Looking Glass' third installment of their civilian flight simulations, Flight Unlimited series.
Seattle is the main region that's modelled for the game. And if you already own Flight Unlimited II you are able to fly its San Francisco scenery in addition. You can also visit eight western locations (but not very detailed ones) like Los Angeles, Yosemite or Grand Canyon.
Flight Unlimited III adds to its content many new user-flyable air crafts (Beechjet 400A, Fokker DR 1, etc.) as well as a strong weather system (including thunderstorms, ice and snow) and an improved air traffic control. Besides, the game features lots of challenges, scenarios and flight training tutorials... all in a very enhanced game engine.
It comes with Looking Glass Flight Editor (FLED) in which you can place objects to Flight Unlimited's virtual world (try to complete the Western U.S. with your creations!).