Probably Boeing's most famous bomber, the B-17 flew mostly out of England, equipping 26 of the 40 bombardment groups of the 8th Air Force. Six B-17 groups were part of 21 groups of the 15th Air Force, which bombed targets in Germany, Austria, Romania and the Balkans from bases in Italy. It will be forever associated with the Allied effort to defeat Nazi Germany. Losses were very heavy in the early months of the bombing campaign against German targets. The heroics of many B-17 crews are legendary. The advent of the long-range fighter escort and a change in fighter tactics reduced the loss rate to a level deemed "acceptable". B-17's also served in the Pacific and Far East in the early days of World War II, but were soon phased out in favor of the long range B-24.
The original intent for the B-17 was the protection of the U.S. mainland from invasion fleets, hence the name Flying Fortress. The first B-17 flew in 1935 as the Boeing Model 299, but the program suffered due to a crash of the prototype aircraft in October 1935. B-17s entered military service prior to World War II, but the entry of America into the War presented a need for aircraft in a hurry. In all, 8,680 B-17G models were built. Total B-17 models built during the War, was 12,731. They were built by Boeing in Seattle, Douglas Aircraft Co. in Long Beach, CA and Vega Aircraft Corp. in Burbank, CA.
The aircraft on display at Castle Air Museum is painted as an aircraft of the 94th Bomb. Group which was commanded by Colonel Frederick Walker Castle from June of 1943 to April 1944 when he was promoted to Brigadier General and given command of the 4th Combat Wing. General Castle lost his life in the skies over France on December 24, 1944 while serving as combat wing commander. After his aircraft was heavily damaged, he ordered the crew to bail out of the aircraft, while he and the co-pilot kept the aircraft under control. Before they could escape themselves, the aircraft exploded, killing both men. Six of the crew survived. For his actions and leadership, General Castle was awarded the Medal of Honor, the United States highest military honor. It is for him that Merced Army Air Field was renamed Castle Air Force Base.