A few big and important questions...

[Sterk]

1.I have several games installed on my mashine and MFS2004 and Serious Sam among them.I notised that my comp shows aircraft model files as "Serious modeler document" because their format .mdl is the same that Serious Sam uses.Serious modeler which comes with the Serious Sam game can read and open .mdl files of the game,so I tried to load aircraft model from MFS into serious modeler(to tell the truth I didnt expected it work)and modeler daznt open it poping out error message that looks something like:Cant open file-MDAT expected but there is RIFF".
So what is MDAT and RIFF?
2.Designing new aircraft and scenery is very interesting for me but I have almost no knowledge and I supposed that  questions like this  have been asked may be million times at this forum and I read many posts about it but they all are very specific and its difficult to get them all together to have a general picture how to do things.
So what I know:
1.Aircraft model can be created,animated and textured in any 3D
application(GMAX or whatever).
2.Aircraft model must be a .mdl file in order to be exported into the Sim
3.Aircraft dynamics must be applied.

Now what I dont know
1.How 3D model turns into .mdl file?
2.How all animations are exported with model,daz mdl file format stores animation?
3.How all arcraft dynamics are applied to model,daz mdl file stores it as well?
4.How I make aircraft respond to commands in game, do I have to know any programming to complete working aircraft model?

So as you see I need something like" Full Aircraft Design Guide for beginners"
As a matter of fact I have enough expierence in 3D model creation texturing and animation,so this part of the guide can be scipped over...

[Hagar]

Hi Sterk. I'll start you off & maybe Felix can fill in the details. With the release of FS2002 it became possible to create aircraft & scenery for the M$ sims with Gmax. FS2002 Pro included Gmax & a special Gamepack for exporting files in MDL & BGL format. FS2004 does not include a Gamepack although Gmax is included on one of the CDs. This is free but has to be registered online before you can use it. The latest version can also be downloaded here. http://www.discreet.com/products/gmax/
Presumably the intention is to release some sort of Gamepack with a forthcoming FS2004 SDK (Software Development Kit).

Meanwhile, I assume the FS2004 developers are using either the original FS2002 Pro Gamepack or the MakeMdl SDK posted here. http://www.microsoft.com/games/flightsimulator/fs2002_downloads_sdk.asp
This does not include a Gamepack but it's theoretically possible to produce a MDL file from a file saved out in X format using the included Makemdl.exe. I've never done this successfully myself.

I never liked Gmax & prefer FS Design Studio 2. This is a commercial 3rd party application developed specifically for FS modelling & distributed by Abacus. As you're already familiar with 3D modelling I think Gmax would suit you better.

I also mess around with scenery design & prefer the conventional freeware applications like FS Scenery Creator & EOD to Gmax.

I hope this is some help.

[Sterk]

Thanx,Hagar this is a good  opening article for our "Complete Aircraft Design Guide for Beginners"!

[Felix/FFDS]

Check the topic - "Flight Design Programs"

1. For building models  - (flightsim *.mdl) you need a modelling program (gmax, FSDS2, AS2002)

WHile FSDS2 and AD2002 are standalone programs - they create their own mdl files, you need the converter from FS2002 Professional.

You can create a model in 3DSMax, etc., as long as you can convert the output to a DirectX file, and use makemdl.exe directly on it.

2.  For flight dynamics, these are separate files an *.air file and the aircraft.cfg file.  THese are modified with an Flight Dynamics File editor (such as AirEd for the *.air file) and a simple text editor for the aircraft.cfg file.

Check the flight dynamics topic for links to flight dynamics sites and utilities.