[] [] [] [] []
There are two environment variables that must be defined to run FlightGear. These tell
FlightGear where to find its data and scenery.
You can set them in a number of ways depending on your platform and
requirements.
This is where FlightGear will find data files such as aircraft, navigational beacon
locations, airport frequencies. This is the data subdirectory of where you installed
FlightGear. e.g. /usr/local/share/FlightGear/data or c:\Program
Files\FlightGear\data.
This is where FlightGear will look for scenery files. It consists of a list of directories that
will be searched in order. The directories are separated by “:” on Unix and “;” on
Windows. e.g.
/home/joebloggs/WorldScenery:/usr/local/share/FlightGear/data/Scenery
c:\Program Files\FlightGear\data\Sc:\Program
Files\FlightGear\data\WorldScenery.
The graphical wizard on Windows and the GUI launcher on Mac OS X internally define
these environment variables so you don’t have to define these yourself. However, in case
you launch FlightGear from command-line, you need to explicitly define these
variables.
Fig. 3: Ready for takeoff: Waiting at the default startup position at San Francisco Itl.,
Before you can run FlightGear, you need to set a couple of environment
variables:
/usr/local/share/FlightGear/lib to
LD_LIBRARY_PATH
FG_ROOT must be set to the data directory of your FlightGear installation.
e.g. /usr/local/share/FlightGear/data.
FG_SCENERY should be a list of scenery directories, separated by ”:”. This
works like PATH when searching for scenery.
e.g. $FG_ROOT/Scenery:$FG_ROOT/WorldScenery.
To add these in the Bourne shell (and compatibles):
LD_LIBRARY_PATH=/usr/local/share/FlightGear/lib:$LD_LIBRARY_PATH
 export LD_LIBRARY_PATH
 FG_HOME=/usr/local/share/FlightGear
 export FG_HOME
 FG_ROOT=/usr/local/share/FlightGear/data
 export FG_ROOT
 FG_SCENERY=$FG_ROOT/Scenery:$FG_ROOT/WorldScenery
 export FG_SCENERY
or in C shell (and compatibles):
setenv LD_LIBRARY_PATH=\
   /usr/local/share/FlightGear/lib:$LD_LIBRARY_PATH
 setenv FG_HOME=/usr/local/share/FlightGear
 setenv FG_ROOT=/usr/local/share/FlightGear/data
 setenv FG_SCENERY=\
   $FG_HOME/Scenery:$FG_ROOT/Scenery:$FG_ROOT/WorldScenery
Once you have these environment variables set up, simply start FlightGear by running
fgfs --option1 --option2…. Command-line options are described in
Chapter .
The pre-built windows binaries come complete with a graphical wizard to start
FlightGear. Simply double-click on the FlightGear Launcher Start Menu item, or
the icon on the Desktop. The launcher allows you to select your aircraft, the start airport
and runway, time of day, current weather, and lots of other settings.
Fig. 4: The FlightGear Launcher
The first time your run it, you will be asked to set your FG_ROOT variable (normally
c:\Program Files\FlightGear\data) and FG_SCENERY. This should be a list
of the directories where you have installed scenery, typically c:\Program
Files\FlightGear\data\Scenery.
If you set invalid values or change your scenery directories later, you can
change the settings by pressing the ”Prev” button from the first page of the
Alternatively, you can run FlightGear from the command line. To do this, you need to set
up the FG_ROOT and FG_SCENERY environment variables manually.
Open a command shell, change to the directory where your binary resides (typically
something like c:\Program Files\FlightGear\bin\Win32), set the
environment variables by typing
SET FG_HOME=~c:\Program Files\FlightGear~
 SET FG_ROOT=~c:\Program Files\FlightGear\data~
 SET FG_SCENERY=~c:\Program Files\FlightGear\data\Scenery~
and invoke FlightGear (within the same Command shell, as environment settings are
only valid locally within the same shell) via
fgfs --option1 --option2… Command-line options are described in
Chapter .
Of course, you can create a batch file with a Windows text editor (like notepad) using
the lines above.
For maximum performance it is recommended that you to minimize (iconize) the text
output window while running FlightGear.
The prebuilt binary package for Mac OS X comes with the GUI launcher. Simply
double-click the FlightGear icon on /Applications folder shows up the GUI launcher
window as shown in Fig. 5. The launcher allows you to :
Select an aircraft and an airport
Enable/Disable automatic scenery download (using TerraSync)
Enable/Disable the Navigation Map (Atlas)
Launch FlightGear
The follow sections describe using these features.
Fig. 5: The GUI Launcher for Mac OS X
At the launcher window, you can select an aircraft and an airport by clicking gear buttons
at the right end of the airport/aircraft name. The thumbnail image of a selected aircraft
will show up at the image panel on the window. The airport that you select
here will be the starting point of your flight. FlightGear uses ICAO 4-letter
airport code, which is composed with one or two prefix letters followed by a
two or three letter airport code. For example, the ICAO code for San Francisco
International Airport is KSFO. “K” in this case is the prefix for The United
States, and SFO is the airport code for San Francisco International Airport. You
can use Advanced features >> Position or Aircraft tab to find an airport or an
By checking Download scenery on the fly at the launcher window, the scenery data will
be downloaded while you’re flying using TerraSync. The scenery downloader will install
the scenery data into /Applications/FlightGear.app/Contents/Resouces/data/Scenery-Terrasync.
