Do .cfg and .air file need to be in agreement ?

[Gringo6]

I've been playing around with Aired and note book and comparing the .air files and the aircraft files and note that there are usually some (and sometimes a lot of) differences between these two files.

Just how do they interact with each other and in the case of a difference between them which takes priority ?

When two men ride a horse one has to ride in front - so which one of these files rides in front ?

[Travis]

The config file is steering.

It takes precedence over the airfile.  There are instances in the airfile which do not appear in the config file, so they are always referenced by FS.

[Milton]

Another way to view it is the air file provides the foundation tables for the all the flight characteristics.

The cfg file parameters provide an easy method to tweak or override some aspects of the air file.  If present, they have precedence.

[Straferr]

Do they have precedence in CFS2??

[Felix/FFDS]

Do they have precedence in CFS2??

Yes.  

Caveat ...  CFS2 doesn't support as many parameters as the later FS versions.