[1]. Peter W. Brooks, The Modern Airliner: Its Origins and Development (London: Putnam & Co., Ltd., 1961), pp. 91–111. Brooks uses the term to describe a category of large airliner and transport aircraft defined by common shared design characteristics, including circular cross-section constant-diameter fuselages, four-engines, tricycle landing gear, and propeller-driven (piston and turbo-propeller), from the DC-4 through the Bristol Britannia, and predominant in the time period 1942 through 1958. Though some historians have quibbled with this, I find Brooks’s reasoning convincing and his concept of such a “generation” both historically valid and of enduring value.
[2]. Quoted in Roy A. Grossnick, et al., United States Naval Aviation 1910–1995 (Washington: U.S. Navy, 1997), p. 15; Gordon Swanborough and Peter M. Bowers, United States Navy Aircraft Since 1911 (New York: Funk & Wagnalls, 1968), p. 394.
[3]. Alexander Lippisch, “Recent Tests of Tailless Airplanes,” NACA TM-564 (1930), a NACA translation of his article “Les nouveaux essays d’avions sans queue,” l’Aérophile (Feb. 1–15, 1930), pp. 35–39.
[4]. For Volta, see Theodore von Kármán and Lee Edson, The Wind and Beyond: Theodore von Kármán, Pioneer in Aviation and Pathfinder in Space (Boston: Little, Brown and Co., 1967), pp. 216–217, 221–222; Adolf Busemann, “Compressible Flow in the Thirties,” Annual Review of Fluid Mechanics, vol. 3 (1971), pp. 6–11; Carlo Ferrari, “Recalling the Vth Volta Congress: High Speeds in Aviation,” Annual Review of Fluid Mechanics, vol. 28 (1996), pp. 1–9; Hans-Ulrich Meier, “Historischer Rückblick zur Entwicklung der Hochgeschwindigkeitsaerodynamik,” in H.-U. Meier, ed., Die Pfeilflügelentwicklung in Deutschland bis 1945 (Bonn: Bernard & Graefe Verlag, 2006), pp. 16–36; and Michael Eckert, The Dawn of Fluid Dynamics: A Discipline Between Science and Technology (Weinheim: Wiley-VCH Verlag, 2006), pp. 228–231.
[5]. Adolf Busemann, “Aerodynamische Auftrieb bei Überschallgeschwindigkeit,” Luftfahrtforschung, vol. 12, No. 6 (Oct. 3, 1935), pp. 210–220, esp. Abb. 4–5 (Figures 4–5).
[6]. Theodore von Kármán, Aerodynamics (New York: McGraw-Hill Book Company, Inc., 1963 ed.), p. 133.
[7]. Ministero dell’Aeronautica, 1° Divisione, Sezione Aerodinamica Resultati di Esperienze (Rome: Guidonia, 1936); the swept “double-ender” wind tunnel study (anticipating the layout of Dornier’s Do 335 Pfeil [“Arrow”] of the late wartime years) was designated the J-10; its drawing is dated March 7, 1936. I thank Professor Claudio Bruno of the Università degli Studi di Roma “La Sapienza”; and Brigadier General Marcello di Lauro and Lieutenant Colonel Massimiliano Barlattani of the Stato Maggiore dell’Aeronautica Militare (SMdAM), Rome, for their very great assistance in enabling me to examine this study at the Ufficio Storico of the SMdAM in June 2009.
[8]. Raymond F. Anderson, “Determination of the Characteristics of Tapered Wings,” NACA Report No. 572 (1936); see in particular Figs. 15 and 16, p. 11.