The Mac version of FlightGear includes Atlas, the navigation map that helps your flight
plan, for your convenience. Checking this option will automatically launch Atlas when
you start the flight. You don’t have to specify any Atlas options. The GUI launcher will
specify these for you.
Clicking Start Flight button at the launcher window opens up another window -
the FlightGear main window. FlightGear immediately starts loading tons of
data required for simulation. It may take a while on slower machines to load
everything.
FlightGear has many features and options that you can specify at launch time. Some of
these are not changeable from the menu in the FlightGear main window. To enable /
disable these features, click the triangle-shaped button at the left-bottom of the launcher
window. This displays the advanced features tabs. All settings are saved so you don’t
have to respecify them.
These tabs let you specify some of FlightGear options:
Save preferences on exit: lets FlightGear save preferences that you changed
from the menu in the FlightGear (fgfs) main window will be saved to $HOME/.fgfs/autosave.xml.
FlightGear.
joystick, mouse, and keyboard are available. You can leave it as auto unless
you really want to change it manually.
Unit: specifies the unit used in FlightGear. feet and |meters are available.
Time of day: specifies the time of day. Available options are real, dawn,
morning, noon, afternoon, dusk, evening, and midnight.
FlightGear
summer or winter.
Sound: disabling this will cut all the sound in FlightGear.
Instrumental panel: specifies if 2D panel is drawn from the beginning. You
can also enable/disable the 2D panel from FlightGear menu
Random objects: specifies whether FlightGear draws random objects or not
AI models: specifies whether FlightGear handles AI aircraft and ships
Clock never advances: specifies whether the clock advances in FlightGear
No fuel consumption: makes aircraft consume no fuel while it’s flying
Start in a frozen state: starts FlightGear with frozen state. it does not seem
working at this moment.
Display HUD: displays HUD at the beginning, I guess. You can turn HUD
on/off by pressing ’h’ while you are flying.
3D HUD: enables 3D HUD if an selected aircraft supports it
Real weather fetch: enables fetching real weather condition using METAR
Horizon effect: enables horizon effect
Clouds: enables drawing clouds
3D clouds: enables drawing 3D clouds. You need to enable 3d clouds by
FlightGear
simulator window.
Turbulence:
turbulence.
severe. You need to specify value from 0.0 through 1.0
Visibility: specifies the visibility in meter. You can specify 5000 or less if
FlightGear runs slow on your machine.
Fullscreen mode: enabling this will launch FlightGear as full-screen mode
Window size: specifies the size of FlightGear window. It will be ignored
when full-screen mode is enabled
Sky blending: enables or disables FlightGear to blend the sky depending
surrounding
environment.
FlightGear crashes.
Textures: enables or disables textures on runways, buildings, and scenery
objects. Disabling this will give you some more fps, effective especially on
Wireframe: lets FlightGear draw wire-frames so you can see how the world
of FlightGear is drawn. This should be enabled only for debug / development
Fog: specifies how fog is drawn. disable, fastest, nicest are available.
Favorite list provides a means of preserving a named set of current options like a book
mark of a web browser. To save the current set of options, press “+” button on the top
window or at the bottom of the Favorite tab. Once favorites are added, You can switch
from one configuration to another by double-clicking a row in the table view in the
Favorite tab. Pressing “-” button (or delete key) on a favorite in the table view deletes the
selected favorite.
You can find airports or aircraft carriers by searching with a keyword into the filter text
area. Available keywords are:
For airports
a part of airport name (e.g. international, ranch, or civil)
country name (such as Japan, USA, or France) if available
location name (such as city or county or U.S. state abbrev. if available)
IATA code (such as SFO, LAX, HND) if available
ICAO code (such as KSFO, KLAX, RJTT) - works on all airports
For aircraft carriers
carrier name (Nimitz or Eisenhower)
“carrier”
Airports and carriers that match the keyword are shown at the table view below the filter text
area. The airport name at the upper pane is synchronized with the currently selected
airport or carrier. You can also open this tab by clicking the gear button at the right end of
airport name on the top pane.
When you choose an airport, available runways show up at the “runway” pop-up
button. You can choose a runway or leave it as “default.”
You can find aircraft by searching with a keyword into the filter text area. Available
keywords are:
a part of aircraft name (e.g. c172, zero, shinden)
configuration file name without -set.xml (e.g. a6m2, p51d)
fdm (Flight Dynamics Model) name (e.g. yasim, jsb)
status (e.g. alpha, beta, production, development)
A list of aircraft that match the keyword shows up at the table view below the filter text area.
The aircraft name at the upper pane is synchronized with the currently selected aircraft.
You can also open this tab by clicking the gear button at the right end of aircraft name on
the top pane.
If you want to find more aircraft data from the internet, click “Get Aircraft” button at
the bottom of the Aircraft tab. It opens a web browser to lead you to the Aircraft Links
page on FlightGear Mac OS X web site. you can visit some links there and download an
aircraft you want. Once an aircraft is downloaded, open “Others” tab to install
If you encounter some weird behavior in searching aircraft, removing a cache file for
aircraft database might solve your problem. open /Applications/Utilities/Terminal.app and type the following commands
to remove the cache file:
  cd /Applications/FlightGear.app/Contents/Resources
   rm AircraftCache.rb
Note that you must not launch FlightGear from mounted disk image of a prebuilt
binary package since the folder in the mounted disk image is read-only, which
prevents you from installing any add-on data. you need to install FlightGear by
copying the FlightGear icon from the mounted disk image to /Applciations
This tab contains two network features of FlightGear. One is multi-player mode and
another is FGCOM (a voice ATC). To enable multi-player mode, specify the
followings:
Enable Multiplay: enables or disables multi-player mode. Enabling this will
open a new browser window to show the map on a multi player server.
