1941 - Intercontinental Bomber
The beginning of work on the B-36 marked a major shift in US foreign policy. The prevailing isolationism in the 1930s suggested that the US interests lay mainly within the Western Hemisphere and that the ocean spaces reliably protected America from possible aggression. The second world war that flared up in Europe, the catastrophic fall of France and the most difficult martial law in England made it necessary to reconsider this position. The initial impetus for the creation of this new bomber was the desire to hedge against the defeat of England and the loss of the possibility of basing in Europe.
The Air Corps opened a design competition for a truly intercontinental bomber a fast, high altitude airplane with a heavy bombload and unprecedented range. Invitations for preliminary design studies were sent to the Consolidated Aircraft Corporation and to the Boeing Aircraft Company on 11 April 1941. The Consolidated Aircraft Corporation and Vultee Aircraft, Inc., merged on 17 March 1943. The new Consolidated Vultee Aircraft (Convair) Corporation became the Convair Division of the General Dynamics Corporation on 29 April 1954. Northrop Aircraft, Incorporated was contacted on 27 May, when it was also asked for further design studies on a "flying wing" bomber having a range of 8,000 miles at 25,000 feet, with 1 ton of bombs.
The preliminary characteristics set forth in the Air Corps requests for proposals of April 1941 called for the creation of a bomber with a 450 mile per hour top speed at 25,000 feet [725 km/h at an altitude of 7600 m], a cruising speed of 275 mile per hour [445 km/h], a practical ceiling of 45,000 feet [13,700 m] and a flight range of 12,000 miles [19000 km] at an altitude of 25,000 feet [7600 m]. it was supposed to make a "big jump" in comparison with the B-17, which had a maximum speed of 510 km / h in the V-17E (1941) version, a practical ceiling of 10,700 m, a maximum range of 5300 km and a bomb load of 1.8 tonnes - a significant gap from the B-29, calculated for speed.
Until the early 1950s, the range and speed of aircraft were usually shown in statute miles. Afterwards, the Air Force began to measure speed in knots and range in nautical miles. Speed records, however, continued to be in miles per hour and distances were expressed in kilometers. (A knot nautical mile per hour is 1.1516 times swifter than a statute mile per hour. A nautical mile represents around 6,080 feet and is 800 feet more than the statute mile.)
Not long afterwards the Douglas Aircraft Company took part in the long range bomber competitions. Douglas Aircraft had been given a contract on 19 April 1941 to check if the Allison 3420 engine could be used in bombardment type aircraft-clearly a closely related project. Douglas had also been working for several years on the XB-19 just recently flown and the largest aircraft ever built in the United States. The Air Corps planned to use the XB-19 as a flying laboratory to gather information that would help the design and construction of future giant aircraft. Solicited much later, the Glenn L. Martin Company declined the invitation due to a shortage of engineering personnel. The Glenn Martin Company had been engaged in a new bomber (the XB-33, under contract since June 1941), before becoming involved in the Northrop "flying wing" program. In addition, by 1943 the company had been approached by the Navy for participation in a new production project.
These characteristics were revised during a conference on 19 August 1941 attended by Robert A. Lovett, Assistant Secretary of War for Air, Maj. Gen. George H. Brett, Chief of the Air Corps, and ranking officers of the Air Staff. Since the conference's main purpose was to accelerate the bomber project, the conferees decided to scale down their requirements.
But their revision was still a tall order- a minimum overall range of 10,000 miles, and an effective combat radius of 4,000 miles with a 10,000-pound bombload. This was about 4 times the combat radius of the Boeing B-17, the AAF's newest and best bomber. Although the word "range" is often qualified, in this context it indicates how far an aircraft can fly under given operating conditions from the moment of takeoff to the time when its fuel supply is exhausted, as in "the aircraft's range was 7,000 miles, enough to fly nonstop from San Francisco to London." The "combat radius" is the radius of action for any given airplane on a combat mission with a specified load and flight plan.
The "radius of action" differs from "range" in that the aircraft is always considered to return to the point at which it takes off. It is like the radius of a circle, and represents the maximum distance at which a given airplane can operate, under given conditions, from the center of the circle and still return to the center. This distance, under combat conditions, is considerably less than one half the distance that the aircraft can fly under noncombat conditions. The conferees further specified that the future intercontinental bomber should have a cruising speed between 240 and 300 miles per hour, and a 40,000 foot service ceiling (5,000 feet less than originally requested).
The further deterioration of the military situation in the world (Hitler's attack on the Soviet Union, the fierce "battle for the Atlantic") prompted the revision of the demands of the Americans, which made the program speed up. Despite the concessions made by the military, the new task was still an uneasy task, the decision of which was entrusted two months later (in October 1941) to the firms Conver and Northrop, who in November 1941 received contracts for the development and construction of two experienced bomber: respectively, XB-36 and XB-35.
After a review of preliminary data from Boeing, Consolidated, and Douglas, the Materiel Division of the Air Corps suggested prompt action on the Consolidated study, which covered several long range bomber designs, both 4 and 6 engine pusher and pusher tractor types. Consolidated, after specializing for many years in seagoing aircraft, reentered the landplane field early in 1940, with development of the B-24 Liberator. Keenly aware of the Air Corps's interest in large bombers with extended ranges, the company at this time had begun work on a number of design possibilities.
This endorsement of Consolidated was in no way a rejection of either Boeing or Douglas services. Yet, it proved to be a turning point in the intercontinental bomber program. Douglas Aircraft stated in late 1941 that it did not desire to undertake an "out and out 10,000 mile airplane project." It proposed instead the development of Model 423, a 6,000 mile bomber, which was rejected. As for Boeing, the AAF believed as late as April 1942 that the company was "overly conservative" and had not yet "really tackled the (long range) airplane design with the necessary degree of enthusiasm." Two Boeing bomber designs (Models 384 and 385) submitted in September were never developed.
The development decision was made by Maj. Gen. Henry H. Arnold, Chief of the new Army Air Forces, on the recommendation of Brig. Gen. George C. Kenney, Commanding Officer of the Air Corps Experimental Division and Engineering School at Wright Field, Ohio. This decision came on 16 October 1941. General Kenney's recommendation rested on a detailed proposal (drawings and bid were submitted by Consolidated on 6 October), which asked for $15 million plus a fixed fee of $800,000 for research and development; mockup, tooling, and production of 2 experimental long range bombers (Model 35). Delivery of the first airplane would be 30 months after approval of the contract; that of the second, 6 months later. Consolidated also stipulated that the project could not be "entangled with red tape" and constantly changing directives.
The collapse of the plan for a lightning victory over the USSR, which put Germany in front of the need for protracted military efforts, weakened the urgency of creating an intercontinental bomber. A new impetus was the attack of Japan on Pearl Harbor on 07 December 1941, which turned the US from a non-belligerent ally into a belligerent. Concerned primarily by the desire to achieve a breakthrough in the fight against Japan, the United States after the battles in the Coral Sea and at Midway Atoll (May-June 1942) made a change in favor of the balance of naval forces in the Pacific. However, the Americans sought to take the war as soon as possible to the territory of Japan itself, if not landing on the beaches, then at least the air bombings to which Germany was already subjected.
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