There is so much to know about the venerable B-29 Superfortress – one of the most powerful warplanes ever built. While the B-29s have long been retired, their flying days are not yet over. Two B-29s (named FIFI and Doc) continue to fly every year at airshows across the United States. Doc offers special flights to passengers who plan ahead (and have at least a spare $600 in their pockets).