Callsign: specifies the name shown in the map. Username must contain only
alphabet letters, numbers, underscores, and dots. FlightGear will exit when
you specify a call sign with invalid characters. A user name with 8 or more
characters will be truncated into the first 7 characters.
mpserver02.flightgear.org is available at the time of writing this.
Your Mac: specifies your Mac’s IP address. Usually the launcher detects the
address automatically. If something is wrong with network connection, clear
this text field.
Port: must be 5000
FGCOM enables you to make a real voice communication using radio setting. You
can talk at a selected radio frequency (COM1) while pressing space bar. You can listen to
some other player’s talking in the frequency if some others are using the same
frequency and you are in range. The options available for FGCOM are listed
Enable FGCOM in Multi Player mode: specifies if you use FGCOM when
Multiplay is enabled.
FGCOM Server: specifies a VOIP server.
For further instructions on FGCOM, and Multiplay, please see Chapter
You can specify any options other than aircraft, airport, and the options shown in the
launcher. Entering space-separated options as shown in Figure 11 will pass additional
options to FlightGear. You can see all available options by pressing “View Options.”
Some options might cause FlightGear crash. If you encounter such crashes with a
specific option, please let us know.
To install additional aircraft and scenery data, press "Install Add-on Data." You can
specify multiple files and/or folders to install to the FlightGear data folder. Acceptable
file types are:
7zip (only if 7zip is installed)
You will see the message window when all the data is successfully installed,
otherwise error message will show up. You can select both aircraft and scenery data at
the same time. If you select an archived file that does not contain aircraft files, it will be
extracted into the data folder, but will be ignored. When you finish installing new
aircraft, you can select the aircraft on the “Aircraft” tab.
You can also launch the simulator from the command line on Mac OS X. To do so, open
Terminal.app (located at /Applications/Utilities) and type the following
  cd /Applications/FlightGear.app/Contents/Resources
   ./fgfs --option1 --option2 ....
See chapter
for detail information on command line options. Unlike the
other platforms, you don’t have to manually specify the environment variables
such as FG_ROOT and FG_SCENERY as long as you use a prebuilt binary
Following is a complete list and short description of the numerous command line options
available for FlightGear. Most of these options are exposed through the FlightGear
launcher delivered with the Windows binaries.
If you have options you re-use continually, you can create a preferences file
containing a set of command-line options that will be set automatically. You can create
the file with any text editor (notepad, emacs, vi, if you like).
On Unix systems (including Mac OS X), put the command line options in a
file called .fgfsrc in your home directory.
command line options in a file called system.fgfsrc in the FG_ROOT
directory (e.g. c:\Program Files\FlightGear\data).
Display the most relevant command line options.
--help--verbose
Display all command line options.
--language=code
Select the language for this session. e.g. pl, nl, it, fr, en, de.
Display the current FlightGear version.
--fg-root=path
Tells FlightGear where to look for its root data files if you didn’t compile it
with the default settings.
--fg-scenery=path
specification
is not at the default position under $FG ROOT/Scenery; this might be
especially useful in case you have scenery on a CD-ROM.
--enable-save-on-exit, --disable-save-on-exit
Enable or disable saving of user-preferences on exit from the simulator.
--enable-freeze, --disable-freeze
Control whether FlightGear starts paused or not. Defaults to not paused.
--control=mode
(joystick,
Defaults to joystick.
--enable-auto-coordination,
--disable-auto-coordination
auto-co-ordination between aileron and rudder on/off. Auto-coordination is
recommended for users without rudder pedals or a ‘twist’ joystick. Defaults
--browser-app=path
Specify location of your web browser. E.g: --browser-app=“C:\Program Files\Internet Explorer\iexplore.exe”
(Note the “ ” because of the spaces!).
--config=path
Load additional properties from the given path. E.g:--config=./Aircraft/X15-set.xml
--units-feet
Use feet as the unit of measurement.
--units-meters Use meters as the unit of measurement.
--enable-ai-models, --disable-ai-models
Enable or disable other aircraft/AI-models in the simulator.
--ai-scenario=name
--ai-scenario=vinson-demo).
May be used multiple times.
--enable-random-objects, --disable-random-objects
(buildings/trees).
--enable-sound, --disable-sound
Enable or disable sound.
--show-sound-devices
Show the available sound devices.
--sound-device=device
Specify the sound device to use for audio.
--enable-intro-music, --disable-intro-music
Enable or disable playing an audio sample when FlightGear starts up.
--aircraft=aircraft
--aircraft=c172p.
$FG ROOT/Aircraft,
“-set.xml”.
specifying
“-set.xml” from
Alternatively,
--show-aircraft option described below to list the available aircraft.
For information on downloading additional aircraft, see Section .
--show-aircraft
Print a sorted list of the currently available aircraft types.
--min-status=status
Display only those aircraft with a specified minimum declared status, one
early-production,
production.
