by Tom Gibson

Introduction and Downloads
Part 1:  Setup
Part 2:  Saving and Animating the Props
Part 3:  FS2004 Import
Part 4:  Setting Up Landing and Taxi Lights
Part 5:  Conversion to FSX
Part 6:  Editing Materials and Textures
Part 7:  VC & Appendix

No support guaranteed, but I often read the FSDeveloper ModelConverterX forum:


12/2/2018 Version 1.1 - adds instructions for the VC (Part 7)  and for better reflections (Part 6).
12/15/2018 Version 1.2 - edited to provide instructions for the latest version of ModelConverterX and improve the prop isolation.
2/10/2019  Version 1.3 - edited to provide instructions for the latest version of ModelConverterX
5/28/2019  Version 1.4 - edited to provide a better work flow, less likely to cause the animations to collapse
6/12/2019  Version 1.5 - edited to provide working landing and taxi lights in P3D - you must download the Extra Definitions file again, and edit your modeldef.xml file.  You must replace the light_taxi_visible section, and add the special_light section.  The rest us unchanged.
12/16/2023 Version 1.6 - warning provided that Arno is working on a new version of ModelConverterX.

NOTICE!  Arno is working on a new version of ModelConverterX that will make this process MUCH easier.  However, during this process the development version of MCX may NOT work as described here.  So it would be best to use the STABLE version of ModelConverterX until this updating is compilete, if you don't want to wait for the new version.

This tutorial will provide a method for converting flyable FS2004 format aircraft MDL files into FSX format, using ModelConverterX (MCX).  This  is a rather exhaustive tutorial designed for a relative beginner to this process, but you will need to have some basic information about how FS planes work.  This tutorial is specifically for propeller planes - for jets with animated engine fans it should be pretty much identical replacing prop0/1/2/3 parts with N1_0/1/2/3 parts.  For things like thrust reversers see the RESOURCES below for some information on that (although they are converting AI aircraft, so I don't know if it applies directly).  But because MCX has been updated since most of that information was released, you may also want to read this tutorial (for simpler techniques for attached landing and taxi lights, fixing animations when adding some Visibility Conditions, and including part names in your modeldef.xml file to eliminate some of the tedious editing of the FS2004 model, for example).

I guess the first question you may ask is "Why would I want to make this conversion?"  For people using FSX and P3D through v3 the answer is that it allows objects (like clouds) to be seen through the prop disks, and allows one to use DDS textures if desired.  A few say you may get a slight frame rate boost too.  Some would probably decide this is not worth the effort, but you may think it is.  If you use P3Dv4 or above the answer is that this will allow you to use the plane at all, since FS2004 format MDL files are not compatible with P3Dv4.


This tutorial would not be possible without Arno, the creater of ModelConverterX and many other wonderful tools.  I couldn't do half the things I do in FS if it weren't for his utility programs.  He has recently modified ModelConverterX to make this  process much less painful.  Thanks so much!

Very little of this tutorial is original to me, I just thought it would be nice to have it here, all in one place.  I have gleaned bits and pieces of this process from many people over at FSDeveloper, AIG, and Sim-Outhouse (see the links below in Resources).  I hereby thank each and every one of them, you are the real pioneers.  One thing I have done is figure out a step order that increases the likelyhood of a successful conversion, without the animations being ruined.


If you are the author of the aircraft you intend on converting (i.e. you created it), then no problems.  If you are not, then you must comply with one of the following conditions:

1.  The resulting MDL file is only for your own use, and you will not release it to anyone else.
2.  You have received permission from the original author(s) of the plane to allow release of a converted version.


If when you Import your plane into ModelConverterX any parts are not correctly animated or are displaced from their normal positions, this tutorial alone will not allow you to convert a usable plane.


To shorten the tutorial, it may refer to multiple variations of animation or visibility names as engine0/1/2/3 (as an example).  This means engine0, engine1, engine2, and engine3.


1.  I am using ModelConverterX version from 2021 - this was the latest version of the "stable  release" as of this tutorial version.  Versions earlier than 1.4.0 will not work.  You can usually assume that later versions will also work, but animation names, etc. may be slightly different.  You can get the stable release here:


Click on the orange button in the upper right to download.

There is a development release that should make this conversion much easier once it is complete (which it is not).  You can download this release here:


Click on the image of the floppy disk to download.

The forum thread describing this updating process is here:


Installation is easy - create a new folder (outside of any Program Files folder) and place the downloaded files into that folder.  I named my folder ModelConverterX.  You can create a desktop shortcut by right clicking the ModelConverterX.exe file of the program and choosing Copy.  Then right click on the Desktop and choose Paste Shortcut.  Click on the name of the Shortcut until it is highlighted.  Click again and edit the name until it says something like ModelConverterX.

2.  The other thing that is required is to have the FSX (or relevant P3D) SDK properly installed, and you are able to create an MDL file from within ModelConverterX.  If the FSX SDK it must be the SP2 version or later.  If you are converting to FSX and you do not own the Deluxe version of FSX that has the SDK in it, then you will need to use the P3D v1.4 SDK, which produces FSX compatible MDL files.  It is beyond the scope of this tutorial to get this process working.  Refer to the FSDeveloper Wiki entries on this subject, and you can ask questions at the GMAX and 3DMax Forum at:



3.  To examine the alpha channels of the textures of your plane you may  need an FS bitmap viewer/editor.  I use DXTBmp, which can be downloaded here:


Click on the DXTBmp button at the bottom of this page and then downloaded from the bottom of that page.  Install as instructed.

4.  In the unlikely event that your converted plane's bounding box is huge, the other program you may need is RADItor, which tests and then resets the bounding box of the FSX aircraft so it will be properly displayed in Spot View.  The ModelConverterX MDL Tweaker tool will do the same thing.  .  Feel free to use the tool within ModelConverterX if you prefer.  You can get RADItor here if you want it:


Installation is easy - create a new folder (outside of any Program Files folder) and place the downloaded files into that folder.  I named my folder RADItor.  You can create a desktop shortcut by right clicking the RADItor.exe file of the program and choosing Copy.  Then right click on the Desktop and choose Paste Shortcut.  Click on the name of the Shortcut until it is highlighted.  Click again and edit the name until it says something like RADItor.

NOTE:  The latest versions of ModelConverterX have reduced (or eliminated?) the need to reset the bounding box.  But I would at least check the bounding box as described in this tutorial after the initial FSX conversion.  The MCX Object Information tool will work fine for this.

If you want to follow along with this tutorial

5.  For this tutorial I will be using a Douglas DC-6B by Greg Pepper and Tom Gibson,  in FS2004 format.  If you want to follow along you can download it  here:

Douglas DC-6B Base Pack with United Air Lines textures:


Install it into FSX or  later sim.  This package has no FSX installation instructions but you can do that.  For FSX or P3D you will need to  press the ... button and browse to your main FSX/P3D folder, then follow the instructions.  At the end you will need to copy the following folders in your FS/Aircraft folder and paste them into your FS/SimObjects/Airplanes folder.

DC-6B CB-16

I will be using the model found in the DC-6B CB-16/model folder.

Information Links

6.  The other resources are the various forum threads that may give you more details than I include here, but hopefully you won't need them.  Thus you probably don't have to read these.  These people were converting planes long before this tutorial, and have provided invaluable information to this tutorial.

The ModelConverterX Forum, which contains many threads related to this conversion process:


A few of the most important threads from this forum:


The thread for converting AI jets, including a PDF tutorial link in the first post is:


And the threads that continue this discussion which often  include another set of downloadable instructions and files:



OK, I think we're ready to begin!