The boeing b 17 flying fortress is a four engine heavy bomber aircraft developed in the 1930s for the united states army air corps usaac the b 17 was primarily employed in the daylight precision strategic bombing campaign of world war ii against german industrial and military targetsthe b 17g is generally considered the definitive b 17 design incorporating all changes made in the b 17f a bit o lace is possibly the most famous b 17g ever it flew 83 missions over europe and featured art by carto