B-52 Stratofortress

by Bill Yenne

  It was here at the Van Cleve Hotel in downtown Dayton, Ohio, that the B-52 was born. Boeing’s aerodynamic genius George Schairer went out to a hobby shop for balsa wood and glue, then sat down for a marathon weekend design session in October 1948 with Vaughn Blumenthal, Art Carlsen, Maynard Pennell, H. W. “Bob” Withington, and Ed Wells.

  At the same time that the Model 464 strategic bomber was working its way across the Boeing drafting tables, one of the other projects taking shape at Boeing was a smaller, shorter-range turboprop medium bomber similar in size and shape to the Model 450/B-47. When the B-47 made its first flight in December 1947 with six jet engines, its initial success and promise led to Boeing winning a contract in June 1948 to build a successor bomber under the designation B-55. This aircraft, the Boeing Model 479, would be like the Model 474, but powered by six jet engines.

  Two of the men most responsible for the B-52 were Boeing chief aerodynamicist George S. Schairer (left) and Boeing chief engineer Edward Curtis Wells.

  The larger Model 464, meanwhile, was still designed to fly with turboprops driving contra-rotating propellers. Such was the configuration that was to be submitted to the U.S. Air Force in October 1948, specifically to the Air Materiel Command (AMC) at Wright-Patterson AFB, better known as Wright-Pat, near Dayton, Ohio. The AMC and its predecessors had been the technical gateway by which new aircraft passed muster since before the U.S. Air Force was the Army Air Corps, and the base long known as Wright Field was established literally across the road from where the Wright brothers tested their earliest airplanes.

  George Schairer, accompanied by fellow aerodynamicist Vaughn Blumenthal and Art Carlsen from the production department, hand-carried the “final” Model 464-49 proposal to Wright-Patterson. The wing was still swept at 20 degrees, and the aircraft was still powered by four turboprops driving contra-rotating propellers—but the turboprop of choice had changed because of concerns about the durability of the shaft of the XT35 at high rpm. Pratt & Whitney, the largest American producer of piston engines during World War II, had started developing turboprop engines, and their TP4 (T45) engine was selected for the Model 464 program in 1947.

  The presentation was scheduled for the morning of Thursday, October 21. Coincidentally, this was exactly two days after Curtis LeMay assumed command of SAC. Of course, LeMay was not present at Wright-Pat that day, but Gen. Kenneth Bonner “K. B.” Wolfe was. The man who had commanded the first operational B-29s during World War II, Wolfe had long been involved in the development and procurement of bombers, and he was now in charge of bomber acquisition for the AMC.

  Sitting next to Wolfe across the table that morning was Col. Henry “Pete” Warden. An MIT-trained engineer, Warden had flown as a fighter pilot in the Philippines in the early days of World War II and had been at Wright Field since 1944. Having been involved in acquisition of both the B-36 and B-47, Warden had studied jet bombers to nearly the same extent as the Boeing men had. In so doing, he had developed some strong opinions.

  The Model 462 was Boeing’s first postwar heavy bomber to be more than a Model 345 (B-29/B-50) derivative aircraft.

  The Model 464-17 started out in 1946 to be a scaled-down, four-engine 462, but it was scaled up to a span of 205 feet and a gross weight of 400,000 pounds.

  The Model 464-29 emerged in August 1947 with increased wing area and a 20-degree sweep to the leading edge.

  The Model 464-35 of early 1948 looked a bit like a turboprop Model 450 (B-47), but with a 20-degree sweep to the whole wing. This was the proposal that George Schairer, Ed Wells, and the others presented in October 1948.

  The Model 464-40 was the result of an Air Force request in May 1948 to take a look at a jet-propelled variant of the Model 464-35.

  The Model 464-41 of 1948 had the same swept tail as the Models 464-35 and 464-40, but longer wings.

  The Model 464-49 was the result of the famous redesign session in the Van Cleve Hotel. It had the jet engines that the Air Force demanded, eight of them, and the wing sweep was increased to 35 degrees.

  The Model 464-54 was like the Model 464-49 in most respects, but the gracefully swept tail seen in the Models 464-35, 464-40, and 464-49 was replaced with the sharply angled, business-like tail that would be used on the B-52.

