Postwar Innovation

The B-47 Stratojet, shown making a rocket-assisted takeoff, was the first U.S. multi-engine swept-wing jet bomber The satisfaction of knowing that Boeing’s long-range heavy bombers had brought closure to the war was immediately supplanted by mounting uncertainty over the  “company’s future. The postwar years boomed for many U.S. industries, less at first for the aviation business. A few weeks after the war’s official end, employees at Boeing plants from Seattle to Wichita received the bad news: all company factories would be shut down. The year had begun with nearly 70,000 employees; 9,000 remained. The same day many Boeing plants stopped production—September 1, 1945—a new president was appointed by the board of directors. William M. “Bill” Allen, a lawyer originally from tiny Lolo, Montana, had his work cut out for him. As Nation’s Business reported, “World War II was over, and Boeing, except for a few small jobs, was out of business.” Sales that had totaled nearly $421 million in 1945 dropped to $13 million in 1946. “Profits turned to losses,” the magazine added. “But, Bill Allen didn’t panic. It was Allen’s nature to remain calm in times of duress. He had been a Boeing board director and its chief legal counsel for 15 years prior to assuming the presidency two years after Phil Johnson’s death (the post had gone unfilled in the meantime). Allen regularly understated his importance and even tried to convince Boeing’s board that he was the wrong man for the job. On that score, he  was completely wrong. As Time magazine stated in 1954, “He was no airman, but he knew Boeing’s finances inside out “Given the company’s ominous financial shape, such knowledge was required. But it was even more important for Allen and his team to strategically determine the types of aircraft the military and commercial airlines would want to buy. Many technological breakthroughs had been realized by the industry through its joint enterprises during the war. When Boeing and the other companies returned to competitive market conditions, all built upon their collective technological achievements to design and develop more advanced aircraft on their own. With military orders a fraction of their wartime volume, Boeing’s focus shifted to commercial airliners, a market that had been static during the war. Building on the company’s developments in military aircraft, Allen directed the manufacture of a luxurious commercial version of the four-engine C-97 military freighter, which itself was a derivative of the B-29 Superfortress. The commercial variant was introduced to the market as the Boeing Model 377 Stratocruiser. When the Stratocruiser entered scheduled transatlantic service from New York to London in 1949, passengers were provided foldaway sleeper berths, gilded dressing rooms, and seats with a “button to signal the stewardess. A staircase led from the main cabin, which seated four abreast, to a lounge below able to accommodate 14 passengers. “The double-decker plane was extolled in advertisements as the “new queen of the skies”—the former queen being Boeing’s 1930s-era Clipper. “Cocktails and delicious full-course meals, prepared in flight, are served with our compliments,” ads promised.“Despite its elegance and Allen’s high hopes, the plane was not a financial success. Chief rival Douglas Aircraft Company returned to prewar form with a new plane in the DC series, the DC-6. The airplane’s four Pratt & Whitney engines delivered twice the power of those used on the wartime DC-4, and the cost to buy and operate it was less than that of the Model 377. While the major airlines bought both planes and Boeing was able for the first time to make significant progress selling its aircraft to foreign airlines, the DC-6 was preferred—by far. Douglas sold 700 DC-6s; Boeing a comparatively paltry 56 Stratocruisers “But in typical Boeing style, even as the Stratocruiser faltered, the company continued to invest in research and development. With the company’s typical instinct for making the right call at the right time—and some luck—it found its footing in the most dramatic of ways. “The stunning turnabout in the commercial airliner market had all the trappings of a great adventure tale. As World War II wound down, General Henry “Hap” Arnold, commanding general of the U.S. Army Air Forces, assembled a team of scientists and engineers to undertake a highly covert operation. The project was called Luftwaffe Secret Technology, nicknamed Operation LUSTY, and the team’s goal was to hunt for German aviation technology. General Arnold appointed Theodore von Karman, a Hungarian-born scientist, to lead the team “Von Karman had escaped Germany as the Nazis came into power, and he became a naturalized American citizen. When Arnold contacted him, he was the director of the Guggenheim Aeronautical Laboratory at the California Institute of Technology. Von Karman was entrusted with assembling the top aviation engineers in the industry to join him in the hunt for the Luftwaffe’s secret aeronautical research—before the Soviets got to it. Among the first people von Karman contacted was Boeing’s chief aerodynamicist, George Schairer. At the time, Schairer was in charge of the design for a new bomber, the XB-47. Military intelligence experts were unsure where the Third Reich’s secret aeronautical research facility was located. It turned out to be deep in the countryside of the “municipality of Volkenrode, east of Hanover and north of the Harz Mountains. The facility was camouflaged much like Boeing’s wartime plant in Seattle. Hitler had directed that it be destroyed, but with the war nearly over, the research center’s superintendent was taking his time. When the Operation LUSTY team arrived, he greeted them warmly and invited them inside. What they discovered would change the course of aviation history and elevate Boeing to the top position as a manufacturer of commercial airliners.

