John Joseph Montgomery (February 15, 1858 – October 31, 1911) was an American inventor, physicist, engineer, and professor at Santa Clara University in Santa Clara, California, who is best known for his invention of controlled heavier-than-air flying machines.

In the 1880s Montgomery, a native of Yuba City, California, made manned flight experiments in a series of gliders in the United States in Otay Mesa in San Diego, California.The Montgomery Evergreen Smithsonian National Air and Space MuseumBerriman, Algernon E. Aviation. An Introduction to the Elements of Flight, Methuen & Co., London, 1912. pp. 213-214."Montgomery's Gliding Experiments", in Hayward, Charles B. Practical Aeronautics: An Understandable Presentation of Interesting and Essential Facts in Aeronautical Science. Chicago: American School of Correspondence, 1912. Although not publicized in the 1880s, these early flights were first described by Montgomery as part of a lecture delivered at the International Conference on Aerial Navigation at Chicago, 1893.Zahm, Albert F. (1923) "Catholic Contributions in the Field of Aeronautics" in Benson, William Shepherd, James J. Walsh, Edward J. Hanna, and Constantine E. McGuire. Catholic Builders of the Nation: A Symposium on the Catholic Contribution to the Civilization of the United States. Boston: Continental Press. These independent advances came after gliding flights by European pioneers such as George Cayley's coachman in England (1853) and Jean-Marie Le Bris in France (1856).The Journal of San Diego History, July 1968, Vol. 14, No. 3. Although Montgomery never claimed firsts, his gliding experiments of the 1880s are considered by some historians and organizations to have been the first controlled flights of a heavier-than-air flying machine in AmericaNational Cyclopedia of American Biography: Being the History of the United States as Illustrated in the Lives of the Founders, Builders, & Defenders of the Republic, etc..., Edited by Distinguished Biographers, James T. White & Co. Volume XVI, 1916.Mark D. Ardema and Joseph Mach, Santa Clara University School of Engineering, and William J. Adams, Jr., "John Joseph Montgomery, 1883 Glider: An International Historic Mechanical Engineering Landmark, Designated by the American Society of Mechanical Engineers, May 11, 1996, at Hiller Aircraft Museum and Santa Clara University" (brochure, 11 pp.) or in the Western Hemisphere,"Montgomery First to Conquer the Air: Austrian Officials after Inquiry Give Palm to California Inventor," San Francisco Examiner, May 16, 1909. See also "Conquering the Air," San Francisco Monitor, June 12, 1909.Jacobs, James W. "John Joseph Montgomery." In James W. Jacobs, Enshrinee Album: The First Twenty-One Years, 13435. Dayton, Ohio: National Aviation Hall of Fame, 1984.L'Écho Des Ailes: Revue Indépendante pour la Défense des Intérêts Aéronautiques, Vol. 17, No. 2, January 23, 1948. By Fédération des Clubs Belges d'Aviation de Tourisme, Brussels, Belgium."Flug-Revue" ("Flight Review"), 1968, Vereinigte Motor-Verlage, p. 155.Hearings, Reports and Prints of the House Committee on Science and Astronautics, United States Congress. House Committee on Science and Astronautics, U.S. Govt. Printing Office, Washington D.C., 1972.Histoire de l'Aéronautique et de l'Espace, 2001.Davy, Maurice J.B. (1935) Aeronautics, Science Museum. depending on the source.

Montgomery devised different control methods for his gliders, including weight shifting for roll and an elevator for pitch (1884). Subsequent designs used hinged, pilot-operated trailing edge flaps on the wings (1885–1886) for roll control,"Machine with Wings Upsets Theories," "Years of Research Applied to Solving the Problem," San Jose Mercury Evening News, March 31, 1905."Third Tests Are All Successful," San Francisco Bulletin, March 26, 1905.Hayward, Charles B. (ed.) (1912) Practical Aeronautics, American School of Correspondence, Chicago.(Introduction written by Orville Wright) and later, full wing warping systems for roll (1903–1905)Chanute, Octave. (1907) "Montgomery." In: Pocket-Book of Aeronautics, edited by Hermann. W. L. Moedebeck, translated by W. Mansergh Varley, Vol. 309, No. 10. London: Whittaker and Co. and for both pitch and roll (1911).Campi, Richard B. (1961) "Description and Analysis of the 1911 Montgomery Controllable Man Carrying Glider." Working paper, December 29, 1961.

Education Montgomery attended St. Ignatius High School, graduating in 1873. At age 16 he attended the preparatory division at Santa Clara College from 1874 to 1876 to prepare for college.

Montgomery attended St. Ignatius College, now known as the University of San Francisco. Here, he studied under Fathers Joseph Bayma, S.J., and Joseph Neri, S.J., two gifted and influential educators. As a student in San Francisco, Montgomery must have mentioned his desire to build a flying machine, according to Fogel and Harwood. They include an observation in their book, made by Montgomery's contemporary, Rev. Fred Morrison, S.J.: “In those days anyone who even mentioned ‘man being able to fly’ was considered a little bit off. So, when John was in the vicinity, there was a general tapping of heads, which in our present day would be the sign that the party was crazy.” At St. Ignatius College, Montgomery received a Bachelor of Arts in physics in 1879 and a master's degree in physics in 1880. He also received an honorary PhD in physics from Santa Clara University in 1901.

