reply such as u mnie jest—Polish for “it is there on mine”—only confirms that the other user’s local setup works. Compare the active view, aircraft, keyboard bindings and type of HUD before concluding that your installation has a wider fault.
Why is my HUD colour red, faint or invisible?
A red generic HUD is normally a display-colour choice, not an aircraft warning, while faint or missing symbols often result from poor contrast against cloud, sky or terrain.
- Red symbology: use the HUD colour, brightness or style controls exposed by your FlightGear configuration to select a more suitable presentation. The Turkish phrase
rengi kırmızımeans “its colour is red”; on the generic overlay, that colour alone does not indicate an emergency. - Faint symbols: increase brightness or choose a colour that contrasts with the background. A setting that is clear over dark terrain can disappear against bright cloud.
- Clipped or displaced symbols: centre the pilot viewpoint and return the zoom to a sensible level.
- Dark aircraft HUD: establish electrical power and avionics, then check that aircraft’s HUD power, mode and brightness controls.
Colours on a modelled aircraft display may have aircraft-specific meanings, so do not apply the generic overlay rule to every cockpit HUD.
Can I use the HUD in an external view?
The generic FlightGear overlay can be available in external views, but a modelled cockpit HUD normally requires the viewpoint to be aligned with its combining glass.
A simulated collimated HUD has a limited eye position. Moving the camera sideways, vertically or too far back can make the image vanish or appear clipped even though the display is powered. Return to the normal pilot position first; our guide to changing and resetting the FlightGear camera view covers the relevant view and zoom controls.
Is this the same as the Microsoft Flight Simulator HUD?
No. These instructions apply to FlightGear—sometimes written as “Flight Gear”—and its lower-case h command, not to Microsoft Flight Simulator.
Microsoft Flight Simulator uses its own assistance, camera and aircraft display controls. If that is the simulator you are using, follow the separate instructions for enabling and using the HUD in Microsoft Flight Simulator rather than trying the FlightGear shortcut.