[1]. Russell E. Lee, “Famous Firsts in Helicopter History,” in Walter J. Boyne and Donald S. Lopez, eds., Vertical Flight: The Age of the Helicopter (Washington: Smithsonian Institution Press, 1984), p. 248; Don Fertman, “The Helicopter History of Sikorsky Aircraft,” Vertiflite, vol. 30, No. 4 (May/June 1984), p. 16; Mike Debraggio, “The American Helicopter Society—A Leader for 40 Years,” Vertiflite, vol. 30, No. 4 (May/June 1984), p. 56.
[2]. F.B. Gustafson, “A History of NACA Research on Rotating-Wing Aircraft,” Journal of the American Helicopter Society, vol. 1, No. 1 (Jan. 1956), p. 16.
[3]. Edgar C. Wood, “The Army Helicopter, Past, Present and Future,” Journal of the American Helicopter Society, vol. 1, No. 1 (Jan. 1956), pp 87–92; Lt. Gen. John J. Tolson, Airmobility, 1961-1971, a volume in the U.S. Army Vietnam Studies series (Washington, DC: Army, 1973), pp. 16–24; and J. A. Stockfisch, The 1962 Howze Board and Army Combat Developments, Monograph Report MR-435-A (Santa Monica: The RAND Corporation, 1994).
[4]. This case study has drawn upon two major sources covering the period 1930 through 1984 published in Vertiflite, the quarterly magazine of the American Helicopter Society: Frederic B. Gustafson, “History of NACA/NASA Rotating-Wing Aircraft Research, 1915–1970,” Vertiflite, Reprint VF-70, (Apr. 1971), pp. 1–27; and John Ward, “An Updated History of NACA/NASA Rotary-Wing Aircraft Research 1915-1984,” Vertiflite, vol. 30, No. 4 (May/June 1984), pp. 108–117. The author (who wrote the second of those two) has extended the coverage beyond the original 1984 end date.
[5]. J.B. Wheatley, “Lift and Drag Characteristics and Gliding Performance of an Autogiro as Determined In Flight,” NACA Report No. 434 (1932).
[6]. J.B. Wheatley, “A Aerodynamic Analysis of the Autogiro Rotor With Comparison Between Calculated and Experimental Results,” NACA Report No. 487 (1934).
[7]. Anon., “Proceedings of Rotating-Wing Aircraft Meeting of the Franklin Institute, Philadelphia, Pennsylvania, Oct. 20–29, 1938,” Philadelphia Section, Institute of the Aeronautical Sciences (IAS); Anon., “Proceedings of the Second Annual Rotating-Wing Aircraft Meeting of the Franklin Institute, Philadelphia, Pennsylvania, Nov. 30–Dec. 1, 1939,” Philadelphia Section, Institute of the Aeronautical Sciences (IAS).
[8]. F.J. Bailey, Jr., “A Simplified Theoretical Method of Determining the Characteristics of a Lifting Rotor in Forward Flight,” NACA Report No. 716 (1941).
[9]. F.B. Gustafson, “Effects on Helicopter Performance of Modifications in Profile-Drag Characteristics of Rotor-Blade Airfoil Sections,” NACA WR-L-26 [formerly NACA Advanced Confidential Report ACR L4H05] (1944).
[10]. Alfred Gessow and Garry C. Myers, Jr., Aerodynamics of the Helicopter (New York: The Macmillan Company, 1952; reissued by Frederick Ungar Publishing Co., 1967).
[11]. R.P. Coleman, “Theory of Self-Excited Mechanical Oscillations of Hinged Rotor Blades,” NACA WR-L-308 [formerly NACA Advanced Restricted Report 3G29] (1943).
[12]. G.W. Brooks, “The Application of Models to Helicopter Vibration and Flutter Research,” Proceedings of the ninth annual forum of the American Helicopter Society (May 1953).
[13]. George E. Cooper, “Understanding and Interpreting Pilot Opinion,” Aeronautical Engineering Review, vol. 16, No. 3, (Mar. 1957), p. 47–51.
[14]. S. Salmirs and R.J. Tapscott, “The Effects of Various Combinations of Damping and Control Power on Helicopter Handling Qualities During Both Instrument and Visual Flight,” NASA TN-D-58 (1959).
[15]. G.E. Cooper and R.P. Harper, Jr., “The Use of Pilot Rating in the Evaluation of Aircraft Handling Qualities,” NASA TN-D-5153 (1969).
