BWI is one of the 3 major airports in the Washington D.C. area. The airport is known most for its low fare carrier service with Southwest being the dominant carrier to one time leader U.S. Airways. It has had an interesting history though. For a short time in the 1930s, it was Pan Am's Clipper Flying boats base for Atlantic flights. It has also been the home of low cost flights to Europe going all the way back to Icelandair in the 1960s and 1970s. BWI was known as Friendship Airport until 1978.