NASA AERONAUTICS BOOK SERIES A I 3 A 1 A 0 2 H D IS R T A O W RY T A Bruce I. Larrimer MANUSCRIP . Bruce I. Larrimer Library of Congress Cataloging-in-Publication Data Larrimer, Bruce I. Thinking obliquely : Robert T. Jones, the Oblique Wing, NASA's AD-1 Demonstrator, and its legacy / Bruce I. Larrimer. pages cm Includes bibliographical references. 1. Oblique wing airplanes--Research--United States--History--20th century. 2. Research aircraft--United States--History--20th century. 3. United States. National Aeronautics and Space Administration-- History--20th century. 4. Jones, Robert T. (Robert Thomas), 1910- 1999. I. Title. TL673.O23L37 2013 629.134'32--dc23 2013004084 Copyright © 2013 by the National Aeronautics and Space Administration. The opinions expressed in this volume are those of the authors and do not necessarily reflect the official positions of the United States Government or of the National Aeronautics and Space Administration. This publication is available as a free download at http://www.nasa.gov/ebooks. Introduction v Chapter 1: American Genius: R.T. Jones’s Path to the Oblique Wing .......... ....1 Chapter 2: Evolving the Oblique Wing ............................................................ 41 Chapter 3: Design and Fabrication of the AD-1 Research Aircraft ................75 Chapter 4: Flight Testing and Evaluation of the AD-1 ................................... 101 Chapter 5: Beyond the AD-1: The F-8 Oblique Wing Research Aircraft ....... 143 Chapter 6: Subsequent Oblique-Wing Plans and Proposals ....................... 183 Appendices Appendix 1: Physical Characteristics of the Ames-Dryden AD-1 OWRA 215 Appendix 2: Detailed Description of the Ames-Dryden AD-1 OWRA 217 Appendix 3: Flight Log Summary for the Ames-Dryden AD-1 OWRA 221 Acknowledgments 230 Selected Bibliography 231 About the Author 247 Index 249 iii This time-lapse photograph shows three of the various sweep positions that the AD-1's unique oblique wing could assume. (NASA) iv On December 21, 1979, the National Aeronautics and Space Administration (NASA) AD-1 Oblique Wing Research Aircraft (OWRA) took off from the main runway at Edwards Air Force Base (AFB), CA, for a 45-minute checkout flight. It marked the world’s first flight of a piloted oblique-wing airplane. This historic flight, which was flown with the airplane’s wing at its “straight” (0-degree angle) position, was soon followed by flights at wing angles of 15 degrees, 20 degrees, 45 degrees, and finally on April 24, 1981, at the 60-degree-angle design goal, thus proving the aerodynamic concept of an airplane with an oblique-wing configuration. This initial oblique-wing program, which ran from 1976 through 1982, was a joint effort between NASA’s Ames Research Center and Dryden Flight Research Center, CA, thus giving rise to the aircraft’s name—Ames-Dryden AD-1 Oblique Wing Research Aircraft.1 Extensive research, wind tunnel and computer-code testing, and model-building and testing projects were undertaken at Ames, and flight simulation, flight testing, and flight evalu- ation were conducted at Dryden. While the concept of the oblique wing was developed during World War II, and the landmark wind tunnel tests of John P. Campbell and Hubert M. Drake were undertaken just follow- ing the end of the war, most aeronautical attention in the postwar era concentrated on the continuous refinement of symmetrical point-forward swept-wing aircraft. Serious attention, however, once again turned to the oblique wing in the 1970s, resulting in the research activities discussed in this book. Chapter 1 reviews the life of NASA aerodynamicist Robert T. Jones and his path to the oblique wing. Chapter 2 covers the extensive wind tunnel, model, computer-code, and simulation testing, first at Langley and later at Ames, as well as a number of NASA industry design contracts undertaken by Boeing and Lockheed. Chapter 3 reviews the design and fabrication of the AD-1 Oblique Wing Research Aircraft and its subsequent proposed use as a joined-wing demonstrator. Chapter 4 describes the flight test- ing and flight evaluation of the AD-1. Chapter 5 reviews the supersonic F-8 followup oblique-wing program. And, finally, chapter 6 reviews the subsequent oblique-wing plans and proposals. Appendices present the physical characteristics of the AD-1 aircraft, a detailed description of it, and a summary flight log of its flight research program. v Thinking Obliquely Writing the history of the AD-1 proved both a challenge and a pleasure. I am very grateful to all who have assisted me in this endeavor. A listing of those who were particularly helpful follows the appendices. Bruce I. Larrimer Columbus, OH March 12, 2012 1. From September 27, 1959, until March 26, 1976, NASA Dryden was known as the NASA Flight Research Center. From March 26, 1976, until October 1, 1981, the Center was known as the NASA Hugh L. Dryden Flight Research Center. From October 1, 1981, until March 1, 1994, the