  The Model 464-67 had an extended forward fuselage and a Model 464-54 tail, but was otherwise much like the Model 464-49 that rode down in the Van Cleve elevator with the Boeing “Dream Team” in October 1948. It was built as a flyable aircraft under the designations XB-52 and YB-52.

  The dramatic rollout on the rainy night in November 1951. The mysteriously shrouded machine was the harbinger of a new chapter in Boeing and USAF history. No one could have imagined that night how long the chapter would last.

  The meeting was over almost as quickly as it began. Warden took one look at Schairer’s drawing and told him that if he did not “get rid of those propellers,” he would recommend that Boeing’s proposal be rejected. The state of the art had changed considerably since 1946, and the Air Force now insisted on jet bombers. This came as a bit of a surprise to the Boeing men, given that they had previously suggested jet propulsion in their 464-40 concept and had been rejected.

  Schairer asked the AMC men for another meeting to present a revised proposal. Warden agreed to schedule them for the following Monday, October 25—if they could meet the specifications and get rid of the propellers.

  Schairer phoned Ed Wells, who was on the next plane out of Seattle. He then went to a hobby shop and bought an armload of balsa wood and some glue. In the meantime, two other Boeing engineers, Maynard Pennell and H. W. “Bob” Withington, happened to be in town to work on the B-55 program. By Thursday night, this six-man “dream team” of Boeing technical expertise were together at the Van Cleve Hotel in downtown Dayton for a marathon redesign session. Wells sketched the new airplane freehand, while the others calculated and recalculated performance parameters. This weekend has long been a cornerstone of Boeing corporate lore. The result was a jet bomber that they called the Model 464-49.

  The YB-52 on the ramp at Boeing Field, with test markings on its fuselage and tires. The first flight of the YB-52, the first Stratofortress to fly, came on April 15, 1952, with Tex Johnston at the controls.

  On Monday morning (though some sources say it was Wednesday), Schairer, Wells, and the others were back at Wright-Pat with a proposal and a balsa-wood model—and no propellers. Instead, Boeing would use eight of Pratt & Whitney’s new J57-P-3 turbojet engines, paired in pods beneath the wings of each bomber. Having been developing the turboprop engines for the Model 464 program in its earlier configuration, Pratt & Whitney was eager to remain with the program.

  Another change that would be very important to the future of the aircraft was an increase in wing area from less than 3,000 square feet to 4,000 square feet. Wing area is an important factor in long-range operations, and the Boeing engineers felt that a mistake had been made in giving the B-47 a smaller, 1,400-square-foot wing. As with the B-47, the wing of the new aircraft was supported with outrigger landing gear on the wingtips.

  Warden liked what he saw on this go-round and promptly departed for Washington, hand-carrying both the proposal and the model, to recommend that the U.S. Air Force acquire two full-scale prototypes. On November 17, the proposal was approved by the Air Force, and a full-scale mock-up was ordered.

  A close-up view of the B-47-type canopy that was common to the XB-52 and YB-52. Curtis LeMay insisted that it be abandoned for side-by-side seating in production series aircraft, and it was.

  After the mock-up was inspected in April 1949, and further refinements were made to the design, General LeMay recommended in early 1950 that the Air Force acquire the aircraft, now designated as Model 464-67. Two virtually identical Model 464-67 jets were ordered under the XB-52 designation, but one would be completed as a service test YB-52 for accounting reasons, though there are varying accounts as to the specifics.

  The name Stratofortress was coined with reference to the
earlier Boeing Flying Fortress and Superfortress, with a nod to Boeing’s Strato airliners, specifically the Model 307 Stratoliner and Model 377 Stratocruiser.

  More than three decades later, Walter Boyne of the Smithsonian National Air and Space Museum asked Wells, Schairer, and others what they “might have done differently with the B-52 if they had had an opportunity now to change it.”

  Boyne reports that “each of the men thought the question over carefully, and each came to the conclusion that given the knowledge available at the time, they would not change the design in any way.”

  Indeed, the 464-67 aircraft were, at a glance, nearly identical to George Schairer’s hand-carved model. The wing remained at 185 feet as it had been since the swept wing was adopted. Like the model, the sweep in the 464-67 was changed from 20 to 35 degrees, the same as on the B-47. One difference was that the fuselage was lengthened by 13 feet 11 inches to 152 feet 8 inches.