[9]. For an example of such work, see Dr. Richard Lehnert, “Bericht über Dreikomponentenmessungen mit den Gleitermodellen A4 V12/a und A4 V12/c,” Archiv Nr 66/34 (Peenemünde: Heeres-Versuchsstelle, Nov. 27, 1940), pp. 6-10, Box 674, “C10/V-2/History” file, archives of the National Museum of the United States Air Force, Dayton, OH. Re: German research deficiencies, see Adolf Baeumker, Ein Beitrag zur Geschichte der Führung der deutschen Luftfahrttechnik im ersten halben Jahrhundert, 1900–1950 (Bad Godesberg: Deutschen Forschungs – und Versuchsanstalt für Luft – und Raumfahrt e. V., 1971), pp. 61–74; Col. Leslie E. Simon, German Scientific Establishments (Washington: Office of Technical Services, Department of Commerce, 1947), pp. 7–9; Helmuth Trischler, “Self-Mobilization or Resistance? Aeronautical Research and National Socialism,” and Ulrich Albrecht, “Military Technology and National Socialist Ideology,” in Monika Renneberg and Mark Walker, eds., Science, Technology, and National Socialism (Cambridge: Cambridge University Press, 1994), pp. 72–125. For science and the Third Reich more generally, see Alan D. Beyerchen, Scientists Under Hitler: Politics and the Physics Community in the Third Reich (New Haven: Yale University Press, 1977); and Kristie Macrakis, Surviving the Swastika: Scientific Research in Nazi Germany (New York: Oxford University Press, 1993).
[10]. USAAF, “German Aircraft, New and Projected Types” (1946), Box 568, “A-1A/Germ/1945” file, NMUSAF Archives; and J. McMasters and D. Muncy, “The Early Development of Jet Propelled Aircraft,” AIAA Paper 2007-0151, Pts. 1–2 (2007).
[11]. See Richard P. Hallion, “Lippisch Gluhareff, and Jones: The Emergence of the Delta Planform and the Origins of the Sweptwing in the United States,” Aerospace Historian, vol. 26, No. 1 (Mar. 1979), pp. 1–10.
[12]. Memo, Michael Gluhareff to I.I. Sikorsky, July 1941, copy in the Gluhareff Dart accession file, National Air and Space Museum, Smithsonian Institution, Washington, DC. Gluhareff’s Dart appeared contemporaneously with a remarkably similar (though with a tractor propeller) Soviet design by Alexandr Sergeevich Moskalev. Though unclear, it seems Gluhareff first conceived the planform. It is possible that an informal interchange of information between the two occurred, as Soviet aeronautics and espionage authorities kept close track of American developments and the activities of the emigree Russian community in America.
[13]. Griswold is best known as coinventor (with Hugh De Haven) of the three-point seat restraint, which formed the basis for the modern automotive seat belt; Saab then advanced further, building upon their work. See “Three-Point Safety Belt is American, not Swedish, Invention,” Status Report, vol. 35, No. 9 (Oct. 21, 2000), p. 7.
[14]. Vought-Sikorsky, “Aerodynamic Characteristics of the Preliminary Design of a 1/20 Scale Model of the Dart Fighter,” Vought-Sikorsky Wind Tunnel Report No. 192 (Nov. 18, 1942), copy in the Gluhareff Dart accession file, National Air and Space Museum, Smithsonian Institution, Washington, DC.
[15]. Letter, Roger W. Griswold to Maj. Donald R. Eastman, Oct. 22, 1946, Gluhareff Dart accession file, NASM.
[16]. M.E. Gluhareff, “Tailless Airplane,” U.S. patent No. 2,511,502, issued June 13, 1950; “Sikorsky Envisions Supersonic Airliner,” Aviation Week (May 4, 1959), pp. 67–68; M.E. Gluhareff, “Aircraft with Retractable Auxiliary Airfoil,” U.S. patent No. 2,941,752, issued June 21, 1960.
[17]. See William Sears’s biographical introduction to the “Collected Works of Robert T. Jones,” NASA TM-X-3334 (1976), pp. vii–ix; and Walter G. Vincenti, “Robert Thomas Jones,” in Biographical Memoirs, vol. 86 (Washington: National Academy of Sciences, 2005), pp. 3–21.
[18]. Transcript of interview of R.T. Jones by Walter Bonney, Sept. 24, 1974, p. 5, in Jones biographical file, No. 001147, Archives of the NASA Historical Division, National Aeronautics and Space Administration, Washington, DC.
