INDIAN ARMED FORCES CHIEFS ON
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— General Manoj Pande, Indian Army Chief

 
 
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My compliments to SP Guide Publications for informative and credible reportage on contemporary aerospace issues over the past six decades.

— Air Chief Marshal V.R. Chaudhari, Indian Air Force Chief
       

George Cayley (1773 - 1857)

Issue: 01-2012By Group Captain (Retd) Joseph Noronha, Goa

He was a man in advance of his time—the first true scientific aerial investigator and the first to grasp the basic principles and forces of flight

Humanity’s conquest of the air began in June 1783 when a Montgolfier hot-air balloon soared skyward near Paris. But for several more decades, aviation was restricted to the ascent of similar lighter-than-air vehicles. Then along came Sir George Cayley who said, “The whole problem (of flight) is confined within these limits: to make a surface support a given weight by the application of power to the resistance of the air.” In other words, he proposed using an engine to create forward motion and predicted that such motion would develop lift via the wings. Sometimes called the Father of Aeronautics, Cayley achieved the first major breakthrough in heavier-than-air flight. It is widely accepted that the basic aeroplane—albeit a powerless one—was invented by Cayley in 1799 at Brompton, Yorkshire. In 1909, Wilbur Wright himself acknowledged,: “About a hundred years ago, an Englishman, Sir George Cayley, carried the science of flight to a point which it had never reached before and which it scarcely reached again during the last century.”

George Cayley was born on December 27, 1773, in Yorkshire, England, and eventually became the sixth baron of Brompton. As a lad, he would sit for hours watching how birds fly, especially the timing and the process of birds flapping their wings as they moved forward. At the time, the main scientific research into flight was devoted to the attempted construction of rudimentary ornithopters—strange contraptions that might fly by flapping their wings like birds. But Cayley later proved the utter impossibility of human flight using attached wings—because while the pectoral muscles of a bird account for more than two-thirds of its whole muscular strength, in a human being, the muscles available for “flying” do not exceed one-tenth of the body’s strength. This fact would not change no matter what mechanism might be used.

Cayley was the first to describe in engineering terms many of the concepts and characteristics of the modern aeroplane, especially lift and thrust. He built a “whirling-arm apparatus” to measure the drag on objects at different speeds and angles of attack and experimented with rotating wing sections of various forms. He would methodically test his ideas with small models before graduating to full-scale demonstrations. In the course of his experiments, he succeeded in developing an efficient cambered aerofoil to produce lift. He discovered the importance of the dihedral angle for lateral stability in flight and intentionally set the centre of gravity of many of his models well below the wings for this reason. And knowing the penalty to be paid for any extra weight in aviation construction, he literally reinvented the wheel, by using string rather than spokes in the landing gear wheel, and thus changing the absorbing force from compression to tension.

In 1799, Cayley designed a configuration that was remarkably like an aeroplane. On one side of a silver disk was etched a depiction of the forces that govern flight; on the reverse, a basic aircraft with a fixed main wing, a fuselage, a cruciform tail unit with surfaces for vertical and horizontal control and a cockpit for the pilot. The propulsion device consisted of revolving vanes, a precursor to the propeller. It lacked just one thing—an engine. Cayley built his first full-scale glider in 1849 and initially carried out trials with ballast. The 10-year-old son of one of his servants became the first person in history to fly when he made a short flight in a Cayley craft. In 1853, 50 years before the Wright Brothers’ first powered flight, Cayley built a triplane glider (a glider with three horizontal wing structures). It reportedly carried his coachman about 900 feet across Brompton Dale in the north of England before crashing—the first recorded flight by an adult in a glider. Cayley’s own portly frame may have prevented him from ever attempting to fly. He died on December 15, 1857.