Category Archives: Tutorials and demonstrations

Tutorials and practical demonstrations of how things do or do not work.

Getting CumulusX! to work in Prepar3D V4


In a comment on my YouTube channel, I was asked how I was able to make CumulusX! work in P3D V4.  CumulusX.exe is a 32 bit application for FSX and not supported in P3D. Because my answer was somewhat complicated, I thought it would be easier to explain in my blog rather than in a YouTube comment. Also, as a blog post it might be useful to a broader audience.

Note that I have FSX Steam Edition installed on my P3D flight sim PC, so my experience might be different to yours if you do not have FSX installed.  In particular, you may find it difficult get the CumulusX! smart tow feature working without first configuring it in FSX – but more on that later.

BTW: The partner application WinchX! works fine with P3D V4, although I had to manually add the code to load it automatically in my exe.xml file.

I installed CumulusX! manually into P3DV4 and  I am very happy so far with the way that it is working, both standalone and in multiplayer flight sessions.  However, I did not keep any notes on the installation procedure that I used, so I am relying on my memory to describe the steps taken. If you plan to follow my steps on your system, do so at your own risk and make backups of everything that you modify.

Step 1.  I copied the “CumulusX!” sub-folder and its contents from the “Modules” sub-folder in the CumulusX! installation package into my P3D “Modules” sub-folder.  Note that CumulusXDLL.dll library is 32 bit and will not work with P3DV4 but my experience suggests that this dll is not required.  So I do not bother trying to load it with P3D V4. In FSX and 32 bit versions of P3D you would normally load it with an entry in your DLL.xml file. The 32 bit CumulusX!.exe file is a standalone application and works fine with P3D V4. Since there is no installer for P3D, I manually added the required code to my Prepar3D exe.xml file – this is covered in step 3 below.

Step 2. I copied the “SimObjects” sub-folder and its contents from the “SimObjects” sub-folder in the CumulusX! installation package and merged it into my P3D “SimObjects” sub-folder. These new miscellaneous SimObjects are needed to create the CumulusX! thermal clouds.

Step 3. I manually added the following lines to:  C:\Users\jfall\AppData\Roaming\Lockheed Martin\Prepar3D v4\exe.xml after making a backup.  Note that I set the “ManualLoad” option to True so that I am prompted and can choose to load CumulusX!, or not, each time that I start a P3D session. You may choose to set this option to “False” if you want CumulusX! to automatically start with every flight. You can always shut the application down later if you don’t need it.  I only use CumulusX! for glider flights because I don’t like the CumulusX! cloud textures, although I can to some degree conceal them among the standard P3D cumulus cloud textures. Also, for powered GA flights I usually prefer to use Active Sky lift and sink features instead of CumulusX!.  On the other hand, when I want to use Active Sky with CumulusX! for a glider flight, I set the lift and sink values in Active Sky wind settings to zero so that they do not conflict with CumulusX! lift and sink.

Note that you can also manually start CumulusX! after starting the sim by double clicking on the CumulusX!.exe file if you don’t want to modify your exe.xml file.

You will find exe.xml in:

C:\Users\<your login name>\AppData\Roaming\Lockheed Martin\Prepar3D V4

Here are the lines added to my exe.xml file, but you must change the path statement to match your own system:

<Path>P:\Prepar3D v4\Modules\CumulusX!\CumulusX.exe</Path>


Step 4. We must prevent the creation of the default P3DV4  thermals, which will conflict with the CumulusX! thermals. To do this I made a backup copy of the ThermalDescriptions.xml file in C:\ProgramData\Lockheed Martin\Prepar3D v4.  I then replaced the ThermalDescriptions.xml file with the following content:

<?xml version=”1.0″?>
<SimBase.Document Type=”AceXML” version=”1,0″ id=”AirObjectVisuals”>
<Descr>AceXML Document</Descr>

<!– Thermal Types –>
<!– 00 Null thermal – For non-thermal areas –>
<!– 01 Damp Green Areas – Medium-large diameter short slow non-tubulent –>
<!– 02 Isolated Rock – Smallish Sharp fast turbulant high –>
<!– 03 Large Hot Area – desert, dense urban Large rough turbulant fast and high –>
<!– 04 Small Hot Area – dirt fields, small urban – Slightly smaller for rural area –>
<!– 05 Grassy Areas – Wide medium strength medium turbulance and semi-low –>
<!– 06 Cool Forests – Small to large, slow to fast, low to medium –>
<!– 07 Warm Forests – medium to large, medium to fast, medium to high –>
<!– 08 Semi-Arid – Wide and medium to fast and high –>
<!– 09 Big Mountain – Fast rowdy high for mountain air –>
<!– 10 Wetlands and Lakes – Mild Sink Large flat smooth slowly sinking air. –>

<!– 00 Null Thermal  –>
<ThermalDescription id=”{4f5e0000-1e81-11db-9897-001372201444}”>

Note that you cannot simply delete or rename the ThermalDescriptions.xml file because P3D V4 will replace it on startup.

