What does the .air file do, and can I change it?

From FlightSim

Q:

Please tell me what does the AIR file do?

A:

Essentially it provides the data that makes the airplane "fly" within the Fs environment. It contains various parameters that can be adjusted by a talented designer/engineer, often known as a Flight Dynamics Editor. These parameters span the range from where the landing gear is located, to engine horsepower / thrust, etc. Even the autopilot comes under its jurisdiction.

It has always been my belief that to have a good panel, you need a good .air file to go with it, and Steve Small does some of the best around. Proper adjustment of this file will allow gauges to provide the proper readings under various power settings, and in various flight configurations. If you'd like to experiment with it, download a program (available here) called AirEd. It allows you to open the file and change the data within it, or just see what is contained within one.

Add: The best air file editor right now is the Abacus Flight Dynamics Editor. It is freely available from abacus.