Sir George Cayley

Date: Born on December 27, 1773, in Scarborough, Yorkshire, England; died on December 15, 1857, in Brompton, Yorkshire, England
Definition: Early nineteenth century theoretician and experimenter who laid the foundation for heavier-than-air vehicle design.
Significance: Cayley was the first to conceive and publish the modern idea of the airplane: namely, the concept that an airplane should consist of one or more fixed wings, a fuselage, and a tail. He also designed and flew model gliders complete with control surfaces, was the first scientist to perform detailed tests of lift and drag as a function of angle of attack, and championed powered airplanes during the age of balloons.
George Cayley was born in Yorkshire, England in 1773 to a wealthy landowning family of noble lineage. He was privately tutored, with emphases on the scientific and mechanical arts, at which he excelled.
Although his official duties revolved around the administration of Brompton Hall, his baronial estate, Cayley applied his inquisitive mind to a wide range of practical issues affecting early nineteenth century English society. He devised a hot-air engine in 1799, more than a decade before the engine built by the Reverend Robert Stirling, whose name has since been attached to the concept. He directed the Polytechnic Institution in Regent Street, London, from its inception in 1839 to showcase technical achievements. He contributed improvements to railway carriage safety during the fledgling years of the railroad industry. He carried out experiments on ballistics and airships. He also invented several versions of an articulated mechanical hand to replace a lost limb.
Despite these many and varied achievements, Cayley is chiefly commemorated as the father of aerial navigation, a title first bestowed on him by the unsuccessful airplane designer William S. Henson, in an 1846 letter to Cayley. The appellation has since been reinforced by the discovery and publication in 1933 of Cayley’s experimental notebooks, which along with his published writings, convey a sound knowledge of the dynamics of heavier-than-air flight almost a century before the Wright brothers applied themselves to the topic.
As early as 1799, Cayley had engraved on a small disk the force balance on a rudimentary aircraft. By 1804, he was performing whirling-arm experiments on the lift and drag characteristics of thin plates at low angles of attack and had noted the benefits of camber. In 1809 and 1810, he published seminal articles in Nicholson’s Magazine that examined power requirements, structural issues, and aerodynamics for airplanes that could carry human passengers, given a sufficiently large lifting surface and a suitably light prime mover, or propulsion system. His sketchbooks show model vehicles with a movable rudder and tail, a variable center of gravity, and a dihedral angle for lateral stability.
Late in life, Cayley designed a remarkable vehicle that was described in an 1843 article in Mechanics’ Magazine. It featured airscrews for vertical liftoff that converted to flat planes for horizontal flight under the impetus of a propeller. In 1849, Cayley published the results of model glider experiments and by 1852 had designed a vehicle with a 500-square-foot lifting surface, weighing 300 pounds and capable of supporting a person on board. It appears that he did oversee some manned glider experiments on his estate in or around the same year. Active almost to the end of his life, Cayley died at home on December 15,1857, just short of his eighty-fourth birthday.