flightgear/docs-mini/README.JSBSim

JSBSim

JSBSim is an ongoing attempt at producing an OO Flight Dynamics Model (FDM)
to replace LaRCsim as the default FDM for FlightGear. It can also be used
standalone.

JSBSim uses config files to represent aircraft and engines. Also, the flight
control system is described in the config file. Normally, for use with
FlightGear, the config files are named this way:
<FG_ROOT>/Aircraft/<aircraft name>/<aircraft name>.cfg . Engines are named
like this: <FG_ROOT>/Engines/<engine name>.dat .

Aircraft and engine config files are present in the FGFS-Base package which
must be downloaded from the FlightGear web site at www.flightgear.org or one
of the mirror sites listed there.

How to run FGFS using JSBSim

All the various FDMs are currently compiled into FGFS. You can specify which
FDM you want at run time. You can also specify which aircraft you want.
Currently, for JSBSim only the X-15 is available, and possibly the C-172.
Here is an example command line used to start up FlightGear using JSBSim as
the FDM:

fgfs --fdm=jsb --aircraft=X15 --units-feet --altitude=60000 --uBody=2000 --wBody=120

[Note: uBody is the forward velocity of the aircraft, wBody is the downward
velocity - from the aircraft point of view. This essentially means that the
aircraft is going forward fast and has an angle of attack of about 4 degrees
or so]

 The above command line sets up the initial velocity and altitude to allow
the X15 to glide down. Note that if you fire up the engine, it will burn for
only about two minutes and then run out of fuel - but you will go very, very
fast!

Check out the JSBSim home page at www.hal-pc.org/~jsb/flightsim.html. Please
report any bugs to jsb@hal-pc.org, or apeden@earthlink.net, or post them to
the fgfs-devel mailing list.

JSBSim is written by Jon S. Berndt and Tony Peden with contributions by
other FlightGear programmers, as well.