Ornithology In the early 1880s Montgomery began studying the anatomy of a variety of large soaring birds to determine their basic characteristics like wing area, weight and curved surfaces. He made detailed observations of birds in flight, especially large soaring birds such as eagles, hawks, vultures and pelicans which soared on thermals near San Diego Bay.

He initially attempted to achieve manned flight with ornithopters. In 1883, he built and experimented with a series of three ornithopters but found that human strength was insufficient to generate the necessary lift. He abandoned flapping-wing flight, preferring instead to emulate soaring birds with fixed-wing craft. He reasoned that it would be possible to solve the physics of gliding and soaring flight and then add a motor.

Fixed-wing gliders Montgomery first tested his concepts for the design, construction and control of gliders with small-scale, free flight models. His first glider in 1883-84 had a cambered airfoil based on the curve of the seagull wing. Pitch was controlled by an operable elevator and roll was controlled by pilot weight shift. Yaw was uncontrolled. This aircraft design served as the basis for three gliders over the period 1883–1886. In the spring of 1884, Montgomery made flights of up to 600 feet (180 m) from the rim of Otay Mesa.Montgomery, James P., direct testimony in response to Q. 16, Jan. 13, 1919, Regina C. Montgomery et al. v. the United States - Equity No. 33852. During experiments with this craft, Montgomery found that the glider would not respond well to side gusts. He returned to ornithology and noted how turkey vultures had significant dihedral and twisted their wings as a form of lateral balance.

Emulating these control methods, in 1884-1885 he incorporated hinged flaps into the trailing edge of a second glider. These were held under spring tension for automatic balance in gusts, but were also connected through cables to the pilot's seat so they could be operated mechanically by the pilot for roll control.Montgomery, Richard J. Direct Testimony in Court (Equity No. 33852) on January 13, 1919. In essence these flaps were early ailerons."Montgomery Hits Wright's Patent: California College Professor Claims He Invented Warped Wings Back in 1885," New York World, April 24, 1910. The second glider had a flat plate airfoil, considerable dihedral for stability and an operable elevator for pitch control. Montgomery devised an inclined rail system so the piloted glider could roll from the top of a hill and attain flight speed.

In the winter of 1885–86, Montgomery constructed a third glider. It had a cambered airfoil modeled after the wings of a vulture, though the leading and trailing edges were turned upward slightly. The wing, spanwise, was "gull" shaped. Controls allowed the pilot to vary the angle of incidence of the left and right wing either in unison or independently. Dihedral and an operable elevator were also included. Montgomery concluded that a better understanding of aerodynamics was needed for the design of a proper airfoil.

In an 1893 speech, Montgomery said that flights were made in these three craft during the period 1884–1886, with the occasional assistance of at least three friends and two younger brothers.United States. n.d. Court of Claims of the United States. No. 33852. Regina Cleary Montgomery, heir, and Richard J. Montgomery, Mary C. Montgomery, Margaret H. Montgomery, and Jane E. Montgomery, assignees of Ellen Montgomery heir of John J. Montgomery, deceased, v. the United States." Testimony provided in direct and cross examination by Charles T. Couts, Charles Burroughs, James P. Montgomery, Richard J. Montgomery, Mary F. McCarthy, January 1919." Of the flight trials with the second craft (of 1885) Octave Chanute's account in 1893 noted "several trials were made, but no effective lift could be obtained." Of the third craft (of 1886) Chanute wrote "this last apparatus proved an entire failure, as no effective lifting effect could be obtained from the wind sufficient to carry the 180 lbs. it was designed to bear.""Chanute, Octave. (1893) Progress in Flying Machines, The American Engineer and Railroad Journal, Dec 1893.

Montgomery's own account made clear that he considered the technology of the second and third gliders of 1885 and 1886 as effective, but the airfoil designs were a disappointment in terms of lift-generation as they produced much shorter gliding flights in comparison to the first craft of 1884. He realized he was getting increasingly farther from understanding the mechanism of lift and began controlled laboratory experiments to investigate airfoils. In 1886, he briefly considered filing a patent caveat for lateral balancing, but did not.

Aerodynamics About 1885 Montgomery began a long series of experiments with a whirling arm device, a smoke chamber, a water current table and large wooden surfaces angled into the wind in order to understand the physics of flow around curved surfaces.Montgomery, John J. (1894) "Discussion of the Various Papers on Soaring Flight," Proceedings of the Conference on Aerial Navigation (M.N. Forney, ed.), Chicago, Illinois, Aug. 1-4, 1893, Published by the American Engineer and Railroad Journal, pp. 247-249. He also used dried bird wings placed in wind currents to observe the effect. His work in the 1880s confirmed that mechanical systems used by a pilot could preserve lateral balance and some degree of equilibrium in gliding flight. His experiments also confirmed the value of a cambered surface for obtaining lift.Montgomery, John J. (1894) "Discussion of the Various Papers on Soaring Flight," Aeronautics Vol. 1, No. 10 (July), pp. 127-128.