As stated by Wags here: http://forums.eagle.ru/showthread.php?p=2039947
Professional Flight Model (PFM). This is generations beyond an AFM/AFM+ and is based upon:
• Use a wider array of wind tunnel tests CFD methods for aerodynamics parameters calculations.
• A higher level of aircraft construction details for forces calculations. For example: our landing gear model includes individual kinematics of retracting/extending is used to calculate its movement, servo-piston forces, etc. In such cases, we truly use real lengths, arms, etc. This also includes such items as a realistic simulation of airflow along the airframe due to the propeller or helicopter rotor thrust.
• Realistic simulation of Flight Control, CAS and Autopilot systems.
• Realistic simulation of Hydraulics, Fuel, Electrical, Engine and other systems influence flight characteristics.
• Unprecedented access to test data packs.
This is combined with much more detailed and accurate accounting of the physical forces on the aircraft and airfoils. DCS examples of the PFM include the A-10C, Ka-50, P-51D, UH-1H, Mi-8MTV2, F-15C and Su-27 (in development) for DCS Flaming Cliffs, and the Fw190-D9 (in development).<br />