#### 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 go through my latest commit (https://github.com/HerbyW/DC-10-Air-Tanker/commit/716d700a3d5e8951efd11bdc3da1b22936c7ec44) to further improve the development of the McDonnell Douglas DC-10-30 Air Tanker, a fire fighting variant.

### New Features
##### Ground filling station
In Blender I made the 3D model for 6 tanks, a tent and the 3 lines to the aircraft as I saw it in different videos. By setting the parking brake and then pushing the button "w" this model is now visible and the filling of retardant or water is starting. (Models/Effects/Refilling/refilling.ac)

![fgfs-screen-037k.png](https://cdn.steemitimages.com/DQmPqYSuBeDWq8BCdRqrsyyAi4UnXp8s98ijokdTbzKAiJe/fgfs-screen-037k.png)

![fgfs-screen-036k.png](https://cdn.steemitimages.com/DQmcaAP9VaGRUUHUCVaAFunSZBZYzsnTRVqwjdazfoerWgC/fgfs-screen-036k.png)

This screenshot gives you an idea how it looks like in multiplayer mode from the perspective of an other model:

![Screenshot_20181207_151255k.png](https://cdn.steemitimages.com/DQmRPsdsMkmLsTDqAgZxCG2ztav9188GpVnjUJpgBYsSJjF/Screenshot_20181207_151255k.png)

#### Realistic fire fighting action
With some adjustments to the retardant model on ground, depending on the settings of coverage level (from 1-8), it is now possible to stop the fire from expanding. In the pictures you see the retardant on ground hindering the fire to expand. Also a wind compass instrument was added to calculate the wind effect on the dropping material.

![fgfs-screen-027k.png](https://cdn.steemitimages.com/DQmfGCRGX911VsRby62s2oJWco1KMwKv4j9h9Jcinq724eq/fgfs-screen-027k.png)

![fgfs-screen-028k.png](https://cdn.steemitimages.com/DQmaQ7DM6WLSVbJ5N9Bcks2LbTz1jwxWg3QvJCb1PNCHi4W/fgfs-screen-028k.png)

##### All functions now in multiplayer
The biggest task was the adjustment of all relevant movements so that they are transmitted over the multiplayer protocol. As an example here is the code change for spinning wheels:

In this file I added the definition of the rollspeed as the generic float number 6:
DC-10-Air-Tanker-set.xml
~~~~
<multiplay>
            <generic>
                <float n="6" alias="/gear/gear[2]/rollspeed-ms" />
            </generic>
</multiplay>
~~~~
Then I had o change the real property to the generic one, here for the first left main wheel:
Models/DC-10-gear.xml
~~~~
- <property>gear/gear[1]/rollspeed-ms</property>
+ <property>sim/multiplay/generic/float[6]</property>
~~~~
In the same way it was done for all wheels, the steering of the front wheel, the control surfaces like rudder, aileron, flaps, the reverser smoke is now also going in the other direction if activated, the compression of all wheels  and all doors.

##### New button for autopilot off
A small but important detail was missing in the cockpit: The button for switching the autopilot off. The model was added with the function programmed here:   Models/Instruments/retardant-controls/AP-out-button.xml
By clicking on the button it sets 5 different properties so that all autopilot functions are off. This switch is normally located on the yoke and is used before landing or in case the manual control is needed.
~~~~
<command>property-assign</command>
               <property>/controls/autoflight/off</property>
               <value>1</value>              
<command>property-assign</command>
               <property>/controls/autoflight/autothrottle-engage[0]</property>
               <value>0</value>              
<command>property-assign</command>
               <property>/controls/autoflight/autothrottle-engage[1]</property>
               <value>0</value>
<command>property-assign</command>
               <property>/controls/autoflight/autopilot[0]/engage-mode</property>
               <value>0</value>
<command>property-assign</command>
               <property>/controls/autoflight/autopilot[1]/engage-mode</property>
               <value>0</value>
~~~~

![fgfs-screen-038k.png](https://cdn.steemitimages.com/DQmNut9jHdzkzYcDUEZirzR3HZKMU4mumw1qcELsSE8UT8j/fgfs-screen-038k.png)
The AP-off button is the red one on the left side.

##### New version number
With the new number comes also a detailed help file for all functions:  Systems/DC-10-help.xml
Additional work was done in some nasal scripts for the logic of the retardant system and the reverser animation. All in all I am very happy to have reached this step now and waiting for pilots to test and fly this new variant in FlightGear.

![fgfs-screen-039k.png](https://cdn.steemitimages.com/DQmdQtS4K2GsDxpZjrfr5FknTifMikXrV8zB7S3UYfSrjyS/fgfs-screen-039k.png)
Reverser in action.

#### Roadmap
Next will be the further improvement of the autopilot, as the new variant has different weights and is therefore much more maneuverable as the standard model of this aircraft.

#### How to contribute?
Pull request to my github repository or direct contact via Mumble FlightGear Chat.
#### GitHub Account
https://github.com/HerbyW
It contains my real name, my git username, my steemit username and my callsign in the multiplayer.