MIAMI – Today in Aviation, Sir George Cayley, 6th Baronet, an English engineer, inventor and pioneer aviator, was born in 1773. He is one of the most influential individuals in aeronautical history. Many consider him the first real scientific aerial investigator and the first person to understand the fundamental principles and forces of flight.

Cayley was an aeronautical engineering pioneer and is often referred to as “the father of aviation.” He discovered and defined the four forces acting on a heavier-than-air flying vehicle: weight, lift, drag and thrust. He is also responsible for conceptualizing the modern aeroplane as a fixed-wing flying machine with separate lift, propulsion, and control systems in the year 1799.

Modern aircraft design is based on these findings and on the significance of cambered wings, also identified by Cayley, who in addition, designed the first aeroplane flying model and diagramed vertical flight components. The first reliably recorded glider to hold a human aloft was also designed by the engineer.

Furthermore, Cayley correctly predicted that once a lightweight engine was built to provide sufficient thrust and lift, sustained flight would occur. As such, the Wright brothers recognized Cayley’s importance to the development of aviation.

Replica of Cayley’s glider at the Yorkshire Air Museum. Photo: Wiki Commons.

Flying Machines

Cayley is also remembered for his pioneering studies and experiments with flying machines, including the pilot glider he designed and constructed. He wrote a seminal three-part treatise, published in Nicholson’s Journal of Natural Philosophy, Chemistry and the Arts, titled “On Aerial Navigation” (1809-1810).

The 2007 discovery of sketches in Cayley’s school notebooks (held in the Royal Aeronautical Society Library archive) revealed that Cayley was forming his thoughts on flight theories even at school. The drawings suggest that the concept of a lift-generating inclined plane was recognized by Cayley as early as 1792.

Cayley’s glider in Mechanics’ Magazine, 1852. Image: Wiki Commons.

He later developed a “whirling-arm apparatus” a development of earlier work in ballistics and air resistance, to test the drag on objects at various speeds and attack angles. In the stairwells at Brompton Hall, he also experimented with rotating wing sections of different types.

These scientific experiments led him to create an effective camber airfoil and to define the four aircraft-influencing vector forces: thrust, lift, drag and weight. For this reason, he discovered the significance of the dihedral angle for lateral stability in flight and purposefully placed the center of gravity of many of his models well below the wings; these concepts informed the designs of his pilot glider and inspired the emergence of hang gliders.

“About 100 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.”


Cayley’s model glider successfully flew in 1804. It had a modern aircraft configuration, with a front kite-shaped wing and an adjustable tailplane consisting of horizontal stabilizers and a vertical fin at the rear. A movable weight allowed the centre of gravity of the model to be changed.

Later, with the continued assistance of his grandson George John Cayley and his resident engineer Thomas Vick, he produced a larger glider, also possibly fitted with ‘flappers’, that flew across Brompton Dale in front of Wydale Hall in 1853.

Model of Sir George Caley’s “Aerial Carriage”, 1843. Licensed under the Creative Commons Attribution-Share Alike 3.0.

The First Aeronautical Engineer

Many consider Cayley as the first aeronautical engineer due to his inquiries into many other scientific aspects of flight. One of many examples is his emphasis on lightness, which led him to develop a new system that is widely used today to create lightweight wheels.

To create his lightweight wheels, the aviator changed the spoke’s forces from compression to tension for his landing wheels by making them from tightly-stretched string, in effect reinventing the wheel.

Furthermore, Cayley was the first to propose the definition of a convertiplane around 1843, an idea that was published in a paper written the same year. He planned and constructed a biplane sometime before 1849, in which an unnamed ten-year-old boy flew.

Cayley died in 1857 and was buried in the graveyard of All Saints’ Church in Brompton-by-Sawdon. In 1974, Cayley was inducted into the International Air & Space Hall of Fame.

Featured image: Sit George Cayley. Photo: Wiki Commons.Article sources:,,