Holden Withington, Last Living B-52 Designer, Dies at 94 On a Friday in 1948, six aeronautical designers from the Boeing Company holed up in a hotel suite in Dayton, Ohio. They stayed put until Monday morning, except for the one who left to visit a hobby shop and returned with balsa wood, glue, carving tools and silver paint. The group emerged with a neatly bound 33-page proposal and an impressive 14-inch scale model of an airplane on a stand. Col. Pete Warden, the Air Force chief of bomber development, studied the result and pronounced, "This is the B-52." One of those six was Holden Withington, and on Dec. 9, at age 94, he became the last of the B-52 designers to die. His daughter, Victoria Withington, said he died at his home on Mercer Island, Wash. He had Alzheimer's disease. It takes a vast team of experts to design a complex airplane, particularly one like the B-52 Stratofortress, with its eight engines and radically swept-back wings. Mr. Withington, called Bob, played down the achievement, saying it evolved from earlier plane designs and not a little luck. The B-52, laden with nuclear warheads, was a forbidding-looking mainstay of American air defense during the cold war and a strategic deterrent to a nuclear attack. It saw substantial duty in Vietnam and the Iraq wars and is still in use. And its fundamental design - novel wings with engine "pods" positioned underneath - became the standard for almost all commercial jet carriers. "Essentially, they discovered the perfect form of the subsonic jet," Michael Lombardi, the Boeing Company's corporate historian, said. Airbus, Boeing, any other company, it's the basic form they follow. A year after the B-52 breakthrough, Mr. Withington and other Boeing engineers turned their attention to designing a civilian jet transport plane. They used many features of the bomber, particularly the wing design and engine placement, to create the Boeing 707, the airliner that ushered in the Jet Age. In 1941 Boeing recruited Mr. Withington from the Massachusetts Institute of Technology, where he had earned a master's degree and done research using the university's wind tunnel. His first assignment was to design and build a state-of-the-art wind tunnel for Boeing. Theodore von Karman, the eminent mathematician and aeronautical expert, passed on a piece of advice: "Make it as fast as you can." Mr. Withington didn't know anything about jets at the time, but he suspected Dr. von Karman was speaking with knowledge of Britain's top-secret research on jets. He built the wind tunnel to produce speeds of 625 miles an hour, close to the sound barrier. In 1945 George Schairer, a renowned Boeing aerodynamicist, was part of an expert group following American troops through Germany to snap up intelligence on German weapons. Mr. Schairer discovered that the Germans had performed extensive studies on swept-back wings. He sent a letter to Mr. Withington, who immediately began testing the concept in his wind tunnel. In less than a month, Mr. Withington proved that swept-back wings worked. When they were combined with jet engines, the way forward seemed clear. He tested the new wing formulation for use in Boeing's B-47 bomber, the B-52"s predecessor. He did his tests at night when power was cheaper, sleeping on a cot next to the tunnel. The resulting six-engine jet bomber perplexed even Mr. Withington. "That's a mighty strange-looking airplane," he recalled thinking in a 2002 interview. I wonder if it will really fly. It did, and the B-47 bomber was used from 1951 to 1965. But the Air Force, wanting a heavier bomber with more range, chose Boeing to build the prototype for the B-52. A debate raged in the service and beyond over the merits of a jet engine versus those of a turbo prop, which would use less fuel but sacrifice speed. The RAND Corporation, the research group, favored the turbo prop. But the turbo prop approach "just wasn't coming together," Mr. Withington told The Times of Shreveport, La., in 2002. "The program was at risk of being canceled," he said. A meeting was held at Wright Field in Dayton to address what Mr. Withington said was now viewed as a crisis. Colonel Warden decreed that the turbo prop idea should be dropped in favor of jet engines, then ordered the group back to their hotel room for their weekend of frenzied work. They used slide rules for calculations. Holden White Withington was born on Nov. 23, 1917, in Philadelphia. His family lived a peripatetic life; his father was a traveling salesman and, for a while, a bootlegger. In addition to his daughter, Mr. Withington is survived by his wife, the former Elizabeth Merrow; his sons, Vincent, Martin and Holden; and five grandchildren. After the success of the B-52, Mr. Withington climbed Boeing's executive ladder. At one point he was vice president and general manager of the company's effort to build a supersonic jetliner to challenge the Concorde of Britain and France and the Tu-144 of Russia. Congress killed the project in 1971 because of worries about sonic booms and environmental damage. He retired as vice president for engineering in 1983. Only then did he get his pilot's license. At 80, he built a two-seater airplane in his backyard.