--show-aircraft.
--aircraft-dir=PATH
executable
$FG ROOT/Aircraft.
--vehicle=name of aircraft definition file
Synonym for --aircraft.
--livery=Name
Set the aircraft livery.
--fdm=abcd
Select the core flight model. Options are jsb, larcsim, yasim, magic,
balloon, external, pipe, ada, null. This option can normally be
ignored, as the --aircraft option will set the FDM correctly.
--aero=aircraft
Specifies the aircraft aeronautical model to load. This option can normally
be ignored, as the --aircraft option will set the aircraft model correctly.
--model-hz=n
Run the Flight Dynamics Model with this rate (iterations per second).
Run the Flight Dynamics Model this much faster than real time.
--trim, --notrim
Trim (or not) when initializing JSBSim. Defaults to trim.
--on-ground, --in-air
Start up at ground level (default), or in the air. If specifying --in-air you
must also set an initial altitude using --altitude, and may also want to
set an initial velocity with --vc. Note that some aircraft (notably the X15)
must be started in mid-air.
--enable-fuel-freeze, --disable-fuel-freeze
Control whether fuel state is constant (e.g. frozen) or consumed normally
(default).
--airport=ABCD
--airport=KJFK for JFK airport in New York. For US airport without
an ICAO code, try prefixing the 3 character code with ‘K’.
--parking-id=ABCD
Start at a specific parking spot on the airport.
--runway=NNN
Start at the threshold of a specific runway (e.g. 28L). If no runway or parking
ID is specified, a runway facing into the wind will be chosen for takeoff.
--vor=ABCD, --ndb=ABCD, --fix=ABCD
Set the starting position relative to a VOR, NDB or FIX. Useful for practising
approaches.
--carrier=NAME
Start on an aircraft carrier. See
for details of carrier operations.
--parkpos=NAME
particular
--carrier. Defaults to a catapult launch position.
--offset-distance=nm, --offset-azimuth=deg
particular
--airport, --vor, --ndb, --fix, --carrier.
--lon=degrees, --lat=degrees
Start at a particular longitude and latitude, in decimal degrees (south, west
negative).
--altitude=feet
Start at specific altitude. Implies --in-air. Altitude is specified in feet
--units-meters,
stalling immediately.
--heading=degrees, --roll=degrees, --pitch=degrees
Set the initial orientation of the aircraft. All values default to 0 - heading
North, in straight and level flight.
--uBody=X, --vBody=Y, --wBody=Z
Set the initial speed along the X, Y and Z axes. Speed is in feet per second
--units-meters,
meters per second.
--vNorth=N, --vEast=E, --vDown=D
South-North,
Speed is in feet per second unless you also select --units-meters, in
which case altitude is in meters per second.
--vc=knots, --mach=num
--altitude, unless you want to stall immediately!
--glideslope=degrees, --roc=fpm
minute. May be positive or negative.
--ceiling=FT ASL[:THICKNESS FT]
Sets an overcase ceiling at a particular height, and with an optional thickness
(defaults to 2000ft).
--enable-real-weather-fetch,
--disable-real-weather-fetch
Control whether real-time weather information is downloaded and used.
--metar=METAR STRING
--metar=~XXXX
000KT 99SM CLR 19/M01 A2992~. The METAR may
be specified in most common formats (US, European). Incompatible with
--enable-real-weather-fetch.
--random-wind
Sets random wind direction and strength.
--turbulence=n
Sets turbulence from completely calm (0.0) to severe (1.0).
--wind=DIR@SPEED
--wind=180:220@10:15.
--season=param
Sets the simulated season. Valid parameters are summer (default), winter.
--visibility=meters, --visibility-miles=miles
--aspect-ratio-multiplier=N
Set a multiplier for the display aspect ratio.
--bpp=depth
Specify the bits per pixel.
--enable-clouds, --disable-clouds
Enable (default) or disable cloud layers.
--enable-clouds3d, --disable-clouds3d
Enable (default), disable 3D clouds. Very pretty, but depend on your graphics
card supporting GLSL Shaders, which some older, or less powerful graphics
cards do not.
--enable-distance-attenuation,
--disable-distance-attenuation
Enable or disable more realistic runway and approach light attenuation.
--enable-enhanced-lighting,
--disable-enhanced-lighting
Enable or disable more realistic runway and approach lights.
--enable-fullscreen, --disable-fullscreen
Enable, disable (default) full screen mode.
--enable-game-mode, --disable-game-mode
Enable or disable full screen display for 3DFX graphics cards.
--enable-horizon-effect, --disable-horizon-effect
Enable (default), disable celestial body growth illusion near the horizon.
--enable-mouse-pointer, --disable-mouse-pointer
Enable, disable (default) extra mouse pointer. Useful in full screen mode for
old Voodoo based cards.
--enable-panel, --disable-panel
Enable (default) the instrument panel.
--enable-skyblend, --disable-skyblend
Enable (default), disable fogging/haze.
--enable-specular-highlight,
--disable-specular-highlight
Enable (default), disable specular highlights.
--enable-splash-screen, --disable-splash-screen
accelerator
board gets initialized (3DFX only).
--enable-textures, --disable-textures
Enable (default), disable use of textures.
--enable-wireframe, --disable-wireframe
Enable, disable (default) display of wireframes. If you want to know what
the world of FlightGear looks like internally, try this!
