Flightgear is one of the very best flight simulator i came across. Though it is opensource, which means no cost is involved, it gives a very realist and highly accurate flight details and experiences. This program comes with many various choices of flight models and when you visit http://www.unitedfreeworld.com you will be amazed to find the tons of free add ons they give away for flightgear. Now put flightgear and www.unitedfreeworld.com together and you seems to have a complete application which is going to take your breath away! i will highly recommend this application to everyone!