In 1868, long before the advent of powered aircraft flight – and within a decade of the birth of both
Orville and Wilbur Wright – Boulton patented the first
aileron. quietly changed their aircraft flight control systems from wing warping to ailerons at that time as well. It is unknown whether Esnault-Pelterie had seen Boulton's patent or reinvented ailerons independently. Gibbs-Smith later wrote in his 1960 opus,
The Aeroplane: An Historical Survey of its Origins and Development, that "Boulton invented a method of control identical with the modern aileron control system in 1868. Had it not been overlooked, the history of the practical aeroplane would have been radically different, since it was the problem of achieving lateral stability and control that plagued the
Wrights,
Langley,
Curtiss, and the whole "European School" 30–40 years later".
Patent description of ailerons Boulton's description of his aileron control system was both clear and complete. It was "the first record we have of appreciation of the necessity for active lateral control as distinguished from [passive lateral stability].... With this invention of Boulton's we have the birth of the present-day three torque method of airborne control" as was praised by
Charles Manly. This was also endorsed by C. H. Gibbs-Smith. The patent's actual wording of ailerons reads (page 16, from line 8): Three figures (No. 5–7) of his aileron system were provided on the patent's attached drawing sheet, and on page 19 his explanation of the drawings reads (page 19, from line 22): Nowhere in the patent is there a description of mounting the ailerons on the trailing edges of the airplane's wings, where they would have induced
adverse yaw, but only "... on arms projecting from the vessel laterally". Indeed, the first ailerons used by
Robert Esnault-Pelterie in 1904 were mounted inter-wing, not on the trailing edges of the
glider's wings where they would have created
unequal aileron drag.
Ongoing controversy There are still conflicting claims today over who first invented the aileron. Other 19th century engineers and scientists, including
Charles Renard,
Alphonse Pénaud, and
Louis Mouillard, had described similar flight control surfaces, possibly serving as further inspiration to Boulton aside from Count d'Esterno. Another technique for lateral flight control,
wing warping, was also described or experimented with by several people including
Jean-Marie Le Bris,
John Montgomery,
Clement Ader,
Edson Gallaudet, D. D. Wells, and Hugo Mattullath. Aviation historian
C. H. Gibbs-Smith wrote that the aileron was "... one of the most remarkable inventions ... of aeronautical history, which was immediately lost sight of". In an apparent oversight by the
U.S. Patent Office, the
Wright brothers, on their second attempt, obtained a patent in 1906, not for the invention of an airplane (which had already existed for a number of decades in the form of gliders) but for the invention of a system of aerodynamic control that manipulated a flying machine's surfaces, including lateral flight control. They did so despite
rudders,
elevators and
ailerons having been invented long before their efforts began, and then aggressively sued other aircraft builders worldwide for failure to pay them licensing royalties on the basis of the lateral flight control described in their expansive 1906 patent. Irrespective of such controversies it was Boulton, indisputably, who was the first to patent ailerons in 1868. The ailerons used by Esnault-Pelterie in 1904 followed Boulton's concept, although it is unknown whether he had studied the 1868 work, or if he had reinvented them independently.
Other aeronautical, gas turbine and engine design research In 1864 Boulton looked at the problems of combustion at constant pressure, in connection with the operation of an
industrial gas turbine. His British patent, No. 1636 of 1864, contains points of interest. He realized that the high velocity of the gas jet exiting his combustion chamber nozzle offered a practical difficulty, and proposed to remedy this by the use of successive induced jets of increasing volume and consequently lower velocity. This was shown in his drawing, with gases being delivered through collinear nozzles of increasing diameter, with the outer nozzles operating at increased gas volumes with reduced velocities, similar to the exhaust of a high-bypass
turbofan jet engine. Another method proposed by Boulton for maintaining combustion at constant pressure was shown with gas burned in an inverted chamber under water, the products of combustion passing up through the water between the baffle plates and the mixed gases and steam being later delivered to a turbine. He went on to file a number of patents related to his gas turbine research (see patents). Boulton also attempted to build an
ornithopter, an aircraft which would create lift by the movement of its articulating wings. A manned ornithopter was later created in 2006 when teams at the
University of Toronto Institute for Aerospace Studies (UTIAS) achieved a working design with large flapping wing areas. With assist from a jet engine it only flew for about 300 meters on its only flight.
Family connection to other aviation works Besides Boulton's invention of a primary flight control, the aileron, the family name may also be associated with the well known British firm that provided wartime aircraft production as
Boulton Paul Aircraft. Boulton Paul Aircraft Ltd was a British aircraft manufacturer that was created in 1934, although its start in aircraft manufacturing began earlier in 1914, and lasted until 1961. The company mainly built and modified aircraft under contract to other manufacturers, but had a few notable designs of its own, such as the
Boulton Paul Defiant. The company's origins date back to a
Norwich ironmonger's shop founded in 1797. William Staples Boulton joined the Norfolk ironworks firm of Moore & Barnard in 1844. By 1870 William had been elevated to a partner and the firm was renamed to Barnard & Boulton, later becoming
Boulton & Paul Ltd. The latter firm began its construction engineering division in 1905. In the early 1900s, Boulton & Paul became a successful general manufacturing firm, also starting an aircraft production operation in 1914–1915. The aircraft manufacturing division was spun off from the main construction business in 1934, subsequently moving to
Wolverhampton. == Published works ==