--fog-disable, --fog-fastest, --fog-nicest
Set the fog level. To cut down the rendering efforts, distant regions vanish in
fog by default. If you disable fog you’ll see farther, but your frame rates will
drop. Using --fog-fastest will display a less realistic fog, by increase
frame rate. Default is --fog-nicest.
--fov=degrees
Sets the field of view in degrees. Default is 55.0.
--geometry=WWWxHHH
Defines the window/screen resolution. E.g. --geometry=..
--shading-smooth, --shading-flat
Use smooth shading (default), or flat shading which is faster but less pretty.
--texture-filtering=N
Configure anisotropic texture filtering. Values are 1 (default), 2, 4, 8 or 16.
--view-offset=xxx
Allows setting the default forward view direction as an offset from straight
ahead. Possible values are LEFT, RIGHT, CENTER, or a specific number
of degrees. Useful for multi-window display.
--enable-anti-alias-hud, --disable-anti-alias-hud
Control whether the HUD (Head Up Display) is shown anti-aliased.
--enable-hud, --disable-hud
Control whether the HUD is displayed. Defaults to disabled.
--enable-hud-3d, --disable-hud-3d
Control whether the 3D HUD is displayed.
--hud-culled, --hud-tris
percentage
rendered in the HUD. Mainly of interest to graphics developers.
--adf=[radial:]frequency
Set the ADF frequency and radial.
--com1=frequency, --com2=frequency
Set the COM1/COM2 radio frequency.
--dme=nav1|nav2|frequency
Set the DME to NAV1, NAV2, or a specific frequency and radial.
--failure=system
Fail a specific aircraft system. Valid systems are pitot, static, vacuum,
electrical. Specify multiple times to fail multiple systems.
--nav1=[radial:]frequency, --nav2=[radial:]frequency
Set the NAV1/NAV2 radio frequency and radial.
--enable-clock-freeze, --disable-clock-freeze
Control whether time advances normally or is frozen.
--start-date-gmt=yyyy:mm:dd:hh:mm:ss,
--start-date-lat=yyyy:mm:dd:hh:mm:ss,
--start-date-sys=yyyy:mm:dd:hh:mm:ss
Specify the exact startup time/date. The three functions differ in that they
take either Greenwich Mean Time, the local time of your virtual flight, or
your computer system’s local time as the reference point.
Incompatible with --time-match-local, --time-match-real.
--time-match-local, --time-match-real
--time-match-real, is default: Simulator time is read from the system clock,
and is used as is. When your virtual flight is in the same timezone as where
desirable,
synchronized. However, when you fly in a different part of the world, it may
not be the case, because there is a number of hours difference, between the
position of your computer and the position of your virtual flight.
The option --time-match-local takes care of this by computing the timezone
difference between your real world time zone and the position of your virtual
flight, and local clocks are synchronized.
Incompatible
--start-date-gmt,
--start-date-lat,
--start-date-sys.
--time-offset=[+-]hh:mm:ss
Specify a time offset relative to one of the time options above.
--timeofday=param
Set the time of day. Valid parameters are real, dawn, morning, noon,
afternoon, dusk, evening, midnight.
--multiplay=dir,Hz,host,port, --callsign=ABCD
Set multiplay options and aircraft call-sign. See Section .
--httpd=port, --telnet=port
Enable http server or telnet server on the specified port to provide access to
the property tree.
--jpg-httpd=port
Enable screen shot http server on the specified port.
--proxy=[user:password@]host:port
Specify a proxy server to use.
--wp=ID[@alt]
Allows specifying a waypoint for the GC it is possible to specify
multiple waypoints (i.e. a route) via multiple instances of this command.
--flight-plan=[file]
This is more comfortable if you have several waypoints. You can specify a
file to read them from.
NB: These options are rather geared to the advanced user who knows what he is
More detailed descriptions of the various IO parameters can be found in the
README.IO file within the Docs directory of your FlightGear installation.
--atlas=params
Open connection using the Atlas protocol (used by Atlas and TerraSync).
--atcsim=params
Open connection using the ATC Sim protocol (atc610x).
--AV400=params
Open connection to drive a Garmin 196/296 series GPS
--AV400Sim=params
Open connection to drive a Garmin 400 series GPS
--generic=params
Open connection using the Generic (XML-defined) protocol.
--garmin=params
Open connection using the Garmin GPS protocol.
--joyclient=params
Open connection to an Agwagon joystick.
--jsclient=params
Open connection to a remote joystick.
--native-ctrls=params
Open connection using the FG native Controls protocol.
--native-fdm=params
Open connection using the FG Native FDM protocol.
--native-gui=params
Open connection using the FG Native GUI protocol.
--native=params
Open connection using the FG Native protocol.
--nmea=params
Open connection using the NMEA protocol.
--opengc=params
Open connection using the OpenGC protocol.
--props=params
Open connection using the interactive property manager.
--pve=params
Open connection using the PVE protocol.
--ray=params
Open connection using the RayWoodworth motion chair protocol.
--rul=params
Open connection using the RUL protocol.
--enable-fpe
Enable abort on a Floating Point Exception.
--fgviewer
simulator,
lightweight
Useful for checking aircraft models.
--log-level=LEVEL
Set the logging level. Valid values are bulk, debug, info, warn, alert.
