KFreeFlight Logo KFreeFlight

The CVS version is available again and kfreeflight have a brand new mailing list.


KFreeFlight is a FlightGear GUI-frontend designed for KDE users. It can launch FlightGear with the most options without writting a very long command line.
This application is integrated as well as possible on the KDE environment.
KFreeFlight work as well with the FlightGear CVS version as the FlightGear 0.9.10 release.

Actually, the application is available in languages :


KFreeFlight is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License (COPYING file) for more details.


All KFreeFlight tools musn't be use for real navigation. This application is made only for entertainment.
Using it for aviation navigation is in fact illegal.



Ver 0.3.2-r2 Updated Dev release

Ver 0.3.2 Updated Dev release

Ver 0.3.1 Updated Dev release

Ver 0.2.1 - Updated Stable release

Ver 0.2 - First Stable release

Ver 0.1.4 - Dev release

Ver 0.1.2 - First Dev release.

Get it

Sources tarball

You can find it at Sourceforge release repository

By distribution

Don't have any hesitation, You can make package for your favorite distribution.

The best way to share it is upload package in a related website of your favorite distribution.
But don't forget to send us an email, and we put its path on the web site.


CVS Version

A CVS version is now available
CVS Web browser

Get a local copy

To check out a new copy of KFreeFlight from CVS,open a terminal, cd into the directory where you want the new KFreeFlight directory to be created and run the commands listed below. When prompted for the password, just press the Enter key. The necessary commands are:

cvs -d:pserver:anonymous@kfreeflight.cvs.sourceforge.net:/cvsroot/kfreeflight login

cvs -z3 -d:pserver:anonymous@kfreeflight.cvs.sourceforge.net:/cvsroot/kfreeflight co -P kfreeflight

And then :

cd kfreeflight

gmake -f Makefile.cvs



make install as root

Update your CVS copy

cvs update -dP

Mailing List


This is the good place for report problem (compilation, bugs, etc...), query a new feature or just taking about kfreeflight.


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Archived Messages

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All versions

Need KDE and Qt libraries (switching your linux distribution : KDE and Qt devel packages).

V0.3.1 (On and after)

The zlib library is required.
KWeather and KWorldWatch (all in kde-toys package) for running, but they are not necessary to build the application.

V0.3.2 (On and after)

glut (for openGL), plib (min 1.8.4) and simgear (min 0.3.10) are required.
For now, it's impossible to choose plib or simgear path (part in progress but remember that is a development version)
Note : All this dependencies are normally already installed on your system if you have FlightGear 0.9.10.


Stable release

execute ./configure && make to build it and make install as root to install it.

Development release

You must run this command first (look's like an autogen script but for KDE)

gmake -f Makefile.cvs

and then, as usual,

./configure && make etc...


Main Window

Click on this window to close

Screenshot General Tab

zoom Zoom

General Tab

In general settings

  • Splashscreen : let you see a splashscreen when FlightGear starting.
  • Game mode : Launch FlightGear in true fullscreen mode.
  • Fullscreen : Launch FlightGear in a maximised window.
  • Intro music : let you ear a music at startup.
  • Joystick : make joystick the main input device.
  • Unit meter : The unit are in feet by default but you can overwrite this setting here

In advanced settings

  • NMEA protocol : usefull option for Atlas which let see your position.
  • http server : Let you change flying values through a web browser. (by default : http://localhost:5500)
  • Atlas too : launch Atlas and FlightGear together
  • Wireframe and objects wireframe options : let you discover the FlightGear's internal world.