[16]. Harry H. Heyson and S. Katzoff, “Induced Velocities Near a Lifting Rotor with Nonuniform Disk Loading,” NACA Report 1319 (1957).
[17]. Edwin P. Hartman, Adventures in Research, A History of Ames Research Center,1940–1965, NASA SP-4302 (Washington, DC: NASA, 1970), p. 411.
[18]. William Warmbrodt, Charles Smith, and Wayne Johnson, “Rotorcraft Research Testing in the National Full-Scale Aerodynamics Complex at NASA Ames Research Center,” NASA TM-86687 (May 1985); J. Sheiman and L.H. Ludi, “Qualitative Evaluation of Effect of Helicopter Rotor Blade Tip Vortex on Blade Airloads,” NASA TN-D-1637 (1963).
[19]. James Sheiman, “A Tabulation of Helicopter Rotor-Blade Differential Pressures, Stresses, and Motions As Measured In Flight,” NASA TM-X-952 (1964).
[20]. John F. Ward, “Helicopter Rotor Periodic Differential Pressures and Structural Response Measured in Transient and Steady-State Maneuvers,” Journal of the American Helicopter Society, vol. 16, No. 1 (Jan. 1971).
[21]. F. Garren, J.R. Kelly, and R.W. Summer, “VTOL Flight Investigation to Develop a Decelerating Instrument Approach Capability,” Society of Automotive Engineers Paper No. 690693 (1969), presented at the Aeronautics and Space Engineering and Manufacturing Meeting, Los Angeles, CA, Oct. 6–10, 1969.
[22]. Wilmer H. Reed, III, “Review of Propeller-Rotor Whirl Flutter,” NASA TR-R-264 (1967).
[23]. William T. Yeager, Jr., and Raymond G. Kvaternik, “A Historical Overview of Aeroelasticity Branch and Transonic Dynamics Tunnel Contributions to Rotorcraft Technology and Development,” NASA TM-2001-211054 / ARL-TR-2564, (Aug. 2001).
[24]. R.J. Huston, “An Exploratory Investigation of Factors Affecting the Handling Qualities of a Rudimentary Hingeless Rotor Helicopter,” NASA TN-D-3418 (May 1966).
[25]. I.H. Culver and J.E. Rhodes, “Structural Coupling in the Blades of a Rotating Wing Aircraft,” IAS Paper No. 62-33 (1962).
[26]. J.R. Kelly, F.R. Niessen, J.J. Thibodeaux, K.R. Yenni, and J.F. Garren, Jr., “Flight Investigation of Manual and Automatic VTOL Decelerating Instrument Approaches and Landings,” NASA TN-D-7524 (July 1974).
[27]. R.G. Kvaternik and W.G. Walton, Jr., “A Formulation of Rotor-Airframe Coupling for the Design Analysis of Vibrations of Helicopter Airframes,” NASA RP-1089 (June 1982).
[28]. Karen Jackson, Richard L. Boitnott, Edwin L. Fasanella, Lisa E. Jones, and Karen H. Lyle, “A Summary of DOD-Sponsored Research Performed at NASA Langley’s Impact Dynamics Research Facility,” Journal of the American Helicopter Society, vol. 51, No. 1 (June 2004).
[29]. H.K. Edenborough, T.M. Gaffey, and J.A. Weiberg, “Analysis and Tests Confirm Design of Proprotor Aircraft,” AIAA Paper No. 72-803 (1972).
[30]. James R. Hansen, Spaceflight Revolution, Langley Research Center From Sputnik to Apollo, NASA SP-4308 (Washington, DC: NASA 1995), pp. 81–111.
[31]. A.W. Linden and M.W. Hellyer, “The Rotor Systems Research Aircraft,” AIAA Paper No. 74-1277 (1974).
[32]. Jack N. Nielsen and James C. Biggers, “Recent Progress in Circulation Control Aerodynamics,” AIAA Paper No. 87-0001 (1987).
[33]. W. Warmbrodt and J.L. McCloud, II, “A Full-Scale Wind Tunnel Investigation of a Helicopter Bearingless Main Rotor,” NASA TM-81321 (1981).
[34]. M. Mosher and R.L. Peterson, “Acoustic Measurements of a Full-Scale Coaxial Helicopter,” AIAA Paper No. 83-0722 (1983).