--prop:[type:]name=value
Set property name to value
--prop:/engines/engine[0]/running=true starts
the simulator with running engines.
Another example:
--aircraft=c172p--prop:/consumables/fuels/tank[0]/level-gal=10--prop:/consumables/fuels/tank[1]/level-gal=10
fills the Cessna for a short flight. You may optionally specific the property
type (double, string, boolean).
--trace-read=params
multiple instances are allowed.
--trace-write=params
Trace the w multiple instances are allowed.
Could you imagine a pilot in his or her Cessna controlling the machine with a keyboard
alone? For getting the proper feeling of flight you will need a joystick/yoke plus rudder
pedals, right? However, the combination of numerous types of joysticks, flightsticks,
yokes, pedals etc. on the market with the several target operating systems, makes joystick
support a non-trivial task in FlightGear.
FlightGear has integrated joystick support, which automatically detects any joystick,
yoke, or pedals attached. Just try it! If this does work for you, lean back and be happy!
You can see what FlightGear has detected your joystick as by selecting Help -> Joystick
Information from the menu.
Unfortunately, given the several combinations of operating systems supported by
FlightGear (possibly in foreign languages) and joysticks available, chances are your
joystick does not work out of the box. Basically, there are two alternative approaches to
get it going, with the first one being preferred.
In order for joystick auto-detection to work, a joystick bindings xml file must exist for
each joystick. This file describes what axes and buttons are to be used to control which
functions in FlightGear. The associations between functions and axes or buttons are
called “bindings”. This bindings file can have any name as long as a corresponding entry
exists in the joysticks description file
/FlightGear/joysticks.xml
which tells FlightGear where to look for all the bindings files. We will look at examples
FlightGear includes several such bindings files for several joystick manufacturers in
folders named for each manufacturer. For example, if you have a CH Products joystick,
look in the folder
/FlightGear/Input/Joysticks/CH
for a file that might work for your joystick. If such a file exists and your joystick is
working with other applications, then it should work with FlightGear the first time you
run it. If such a file does not exist, then we will discuss in a later section how to create
such a file by cutting and pasting bindings from the examples that are included with
FlightGear.
Does your computer see your joystick? One way to answer this question under
Linux is to reboot your system and immediately enter on the command line
dmesg | grep Joystick
which pipes the boot message to grep which then prints every line in the boot message
that contains the string “Joystick”. When you do this with a Saitek joystick attached, you
will see a line similar to this one:
input0: USB HID v1.00 Joystick [SAITEK CYBORG 3D USB] on
This line tells us that a joystick has identified itself as SAITEK CYBORG 3D USB to the
operating system. It does not tell us that the joystick driver sees your joystick. If you are
working under Windows, the method above does not work, but you can still go on with
the next paragraph.
FlightGear ships with a utility called js demo. It will report the number of joysticks
attached to a system, their respective “names”, and their capabilities. Under
Linux, you can run js demo from the folder /FlightGear/bin as follows:
$ cd /usr/local/FlightGear/bin$ ./js demo
Under Windows, open a command shell (StartAll ProgramsAccessories), go to the
FlightGear binary folder and start the program as follows (given FlightGear is installed
under c:\Flightgear)
cd \FlightGear\binjs demo.exe
Under Mac OS X, open Terminal.app (/Applications/Utilities/) and run
js demo as follows:
$ cd /Applications/FlightGear.app/Contents/Resources$ ./js demo
On our system, the first few lines of output are (stop the program with Ctrl-C if it is
quickly scrolling past your window!) as follows:
Joystick test program.Joystick 0: “CH PRODUCTS CH FLIGHT SIM YOKE USB ”Joystick 1: “CH PRODUCTS CH PRO PEDALS USB”Joystick 2 not detectedJoystick 3 not detectedJoystick 4 not detectedJoystick 5 not detectedJoystick 6 not detectedJoystick 7 not detected+——————–JS.0———————-+——————–JS.1———————-+| Btns Ax:0 Ax:1 Ax:2 Ax:3 Ax:4 Ax:5 Ax:6 | Btns Ax:0 Ax:1 Ax:2 |+———————————————-+———————————————-+|
+0.0 +1.0 -1.0 -1.0 +0.0 +0.0 . |
-1.0 -1.0 . . . . . |
First note that js demo reports which number is assigned to each joystick recognized by
the driver. Also, note that the “name” each joystick reports is also included between
quotes. We will need the names for each bindings file when we begin writing the binding
xml files for each joystick.
Axis and button numbers can be identified using js demo as follows. By observing the
output of js demo while working your joystick axes and buttons you can determine what
axis and button numbers are assigned to each joystick axis and button. It should be noted
that numbering generally starts with zero.
The buttons are handled internally as a binary number in which bit 0 (the least
significant bit) represents button 0, bit 1 represents button 1, etc., but this number is
displayed on the screen in hexadecimal notation, so:
0001 ⇒ button 0 pressed0002 ⇒ button 1 pressed0004 ⇒ button 2 pressed0008 ⇒ button 3 pressed0010 ⇒ button 4 pressed0020 ⇒ button 5 pressed0040 ⇒ button 6 pressed... etc. up to ...8000 ⇒ button 15 pressed... and ...0014 ⇒ buttons 2 and 4 pressed simultaneously... etc.