Viewers admire a cutaway model of the 377 Stratocruiser. Boeing had high hopes for the elegant passenger plane, but it would be eclipsed by the Douglas DC-6.

Douglas returned to its pre-war dominance in passenger aircraft with the DC-6.The group uncovered a cache of priceless aeronautical data indicating that the Luftwaffe was far more technologically advanced than previously believed. This intellectual treasure included research reports describing “a jet plane with novel wings that were swept back at a diagonal toward the tail, as opposed to crossing the fuselage in the shape of the letter T. Germany had already produced the first operational jet fighter, the Messerschmitt Me 262, near the end of the war, which looked like a conventional plane, minus the propellers. The new swept-wing jet was a startling departure. The treasure trove of data also included assessments of the unique jet’s performance in a German wind tunnel, which indicated it could fly at nearly the speed of sound. The team was awed by the findings. “Even better, they were given the opportunity to interview the facility’s director, Adolf Busemann, who had worked with von Karman before the war and was considered the Luftwaffe’s top aerodynamicist. Busemann elaborated on the research findings and reminded the group that he had given a paper on swept-wing development at a conference in 1935, which several team members had actually attended and recalled. Back then they did not see the promise in the research. Now they had a different reaction: Busemann had all but built a near-supersonic jet.

Boeing’s new high-speed wind tunnel, prompted by test pilot Eddie Allen and finally built in 1944, would prove crucial to the company’s development of jet airplanes. The B-47 jet bomber was the first aircraft design tested in the wind tunnel.

“Seizing on the vital importance of the research, George Schairer dashed off a seven-page letter to his Boeing colleagues that included a drawing of the swept-back wings and key mathematical formulae. He tucked the letter into an envelope stamped “Censored” to ensure that it was delivered immediately. “We’d been searching all these years for ways to make our airplanes go faster, and here was the knowledge,” he later said. Boeing designers and engineers immediately tested the research data in the company’s new high-speed wind tunnel in consideration of using the swept-back wings on the new XB-47 bomber. The wind tunnel, competed in 1941 at the behest of test pilot Eddie Allen and at a cost of about $1 million, could reach speeds of Mach .9, just below the speed of sound. “[Schairer] made the very gutsy call to immediately stop all design work on the XB-47 [and] transform it instead into a swept-wing turbojet bomber,” said aviation expert Richard P. Hallion.Schairer’s decision was risky—Boeing was in competition with other aircraft manufacturers to win a major contract for a next-generation bomber. A revolutionary design might be considered too radical a “departure from the propeller-powered planes of the period. But as Bill Boeing had written in 1929, “Let no new improvement in flying equipment and flying pass us by.” Schairer understood the need to seize and adapt to the next technological advancement. “Not only were the jet’s swept wings decidedly progressive, but so were the engines. Although the original design for the jet had the engines mounted on the fuselage, the German engineers’ research showed that this placement increased the risk of fire. Boeing design team leaders Ed Wells and Bob Jewett decided to mount the engines in pods suspended on struts below the wing. Their wind tunnel tests of the concept proved its merit: the jet’s wing performed as if there were no pods attached. “Upon his return to America, Schairer led the effort to develop the XB-47 Stratojet bomber. Among his engineers’ concerns was that a swept-wing plane would have less lift compared to traditional straight-wing aircraft, but tests in the wind tunnel indicated that the jet’s speed made up for any difference in lift. The wind tunnel revealed other findings that resulted in more than a dozen major design revisions to the original plans and solved complex problems challenging the development of jet airplanes flying at supersonic speeds. The XB-47 was ready for takeoff. “On its maiden flight in December 1947, the jet bomber’s performance greatly exceeded that of conventional propeller-powered aircraft. Its narrow swept wing created less drag than a straight wing, permitting the jet to fly at a speed of more than 600 miles per hour, faster than any other aircraft. “When they demonstrated it for the first time to the Air Force, the Air Force sent up a fighter to chase it, and they lost the bomber,” said author Clive Irving. “They couldn’t find it. The bomber was faster than the fighter. That had never happened before. “Boeing won the contract to build the world’s first swept-wing jet bomber, later released to the Air Force as the B-47. In 1948, the government ordered 10 B-47s, which were built at Boeing’s Wichita plant. More than 2,000 B-47s ultimately were manufactured, more than a quarter of them by competitors Douglas Aircraft and Lockheed Corporation under a cooperative arrangement similar to what existed during the war. Once again, companies were eager to collaborate and learn from each other’s technological expertise and adapt this knowledge for the development of next-generation aircraft.

