B17G Flying Fortress
The Boeing B-17 Flying Fortress is a four-engine heavy bomber aircraft developed for the United States Army Air Corps (USAAC). Competing against Douglas and Martin for a contract to build 200 bombers, the Boeing entry outperformed both the other competitors and more than met the Air Corps’ expectations. Although Boeing lost the contract due to the prototype’s crash, the Air Corps was so impressed with Boeing’s design that they ordered 13 B-17s. The B-17 Flying Fortress went on to enter full-scale production and was considered the first truly mass-produced large aircraft, eventually evolving through numerous design advancements.