Realistic Flight Simulator

I like this, I was wondering if it were possible to create a flight sim with this gorgeous engine. I am also playing around with the idea of creating a sim myself but a combat flightsim in the style of EF2000, F22 TAW, JSF, or Janes Fighters Anthology you know from the good late 90’s era.
Have you tried how big the terrain can be? Just flying in a 20x20km patch would get boring soon I think.
If you release your work would it be possible for others to use your aerodynamics framework for their own work?