DC-10-Air-Tanker: Development for FlightGear Flightsimulator

Repository

https://github.com/HerbyW/DC-10-Air-Tanker

Introduction

FlightGear (http://www.flightgear.org) is an open source flight simulator that is even used in flight schools to train basic maneuvers, radio communication and navigation tasks. It is available for windows, mac and linux.

In this article I want to introduce my new development of the McDonnell Douglas DC-10-30 Air Tanker, this version is used for fire fighting with water or retardant.

Development steps

• Downloading the existing model DC-10-30 which was developed until 2015 by Ryan Miller.
  Resource: http://wiki.flightgear.org/McDonnell_Douglas_DC-10-30
  After downloading and installing I made some test flights to get to know the aircraft and its flight capabilities. Then I did some deep research about the aircraft in various internet sources and on youtube to get a realistic viewpoint of the working aicraft.
• Due to big changes in the internal properties and the model files for the new variant it could not be added as a new variant into the existing model, a new model with new model name has to be made. This makes it a new airplane in the simulator, all credits to the original author are included in the license files. All files had to be checked for the new folder names and changed accordingly.
• Modeling the external tank with blender and writing the xml-file for controlling the water-doors. source
  As an example the code for opening the left water door:

<animation>
    <type>rotate</type>
    <object-name>door-l</object-name>
    <property>sim/multiplay/generic/float[19]</property>
    <factor> 45 </factor>
    <axis>
      <x1-m> 1.9763 </x1-m>
      <y1-m> -0.1744 </y1-m>
      <z1-m> 0.49731 </z1-m>
      <x2-m>-7.62005 </x2-m>
      <y2-m> -0.1744 </y2-m>
      <z2-m> 0.49731 </z2-m>
    </axis>
</animation>

The property was defined in the multiplayer. xml in this way: source

<reference> (html comment removed:  Water doors )
        <type>float</type>
        <index type="int">19</index>
        <property>sim/model/door-positions/waterdoors/position-norm</property>
    </reference>

• Working in some blender files to enhance the quality of colors in the cockpit. A typical line for material definition looks like this:

MATERIAL "DefaultWhite" rgb 1.0000 1.0000 1.0000  amb 1.0000 1.0000 1.0000  emis 0.0000 0.0000 0.0000  spec 1.0000 1.0000 1.0000  shi 10 trans 0.0000

To get the right light and color in different simulator settings it is important to set the "amb" colors to the same as "rgb".

• Changing the FDM (flight-dynamic-model) to the new weight of the model and the fuel tanks. In this variant both of the center tanks are empty and not used. Fuselage elements are used from the yasim FDM to get the right drag in flight. Reserch results for the mass gave me the right values of 12,000 US gallons of retardant, it is equal to 45,425 liters and due to the material of retarant it sums up to 110,000 lbs. source

<airplane mass="210191">
(html comment removed:  water tank )
    <fuselage ax="12.90" ay="0.0" az="1.42" bx="10.90" by="0.0" bz="1.42" width="1.96" taper="0.5" midpoint="1" />
    <fuselage ax="10.90" ay="0.0" az="1.42" bx="-4.12" by="0.0" bz="1.42" width="1.96" taper="1.0" midpoint="0.5" />
    <fuselage ax="-4.12" ay="0.0" az="1.42" bx="-6.12" by="0.0" bz="1.42" width="1.96" taper="0.5" midpoint="0" />
(html comment removed:  Center tanks (main, auxilary) )
    <tank x="15.0" y="0.0" z="3.5" jet="true" capacity="0" />
    <tank x="0.0" y="0.0" z="3.5" jet="true" capacity="0" />
(html comment removed:  Water Tanks )
    <weight x="-2.8219" y="0.0" z="1.286" mass-prop="/sim/weight[2]/weight-lb" size="0.0" solve-weight="0.0" idx="0" weight="110000.0" />

• Adding shortcuts for waterdoors, viewpoints and Autostart.

<key n="115">
            <name>s</name>
            <desc>Autostart</desc>
            <binding>
                <command>property-toggle</command>
                <property>sim/model/start-idling</property>
            </binding>
        </key>
        
        <key n="60">
            <name> > </name>
            <desc>Change Pilot Model View</desc>
            <binding>
                <command>property-cycle</command>
                <property>/sim/current-view/view-number</property>  
                <value>0</value>
                <value>7</value>
            </binding>
        </key>        
        
        <key n="68">
            <name>D</name>
            <desc>Close water-door</desc>
            <binding>
                <command>nasal</command>
                <script>
                    DC10.doors.waterdoors.close();
                </script>
            </binding>
        </key>
        
        <key n="108">
            <name>l</name>
            <desc>water bombing</desc>
            <binding>
                <command>nasal</command>
                <script>
                    DC10.doors.waterdoors.open();
                </script>
            </binding>
        </key>

• Developing the retardant smoke as it appears in videos as realistic as possible.
  
  

• Going through all folders and files to delete not needed stuff.

• Setting the sound to more realistic 3D mode.

• Adding an aircraft help-file to the menu with description of all shortcuts. source

• Fixing the doors menu to full functionally.

Resources

The original model was downloaded from here:
http://wiki.flightgear.org/McDonnell_Douglas_DC-10-30

Roadmap

Next will be the implementation of multiplayer functionality for the fire fighting action and building the instruments for controlling the water dropping.

How to contribute?

Pull request to my github repository or direct contact via Mumble FlightGear Chat.

Proof of work

The screenshot contains my real name, my git username, my steemit username and my callsign in the multiplayer.

Series Backlinks

This is the first post in this development.