Click on this window to close

Screenshot Render Tab

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Render Tab

Rendering options

  • Specular highlight : Enable specular reflections on textured objects
  • Distance attenuation : Enable runway light distance attenuation
  • Enhanced lightning : Enable enhanced runway lighting
  • Clouds : Enable 2D (flat) cloud layers
  • Bump mapped clouds :
  • Cloud 3D : Enable 3D (volumetric) cloud layers
  • Random objects : Include random scenery objects (buildings, etc.)
  • Mouse pointer : Enable extra mouse pointer (i.e. for full screen Voodoo based cards)
  • Sky blend : Enable sky blending
  • Horizon effect : Enable celestial body growth illusion near the horizon
  • Textures : Enable textures
  • Lightning : Enable lightning rendering
  • Precipitations : Enable precipitations endering

Display resolution, shading and shadows

  • You can choose here the screen resolution and the color depth. This is the place of your personnal screen resolution defined in the settings window.
  • Shading : choose the shading level. Smooth is more beautiful, but need more processor ressource.
  • Shadows : choose the objects which must have a shadow (plane, transparency: plane have shadow on ground only, scenery objects, ai objects)

Click on this window to close

Click on this window to close

Screenshot Airport Tab

zoom Zoom

Airport Tab

Here is a list of your favorites airports (not all the "apt.dat.gz" file).

You can easily add another aiport by clicking on the "add" button after put the ID and the name of airport on the good place.
You can delete an airport too by clicking on the "delete" button after selected one in the airport list.

You can easily add runways for each airport present in the list. Put the runway name and click on the "add" button.
You can delete an runway too by clicking on the "delete" button after selected one in the runway list.

You can make a research in the "apt.dat.gz file" by clicking the "Search Airport" button.
This action make the popup airport Window appears

The last button "Web search" open the web browser (configured in the configuration dialog) at a preselected page.
Actually, it's working only for french airports

Screenshot Airport Menu
Airport Menu

This menu appears when you right click on an item

Screenshot Popup Airport Window

zoom Zoom

Popup Airport Window

Enter a Airport ID or a name and click on the "Search" button.

You can also search an airport by coordinates.
In that case, check "Search by coordinates" and the popup Search by coordinates Window appears.

A list of all airports found was created and you can double click on one of them to get informations about it (relaunch the searching).

The search is on the "apt.dat.gz" file, and the engine propose you to search in the KWeather database too.

Informations are always about the last airport found. Informations are :

  • Name
  • Elevation
  • Longitude and latitude
  • Tower, ATIS and some others importants Comm frequencies
  • All Runways with their informations : direction, lenght, width and ILS frequency
Screenshot Popup World Map Window
Popup World Map Window

This popup let you see where the current airport (the last in the list) are in a world map
This window appear when the button "Where is it ?" is pressed.

Screenshot Popup Search by coordinates Window
Popup Search by coordinates Window

Enter a world location (coordinates) and a search radius.
This window appear when the check box "Search by coordinates" is checked.
A click on the "OK" button close this window
Then press the "Search" button on the Popup Airport Window which make a list of all airports found in the search radius

Screenshot Popup Favorite Airports Window
Popup Favorite Airports Window

Screenshot Carrier Tab
Carrier Tab

By default, FlightGear (ver 0.9.9) became with a carrier, the Nimitz, near San-Fransisco bay (KSFO airport). But it must be actived first.
KFreeFlight do it automatically. KFreeFlight let you change this value if you have a customized FlightGear.

The default values are Nimitz (case sensitive) for carrier name and --prop:sim/ai/scenario=nimitz_demo for prop to actived

In carrier tab, select a start place (catapult 1, 2, 3, 4, parking 1). Then in Aircraft tab select a navy aircraft : seahawk, a4, seafireIIIc, and checked "On carrier" for starting position.

After launch FlightGear, press shift+L to engage aircraft in catapult and shift+C to launch it. Before landing on flight desk, don't forget the arrester hook : shift+O.

Screenshot Aircraft Tab
Aircraft Tab

The aircraft are 3D rendering thumbnail now. It can be build by plib directly or by simgear. In that case, add the aircraft name you want to have simgear rendering in the aircraft.dat file in the /home/<USER>/.kfreeflight directory.

You can also load any model you want by pressing "Load Model" button (plib only).

