Where do flight sims get their data on aircraft flight characteristics?
It comes from a few places and it depends on the type of simulator you are talking about, while the data is not necessarily &quot;confidential&quot; I would call it proprietary although much of it is actually out there:
The Public Domain: Home simulators like X-Plane offer the ability to build your own aircraft models and there are many readily available for sale. People may build these planes experimentally or based on the associated POH information. In many cases the airfoil information for light singles like the Cessna 172 is fairly readily available since its based on a specific NACA airfoil.
The aircraft companies: Since a great deal of training occurs in D-Level simulators these days (because its cheaper than burning Jet-A) the aircraft manufacturers may also build simulators for the real aircraft they build in this case they have the engineering data on hand to build the models.

A great deal of the &quot;experience&quot; also has to do with things that have nothing to do with the aircraft flight model. Things like weather simulation, graphics, airport markings, radio chatter, cockpit sounds, button availability, instrument response and avionics functionality. When I fly my sim its just as important to me that I can simulate the same GPS unit (Garmin 430) that I fly with as is the ability for the 172 to fly like it does in real IFR conditions.