For Linux users, there is another option for identifying the “name” and the numbers
assigned to each axis and button. Most Linux distributions include a very handy program,
“jstest”. With a CH Product Yoke plugged into the system, the following output lines are
displayed by jstest:
jstest /dev/js3Joystick (CH PRODUCTS CH FLIGHT SIM YOKE USB ) has 7 axes and 12 buttons. Driver version is 2.1.0Testing…(interrupt to exit)Axes: 0:
0 Buttons: 0:off 1:off 2:off 3:on 4:off 5:off 6:off 7:off 8:off
9:off 10:off 11:off
Note the “name” between parentheses. This is the name the system associates with your
When you move any control, the numbers change after the axis number
corresponding to that moving control and when you depress any button, the “off” after
the button number corresponding to the button pressed changes to “on”. In this way, you
can quickly write down the axes numbers and button numbers for each function without
messing with binary.
At this point, you have confirmed that the operating system and the joystick driver both
recognize your joystick(s). You also know of several ways to identify the joystick
“name” your joystick reports to the driver and operating system. You will need a written
list of what control functions you wish to have assigned to which axis and button and the
corresponding numbers.
Make the following table from what you learned from js demo or jstest above (pencil
and paper is fine). Here we assume there are 5 axes including 2 axes associated with the
elevator = 0
view cycle = 0
rudder = 1
all brakes = 1
aileron = 2
up trim = 2
throttle = 3
down trim = 3
leftright hat = 4 extend flaps = 4
foreaft hat = 5
retract flaps = 5
decrease RPM = 6
increase RPM = 7
We will assume that our hypothetical joystick supplies the “name” QUICK STICK
3D USB to the system and driver. With all the examples included with FlightGear,
the easiest way to get a so far unsupported joystick to be auto detected, is to
edit an existing binding xml file. Look at the xml files in the sub-folders of
/FlightGear/Input/Joysticks/. After evaluating several of the xml binding
files supplied with FlightGear, we decide to edit the file
/FlightGear/Input/Joysticks/Saitek/Cyborg-Gold-3d-USB.xml.
This file has all the axes functions above assigned to axes and all the button functions
above assigned to buttons. This makes our editing almost trivial.
Before we begin to edit, we need to choose a name for our bindings xml file, create
the folder for the QS joysticks, and copy the original xml file into this directory with this
$ cd /usr/local/FlightGear/Input/Joysticks$ mkdir QS$ cd QS$ cp /usr/local/FlightGear/Input/Joysticks/Saitek/Cyborg-Gold-3d-USB.xml QuickStick.xml
Here, we obviously have supposed a Linux/UNIX system with FlightGear being
installed under /usr/local/FlightGear. For a similar procedure under Windows
with FlightGear being installed under c:FlightGear, open a command shell and type
c:cd /FlightGear/Input/Joysticksmkdir QScd QScopy /FlightGear/Input/Joysticks/Saitek/Cyborg-Gold-3d-USB.xml QuickStick.xml
Next, open QuickStick.xml with your favorite editor. Before we forget to change the
joystick name, search for the line containing <name>. You should find the line
<name>SAITEK CYBORG 3D USB</name>
and change it to
<name>QUICK STICK 3D USB</name>.
This line illustrates a key feature of xml statements. They begin with a <tag> and end
with a </tag>.
You can now compare your table to the comment table at the top of your file copy.
Note that the comments tell us that the Saitek elevator was assigned to axis 1. Search for
the string
<axis n=~1~>
and change this to
<axis n=~0~>.
Next, note that the Saitek rudder was assigned to axis 2. Search for the string
<axis n=~2~>
and change this to
<axis n=~1~>.
Continue comparing your table with the comment table for the Saitek and changing the
axis numbers and button numbers accordingly. Since QUICKSTICK USB and the Saitek
have the same number of axes but different number of buttons, you must delete the
buttons left over. Just remember to double-check that you have a closing tag for each
opening tag or you will get an error using the file.
Finally, be good to yourself (and others when you submit your new binding file to a
FlightGear developers or users archive!) by taking the time to change the comment table
in the edited file to match your changed axis and button assignments. The new
comments should match the table you made from the js demo output. Save your
Several users have reported that the numbers of axes and buttons assigned to
functions may be different with the same joystick under Windows and Linux. The above
procedure should allow one to easily change a binding xml file created for a different
operating system for use by their operating system.
Before FlightGear can use your new xml file, you need to edit the file
/FlightGear/joysticks.xml,
adding a line that will include your new file if the “name” you entered between the name
tags matches the name supplied to the driver by your joystick. Add the following line to
joysticks.xml.
<js-named include=~Input/Joysticks/QS/QuickStick.xml~/>
You can tell how FlightGear has interpreted your joystick setup by selecting Help ->
Joystick Information from the Menu.
Basically, the procedures described above should work for Windows as well. If
your joystick/yoke/pedals work out of the box or if you get it to work using the
methods above, fine. Unfortunately, however, it’s likely you may encounter a few
The first one concerns users of non-US Windows versions. As stated above,
you can get the name of the joystick from the program js demo. If you have a
non-US version of Windows and the joystick .xml files named above do not
contain that special name, just add it on top of the appropriate file in the style of
<name>Microsoft-PC-Joysticktreiber </name>
No new entry in the base joysticks.xml file is required.