You can choose failures too (check to activate failures): pitot, static, vacuum, or electrical system

Note: The background color of rendering widget is set by the background openGL color in the settings window

Screenshot Aircraft Menu
Airport Menu

This menu appears when you right click on the aircraft

Start position Tab

You have the choice between four possibilities :

  • Start on the selected airport (on Airport tab).
  • Start on the selected carrier (on Carrier tab).
  • Start in Air : you can specify the initial altitude and speed.
  • Start on a place specified by coordinates

You can activate some options too :

  • Enable AI traffic.
  • Enable auto-ccordination.
  • Start in a frozen state.
  • Freeze fuel level

Screenshot Date Time Tab
Date Time Tab

There is three possibilities for time :

  • True local time.
  • Enter a date and a time (date not affect season textures pack).
  • Choose the time of day between dawn, morning, noon, afternoon, dusk, evening, midnight.

You can check the frozen time option (can freeze FlightGear).

You can specify the season between summer and winter.

Screenshot Weather Tab
Weather Tab

Set here the weather options

  • Wind direction and speed
  • Turbulences level
  • Visibility
  • Fog rendering level

You can choose the real weather option for the place to fly. Need an active internet connexion.

You can see the weather before launching FlightGear by clicking the "Get the weather" button.
In that case the popup Weather Window appear.

Popup Weather Window

Just enter the ICAO ID code of airport and click on the "Download" button. You can find this code by making a research on the Airport Tab.
In case of you already have downloaded the metar and you want an updated one, check the update option.
Note that only one metar was available on the server per hour.

Informations reported are :

  • Airport ID.
  • Date and time (UTC).
  • Pressure
  • Wind direction and speed and if reported the max speed and wind direction group.
  • Temperature and Dew point
  • Weather phenomena
  • Visibility
  • Sky condition

Flight plan Tab

There is two way :

  • By enter manually ID and Altitude.
  • By loading a file (text only, not FlightGear xml flight plan file).

File must content a simple list of way points (eventually with the altitude). Take a look at the example file (promenade_marseille.txt) in the /home/<USER>/.kfreeflight directory.

You can found ID with Atlas.

The GC autopilot will follow the flight plan for you.

Screenshot Network Tab
Network Tab
Local service

You can configure here the http server name and the http server port. Default values are localhost for server name and 5500 for the http port number.
This informations are usefull for using the http option (which can let you change FlightGear values in a web browser) and the NMEA protocol (protocol using by Atlas)

Local network

You must specifie some values :

  • IP in and out : three integer numbers (0 to 255) which are your local network IP address range (broadcast) (ex: Note that 255 was automatically added.
  • the player number (which make, for example --callsign=player1 property)
  • the refresh frequency to the server.You can keep safely the default value : 10 Hz
  • The port number (which can be the same that the http port number)
Remote server

You must specifie some values :

  • IP in : four integer numbers (0 to 255) which are your local machine IP address (even your behind a NAT) (ex:
  • IP out : four integer numbers (0 to 255) which are the server IP address
  • the player login (alphanumeric ).
  • the refresh frequency to the server.You can keep safely the default value : 10 Hz
  • The port number of server

Note : You can select a server on the selector which configure IP out and port number automatically for this servers.

Screenshot Radio NAV Tab
Radio NAV COM Tab

Enter here the NAV radio frequencies :

  • NAV1 active and standby with the radial.
  • NAV2 active and standby with the radial.
  • ADF active and standby with the rotation.
  • TACAN code.
  • Slave DME with NAV1 or NAV2 or enter another NAV radio frequency.

Enter here the Comm radio frequencies :

  • Comm1 active and standby.
  • Comm2 active and standby.

You can activate the background ATC voices too.

Screenshot Scenarii Tab
Scenarii Tab

Screenshot Properties Tab
Properties Tab

Screenshot Others options Tab
Others options Tab

Configure window

Screenshot General Settings
General Settings

You can make application more talkative.

You can choose here your web browser.