Upon discovering advanced German jet research, George Schairer immediately wrote a letter to his co-workers detailing the significance of the swept wing.

The XB-47 Stratojet prototype would use the German research found by Schairer to usher the United States into the jet age.

The B-47 (above and next) was the first American plane to feature swept wings and podded engines.The Douglas F4D Skyray was the Navy’s first carrier jet capable of supersonic speeds. One initial drawback to the B-47 was its range. The jet needed a large volume of fuel to reach and sustain top speed. Boeing’s solution involved another adaptation of the C-97 military freighter. The company developed an aerial tanker version of the C-97, called the KC-97 Stratofreighter, that could refuel other planes in flight using a novel telescoping pipe called a “flying boom,” which was akin to a gas station pump in the sky. An operator controlled the boom, positioning it from the tanker into a receptacle on the receiving aircraft. This was a game-changing innovation. By the mid-1950s, the KC-97 tanker could rendezvous midair with the B-47 Stratojet and quickly transfer large quantities of jet fuel, thus extending the bomber’s range. Boeing has been the U.S. military’s chief manufacturer of tanker planes ever since. North American Aviation also benefited from German research in its development of the F-86 Sabre Jet, the country’s first swept-wing jet fighter. The company manufactured more than 6,000 F-86s at its Los Angeles and Columbus, Ohio, divisions. The Sabre was the top-“performing jet fighter of its time and was followed by the F-100 Super Sabre, which served the U.S. Air Force from 1954 to 1971.

North American Aviation’s F-100 Super Sabre was the world’s first operational fighter to reach supersonic speeds in level flight. The U.S. Air Force used the jets for the Thunderbirds demonstration team from 1956 to 1968. German technical knowledge also would guide the U.S. aircraft industry’s development of missiles. The engineer in charge of the devastating German V-2 rocket’s design was Wernher von Braun. Despite his former allegiance to the Third Reich, the U.S. government was able to transfer von Braun and a number of his colleagues to America to work in rocket development. Among them was Rudolph Herman, who in 1946 would help design Boeing’s experimental Ground-to-Air Pilotless Aircraft (GAPA), a project initially funded by the U.S. Army Air Forces. The needle-nosed GAPA prototype rocket flew at supersonic speed, launching into the Utah desert sky with a thunderous roar. U.S. aircraft manufacturers combined the German scientists’ knowledge with their own engineering insights to develop a series of extremely innovative next-generation jet aircraft as well as missile and rocket technology. As had been the case from the very beginning, each aviation company’s goal was to do better than the others’ and its own previous efforts—a process of continuous improvement that is standard operating practice at Boeing today. 

Bill Allen led Boeing as the company president from 1945 until 1968. He is shown here boarding a B-47 Stratojet. Perhaps the person most impressed by the B-47 was Boeing president Bill Allen. Eager to experience the sensation of jet flight, Allen caught a ride on the military jet plane in 1950. As it ascended at 600 miles per hour to an altitude of 35,000 feet, Allen had a transforming experience. The jet traveled so smoothly and quickly, he was convinced that the future of passenger air travel was by jet. “From that moment on, there was no looking back,” said aviation writer Guy Norris. The B-47 altered the trajectory of aircraft manufacturing. For Boeing, the decision to manufacture the jet plane marked a historic transition; it would never again mass-produce a manned propeller plane. And it would never again fall behind chief rival Douglas Aircraft in the airliner market. Plans were now put forth for the 707, the jet plane that would profoundly alter the future of passenger air travel. In the meantime, the evolving Cold War continued to put pressure on American foreign policy objectives, which in turn would generate spectacular advancements in military aircraft, missiles, and rockets.

Data collected from Operation Paperclip were instrumental in the development of experimental Ground-to-Air Pilotless Aircraft (GAPA) missile tests.

Wing technology has continued to evolve since the introduction of the swept wing, as a comparison of the XB-47 Stratojet (above) and a Boeing X-48C subscale unmanned research aircraft (next) shows.