Step 5. The Smart Tow Plane configuration menu in CumulusX! does not seem to work properly with P3D. I think it tries to update the FSX.cfg file instead of Prepar3D.cfg. To get the smart tow feature configured the way I like it with the aircraft model of my choice, I configured it first in FSX first then copied the “[SIM]” configuration lines from FSX.cfg to Prepar3D.cfg.  Naturally, I had to install the same tow plane model in both sims. I am fairly sure that I was able to configure the tow plane speed in P3D itself but if I am wrong then the default speed is working OK.  These are the SIM config  lines that I added to my Prepa3D.cfg file – yours may be different:

TowPlaneTitle=PA36 Pawnee Brave 375 N55128 (Without Dispersal Equipment)

I suppose that if you do not have FSX installed, you could try and  change, or add,  the [SIM]  entry shown above into your Prepar3D.cfg file and change the TowPlaneTitle to your tow plane of choice, and  see if that works. You could then use trial and error to find a suitable TowPlanePitch value – note that it is a negative value.

Do not forget that you can ask for help and advice from Peter Lürkens and other CumulusX! users on the Aerosoft forums, although keep in mind that CumulusX! is not supported in P3D and you will need sign up if you do not already have an Aerosoft forums account. Here is the link to the CumulusX! topic:

Also help and advice is available for CumulusX! and virtual gliding issues in general on the UK Virtual Gliding Association  forum (membership of the association is free, although donations are welcome.) Our members mainly use FSX but many have experience with P3D, X-Plane and Condor.

CumulusX! has an excellent and detailed manual. You can find it online or in the Manual sub-folder in the CumulusX! folder. I recommend that you read it at least five times if you want to get the most out of this outstanding add-on. CumulusX! also comes with some example configuration files (.cmx), so try them out. In particular, if you are just getting started with CumulusX!, try the Beginner.cmx configuration.

Condor2 – Creating a cross-country gliding task with wave lift

After an extensive and time-consuming upgrade of my flight sim system,  I decided that it was time to take the plunge and try some wave lift in Condor2.

I created a small (< 62 nautical miles) triangular task at Lesce Bled, Slovenia.  The first leg of my task crossed some parallel ridges, over which I intended to blow enough wind to hopefully generate some useful wave lift. I had in mind a notion to use either thermal lift or ridge lift to climb high enough to engage with the wave lift.  Then, using the wave lift,  I hoped to climb above final glide to complete the task. However, as I have repeatedly said, every cross-country gliding is an adventure and it remains to be seen if my plan works or not.

I captured my task design and configuration in the following YouTube video.  I plan to make another video of my attempt to fly this task in Condor.  The final production of that second video may take some weeks given the fact that I am currently rebuilding my editing system.  I have not decided yet whether the task flight video will be a full flight video or just edited highlights.

VIDEO (PART 1): Creating a cross-country task with wave lift in Condor2

Following are some key screenshots with comments of the task development.


Flight Plan



I set the surface wind direction and speed to create some ridge lift over the ridge lines at the north-western corner of my task triangle. I assume that this surface level wind setting also governs the wind direction for the upper-level winds, which should hopefully create some useful wave lift in conjunction with subsequent wave lift configuration settings.




I tried to create some typical summer thermal conditions to help me get started on this cross-country task.  I also set the “streeting” effect to moderate because my chosen surface-wind strength is 30 kph, which I believe should be conducive to thermal “streeting”.




Here, I simply adjusted the upper-wind speed setting to generate what looked like reasonable wave lift in the wave-lift display window.  Then I adjusted the airmass moisture to create lenticular clouds for strong to medium lift bands.




I set upper-level cloud coverage to zero to avoid any possibility of confusing these cirrus clouds with the lenticular clouds generated by the wave lift. I wanted to be able to use the lenticular clouds to help me locate potential areas of wave lift.

Cirrus clouds



For this task, I chose to use the add-on LS8neo glider model, which I had recently purchased. This is a 15 metre standard class glider with reasonable performance, which can carry water ballast but is not equipped with flaps.




I chose to use a full load of water ballast to boost performance in the breezy conditions of this task.




