In lieu of an abstract, here is a brief excerpt of the content:

14  H I G H - S P E E D D R E A M S World War II witnessed the introduction of two key technologies that promised to revolutionize air transportation in the postwar period, the turbojet engine and the swept wing. Both of these permitted substantial increases in aircraft speed. Even before war’s end, the U.S. Army Air Forces and the National Advisory Committee for Aeronautics (NACA) had taken steps to develop and integrate these technologies into faster aircraft. By 1947, the two agencies were preparing several different aircraft that they hoped would fly at supersonic speeds. Their attempt to break the sound barrier was driven in equal measure by a belief that faster aircraft would have great military utility and by the NACA’s desire to investigate the exotic conditions of supersonic flight. Above about Mach .8, shockwave formation on aircraft surfaces caused control problems and a rapid increase in drag. Above the speed of sound, estimated drag would be twice that experienced by a subsonic jet airliner at its cruising speed. As speed increased further, aircraft would experience heating, although aerodynamicists had no good estimates of this effect. Using an experimental rocket plane, the two organizations succeeded at “going supersonic” in October 1947; over the next fifteen years, working with several different contractors, they pursued ever larger, faster supersonic aircraft. By 1958, the Air Force’s Wright Air Development Center had produced a supersonic bomber roughly the same size as the Boeing B-47 and had a far larger supersonic bomber prototype being built by North American Aviation. The rapid progress in supersonics led to tremendous enthusiasm for the technology. Aircraft engineers who had entered the 1950s highly skeptical of the commercial potential of supersonic aircraft met the next decade believing that commercial supersonic flight was just around the corner. 1CONSTRUCTING THE SUPERSONIC AGE Accomplishing supersonic flight required massive investments of both money and skills. While the first breaching of the sound barrier proved surprisingly easy, the rocket plane the United States had used could not stay supersonic—or even airborne—for more than a few minutes. There were a variety of reasons for this: its rocket engine burned fuel prodigiously, the craft’s aerodynamics proved not to be particularly efficient, and the aircraft had not been designed to withstand the heat supersonic flight produced over long periods of time. Replacing the voracious rocket engine with a more fuel-efficient air-breathing jet meant coming to an understanding of how supersonic air would behave in an engine. Jet engines capable of operating efficiently at the high temperatures involved in supersonic flight had to be developed. Militarily useful supersonic aircraft would also have to be more aerodynamically efficient. These problems all appeared solvable in 1950, but they would require time and money. The Air Force and the NACA developed a wide variety of experimental aircraft and prototypes in their effort to make supersonic flight routine. The two agencies did not formally collaborate outside the X-plane research they performed at Muroc Dry Lake, in the California desert.1 Instead, research activities at the NACA’s major laboratories in Virginia, Ohio, and California produced new concepts that the Air Force had its contractors immediately apply to new aircraft programs. The new ideas were often communicated informally by contacts between engineers at the two agencies well before they were fully explored and published. This led to very rapid innovation and also high technical risk. Applying a new idea that was not yet fully understood could result in a superior aircraft or a bad one. In the hothouse aeronautical R&D environment that existed during the 1950s, success and failure came in roughly equal measure. But engineers learn at least as much from failure as from success, and by the late 1950s, the aeronautical engineering community had learned a great deal about supersonics.2 Yet while the engineering community had learned a great deal during their military quest for ever higher speed, it ended the decade with a substantial gap in its collective knowledge. Engineers still had not developed the ability to accurately estimate the performance of supersonic aircraft from paper studies and wind tunnel experiments, and one historian has argued that the Air Force’s technological ambitions had run far ahead of aeronautical science.3 This helped lead to enormous contract overruns as companies struggled to meet performance guarantees they had given. The quest for speed also caused C O N S T R U C T I N...

Share