Center was part of NASA Ames and was known as the NASA Ames-Dryden Flight Research Facility. On March 1, 1994, the Center once again became a separate operational entity and since then has used its previous designation as the NASA Hugh L. Dryden Flight Research Center, being more simply known as the NASA Dryden Flight Research Center, which is how it is referred to throughout this book. vi NACA-NASA research scientist Robert T. Jones. (NASA) viii CHAPTER 1 American Genius R.T. Jones’s Path to the Oblique Wing Robert Thomas “R.T.” Jones was born on May 28, 1910, in the farming com- munity of Macon, MO, and died on August 11, 1999, in Los Altos Hills, CA. In the intervening 89 years, Jones more than fulfilled the definition of genius, and his lifetime in aeronautics constituted a particularly productive and well- lived life. In his progression to distinction, Jones resembles far more the 17th century’s largely self-taught and broadly interested “natural philosopher” than the rigorously educated, university-trained STEM (science, technology, engi- neering, and mathematics) über-specialized professional of the modern era.1 Jones’s lifelong consuming interest in aviation started at an early age when he built rubberband-powered model airplanes and assembled airplane models with scaled drawings from the Ideal Model Airplane Supply Company. In his rural Macon, MO, high school, Jones acquired an interest in mathematics from his math teacher, Iva Z. Butler, who guided him “along the intricate path through exponents, logarithms, and trigonometry.”2 Following the nationwide increase in interest in aviation resulting from Charles Lindbergh’s nonstop transatlantic flight in 1927, Jones was readily able to purchase the magazines Aviation and Aero Digest in his hometown of Macon. These pub- lications contained technical articles, which Jones read with great inter- est, as well as notices of Technical Reports (TRs) of the National Advisory Committee for Aeronautics (NACA, the forerunner to NASA), which Jones was able to purchase from the Government Printing Office for as little as 10 or 15 cents. In regard to his interest in aviation, Jones noted that he must have puzzled his high school English teacher with all the essays he wrote on aeronautics-related subjects. After graduation, Jones attended the University of Missouri to study engineering but left college after the first year because the university did not offer courses in aeronautics and he “found the other subjects rather uninteresting.”3 In dropping out of college after a year, Jones followed in the footsteps of his father, who also had quit after 1 year, and then read the law and passed the bar examination to practice as an attorney in Missouri. 1 Thinking Obliquely The Evolution of a Practical Engineer-Scientist After leaving college, Jones returned to Macon, working for the Marie Meyer Flying Circus. In exchange for odd jobs, such as fueling its Curtiss JN-4 Jenny aircraft and patching its often-damaged fabric-covered lower wingtips, Jones received free flying lessons—although it would take another 50 years before he would make his first solo flight and subsequently receive his pilot’s license. In 1929, at the age of 19, Jones was hired as the chief and only engineer of the Nicholas-Beazley Airplane Company, Inc., of Marshall, MO, after Charles Fower, a friend of Jones’s, told Russell Nicholas that Jones “knew everything there was to know about airplanes.” Jones obtained this engineering position due to the departure of Walter Barling, who had been the principal designer of the company’s NB-3 of 1928, a low-wing, single-engine, two-place, open-cockpit monoplane of straightforward design that enjoyed brief, modest commercial success. Later, the company hired Thomas Kirkup, a certified engineer from England who taught Jones how to undertake stress calculations. At its peak production, Nicholas-Beazley, which Jones noted was well-placed to become the center of small airplane production in the United States, was producing an airplane per day, but the company failed during the Great Depression and Jones soon found himself back in his hometown of Macon. During this time back in Macon, Jones continued his self-study by reading books on aeronautics, includ- ing Max M. Munk’s Fundamentals of Fluid Mechanics for Aircraft Designers, his introduction to an individual who was himself a towering figure in aeronautics and who would have a profound effect upon Jones’s life and work.4 During the depth of the Depression, Jones, desperate for work, hitched a ride to Washington, DC, with some neighbors. Once in Washington, he immediately visited his local Congressman, who secured for him a position as an elevator operator in the House Office Building. Jones took advantage of this welcome security to further his study of mathematics by studying books from the Library of Congress and attending evening classes in aerodynam- ics taught by Max Munk at Catholic University.