THE PRODUCTION OF THE GIANT P-47 WAS MADE POSSIBLE ONLY AS THE RESULT OF THE SUCCESSFUL EFFORTS OF AMERICAN ENGINEERS TO REDUCE THE WEIGHT PER HORSEPOWER OF AIRCRAFT ENGINES. MODERN ENGINES, LIKE THE ONE THAT POWERS THE P-47, WEIGH ABOUT ONE POUND PER HORSEPOWER.] [Illustration] The Republic P-47 _Thunderbolt_ proved to be one of the most versatile airplanes developed in this war. It performs equally well at high or low altitudes. Armed with eight .50-caliber machine guns, it is a hard-hitting escort fighter which can out-fight any plane sent up to hinder our big bombers. When used for ground strafing it has no superior. With two 1000-pound bombs tucked under its wings it becomes a deadly dive-bomber. Armed with rocket tubes and its eight big machine guns blazing, it can blast enemy tanks, transport, and gun emplacements effectively. SUPERFORTRESS The first giant _Flying Fortress_ had hardly taken off from the Boeing factory at Seattle, in 1935, before its engineers began to think about bigger and faster super-bombers. As the new _Fortresses_ shattered records for speed, pay load, distance, and altitude, farsighted Air Corps leaders also began to think about more powerful super-bombers. By 1937 the brains and labor of Boeing engineers and production men created the first of the super-bombers. It was the giant Boeing XB-15 and it actually dwarfed the _Flying Fortress_. With a gross weight of 35 tons, 13 tons more than the _Fortress_, the XB-15 was 20 feet longer, 3 feet higher, and had a wingspan 45 feet greater. Its general appearance, however, was patterned after the _Fortress_. Only one XB-15 was built. It was used for experimental purposes by the Air Corps, and the Boeing Company went ahead to build the high-altitude _Stratoliner_ and the big _Clipper_ planes for civilian use. Thus it was that even before the Nazis swept into Poland in 1939 the Air Corps had been thinking of an airplane that would dwarf the _Flying Fortress_. Size alone was not enough. General Arnold and his associates wanted an airplane which would carry a heavier bomb load farther, faster, and higher than ever before. Few people aside from the Army knew of the XB-15, and the development of the super-bomber was one of the best kept secrets in history. One of the greatest surprises of the war was the War Department’s announcement on June 15, 1944: “B-29 _Superfortresses_ of the United States Army Air Forces’ 20th Bomber Command bombed Japan.” Just one year after the announcement of the first _Superfortress_ attack on Japan, five hundred of these giant ships took part in a single raid against targets on the Japanese mainland. In groups of four and five hundred they blasted Japan almost daily. _Superfortresses_ bombed Japan to her knees in the spring and summer of 1945. Then in August of that year a lone _Superfortress_ dropped the world’s first atomic bomb on Hiroshima for the knockout blow that brought us victory. [Illustration: 1944-1945