Boeing B-29 Superfortress

The Boeing B-29 Superfortress was the most technologically advanced aircraft of World War II and the weapon that ended the conflict. Incorporating pressurized crew compartments, remote-controlled gun turrets, advanced fire-control computers, and an innovative central station gunnery system, the B-29 represented a generational leap over every other bomber in the world. It was the most expensive weapons program of the war, more costly than the Manhattan Project itself.

From bases in the Mariana Islands, B-29s of the XXI Bomber Command conducted the strategic bombing campaign that burned Japan's cities, destroyed its industry, and brought the empire to its knees. General Curtis LeMay's decision to strip the B-29s of most defensive armament and send them in low-altitude incendiary raids transformed the air war. The March 9-10, 1945, firebombing of Tokyo killed an estimated 100,000 people and destroyed 16 square miles of the city, making it the single most destructive air raid in history.

On August 6, 1945, the B-29 "Enola Gay" dropped the uranium bomb "Little Boy" on Hiroshima. Three days later, "Bockscar" dropped the plutonium bomb "Fat Man" on Nagasaki. Japan surrendered on August 15. The B-29 thus holds the unique and somber distinction of being the only aircraft to deliver nuclear weapons in combat, forever changing warfare and world politics.

Boeing began privately studying a "superbomber" concept in 1938, anticipating that the Army Air Corps would need a bomber capable of striking targets at intercontinental range. The official requirement, issued in January 1940, called for a bomber with a speed of 400 mph, a range of 5,333 miles, and the ability to carry 2,000 pounds of bombs. Boeing's Model 345 won the competition against designs from Consolidated, Douglas, and Lockheed.

The XB-29 prototype first flew on September 21, 1942, but the development program was plagued with problems, particularly the Wright R-3350 engines, which were prone to overheating and catching fire. The engine problems would plague the B-29 throughout its service life and were responsible for numerous losses. General Hap Arnold pushed the B-29 program with extraordinary urgency, ordering production before testing was complete, a "billion-dollar gamble" that was the most expensive weapons program of the war at $3 billion.

The B-29 incorporated technologies that were revolutionary for a production bomber. The pressurized crew compartments connected by a crawl tunnel over the bomb bays allowed crews to fly at high altitude without bulky flight suits and oxygen masks. The remote-controlled gun turrets were aimed via a central fire-control computer that calculated lead, range, and ballistic corrections, a system that would not be surpassed until guided missiles replaced guns decades later. The central fire-control officer could assign any turret to any gunner.

Four plants produced B-29s: Boeing in Wichita and Renton, Bell in Marietta (Georgia), and Glenn L. Martin in Omaha. The production ramp-up required the largest sub-contracting network ever assembled, with parts flowing from over 1,400 suppliers across the country.