Boeing B-9 Bomber and a Boeing P-26 Fighter.
In the fifteen years that followed WW I, the meager funds allotted for air power had gone mainly for manufacturing training planes or fighter types. Nevertheless, there were enthusiasts even then who had crude visions of a strategic bomber. Arguments for such a plane — one that could reach into enemy territory — ebbed and flowed according to political beliefs, limited funds, and embedded, archaic military thinking. The development of such models as the Douglas YIB-7, the Keystone B-2, and the Boeing B-9 gave promise that an all-metal, enclosed cockpit, multi-engine, long-range bomber could be built.
In 1931, Boeing Aircraft had made the transition from wood and fabric to metal when it built a fighter plane named the Peashooter. In that same year, Boeing also produced the B-9, America’s first all-metal monoplane designed specifically for a bombardment role. Although the B-9 never went into large scale production, its concepts led to designs which appeared in several later models.
The first strategic American bomber was about to emerge, and it did so as the Boeing Flying Fortress. It was none too soon, for Japan by then was well on its way to conquest of the Asian rim, and in Europe both Benito Mussolini and Adolph Hitler were casting ominous shadows.
In late 1935, the U. S. Air Corps arranged competitive flights for aircraft from Douglas Manufacturing and Boeing Aircraft. Douglas Manufacturing adapted its DC-2 transport into a stubby, deep fuselage aircraft called DB-1 (for Douglas Bomber One). In production, these planes were known as B-18 Bolos because the fuselage profile resembled that type of knife.
Boeing Aircraft chose as its entry a modification of its B-9, equipping it with twin in-line engines. In this competition, Boeing Aircraft lost the production contract, but the company capitalized on the design of the B-9 to produce an all-metal, low-wing airliner known as Model 247. The structural design of Model 247, combined with the military features of Boeing’s later XB-15 were precursors to the design of the B-17.
Douglas B-18 Bolos
Between 1937 and 1941, the Douglas B-18 Bolos made up about half the entire bomber fleet of the U.S. Air Corps. Based on a production run of 220 aircraft, the B-18 Bolos cost only 59% of Boeing’s B-17 ($58,000 vs. $99,000). Cost was the determining factor, therefore, when the army decided to buy Bolos rather than Flying Fortresses.
On that fateful December 7, 1941, one hundred and twelve Bolos, half the original production run, were stationed at bases overseas with bomber and reconnaissance units. Fortunately, the Air Corps had been impressed enough with Boeing’s models that thirteen of them had been ordered in1937. Designated as the YB-17, the initial thirteen ships were patterned after the B-9, Model 247, and Model 299. More powerful engines replaced earlier ones, increasing the horse power from 750 to 1,000 per engine, and soon turbo-superchargers were installed, which vastly improved the plane’s performance at higher altitudes. Now although limited in numbers, the B-17 was the largest and most complex aircraft in the Air Corps inventory.
In 1939 when war in Europe began, several U.S. manufacturers were producing airplanes, but the ones they turned out were mainly for defense: fighters, pursuit, or ground support. The Bell P-39 was the principal fighter plane in service then.
Nicknamed the Aircobra, the P-39 saw combat throughout the world, particularly in the Southwest Pacific, the Mediterranean, and Russian theaters. It had an innovative layout with the engine installed in the center fuselage behind the pilot, relied on a tractor-type propeller with a long shaft, and was the first American fighter to be fitted with a tricycle landing gear. Because its engine was only equipped with a single-stage, single-speed supercharger, the P-39 performed poorly above 17,000 ft. In both Europe and the Pacific, the P-39 found itself outclassed as an interceptor and was gradually relegated to other duties, usually at lower altitudes for such missions as ground strafing.
The most renowned of the P-40s were the 100 dispatched to China for use by the American Volunteer Group, or the “Flying Tigers” as they were called.
Another pursuit plane in America’s air fleet in 1941 was the Curtiss P-40, called the Warhawk. The P-40s first saw action at Pearl Harbor on December 7th. Of the ninety-nine Warhawks stationed in Hawaii that day, only seven managed to get airborne during the attack. The seven shot down five Japanese planes — two Nakajima torpedo bombers, a Mitsubishi Zero fighter, and two dive bombers. By the end of the day, however, only twenty-five P-40s remained operational; three had been shot down, the rest destroyed on the ground.
The most renowned of the P-40s were the 100 dispatched to China for use by the American Volunteer Group, or the “Flying Tigers” as they were called. The Flying Tigers got the idea for their famous shark mouth markings from magazine photographs of one squadron’s colorful ships. Exploits of other squadrons flying P-40s all over the world quickly copied the icon.
A few visionaries in the American Air Service were looking beyond coastal defenses and thinking of offensive air tactics, that is, aircraft used to destroy an enemy’s ability to wage war. General Billy Mitchell had seen the potential for such strategy as early as WW I, but targeting factories, ammunition storages, power plants, and cities called for planes different from fighters built for defense. Isolationist factions within the U.S., sheltered by two ocean fronts, remained adamantly opposed for increased expenditures.
In the year the war broke out in Europe, the U.S. had fewer than 1800 operational aircraft, mostly fighters or observation planes, but there was a small collection of two-engine planes, mainly the North American B-25 and the Martin B-26, that could carry bombs or torpedoes.
The B-25, named the Mitchell in honor of the legendary General Billy Mitchell, was a twin-rudder, mid-wing monoplane powered by two 1700 horsepower Wright Cyclone engines. Normal bomb capacity was 5,000 lbs., and some versions carried 75 mm. cannon, machine guns, with added firepower of two .50 caliber guns in the bombardier’s compartment. Another model mounted two guns in the top turret, manned by the flight engineer. These two, in addition to the pair in the bombardier’s space and four in the sides of the fuselage just below the pilots’ seats, totaled eight 50 caliber guns in the nose — an arrangement that provided the ship with fourteen forward-firing guns.
The B-25 was used for high and low level bombing, strafing, photo reconnaissance, submarine patrol, and even as a fighter. It gained special recognition as the aircraft that completed the historic raid on Tokyo in April, 1942. Standard equipment for the Allied Air Forces throughout WW II, the Mitchell perhaps was the most versatile combat plane of the war.