  Ironically, a casualty of this turn of events was the B-55 program. If the Air Force already had the B-47, and if they were now soon to have a high-performance jet bomber with intercontinental range, what did they need with another jet medium bomber?

  Meanwhile, the Air Force had also approved a competing proposal from Convair. Because of the high priority attached to a strategic jet bomber, they decided to order two prototypes from Boeing’s rival as well and then evaluate the two pairs side by side. The Convair proposal, designated as the YB-60, was essentially a production B-36 fuselage with swept wings. Like the B-52 prototypes, each YB-60 would be powered by eight Pratt & Whitney J57-P-3 turbojets.

  Across the globe, the Soviet Union was also working on a strategic bomber with intercontinental range. Developed by the design bureau headed by Andrei Tupolev, this aircraft was nearly as large as the B-52 and it had the same parent—insofar as Tupolev had entered the field of large strategic bombers by reverse-engineering copies of the Boeing B-29 Superfortress! These aircraft, which had been interned in the Soviet Union after raids on Japan during World War II, had been meticulously copied as the Tupolev Tu-4.

  Tupolev’s new intercontinental bomber, originally designated as the Tu-20, first flew in 1952 and had the same 35-degree wing sweep as the B-52—another feature “borrowed” from Boeing. Unlike Boeing, though, Tupolev stuck with turboprop engines driving contra-rotating propellers, exactly as Boeing had proposed in the Model 464-35. Designated as Tu-95, this aircraft would be a mainstay of Soviet strategic air power throughout the Cold War, and it was still flying in the twenty-first century.

  Formal Debut

  On the rainy night of November 29, 1951, East Marginal Way was closed to traffic, and a huge airplane, draped with hundreds of square yards of white muslin, was towed across the street to Boeing Field. Some say that it was concealed for security reasons because Boeing and the Air Force wanted to conceal it from prying Soviet eyes, but others have suggested wryly that it was merely for dramatic effect.

  Some sources say that the airplane was the XB-52 (tail number 49-230), while others say that it was the YB-52 (tail number 49-231), because the YB-52 was the first to fly. Originally it was said that delays in equipment installation put the XB-52 behind schedule, but in later years, information has come to light to suggest that it was because the XB-52’s pneumatic system malfunctioned during tests, and the wings were damaged.

  With its wheels rotating into the wheel wells, the YB-52 takes off for a test flight, circa 1952.

  Alvin “Tex” Johnston, the legendary Boeing test pilot, was in the pilot’s seat for taxi tests, as well as for the April 15, 1952, debut flight of the YB-52. Col. Guy Townsend, the U.S. Air Force’s program man, was flying as copilot.

  “The historic importance of this initial flight was in my mind as I taxied into position,” Johnston recalls in his memoirs. “Boeing Field’s single runway stretched ahead past the company ramp, with city streets and hillsides crowded with men and women whose hopes and dreams hinged on the success of this airplane. With temperatures and pressures normal, all takeoff checks completed, and takeoff clearance, I advanced the throttles to l00-percent power and released the brakes. With an awesome eight-engine roar, the YB-52 sprang forward, accelerating rapidly, wings curving upward as they accepted the 235,000-pound initial flight gross weight. At [takeoff speed] the airplane lifted off the runway, because of the 6-degree angle of incidence of the wing, and at 11:08 a.m. we were airborne. . . . At three hours and eight minutes, the flight of the YB-52 [to Larson AFB in Moses Lake, Washington] was the longest duration maiden flight in the history of aviation and it introduced one of the world’s great airplanes.”

  The first Convair YB-60 made its debut flight three days later. The XB-52 followed on October 2, but by then the YB-60 program had been terminated, the aircraft having proven itself to be too slow.

  In demonstrating the Stratofortress for President Dwight Eisenhower, Tex Johnston took off with a partial fuel load and a light gross weight, which permitted a spectacular climb-out angle and a steep left chandelle as he brought the Stratofortress back over the field at 300 feet.