Unfortunately, there is one more loophole with Windows joystick support. In the case
that you have two USB devices attached (for instance, a yoke plus pedals), it’s
possible that the same driver name will be reported twice. In this case, you can at
least get the yoke working by assigning it number 0 (out of 0 and 1). For this
purpose, rotate the yoke (aileron control) and observe the output of js demo. If
figures in the first group of colons (for device 0) change, assignment is correct. If
figures in the second group of colons (for device 1) change, you have to make
the yoke the preferred device first. For doing so, enter the Windows “Control
panel”, open “Game controllers” and select the “Advanced” button. Here you
can select the yoke as the “Preferred” device. Afterward you can check that
assignment by running js demo again. The yoke should now control the first group of
Unfortunately, we did not find a way to get the pedals to work, too, that way. Thus, in
cases like this one (and others) you may want to try an alternative method of assigning
joystick controls.
Thanks to Mac OS X, most of HID compatible joysticks are recognized and usable on
Mac OS X. Some of joysticks are already defined properly in FlightGear. However,
sometimes your joystick does not work as you expect due to some reasons such as
missing joystick ID, and misconfigured buttons or axis. In such cases, you need to
modify a joystick configuration file.
The basic procedures in configuring joysticks under Mac OS X are the same as those
of Linux as described above. The main differences are the path to the joystick
configuration files and the means of finding a joystick name. The joystick configuration
files are at Contents/Resources/data/Input/Joysticks under the
FlightGear.app folder. You can open the data folder by choosing “Advanced Features >>
Others >> Open data folder” on the GUI launcher. You can also open it by right-clicking
the FlightGear icon at Applications folder and choose “Show Package Contents” to
access the folders inside the application. To find a joystick name, follow the steps
Open System Profiler by choosing Apple Menu | About this Mac | More Info...
Select USB from the Hardware list in the left pane.
Find the name of your joystick (e.g. Logitech Extreme 3D) from the USB
Device Tree.
Add a name tag with the recognized joystick name to a proper configuration
XML file (e.g. <name>Logitech Extreme 3D</name>)
Check if your device name is shown properly by choosing Help | Joystick
information from the menu on the FlightGear simulator window.
In case your joystick doesn’t work as expected even it is recognized properly, you
need to modify the button and/or axis settings. Some Mac users reported that twisting a
joystick controls the throttle instead of the rudder. This is a typical joystick
misconfiguration on Mac OS X. To fix this issue, you need to edit two axis tags in a
joystick configuration file.
In many cases, the rudder is assigned to axis 2 and the throttle to axis 3 in driver
level. Editing or adding a mac tag inside an axis tag for the rudder (and throttle) will fix
this problem. The example below is a part of a joystick configuration file that assigns axis
3 for rudder control.
<axis>
  <desc>Rudder</desc>
  <number>
    <linux>2</linux>
    <mac>3</mac> <!-- This must be 2 -->
    <windows>3</windows>
   </number>
   .....
Fortunately, there is now a utility available which makes things easier for the average,
non-XML savvy user.
To configure your joystick using this approach do the following:
Start -> All programs ->
Accessories
/FlightGear/bin
c:\FlightGear\bin).
Run the fgjs tool.
The program will tell you which joysticks, if any, were detected. Now follow the
commands given on screen, i.e. move the axis and press the buttons as required. Be
careful, a minor touch already “counts” as a movement. Check the reports on screen. If
you feel something went wrong, just re-start the program.
After you are done with all the axes and switches, the directory above will hold a file
called fgfsrc.js. The contents on this file can be copied into your personal
preferences file (.fgfsrc/system.fgfsrc). See
for details of how to create this
Note that output of fgjs is UNIX formatted. As a result, Windows Editor may not
display it properly. It may be helpful to use an editor capable of handling UNIX files as
well. My favorite freeware file editor for that purpose, although somewhat dated, is PFE,
which can be obtained from .
The axis/button assignment of fgjs should at least get the axis assignments
right, but the output may need some tweaking. For example, some axes may be
moving the opposite way they should, or the dead zones may be too small.
For instance, the elevator axes on my USB CH Yoke was reversed so I had to
--prop:/input/joysticks/js[1]/axis[1]/binding/factor=-1.0
--prop:/input/joysticks/js[1]/axis[1]/binding/factor=1.0
To help with tuning, here is a short introduction into the assignments of joystick
properties. Basically, all axes settings are specified via lines having the following
structure:
--prop:/input/joysticks/js[n]/axis[m]/binding/command=property-scale--prop:/input/joysticks/js[n]/axis[m]/binding/property=/controls/steering option--prop:/input/joysticks/js[n]/axis[m]/binding/dead-band=db--prop:/input/joysticks/js[n]/axis[m]/binding/offset=os--prop:/input/joysticks/js[n]/axis[m]/binding/factor=fa
n=number of device (usually starting with 0)
m=number of axis (usually starting with 0)
steering option=elevator, aileron, rudder, throttle, mixture, pitch
dead-band=range within which signals are discarded.
Useful to avoid jittering for minor yoke movements
offset=Applies an offset after any factor.
Useful to handle devices where the neutral position does not map to 0.
factor=controls sens defaults to +1,
with a value of -1 reversing the behavior
You should be able to at least get your joystick working along these lines.
Concerning all the finer points, such as getting the joystick buttons working, John
Check has written a very useful README included in the base package under
$FG_ROOT/Docs/README.Joystick.html. In case of any trouble with your
input device, it is highly recommended to read this document.
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