B-52 Stratofortress

by Bill Yenne

  The slogan summarized what had happened across the street at Boeing Field. The company’s Plant 2 had indeed become the “World Center of 4-Engine Airplane Development.”

  The actual road may have been East Marginal Way South, but the metaphorical road was the one that would lead to the B-52 Stratofortress.

  This road had begun back in 1933, with two secret U.S. Army Air Corps programs that were called Project A and Project D. Two years later, these were merged as the Bomber, Long Range (BLR), program, which resulted in the Boeing XBLR-1. Redesignated as XB-15, the aircraft made its first flight in 1937 as the largest bomber yet built in America. However, the Air Corps had already moved on to requesting a smaller (though still large) and more modern aircraft. In response to this request, Boeing had proposed its Model 299, which had first flown in 1935, two years ahead of the XB-15.

  This 1941 billboard, across from Boeing Field on East Marginal Way South, touted the company as the “World Center of 4-Engine Airplane Development.” Left to right are the Model 307 Stratoliner, the Model 314 Clipper, and the B-17 Flying Fortress.

  A classic image of USAAF B-17Fs high in the cold winter air, en route to Hitler’s Germany. Boeing’s Flying Fortress was the signature warplane in the massive strategic air offensive that helped defeat the Third Reich.

  The Model 299 was designed by a team of brilliant young Boeing engineers, notably Edward Curtis Wells, and built at company expense. It first flew on July 28, 1935, powered by four Pratt & Whitney R1690 Hornet engines. At the rollout, a journalist described Boeing’s huge, four-engine bomber as a “flying fortress.” The nickname was quickly adopted as the official name. The Air Corps tested the Boeing-owned Model 299 under the unofficial XB-17 designation for nearly three months and ordered 13 service test Model 299B aircraft under the designation Y1B-17.

  When World War II began in Europe in 1939, the U.S. Army began planning for the long-range defense of the Western Hemisphere against possible Axis incursion. In 1940, the then Army Air Corps (becoming the U.S. Army Air Forces after June 1941) ordered eighty additional B-17C and B-17D aircraft with more armor and armament, and by the time that the United States entered the war in 1941, Boeing was delivering the B-17E, the first variant with the distinctive tail turret.

  The Flying Fortress became the nucleus of the USAAF Eighth Air Force, which would undertake the great strategic offensive against Germany. The B-17F variant, with greater range and payload capacity, was introduced in 1942, followed in 1943 by the B-17G (Model 299P), the definitive Flying Fortress. It had the ball turret, the R1820-97 engines, and all of the other B-17F improvements, as well as a forward-firing Bendix “chin” turret that made it a true Flying Fortress. It also typically carried a bomb load of nearly 10,000 pounds.

  The Boeing B-29 Superfortress was the ultimate expression of strategic air power during World War II.

  First flown in June 1947, the Boeing B-50 was a “Super” Superfortress, a variation on the World War II B-29 that featured more powerful Pratt & Whitney R4360 radial engines and a taller tail. Seen here is the B-50B variant. USAF

  As the backbone of the great Eighth Air Force and Fifteenth Air Force air offensive against German-occupied Europe, B-17s dropped over 640,000 tons of bombs, roughly half of the overall total dropped by American bombers of all types.

  Meanwhile, Boeing had begun to produce a new heavy bomber with a longer range and a greater capacity than any of the others. It went on to become the ultimate expression of strategic air power in World War II. This aircraft, which was so secret that its name could only be whispered until the war was nearly half over, was the Boeing B-29 Superfortress. It was also the aircraft that established the primacy of the Boeing Aircraft Company as the world leader in strategic bombers, positioning the company for the postwar steps that led it on the road that culminated with the B-52 Stratofortress.

  The USAAF concentrated the entire force of B-29s against Japan and assigned them to the new, all-Superfortress Twentieth Air Force. The first B-29 mission was flown on June 5, 1944, and through the winter of 1944–1945, the number of B-29s grew rapidly, as did the intensity of the attacks on Japan. In March 1945, Gen. Curtis LeMay, the field commander of the Twentieth Air Force, began three-hundred-plane raids on major Japanese industrial centers, a pattern that continued through the spring and into the summer. The number of aircraft available for the missions grew, and on August 1 a total of 784 B-29s reached their targets. LeMay’s plan was to defeat the Japanese from the air so that a costly ground invasion would not be necessary.