[19]. Transcript of Jones-Bonney interview, p. 5; Hallion conversation with Dr. Robert T. Jones at NASA Ames Research Center, Sunnyvale, CA, July 14, 1977; Max M. Munk, “The Aerodynamic Forces on Airship Hills, NACA Report No. 184 (1923); Max M. Munk, “Note on the Relative Effect of the Dihedral and the Sweep Back of Airplane Wings,” NACA TN-177 (1924); H.S. Tsien, “Supersonic Flow Over an Inclined Body of Revolution,” Journal of the Aeronautical Sciences, vol. 5, No. 2 (Oct. 1938), pp. 480–483.
[20]. Note that although Lippisch called his tailless aircraft “deltas” as early as 1930, in fact they were generally broad high aspect ratio wings with pronounced leading edge taper, akin to the wing planform of America’s classic DC-1/2/3 airliners. During the Second World War, Lippisch did develop some concepts for sharply swept deltas (though of very thick and impracticable wing section). Taken all together, Lippisch’s deltas, whether of high or low aspect ratio planform, were not comparable to the thin slender and sharply swept (over 60 degrees) deltas of Jones, and Gluhareff before him, or Dietrich Küchemann at the Royal Aircraft Establishment afterwards, which were more akin to high-supersonic and hypersonic shapes of the 1950s–1960s.
[21]. For DM-1 and extrapolative tests, see Herbert A. Wilson, Jr., and J. Calvin Lowell, “Full-Scale Investigation of the Maximum Lift and Flow Characteristics of an Airplane Having Approximately Triangular Plan Form,” NACA RM-L6K20 (1947); J. Calvin Lovell and Herbert A. Wilson, Jr., “Langley Full-Scale-Tunnel Investigation of Maximum Lift and Stability Characteristics of an Airplane Having Approximately Triangular Plan Form (DM-1 Glider),” NACA RM-L7F16 (1947); and Edward F. Whittle, Jr., and J. Calvin Lovell, “Full-Scale Investigation of an Equilateral Triangular Wing Having 10-Percent-Thick Biconvex Airfoil Sections,” NACA RM-L8G05 (1948).
[22]. In 1944, Kotcher had conceived a rocket-powered “Mach 0.999” transonic research airplane (a humorous reference to the widely accepted notion of an “impenetrable” sonic “barrier”) that subsequently inspired the Bell Aircraft Corporation to undertake design of the XS-1, the world’s first supersonic manned airplane.
[23]. Kantrowitz would pioneer high-Mach research facilities design, and Soulé would serve the NACA as research airplane projects leader, supervising the Agency’s Research Airplane Projects Panel (RAPP), a high-level steering group coordinating the NACA’s X-series experimental aircraft programs.
[24]. Memo, Jones to Lewis, Mar. 5, 1945; see also ltr., Jones to Ernest O. Pearson, Jr., Feb. 2, 1960, and Navy/NACA Record of Invention Sheet, Apr. 10, 1946, Jones biographical file, NASA.
[25]. Robert T. Jones, “Properties of Low-Aspect-Ratio Pointed Wings at Speeds Below and Above the Speed of Sound,” NACA TN-1032 (1946), p. 11 [first issued at NACA LMAL on May 11, 1945].
[26]. For Millikan visit to Germany, see Millikan Diary 6, Box 35, Papers of Clark B. Millikan, Archives, California Institute of Technology, Pasadena, CA; Alexander Lippisch, ltr. to editor, Aviation Week and Space Technology (Jan. 6, 1975); in 1977, while curator of science and technology at the National Air and Space Museum, the author persuaded Jones to donate his historic delta test model to the museum; he had been using it for years as a letter opener!
[27]. Jones noted afterward that at Volta, Busemann “didn’t have the idea of getting the wing inside the Mach cone so you got subsonic flow. The real key to [the swept wing] was to get subsonic flow at supersonic speed by getting the wing inside the Mach cone . . . the development of what I would say [was] the really correct sweep theory for supersonic speeds occurred in Germany in ’43 or ’44, and with me in 1945.” (See transcript of Jones-Bonney interview, p. 6). But German researchers had mastered it earlier, as evident in a series of papers and presentations in a then-“Geheim” (“Secret”) conference report by the Lilienthal-Gesellschaft für Luftfahrtforschung, Allgemeine Strömungsforschung: Bericht über die Sitzung Hochgeschwindigkeitsfragen am 29 und 30 Oktober 1942 in Berlin (Berlin: LGF, 1942).