  The Boeing YB-52, circa 1953. USAF

  After the flight, Johnston invited Eisenhower aboard for a cockpit tour, “which the president accepted, much to the alarm of the Secret Service agents.” With the president seated in the pilot’s seat, he explained the cockpit and the president “made it clear that he was amazed that an airplane of such magnitude could execute the flight maneuvers he had witnessed. So were many other people.”

  Like the B-47, both the XB-52 and YB-52 prototypes had tandem seating for the flight crew under a narrow teardrop canopy. After LeMay’s first flight in the YB-52, Boeing president Bill Allen asked “How do you like her, General?”

  As Tex Johnston writes, “LeMay lit a cigar, placed the Zippo lighter in his pocket, looked Allen in the eye, and said, ‘You have a hell of an airplane, Allen. As soon as you put a side-by-side cockpit on it, I’ll buy some.’” The Boeing team quickly redesigned the flight deck for side-by-side seating in all subsequent aircraft.

  Recalling his own first flight in the B-52 with LeMay aboard, Johnston explains that he rolled to a 40-degree bank, executed a 180-degree turn, rolled to 40 degrees in the opposite direction, pulled around another 180 degrees, and said, “‘It’s all yours.’ [LeMay] wasn’t bashful. He executed several identical maneuvers and said, ‘This is what we’ve been waiting for.’”

  A head-on view of the B-52B assembly line at Boeing Field in Seattle. Note the tipped-down position of the tail, a feature that permitted the huge bomber to be built in a factory that once built B-17s.

  THE STRATOFORTRESS was formally ordered into production on December 16, 1952, less than three months after the first flight of the XB-52. The initial order called for thirteen B-52As (Model 464-201-0), but only three were built, as more of a service test series. By the time of the first flight, the other ten had been redesignated as RB-52B reconnaissance variants (Model 464-201-3) with an increased gross weight, designed to carry crewed reconnaissance pods in their bomb bays.

  The pods had the capability of carrying a variety of optical equipment, including K-17, K-22, K-36, or K-38 cameras, as well as T-11 mapping cameras. Electronic equipment carried included AN/APR-9, AN/APR-14, and AN/ARR-88 panoramic radar receivers. Photoflash bombs were also carried in the bomb bay adjacent to the pod. The pods were removable, so that the aircraft could still be used to carry bombs. In fact, unlike the B-47, which was widely used in a reconnaissance role, the RB-52Bs were rarely flown with their pods.

  Originally ordered in June 1952, the “B” series was to have been comprised entirely of RB-52B reconnaissance aircraft, but additional orders for RB-52Bs alternated with orders for B-52B bombers (Model 464-201-4) after 1953. In the end, twenty-seven RB-52Bs and twenty-three B-52Bs were built. Because of the infrequent use of the reconnaissance capability, the Air Force generally referred to the fleet simply by the B-52B designation. In fact, the aircraft delivered as B-52B also had the capability of accommodating
the pods, so the differences were slight.

  One difference which did set the B model apart from other Stratofortresses was the tail gun arrangement. While the turrets of all other variants, from the B-52A through the B-52G, used the quad-fifty arrangement of four .50-caliber machine guns, the turrets of eighteen RB-52Bs and sixteen B-52Bs were delivered with a pair of M24A1 20mm cannons and an MD-5 fire control system.

  The Stratofortress production series aircraft evolved quickly. The first B-52A (Model 464-201-0) made its maiden flight on August 5, 1954, followed by the first B-52B (Model 464-201-3) on January 25, 1955. The first of thirty-five B-52Cs (Model 464-201-6) took to the air on March 9, 1956. Like all the “B” models, the B-52Cs were built with a reconnaissance capability but were designated as B-52C rather than RB-52C. The B-52C was also equipped with the AN/ASB-15 navigation and bombing system, an improvement over the Sperry K-3A bombing system of the B-52B.

  Through the eleventh B-52B, the engines for the Stratofortress were Pratt & Whitney J57-P-1Ws, like those of the prototypes but with water injection for improved performance. As the aircraft rolled out, the engines were gradually upgraded to J57-P-19W standard in the B-52B and J57-P-29W in the B-52C.

  A Block 35 B-52B over a winter wonderland, circa 1955. USAF

  The second of a total of thirty-five B-52C aircraft in flight. The variant made its first flight on March 9, 1956. USAF