  Meanwhile, the United States had developed nuclear weapons. President Harry Truman had decided to use them to force the Japanese into an unconditional surrender. Because the B-29 was the largest bomber in the USAAF, the two available atomic bombs were designed to be dropped by B-29s. Nuclear strikes would be made against Hiroshima and Nagasaki on August 6 and August 9.

  By the time that the Japanese agreed to an unconditional surrender on August 15, Boeing had cinched its position as “the World Center of 4-Engine Airplane Development.” The number of Flying Fortresses had reached 12,731, and nearly 3,000 Superfortresses had been produced. The planemaker on East Marginal Way was ready to move into jet bombers.

  The RB-36D reconnaissance variant preceded the B-36D bomber by two months. When it was released on September 27, 1950, this striking photo of the Convair RB-36D was described as “the first flight view released of the Air Force’s intercontinental fact-finding weapon.”

  DURING WORLD WAR II, the USAAF became the largest air force in history and, in the process, proved the importance of the strategic air power doctrine in affecting the outcome of a major war. No longer theoretical, the strategic air power doctrine was now central to the entire concept of military organization and planning. This fact would greatly influence the structure of the postwar U.S. Air Force into which the USAAF evolved in 1947.

  The insignia of the Strategic Air Command was designed in 1951 by Sgt. R. T. Barnes, then assigned to the 92nd Bombardment Wing at Fairchild AFB. He was the winner of a design competition that was judged by Gen. Curtis LeMay, among others, and was awarded a $100 United States Savings Bond. USAF

  Meanwhile, the service was reorganized, based on a view of the role of modern air power that was tempered by the experience of World War II. Combat assets were divided into separate components: the Tactical Air Command (TAC), the Air Defense Command (ADC), and, of course, the Strategic Air Command (SAC).

  Gen. Carl Spaatz, the wartime commander of U.S. Strategic Air Forces in Europe, and now commanding general of the USAAF, outlined SAC’s mission, stating that it would “be prepared to conduct long-range offensive operations in any part of the world either independently or in cooperation with land and naval forces; to conduct maximum- range reconnaissance over land or sea either independently or in cooperation with land and naval forces; to provide combat units capable of intense and sustained combat operations employing the latest and most advanced weapons.”

  In 1946, such a description was dry and theoretical against the backdrop of the euphoria brought by the end of World War II. Peace had been achieved, and all seemed well. However, even before World War II concluded, dark clouds were gathering in the east that would soon impose a new kind of war upon the world, one in which the Strategic Air Command would play a key role. This new war would be called the Cold War because it was not war in the sense of World War II, but rather an epoch of global tensions in which the world lived under the threat of World War III.

  During World War II, as the Soviet Army pushed the Germans out of Eastern Europe, they used the force of arms to impose puppet governments throughout the region. While the Anglo-American Allies demobilized, the Soviet Army remained as an imposing force to dominate Eastern Europe and constituted an implicit threat to Western Europe and the rest of the world beyond. As World War II ended, a dividing line formed across Europe that Winston Churchill, Britain’s wartime prime minister, referred to as the Iron Curtain.

  As postw
ar demobilization had greatly reduced the size of the Anglo-American armies, the one ace in the hole that the United States still held was its monopoly on nuclear weapons. Therefore, the threat of nuclear weapons was the only thing that caused Stalin to think twice about sending his armies west of the Iron Curtain. In the early years of the Cold War, in the late 1940s, the only entity in the world that was capable of delivering nuclear weapons against a foe such as the Soviet Union was the Strategic Air Command.