The only thing I changed from defaults here was the start height. I increased it to approximately 3000 feet AGL to lessen the time spent scratching about for lift to get to a decent task start height.


Connecting XCSoar to X-Plane 11 from a networked PC


I had a request in a comment on my previous post asking me to describe how I connect XCSoar to X-Plane from a networked PC. The following method is the one that I use, but there is at least one other way to do this using a freeware serial port emulation product called “HW VSP”. I have not tried the freeware option myself.   If you want to use the freeware “HW VSP” for virtual ports emulation then I suggest that you join the UK Virtual Gliding Association (also free) and ask for help on their forum. I believe that some of the UKVGA members use “HW VSP”.

I use the product called Virtual Serial Ports Emulator (VSPE) by You have to purchase a license to use it on 64 bit MS Windows.   I believe it is free on 32 bit MS Windows. Because I am running it on two 64 bit PCs, I bought two licenses but I am not sure if that is necessary or not. I have used it successfully on both a wired LAN and WIFI.  There may be a simpler way to do this, but this works and I have not bothered to try any other methods.

1. Install VSPE on X-Plane 11 PC and configure as follows:

Create a COM1 Connector device using default settings (this is the port that we will send X-Plane GPS output to). If COM1 is already in use on your system, you can use a different COM number.

Create a Splitter device with COM5 as the virtual serial port and COM1 as the Data source serial port. This will connect the X-Plane GPS output via COM1 to the TCP network server created in the next step.

Create a TcpServer device with Local TCP port 5555 and Source serial port is COM5. This virtual device will send the serial data stream received from the Splitter across the network to any TcpClients created with VSPE.

Save the configuration.  To re-load a saved configuration, you may have to stop the emulation first.

Click on the green start icon below the menu bar to start the emulation. Below is a screenshot of how it should look when you have started the emulation. NOTE: The emulation probably needs to be started before X-Plane  (it definitely does for FSX).

VSPE on X-Plane PC

I set this configuration up years ago, so I am not sure, but I believe that I used default settings for the VSPE emulation devices.  I provide screen captures of my settings in VSPE just in case I am wrong:

X-Plane PC COM1 properties:

X-Plane COM1 port properties

X-Plane PC Splitter properties:

X-Plane Splitter properties

X-Plane PC Splitter settings:

X-Plane Splitter settings

X-Plane PC TCP Server properties:

X-Plane tcp server properties

X-Plane PC TCP Server settings:

X-Plane tcp server settings


2. Install VSPE on networked PC with XCSoar installed and configure VSPE as follows:

Create a COM2 Connector device using default settings. This is the port that that XCSoar will read the GPS serial data stream sent from your X-Plane PC.

Created a Splitter device with COM5 as the virtual serial port and COM2 as the Data source serial port. This will get the serial data stream from the TCP Client device created in the next step and output it via COM2.

Create a TcpClient device with Remote TCP port 5555, The Remote TCP host  is the IP address of your X-Plane PC.  The Source serial port is COM5. This virtual device will receive the serial data stream across the network from the specified VSPE server PC.

Save the configuration.  To re-load a saved configuration, you may have to stop the emulation first.

Below is a screenshot of how it should look when configured.  Click on the green start icon below the menu bar to start the emulation.

With VSPE emulations running on both the server and client PCs and a successful network connection the status for each emulation device should change to “OK”.

NOTE: You may need to open port 5555 through your firewall on both the server and client PCs for the VSPEmulator.exe application.


XCSoar PC COM2 properties:

XCSoar COM2 properties

XCSoar PC Splitter properties:

XCSoar Splitter properties

XCSoar PC Splitter settings:

XCSoar Splitter settings

XCSoar TCP Client properties:

XCSoar tcp client properties

XCSoar TCP Client settings:

XCSoar tcp client settings


3. Start X-Plane 11 Go to Settings –> GPSHardware

Enable the moving map/NMEA COM port and set COM1 with 5 NMEA transmissions per second. You can experiment with the transmissions per second, but 5 per second seems to work OK for me.  (click on image to view larger size)

EDIT: I have carried out some testing of the transmission rate since this post and found that values less than 4 per second or greater than 5 per second impact frame rates and cause stutters.  So on my system, 4 to 5 per second works best.

X-Plane 11 GPS output setting


4. Start XCSoar on the networked PC.  Double click on map display to open menu buttons. Click on Config menu button, select Devices button and configure Device A to COM2 with Baud rate of 4800. The serial driver is optional, but I use the Condor Soaring Simulator driver, which seems to work OK.  There are an extensive range of drivers available in XCSoar. (click on image to view larger size)

XCSOAR Device config