[28]. For his report, see Robert T. Jones, “Wing Planforms for High-Speed Flight,” NACA TN-1033 (1946) [first issued at LMAL on June 23, 1945, as Confidential Memorandum Report L5F21]. Jones’s tortuous path to publication is related in James R. Hansen’s Engineer in Charge: A History of the Langley Aeronautical Laboratory, 1917–1958, SP-4305 (Washington: NASA, 1987), pp. 284–285.
[29]. Jones, “Wing Planforms for High-Speed Flight,” NACA TN-1033, p. 1.
[30]. For the United States, this meant that Soviet intelligence collectors increasingly focused on American high-speed research. Bell Aircraft Corporation, manufacturer of the first American jet airplane, the first supersonic airplane, and advanced swept wing testbeds (the X-2 and X-5), figured prominently as a Soviet collection target as did the NACA. NACA engineer William Perl (born Mutterperl), a member of the Rosenberg spy ring who passed information on aviation and jet engines to Soviet intelligence, worked as a postwar research assistant for Caltech’s Theodore von Kármán, director of the Guggenheim Aeronautical Laboratory of the California Institute of Technology (GALCIT), the Nation’s premier academic aero research facility. He cultivated a close bond with TvK’s sister Josephine (“Pipa”) and TvK himself. Perl had almost unique access to the highest-level NACA and GALCIT reports on high-speed flight, and the state of advanced research and facilities planning for them and the U.S. Air Force. He associated as well with NACA notables, including Arthur Kantrowitz, Eastman Jacobs, and Robert T. Jones. So closely was he associated with von Kármán that he once helpfully reminded him where to find the combination to an office safe! He helped screen sensitive NACA data for a presentation TvK was making on high-speed stability and control, and TvK recommended Perl for consultation on tunnel development at the proposed new Arnold Engineering Development Center (AEDC) in Tennessee. Perl was unmasked by the Venona signals intelligence decryption program, interrogated on his associations with known Communists, and subsequently arrested and convicted of perjury. (He had falsely denied knowing the Rosenbergs.) More serious espionage charges were not brought, lest court proceedings compromise the ongoing Venona collection effort. The Papers of Theodore von Kármán, Box 31, Folder 31.38, Archives of the California Institute of Technology, and the Federal Bureau of Investigations’ extensive Perl documentation contain much revealing correspondence on Perl and his associates. I thank Ernest Porter and the FBI historical office for arranging access to FBI material. See also Katherine A.S. Sibley, Red Spies in America: Stolen Secrets and the Dawn of the Cold War (Lawrence: University Press of Kansas, 2004); and John Earl Haynes and Harvey Klehr’s Early Cold War Spies: The Espionage Trials that Shaped American Politics (Cambridge: Cambridge University Press, 2006) for further details on the Perl case.
[31]. George W. Gray, Frontiers of Flight: The Story of NACA Research (New York: Knopf, 1948), p. 348.
[32]. Re: German high-speed influence in the U.S., Britain, and Russia, see H.S. Tsien, “Reports on the Recent Aeronautical Developments of Several Selected Fields in Germany and Switzerland,” in Theodore von Kármán, ed., Where We Stand: First Report to General of the Army H.H. Arnold on Long Range Research Problems of the Air Forces with a Review of German Plans and Developments (Washington: HQ AAF, Aug. 22, 1945), Microfilm Reel 194, Papers of Gen. Henry H. Arnold, Manuscript Division, U.S. Library of Congress, Washington, DC; Ronald Smelt, “A Critical Review of German Research on High-Speed Airflow,” Journal of the Royal Aeronautical Society, vol. 50, No. 432 (Dec. 1946), pp. 899–934; Andrew Nahum, “I Believe the Americans Have Not Yet Taken Them All!” in Helmuth Trischler, Stefan Zeilinger, Robert Bud, and Bernard Finn, eds., Tackling Transport (London: Science Museum, 2003), pp. 99–138; Matthew Uttley, “Operation ‘Sturgeon’ and Britain’s Post-War Exploitation of Nazi German Aeronautics,” Intelligence and National Security, vol. 17, No. 2 (Sum. 2002), pp. 1–26; M.I. Gurevich, “O Pod’emnoi Sile Strelovidnogo Kryla v Sverkhzvukovom Potoke,” Prikladnaya Matematika i Mekhanika, vol. 10 (1946), translated by the NACA as “Lift Force of an Arrow-Shaped Wing,” NACA TM-1245 (1949). Gurevich, cofounder of the MiG bureau (he is the “G” in “MiG”) was subsequently principal aerodynamicist of the MiG-15, the Soviet Union’s swept wing equivalent to the American F-86. For a detailed examination of F-86 wing development and the influence of German work (particularly Göthert’s) upon it, see Morgan M. Blair, “Evolution of the F-86,” AIAA Paper 80-3039 (1980).