[35]. Robert C. Ball, “Summary Highlights of the Advanced Rotor Transmission (ART) Program,” AIAA Paper No. 92-3362 (1992).
[36]. Wayne Johnson, Helicopter Theory (Princeton: Princeton University Press, 1980).
[37]. D.C. Dugan, R.G. Erhart, and L.G. Schroers, “The XV-15 Tilt Rotor Research Aircraft,” NASA TM-81244 / AVRADCOM Technical Report 80-A-15 (1980).
[38]. Martin D. Maisel, Demo J. Giulianetti, and Daniel C. Dugan, The History of The XV-15 Tilt Rotor Research Aircraft From Concept to Flight, NASA SP-2000-4517 (Washington, DC: NASA, 2000).
[39]. Brenda Forman, “The V-22 Tiltrotor ‘Osprey:’ The Program That Wouldn’t Die,” Vertiflite, vol. 39, No. 6, (Nov./Dec. 1993), pp. 20–23.
[40]. Jack G. McArdle, “Outdoor Test Stand Performance of a Convertible Engine with Variable Inlet Guide Vanes for Advanced Rotorcraft Propulsion,” NASA TM-88939 (1986).
[41]. Raymond G. Kvaternik, “The NASA/Industry Design Analysis Methods for Vibration (DAMVIBS) Program—A Government Overview,” AIAA Paper No. 92-2200 (1992).
[42]. B.P. Gupta, A.H. Logan, and E.R. Wood, “Higher Harmonic Control for Rotary Wing Aircraft,” AIAA Paper No. 84-2484 (1984).
[43]. Ruth M. Martin, “NASA/AHS Rotorcraft Noise Reduction Program: NASA Langley Acoustics Division Contributions,” Vertiflite, vol. 35, No. 4, (May/June 1989), pp. 48–52.
[44]. W.R. Mantay, W.T. Yeager, Jr., M.N. Hamouda, R.G. Cramer, Jr., and C.W. Langston, “Aeroelastic model Helicopter Testing in the Langley TDT,” NASA TM-86440 / USAAVSCOM TM-85-8-5 (1985).
[45]. Robert J. Huston, Robert A. Golub, and James C. Yu, “Noise Considerations for Tilt Rotor,” AIAA Paper 89-2359 (1989).
[46]. Glenn E. Bugos, Atmosphere of Freedom, Sixty Years at the Ames Research Center, NASA SP-4314 (Washington, DC: NASA 2000), pp. 211–246.
[47]. Maisel, et al., History of the XV-15 Tilt-Rotor, pp. 110–114.
[48]. William J. Snyder, John Zuk, and Hans Mark, “Tilt Rotor Technology Takes Off,” AIAA Paper 89-2359 (1989).
[49]. Wayne Johnson, “Model for Vortex Ring State Influence on Rotorcraft Flight Dynamics,” NASA TP-2005-213477 (2005).
[50]. The Center for Rotorcraft Innovation (CRI) Web site is: http://www.irotor.org.
[51]. David D. Few, “A Perspective on 15 Years of Proof-of-Concept Aircraft Development and Flight Research at Ames—Moffett by the Rotorcraft and Powered-Lift Flight Projects Division, 1970-1985,” NASA RP-1187 (1987).
[52]. Edwin W. Aiken, Robert A. Jacobson, Michelle M. Eshow, William S. Hindson, and Douglas H. Doane, “Preliminary Design Features of the RASCAL—A NASA/Army Rotorcraft In-Flight Simulator,” AIAA Paper 92-4175 (1992); Robert T.N. Chen, William S. Hindson, and Arnold W. Mueller, “Acoustic Flight Tests of Rotorcraft Noise-Abatement Approaches Using Local Differential GPS Guidance,” NASA TM-110370 (1995); Robert M. Kufeld and Paul C. Loschke, “UH-60 Airloads Program—Status and Plans,” AIAA Paper 91-3142 (1991).
[53]. In 2003, Congress authorized the Joint Planning and Development Office (JPDO) coordinating the activities of multiple Federal agencies in planning Next Generation Air Transportation System to implement the transformation of the national airspace system.
[54]. Mark Liptak, “International Helicopter Study Team (IHST) Overview Briefing,” presented at Helicopter Association International HELI EXPO Meeting, Houston, TX, Feb. 21–23, 2009 (see http://www.ihst.org).