  A Boeing B-47 Stratojet carrying a Bell B-63 (later GAM-63) strategic stand-off missile. USAF

  A B-36 on the ramp at Carswell AFB, with the fuel trucks required to service the huge bomber. USAF

  For its long-range mission, SAC was initially dependant on piston-engine aircraft. SAC’s early fleet was comprised of wartime B-29s, as well as Boeing B-50s, much-improved and updated variations on the B-29. Also in development in the mid-1940s was the Convair B-36 Peacemaker, an enormous bomber with an intercontinental range. It was a slow, piston-engined aircraft, but it gave SAC a range capability of 10,000 miles that would not be matched or exceeded by a jet bomber until the advent of the B-52.

  The U.S. Air Force ordered its first generation of long-range jet bombers in 1947, the same year it was created. Among these was the Boeing B-47. Boeing engineers had been studying the idea of a jet bomber since 1943, and their early designs, such as the Model 424, had straight wings. When the war ended, however, Boeing’s chief aerodynamicist, George Schairer, traveled to Germany with Dr. Theodore von Karman of Caltech and the group of American scientists who constituted the U.S. Army Scientific Advisory Group. Germany had led the world in jet aircraft development during the war, and the group wanted to evaluate their scientific and technical data. It was here that Schairer discovered that the 18.5-degree sweep of the Messerschmitt Me 262 wing improved performance to a significant extent.

  This revelation led to Boeing recalculating and redesigning its jet bomber project. Schairer sold his boss, Ed Wells, on the idea of the swept wings, and Wells sold the concept to the USAAF. The result was the Model 448, which emerged in September 1945. Over the coming year the design was further refined, emerging finally as the six-engine Model 450 Stratojet—a futuristic airplane larger than the B-29. The USAAF ordered a pair of Stratojets under the designation XB-47. Ultimately, it would be produced in far larger numbers—more than two thousand—than any other American strategic jet bomber.

  After a first flight on December 17, 1947, the Stratojet entered a flight test program that would result in a modest contract for ten B-47A production aircraft being issued ten months later. Though the prototypes were built at Plant 2 in Seattle, the production aircraft would all be built at their big Wichita facility, which had been expanded for wartime production of the B-29. While SAC’s B-36 arsenal reached its peak in 1954 with 342 of the huge planes (133 were RB-36 variants), there were more than 1,500 B-47s and RB-47s in service by 1956.

  A good side view of a B-47E. Note the distinctive “starry blue” SAC stripe on the forward fuselage. USAF

  Simultaneously with the development of the warplanes, SAC was also developing the operational principles that would guide the application of strategic air power in the event that the Cold War devolved into a global nuclear war. The man who would oversee the development of the organization and tactics to make this possible was Gen. Curtis LeMay, who had presided over the defeat of Japan as commander of the B-29 force and who became SAC’s commander-in-chief in October 1948. LeMay came aboard with a mandate to make SAC a force that was second to none, but found it critically lacking, not just in aircraft, but in readiness. Demobilization had created widespread demoralization. Reenlistments were down, and that was cutting the heart out of SAC’s cadre of veteran pilots. Over the course of the first year and a half of his command, LeMay turned SAC into a first-rate, professional service.

  It was not a moment too soon. At the beginning of the Cold War, the United States could bank on its ace-in-the-hole monopoly on nuclear weapons to make the Soviet Union think twice about launching a major armed conflict. After the Soviet detonation of its first nuclear device in 1949, the real threat of a “nuclear Pearl Harbor” became a guiding force in the formulation of American strategic policy. The Soviet sneak attack, it was theorized, could be prevented if the Russians knew their attack would result in a counterattack of greater magnitude.

  In the early 1950s, the combined inventory of B-36 and B-47 bombers provided SAC with unprecedented range, bomb capacity, and speed. They were Curtis LeMay’s “Big Stick.” However, they were products of a passing era in the rapidly advancing world of aviation technology. The B-36 was slow, and the B-47 did not have the range needed for SAC’s intercontinental mission. LeMay may have had a Big Stick, but he needed one that was both bigger and better. In Seattle, there were men at Boeing who were ready to oblige.

  A classic view of the XB-52 on an early test flight.

  BECAUSE TECHNOLOGY had advanced at a breathtaking pace during World War II, the immediate postwar period was an exciting time to be involved in aircraft engineering. However, in 1946, engineering was the only exciting place to be within the American aircraft industry.

