December 17, 1903, is remembered as a monumental day in aviation history — the day that Orville and Wilbur Wright achieved the age-old dream of flight and took off on the first sustained airplane ride. Several decades before the Wright brothers ascended from Kitty Hawk, however, Sir George Cayley of Yorkshire, England, launched another human briefly into flight in a makeshift glider.
Cayley, the true father of modern aviation, was the first to succeed in heavier-than-air flight and construct a human-carrying glider. He identified and mapped out the components of the modern airplane before the Wright Brothers were even born and was able to resolve some of the biggest aviation engineering challenges of his time. Although he didn’t live to see his efforts through to fruition, he turned the impossible into reality and changed the face of modern transportation forever.
“About 100 years ago, an Englishman, Sir George Cayley, carried the science of flying to a point which had never been reached before and which it scarcely reached again during the last century.”
– Wilbur Wright, 1909
Cayley’s Goals and Achievements
Sir Cayley was a bright, well-educated individual with a background in science and engineering. He had a clear vision and purpose for his work and understood the importance of overcoming the problems of flight. According to the Royal Aeronautical Society, he once said, “The ability to navigate the ocean that comes to the threshold of every man’s door is a most important goal.”
This motivation led him to several major breakthroughs in aeronautics: the invention of the passenger glider, the identification of the four aerodynamic forces, and the conditions under which these forces can achieve flight.
Before these breakthroughs, the world was still very much in the dark ages of aerodynamics.
“Nothing really mattered before Cayley… [he] is the watershed figure in terms of real progress towards the airplane.”
– Peter Jakab, National Air and Space Museum Aeronautics Division Chairman
Undoing Widespread Misconceptions About Flight
In Cayley’s time, people didn’t fully comprehend aerodynamic forces. Their crude understanding led to widespread misconceptions about how flight could be achieved. To dispel the confusion, Cayley identified and defined the four forces as:
- Weight: The pulling force of gravity
- Lift: The force that keeps an object suspended above the ground, i.e. wings
- Drag: The friction caused by air pressure differences that slows down a traveling object
- Thrust: The force required to send an object into motion
Engineers observed birds and understood the propellers of flying machines to be responsible for generating the forward motion and sustaining lift simultaneously. Airplane concepts of the time were built with flapping wings (these contraptions were referred to as ornithopters) until Cayley determined that the wings of ornithopters weren’t shaped in a way that could create sufficient lift for objects heavier than air.
Testing Theories of Propulsion Through Trial and Error
Through extensive research and engineering, he realized that propellers could do the thrusting work but that the wings needed to be reimagined to provide sufficient lift for heavy objects. Sir Cayley went to great lengths to test his theories of propulsion, beginning with small models and working his way up to large-scale simulations.
He determined that one of the biggest problems facing aircraft conceptualization was the inadequacy of the power unit. One of his models attempted to use gunpowder to power the engine, but this proved unfruitful. Steam engines were too heavy and produced too little power to be a viable option for an aircraft, so Cayley devoted much of his time to developing an air engine — and to no avail. Without any better ideas, he revisited DaVinci’s flapping propulsion model and designed several new ornithopter prototypes around it, but nothing noteworthy came from these new concepts.
Each time one of Cayley’s models failed, he kept detailed records on the cause of the design flaws and adapted his next model accordingly. By 1799, Cayley’s records of failed models helped him to see patterns and recognize the supreme importance of overcoming drag with thrust and balancing weight with lift. This was the year he arrived at the aircraft design that resembles the modern airplane in its body and wings.
Incorporating the Concepts of Aerodynamics Into a Working Model
Once again, Cayley abandoned the flapping-wing concept. Sir Cayley drew out his newest design on a silver medal, which included the flight-governing forces on one side and a model of the forces working together on the other side. The model had a pilot’s cockpit, one main fixed wing attached to the body (fuselage), a cross-shaped tail piece that could be controlled vertically or horizontally, and revolving vanes for propulsion. Some of these principles and design aspects are still used in today’s airplanes.
To show how this new prototype would work in action, Sir Cayley turned his concepts into real models. As he experimented with and observed his models in action and spent time watching flight occur in nature, he was able to refine his designs. For example, he noticed that birds could twist the arched portion of their wings and realized that if fixed wings were slightly curved, they would create lift and make the aircraft fly more easily.
Sir Cayley’s “Firsts” in History
Once he finished experimenting, Sir Cayley built what is recognized as history’s first real airplane. It only measured 5 feet in length, and the fixed wing was attached to the body via universal joints. To his delight, this model flew successfully, so he designed a larger glider with more rigid wings to give the aircraft more lift stability.
By 1810, Cayely felt confident enough in his work to make it public. He published a paper in Nicholson’s Journal of Natural Philosophy, Chemistry and the Arts entitled On Aerial Navigation, but it wasn’t discovered or recognized until much later on. This paper laid the foundation for aerodynamic studies.
With a full working knowledge of aerodynamics and a successful model under his belt, Cayley continued on with his experiments and went on to design full-sized gliders by 1849. This also happened to be the year that Cayley sent a 10-year old boy into flight in his glider. The event went down in history as the first person to make it into flight. By 1853, Cayley built a triplane glider, which had three wing-like structures, and used it to carry several people 900 feet before it crashed. This was the first documented adult flight in an aircraft.
Sir George Cayley’s Lasting Impact on Modern Society
Cayley made the correct assessment that sustained flight wouldn’t be possible unless the aviation industry could design and manufacture a lightweight engine for planes that would allow sufficient thrust and lift. The air engine was finally invented in 1903 when an American mechanic and inventor crafted a 12-horsepower inline engine from aluminum for the Wright Brothers’ plane.
Even though Cayley passed away in 1857 without getting to experience the fruits of his labor, he achieved his goal of making flight possible. His failures never caused him to waiver in his unfailing determination to solve the fundamental issues of aviation. His discoveries played a key role in the first sustained flight, and he will always be remembered, by those who know his legacy, as the Father of Aviation.