[33]. Pitch-up was of such significance that it is discussed subsequently in greater detail within this essay.
[34]. First comprehensively analyzed by Max M. Munk in his “Note on the Relative Effect of the Dihedral and the Sweep Back of Airplane Wings,” NACA TN-177 (1924).
[35]. See John E. Steiner, “Transcontinental Rapid Transit: The 367-80 and a Transport Revolution—The 1953–1978 Quarter Century,” AIAA Paper 78-3009 (1978), p. 93; John E. Steiner, “Jet Aviation Development: A Company Perspective,” in Walter J. Boyne and Donald H. Lopez, eds., The Jet Age: Forty Years of Jet Aviation (Washington: Smithsonian Institution Press, 1979), pp. 145–148; and William H. Cook, The Road to the 707: The Inside Story of Designing the 707 (Bellevue, WA: TYC Publishing Co., 1991), pp. 145–205.
[36]. See, for example, Richard T. Whitcomb, “An Investigation of the Effects of Sweep on the Characteristics of a High-Aspect-Ratio Wing in the Langley 8-Ft. High Speed Tunnel,” NACA RM-L6J01a (1947), conclusion 4, p. 19; Stephen Silverman, “The Next 25 Years of Fighter Aircraft,” AIAA Paper No. 78-3013 (1978); Glen Spacht, “X-29 Integrated Technology Demonstrator and ATF,” AIAA Paper No. 83-1058 (1983).
[37]. A.M. “Tex” Johnston with Charles Barton, Tex Johnston: Jet-Age Test Pilot (Washington: Smithsonian Institution Press, 1991), p. 105. The designation “L-39” could be taken to imply that the swept wing testbeds were modifications of Bell’s earlier and smaller P-39 Airacobra. In fact, it was coincidence; the L-39s were P-63 conversions, as is evident from examining photographs of the two L-39 aircraft.
[38]. Corwin H. Meyer, Corky Meyer’s Flight Journal: A Test Pilot’s Tales of Dodging Disasters—Just in Time (North Branch, MN: Specialty Press, 2006), p. 193.
[39]. NACA’s L-39 trials are covered in three reports by S.A. Sjoberg and J.P. Reeder: “Flight Measurements of the Lateral and Directional Stability and Control Characteristics of an Airplane Having a 35° Sweptback Wing with 40-Percent-Span slots and a Comparison with Wind-Tunnel Data,” NACA TN-1511 (1948); “Flight Measurements of the Longitudinal Stability, Stalling, and Lift Characteristics of an Airplane Having a 35° Sweptback Wing Without Slots and With 40-Percent-Span Slots and a Comparison with Wind-Tunnel Data,” NACA TN-1679 (1948); and “Flight Measurements of the Stability, Control, and Stalling Characteristics of an Airplane Having a 35° Sweptback Wing Without Slots and With 80-Percent-Span Slots and a Comparison with Wind-Tunnel Data,” NACA TN-1743 (1948). The American L-39s were matched by foreign equivalents, most notably in Sweden, where the Saab company flew a subscale swept wing variant of its conventional Safir light aircraft, designated the Saab 201, to support development of its J29 fighter, Western Europe’s first production swept wing jet, which first flew in Sept. 1948. Like both the F-86 and MiG-15, it owed its design largely to German inspiration. Saab researchers were so impressed with what they had learned from the 201 that they subsequently flew another modified Safir, the Saab 202, with a more sharply swept wing planform intended for the company’s next jet fighter, the J32 Lansen (Lance). See Hans G. Andersson, Saab Aircraft Since 1937 (Washington: Smithsonian Institution Press, 1989), pp. 106, 117.
