    ************************************************
    *                                              *
    *  FGFS Reconfigurable Aircraft Flight Model   *
    *  Sample Input Files                          *
    *  Version 0.73, June 27, 2000                 *
    *                                              *
    *  Authors:                                    *
    *  Jeff Scott (jscott@mail.com)                *
    *  Bipin Sehgal (bsehgal@uiuc.edu)             *
    *  Michael Selig (m-selig@uiuc.edu)            *
    *  Dept of Aero and Astro Engineering          *
    *  University of Illinois at Urbana-Champaign  *
    *  Urbana, IL                                  *
    *  http://amber.aae.uiuc.edu/~m-selig          *
    *                                              *
    ************************************************

    The simulator executable, fgfs.exe, uses the aircraft.dat files
    located in Aircraft-uiuc to fly the desired aircraft.  This file
    should either be in the same directory as fgfs.exe or should be called
    from the command line.  To do the latter, open a DOS or Cygwin shell
    and go to the directory containing fgfs.exe.  Type the following:

    > fgfs.exe --aircraft-dir=Aircraft-uiuc/Cessna172

    The same procedure can be accomplished using a batch file.  A sample
    batch file (runfgfs.bat) is provided in the top level directory.  To
    run the desired aircraft, simply delete the "rem" command from the
    beginning of the line.  Make sure that all the other model lines still
    begin with "rem" or you may not actually be flying the plane you
    want.  Double click the file runfgfs.bat to begin the simulation.

    There is also a record feature that generates a file called
    uiuc_record.dat.  The desired variables can be recorded in this file
    using the proper record lines.  The syntax of these lines and the
    aircraft.dat files in general is provided in the documentation file
    README-uiucDoc.txt.

    The runfgfs.bat file also provides samples of other command line
    options, including time of day, cloud and fog options, and the airport
    from which the flight begins.  The airport commands are provided in
    README-airports.html.  An overview
    of all the options available for the command line is provided in
    README-options.html.

    Note that the proper scenery for that segment of the world must be
    provided for the scenery at that airport to be rendered.  If the
    desired airport is not available (i.e. you see a bluish terrain when
    the program begins), you will need to download the additional terrain
    at
    http://www.flightgear.org/Downloads/world-scenery.html.
    Simply click on the grid containing the desired airport, save to your
    computer and unzip the file to the Scenery directory.  Note that the
    scenery files are very large and occupy a large amount of disk space!

    Notes:
    ------

    - All aircraft use the C172 gear model, and this gets overloaded for
      some of the heavier aircraft.  Adding throttle will eventually lead
      to enough airspeed to fly.  Once airborne, some corrective control
      inputs may be necessary.

    - For each aircraft, the thrust was set to give more or less
      "reasonable" performance characteristics.  Users are encouraged to
      vary the thrust (see line
         > engine simpleSingle [simpleSingleMaxThrust]
      and change the value) to improve performance.

    - Most aircraft are modeled using cruise condition data only.  Takeoff
      and landing configurations and associated changes in aerodynamic
      characteristics are not currently modeled.

    - Some files use "record" lines to produce flight-data recorder
      output.  These data are written to the file uiuc_record.dat.  Be
      aware that when flying for an extended period of time this file (if
      written by using record lines) can become very large.

    To fly, use one of the aircraft.dat files.
    The aircraft data used in each of these models is provided in the
    Simulation Specifications.
    Note that these models may be updated, revised, or extended.  For the
    most recent versions, be sure to visit the on-line
    version.

    Beech99:
      Beech 99, small commercial commuter aircraft
      very smooth characteristics

    Boeing747:
      Boeing 747, large commercial jetliner
      too heavy for gear so noses down into ground at 70 degree angle, but
      this can be fixed by going to max throttle till plane rotates and
      becomes airborne; sluggish, but flies well

    Cessna172:
      Cessna 172, small general aviation aircraft
      based on Tony Peden's model, but uses stability derivatives only
      flies very well

    Cessna172-TD:
      Cessna 172, small general aviation aircraft
      uses lift curve data from Peden model to model stall
      also flies well

    Cessna310:
      Cessna 310, twin engine general aviation aircraft
      elevator seems too effective and slight instability in roll

    Cessna620:
      Cessna 620, four engine business aircraft
      very sluggish

    Convair880:
      Convair 880, medium commercial jetliner
      too heavy for gear so noses down into ground, but this can be fixed
      by going to max throttle till plane rotates and becomes airborne;
      play with the controls to obtain the proper orientation; sluggish,
      but flies pretty well
      *This model works best already in flight.  The example in
      runfgfs.bat begins at 35,000 ft.  To fly, increase the throttle and
      use small elevator and aileron deflections to level the aircraft.

    F104:
      Lockheed F-104, small supersonic fighter
      flies pretty smoothly but it's called "the Widow maker" for a reason

    F4:
      McDonnell F-4 Phantom, fighter/attack plane
      very difficult to fly and sometimes will have problems taking off
      from the ground
      *This model is somewhat buggy and behaves differently on different
      computers.  If it becomes uncontrollable during takeoff, try using
      the --altitude command (also with --uBody set to a high number) to
      start already in flight.  Increase the throttle and use small
      elevator and aileron deflections to level the aircraft.

    Learjet24:
      Learjet 24, business jet
      flies very well

    Marchetti:
      SIAI-Marchetti S-211 military jet trainer
      flies very smoothly, probably the easiest aircraft to fly

    Pioneer:
      IAI Pioneer UAV, small reconnaissance unmanned aerial vehicle
      version uses stability derivatives only
      slight roll instability, but very responsive

    Pioneer-TD:
      IAI Pioneer UAV, small reconnaissance unmanned aerial vehicle
      version uses lookup tables for lift and drag and most control
      surface deflections
      slight roll instability, but very responsive

    T37:
      Cessna T-37 twin jet engine military trainer
      flies very well

    TwinOtter:
      DeHavilland Canada DHC-6 Twin otter, small commuter aircraft
      NASA Glenn Twin Otter for icing research
      clean version (no ice), flies well

    TwinOtterAllIce:
      DeHavilland Canada DHC-6 Twin otter, small commuter aircraft
      NASA Glenn Twin Otter for icing research
      note the degradation in performance after ice accretion begins
      (icing begins 2 minutes into flight; transition from clean to iced
      aerodynamics lasts 5 seconds--this is not very realistic, but you
      can vary these times and the icing severity factor, eta [0=no ice,
      1=max ice], to see the impact on performance)

    TwinOtterTailIce:
      DeHavilland Canada DHC-6 Twin otter, small commuter aircraft
      NASA Glenn Twin Otter for icing research, tail icing only

    TwinOtterWingIce:
      DeHavilland Canada DHC-6 Twin otter, small commuter aircraft
      NASA Glenn Twin Otter for icing research, wing icing only

    X15:
      North American X-15, rocket-powered high-speed research aircraft
      go easy on the throttle since this is a very over-powered aircraft,
      very slow elevator but extremely responsive ailerons
      *This model is somewhat buggy and behaves differently on different
      computers.  If it becomes uncontrollable during takeoff, try using
      the --altitude command (also with --uBody set to a high number) to
      start already in flight.  Increase the throttle and use small
      elevator and aileron deflections to level the aircraft.