.air File And .cfg File, What's the Deal?

[thanosnaranja]

I know that the model really has nothing to do with the flying aircraft in the sim as long as you place it correctly before export. The cfg and air files are everything. Maybe someone can explain why there is a cfg file and a air file. It really seems unnecessary to have both. I've been into my air file and it mostly duplicates the cfg. Obviously there are differences. But what are the separate roles/functions of these two files in relation to the function of the sim?

I've read the SDK's and they don't go into it deeply enough. Maybe one of the old hands out there can give this newbie a glimpse behind the curtain.

[EngEd]

Hello,
I defer to more techie folks (though not necessarily older...). But be aware that an .air file has been part of a fs model for several generations of sim. By contrast, aircraft.cfg is relatively newer.
I believe I've read somewhere that aircraft.cfg information overrules .air file data. But there are unique entries addressed in each one.
As you probably know, you can open aircraft.cfg with Notepad as a text file. You need more specialized software to access an .air file. (I use aired.)
I look forward to learning more myself....
Regards.
Dennis S

[mgh]

My understanding is that the .cfg file provides the "public" interface and so can readily be changed by the user and that the .air is effectively "private". Microsoft have never published and SDK on the structure of the .air file and, according to this thread it never will.

http://www.flightsim.com/dc/dcboard....278&page=#1358

Microsoft offers FSEdit to give users a way to change in the values the .cfg file and then make corresponding changes to the .air file. I've found that simply chanfing the .cfg doesn't always changed the aircraft's behaviour. I needed to use FSEdit to get the changes into the .air file.

Also, you can use FSEdit to create a new aircraft. It generates a new folder and subfolders for the aircraft in the Aircraft folder together with generic .air and .cfg files. You can then change the .cfg file and use FSEdit to update the .air file.

People claim that FSEdit makes unwanted changes to the .air file. I've never experienced this but then I've never made changes directly to the .air file. I suspect that if you do change the .air file then use FSEdt it may affect those changes. This isn't really surprising - after all how can FSEdit identify those parts of the .air file you've changed yourself?

My impression (and I've no real evidence for this) is that Microsoft was/is moving towards putting more of the aircraft's characteristics into the .cfg file and relying on FSEdit to update the .air file. Maybe FSX will prove me right or wrong.

[thanosnaranja]

I use AirEd because I cannot, simply cannot get FSEdit to work. It keeps giving me stupid errors; it can't open the aircraft folder, can't save the aircraft folder, can't copy the aircraft folder, can't duplicate the aircraft folder; its always something so I gave up on it. To be truthful Flight Simulator is the only piece of microsoft software I ever paid for. The rest of it is mostly trash I suffer with oon account of FS and work.

[EngEd]

Hello,
As noted above, I use AirEd as well. To the best of my knowledge, it's never double-crossed me.
And, as I believe has already been confirmed, most of the work is done in aircraft.cfg anyway.
Regards.
Dennis S

[FelixFFDS]

My feeling is that if one starts from a "seed" plane with characteristics close enough to what one wants, tweaking the aircraft.cfg only will produce acceptable results.

For the flight dynamics purists, tweaking both what is known in the *.air file (with specifc tools like AirEd) will enhance the model's fight dynamics, with that added degree of accuracy.

There is no such thing as a "perfect" flying model, since even in real life, flight characteristics will vary between airplanes. I got that leasson from a couple of mechanics working on SNJs .. One was "sweet" and the other, according to them, just wasn't the same, even though everything was adjusted the same way.



Felix/[link:www.aerodynamika.com/forum.html|FFDS]
Pegasus Aviation Design

[mgh]

I've found that starting with an aircraft that's similar to the one I want gives me acceptable flight characteristics with changing the .air file.

Your point about real life is valid. I learned to fly on C150s. The school's normal C150s wouldn't spin consistently and reliably so they used one of their two C150 Aerobats. Even then, only one of these spun reliably yet they were nominally identical.