You can choose to have the FlightGear output messages

You can reset the "Don't show it again" messages

You can integrate KFreeFlight on the system tray bar, and choose a minimized starting.

Screenshot Font Settings
Font Settings

Select the KFreeFlight's font (all windows).

Screenshot Colors Settings
Colors Settings

Select the KFreeFlight's colors (all windows). The foreground, the foreground and background of edit widgets, and the openGL background colors.

Screenshot FlightGear Settings Page 1
FlightGear Settings Page 1

Here is the place to configure KFreeFlight with your FlightGear installation. You must specifie the FlightGear's data directory, your addon directory (the directory where you dezip scenery files). The main scenery (W130n30) is automatically include in this path when FlightGear is launching.

You can choose another executable file to launch FlightGear (useful for patched version). A double click on a list element make automatically it the default executable.

You can pass anothers options which is not supported natively by KFreeFlight. (Double click to edit list element).

Screenshot FlightGear Settings Page 2
FlightGear Settings Page 2

You can specify the host name and the FlightGear port (for http server and NMEA protocol)

You can add a personnal screen resolution which be appeared in the combo box (main window)

You can permit only one instance of FlightGear

Screenshot Atlas Settings
Atlas Settings

Choose the directory where Atlas can find its images and the Altas executable.

You can force Atlas to use the GLUT font.

You can permit only one instance of Atlas


How send a bug report if I can't build the application ?

Send it by using the email address which is at the bottom of the TODO list section

Does KFreeFlight support the nice option for FlightGear executable ?

No. The "nice -x fgfs" executable doesn't make aircraft list.

Is it possible to remove the KDE dependency which make application more cross-platform?

No it's impossible : KFreeFlight was born because KDE haven't any launcher. I don't want to make a clone but offer something which is different and integrated as well as possible.
Otherwise I will NEVER change the code for the Redmond operating system which isn't a friendly platform for Open Source


Why the 0.3.1 version is in the development branch ?

The application is stable but some features aren't enough tested, especially the weather report which may making a stable but false report.

Why have I an error when i dezip the tarball ?

You must dezip the tarball by taping tar -xzf kfreeflight-<version>.tar.gz in a terminal.
You couldn't using ark or anything else.

Why have I some warnings about aclocal ?

This part is in progress and appear because of an updated autoconf automake. Actually, this isn't a problem for building executable

Why the application's building fail in the linking stage ?

You can try gmake -f Makefile.cvs and relaunch the building process. If it's not solve the problem, send me a bug report.

I can see the splashscreen but the application crash after !

Relaunch the application (this part is in progress).
Some crash came because of false aircraft xml file (In that case change manually the number of aircraft in the config file : /home/<USER>/.kfreeflight/<Current config name>

The splashscreen doesn't diseappear ! (v0.3.2 only)

This is a bug already reported : please download this file kfreeflight.cpp and replace the older one in kfreeflight-0.3.2/src directory before relaunch the buiding process :
gmake -f Makefile.cvs && ./configure && make.
The 0.3.2-r2 release correct this problem.

There is no 3D render or thumbnail for the aircraft on the first launch ! (v0.3.2 only)

This is a bug already reported : before i can fix this problem, relaunch the application.
The 0.3.2-r2 release correct this problem.

Help wanted

If you want to join the KFreeFlight developer group, or make a translation of the application, post a message on the developers forum

TODO list


But I can't do it myself and if someone can do it, contact me on the developers forum

Otherwise, it rest a lot of things

How to translate KFreeFlight ?

This part is very simple : KFreeFlight put pot file in your $KDE/share/apps/kfreeflight directory (min version 0.2).
Just open the kfreeflight.pot file with KBabel or another po file editor and rename it with locale and the po extention.
example : for french translation rename the file fr.po
Now you can translate the application. Don't forget to send us this file at email adress

But it's a good idea to send us an email before, in that case you can work with the last pot file in development or taking the CVS version.


Developers web site :


Gérard Robin

Download web site :



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If you think that you must be present in this part, contact the team on the following forum.

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