  In the space of six years, according to the Civil Aeronautics Administration Statistical Handbook, the American aircraft industry had built 324,750 aircraft. Of these, Boeing alone had turned out 18,229. In 1944, you could walk onto the factory floor at Plant 2 of Boeing Field in Seattle and gaze upon gleaming aluminum B-17s as far as the eye could see. In 1945, you could drive a few miles to Renton and the same was true of B-29s. In 1946, you could visit either place and practically be alone with the echo of your own voice.

  Boeing’s last B-17 had rolled out early in 1945, and the B-29 program wound down a year later. An order for five-thousand B-29C aircraft, scheduled for Plant 2, had been cancelled when the war ended. The B-29D program, which was redesignated as B-50A, would proceed, but only fifty-nine were ordered through all of 1946. Boeing had the Model 377 Stratocruiser airliner program in progress, but again, the numbers were small. The aircraft industry was a bad place to be unless you were an engineer lucky enough to be assigned to looking into the future.

  For Boeing engineers, the future as viewed from 1946 included a number of aircraft that would never be built—jet fighters and long-range military transports—as well as a number of jet bomber concepts, such as Models 424, 432, and 448, which would eventually be funneled toward the Model 450, which in turn became the B-47.

  Meanwhile, the USAAF had been sifting through the technical data compiled from the success of the B-29 deployment in the strategic air war against Japan and decided upon where it wanted to go with its next-generation strategic bomber. On the Friday after Thanksgiving 1945, the USAAF completed its overview and signed off on its conclusion. Though the first flight of the B-36 was still nine months away, they were looking to the future beyond.

  The twinkle in the eye of the USAAF that became the B-52 was first seen less than a year after the end of World War II. Like the Project A and D programs a dozen years (and a technological lifetime) earlier, it was born as a design study aimed at answering a government request for proposals for an aircraft that would push the limits of performance, especially with regard to range and payload.

  The official request for proposals was sent on February 13, 1946, to Martin, as well as to Convair, the builder of the B-36, and to Boeing, who had originated the B-29. The requirements in the USAAF request called for an aircraft with a cruising speed of 300 miles per hour, a service ceiling of 34,000 feet, a 5,000-mile combat radius, and a 10,000-pound bomb load.

  On March 7, with Ed Wells leading the way, Boeing’s engineers began work on the project, which they designated as Model 462. However, to meet the requirements in the new USAAF request, jet engines could not be specified for the long-range Model 452 because they could not supply the needed range with the state of the art in 1946.

  The Model 462 took shape as straight-winged aircraft with a span of 221 feet, a sh
ade less than that of the B-36’s 230 feet. The shapes of the tail and wing design clearly showed that the 462 had roots growing out of the B-29 program. The 462 was to be powered by six Wright XT35 turboprop engines, each delivering 8,900 shaft horsepower. Boeing engineers struggled to meet the range requirement and went back to the drawing board. The result this time was the first of a long series of designs that would be designated by the company as Model 464.

  The model number was first used on May 28, 1946, with the project assigned to Donald W. Finlay, who joined Boeing in 1935 and, according to company records, was “associated in project design or in preliminary design work on every multi-engine aircraft type.”

  The early designs, such as Models 464-16 and 464-17, retained the straight wing of the Model 462, but had a shorter wingspan and four turboprops. The scale-down was reportedly to address Air Force concerns about the cost of such a new aircraft, although when it was presented the customer expressed some reticence because the early 464 designs were not a sufficient improvement over the existing B-36.

  In the meantime, Boeing aerodynamicist George Schairer had convinced Ed Wells to exploit the potential of swept wings on jet aircraft performance. This innovation, which was about to famously transform the Model 450/B-47 program, would do the same for the Model 464. Over the course of the next two years, the Model 464 program gradually changed and evolved. By the time that the series of studies progressed to the Models 464-29 through 464-35 series, the proposed aircraft’s wings had a span of 185 feet and a 20-degree sweep, but the plane was still intended to be powered by four XT35 turboprops.