[40]. XP-86 test report, May 21, 1948, reprinted in Roland Beamont, Testing Early Jets: Compressibility and the Supersonic Era (Shrewsbury: Airlife, 1990), p. 36. Beamont’s achievement remained largely secret; the first British pilot to fly through the speed of sound in a British airplane was John Derry, who did so in Sept. 1948.
[41]. Quote from Nigel Walpole, Swift Justice: The Full Story of the Supermarine Swift (Barnsley, UK: Pen & Sword Books, 2004), p. 38.
[42]. Charles Burnet, Three Centuries to Concorde (London: Mechanical Engineering Publications Ltd., 1979), pp. 121, 123.
[43]. Michael Collins, Carrying the Fire: An Astronaut’s Journeys (New York: Farrar, Straus, and Giroux, 1974), p. 9. Another Sabre veteran who went through Nellis at the same time recalled to the author how he once took off on a training sortie with ominous columns of lingering smoke from three earlier Sabre accidents.
[44]. For development of control boost, artificial feel, and control limiting, see Robert G. Mungall, “Flight Investigation of a Combined Geared Unbalancing-Tab and Servotab Control System as Used with an All-Movable Horizontal Tail,” NACA TN-1763 (1948); William H. Phillips, “Theoretical Analysis of Some Simple Types of Acceleration Restrictors,” NACA TN-2574 (1951); R. Porter Brown, Robert G. Chilton, and James B. Whitten, “Flight Investigation of a Mechanical Feel Device in an Irreversible Elevator Control System of a Large Airplane,” NACA Report No. 1101 (1952); James J. Adams and James B. Whitten, “Tests of a Centering Spring Used as an Artificial Feel Device on the Elevator of a Fighter Airplane,” NACA RM-L52G16; and Marvin Abramovitz, Stanley F. Schmidt, and Rudolph D. Van Dyke, Jr., “Investigation of the Use of a Stick Force Proportional to Pitching Acceleration for Normal-Acceleration Warning,” NACA RM-A53E21 (1953).
[45]. George E. Cooper and Robert C. Innis, “Effect of Area-Suction-Type Boundary-Layer Control on the Landing-Approach Characteristics of a 35° Swept-Wing Fighter,” NACA RM-A55K14 (1957), p. 11. Other relevant Ames F-86 studies are: George A. Rathert, Jr., L. Stewart Rolls, Lee Winograd, and George E. Cooper, “Preliminary Flight Investigation of the Wing-Dropping Tendency and Lateral-Control Characteristics of a 35° Swept-Wing Airplane at Transonic Mach Numbers,” NACA RM-A50H03 (1950); and George A. Rathert, Jr., Howard L. Ziff, and George E. Cooper, “Preliminary Flight Investigation of the Maneuvering Accelerations and Buffet Boundary of a 35° Swept-Wing Airplane at High Altitude and Transonic Speeds,” NACA RM-A50L04 (1951).
[46]. Edwin P. Hartman, Adventures in Research: A History of the Ames Research Center, 1940–1965, SP-4302 (Washington: NASA 1970), p. 252.
[47]. A. Scott Crossfield with Clay Blair, Always Another Dawn: The Story of a Rocket Test Pilot (Cleveland: World Publishing Co., 1960), pp. 193–194. See also W.C. Williams and A.S. Crossfield, “Handling Qualities of High-Speed Airplanes,” NACA RM-L52A08 (1952), p. 3; Melvin Sadoff, John D. Stewart, and George E. Cooper, “Analytical Study of the Comparative Pitch-Up Behavior of Several Airplanes and Correlation with Pilot Opinion,” NACA RM-A57D04 (1957).
[48]. Sadoff, Stewart, and Cooper, “Analytical Study of Comparative Pitch-Up Behavior,” p. 12.
[49]. S.A. Mikoyan, Stepan Anastasovich Mikoyan: