THE AERIAL EXPERIMENT ASSOCIATION:
Kites and Aerodromes -
From Tethered Flight to Aviation
Section 1: Background to the Era
The principle upon which all heavier-than-air machines depend is that of a kite.
A kite, as every schoolboy knows, is supported by the wind while being held against it by a string. If there is no wind it can still be kept aloft by running with it, because in this way an artificial wind is created.
Now the motor-driven machine is like the kite that is kept up by running, the running boy with his string being replaced by the motor and propellers which by driving it rapidly forward make the artificial supporting wind.
F.W. 'Casey' Baldwin
Member of the Aerial Experiment Association
in a lecture given at the University of Toronto, Feb. 27, 1909
four days after the flight of the Silver Dart at Baddeck, NS, Canada.
To completely understand the achievements of the Aerial Experiment Association in the history and development of aviation, it is useful to understand the era in which the Association worked.
As with all advances and developments, the cross-pollination of ideas, experiences and achievements informs and guides the work of most inventions.
This was also true for the work of the aviation pioneers who made up the Aerial Experiment Association.
The Earliest Practical Science of Aviation:
In 1790 Englishman Sir George Cayley worked with the principles of physics and began his study of the science that we now know to be aerodynamics. By 1804 he had constructed a workable monoplane model glider with an adjustable tail and kite shaped wings mounted above the main body of the device. These wings were trimmed in an uplift dihedral. The model flew gracefully and by 1816 he had mastered most of the principles of flight that we now know apply to the flight of modern aircraft. By1853 Cayley had managed to build a machine that could carry the weight of a man. He also built a triplane and in 1853 persuaded his coach driver to fly 275 m (900 feet) across a small valley. This was the first recorded flight by a person in an aircraft and Cayley has been described as the "true inventor of the aeroplane". It is generally believed that it was the first practical heavier-than-air flying machine.
Although Cayley made extensive notes and detailed drawings of his work, he was so far ahead of his peers that for years to come his work did not give the jump start to powered aerial flight that in retrospect one would think it should have. His writings have been preserved and his models recreated in the present day to demonstrate his sound knowledge of flight.
Richard Dee in his outstanding book The MAN who DISCOVERED FLIGHT: George Cayley and the First Airplane 1 provides a compelling biography of this scientist and his contributions to aviation. Dee notes that Cayley was so far ahead of his time that many colleagues and members of his family saw him as an accomplished dreamer. Dee states: "When Cayley died in 1857 , most people, his son and heir included, tried to forget about Sir George's rather embarassing 'aerial crochets'". 2
It was not until nearly three quarters of a century later, in the 1920's, that aviation historians would come across his work and wish that it had been widely disseminated to advance the development of airplanes. By then other pioneers had discovered the principles of flight and built the necessary foundations of aeronautics.
The Context of the Era of the Aerial Experiment Association
Without having the advantage of the knowledge of George Cayley, aeronautic pioneers worked to grind out the knowledge of aeronautical science by speculation, trial, observation and adjustment.
The late 1800's and first decade of the 1900's was an era of purposeful scientific experimentation and inventive attempts to explore the possibility of creating flying machines that could carry people aloft in sustained, controlled flight.
In Europe and North America the dreams of many inventors were centred on creating a device that would qualify as a flying machine. Although the general hopes of the era were with the inventors and scientists, sceptics abounded and criticized every step taken on this bold new frontier of proposed manned flight.
In nature, scientists and inventors had long looked at the flight of birds to attempt to discern the secrets of their flight. Numerous scientists studied the wings of birds and the manner in which these wings provided lift and directional control when combined with body movements of the bird in gliding and soaring. These scientists believed that the secrets of flight were contained in this study.
Still other inventors looked to aerial devices that had a long history which could potentially be improved upon to hold some of the keys to powered flight: balloons and kites. Each of these devices had their proponents and detractors; each had their strengths and weaknesses.
Balloons and Dirigibles:
Balloons held the promise of proven lift, having carried people aloft over good distances ever since the first demonstration flight in France by the Montgolfier brothers in 1783. The problems with balloons resided in the inability to control direction and forward momentum as well the ability to fly in difficult weather.
Efforts to elongate the balloon and make a more rigid superstructure that would permit the mounting of a power source led to the development of dirigibles by Ferdinand von Zeppelin. His maiden flight on July 2, 1900 proved that this type of airship could well be the best way of air travel and at the turn into the 20th Century dirigibles led the way.
As progress with rigidly framed balloons progressed, several inventors led the way in testing and defining how the dirigible might be developed. In addition to von Zeppelin, Brazillian Alberto Santos-Dumont made huge steps in aviation with powered rigid ballon structures. Santos-Dumont was the first person to demonstrate that routine, controlled flight was possible by navigating his dirigible around the Eiffel Towen in October 1901. Santos-Dumont went on to be the first to publicly fly an airplane in Europe on October 23, 1906.
In the United States, Captain Thomas Scott Baldwin pioneered rigid balloon structures and gained considerable fame with this type of powered air vehicle in the early 1900's. Baldwin went on to power his rigid balloons with motors produced by Glenn H. Curtiss, a motorcycle manufacturer from Hammondsport NY. He also secured contracts to produce these aerial machines for the United States Army.
However, other inventors and experimenters saw in the kite, a device that had a history of centuries of flight, the key to developing a winged type of flying machine that would be able to lift people in controlled flight. The promise of the kite lay in it's ability to provide insights to those who studied the principles of flight (lift, drag, yaw, pitch).
Many scientists and inventors believed that the ultimate hope in developing a flying machine would come from the study of these principles using kites and the ability to harness them in some type of newly designed aircraft that might embody some of the features of the kite. The problems with kites as prototypes were their light structure or minimal lift to weight ratio and the fact that they needed a lifting source, the wind, and that they remained tethered.
Nevertheless, many scientific and inventive minds focused on the kite to experiment with and attempt to utilize the principles of flight to lead to the creation of an independent flying machine.
Among the notable inventors of the 1890's and first decade of the 1900's to concentrate on the kite were: Major Baden Fletcher Smyth Baden-Powell and Samuel Franklin Cody who both worked with kites and kite arrays to lift heavy objects and people in Great Britain. Major BFS Baden-Powell of the Scotts Guards used his patented 'Levitor' kites to lift observers in both trials and under wartime conditions in the Boer War in South Africa. Samuel Franklin Cody, an American working in Britain, developed the famous Cody kite, an elaborate winged-box kite, that produced enormous lift and was also used to lift men to survey battlefield terrain.
In Australia, Lawrence Hargrave, an English born engineer, made numerous experiments and models that led to the development of the famous Hargrave box kite in 1893. This box kite provided good lift and steady lateral control. Hargrave's kite turned out to be one of the major influences on the bi-plane wing formations of early aircraft.
In America, Dr. Alexander Graham Bell strongly believed that the kite held answers to the secrets of controlled powered flight. His experiments were carefully recorded and documented with his notes and by a comprehensive series of photographs. His unique tetrahedral kites were inspired by Hargrave's success with the box kite. Bell turned to the mathematical tetra shape to provide strength and limit the weight of his kite structures as he explored the principles of flight.
By the 1890's, gliding machines, often inspired by box kites, began to lead in the understanding of flight and how a person carried by such a device would have to exert control over three dynamics of the device (roll, pitch, yaw) for stable flight to occur.
Samuel Pierpont Langley, a noted physicist and Secretary of the Smithsonian Institution, developed gliders, rubber and steam powered flying models and a full-scale powered aircraft that he attempted to launch over the Potomac River in October and December of 1903. The device snagged on the catapult that was built to launch it and plunged into the river in spectacular fashion.
Another notable American experimenter using gliders was Octave Chanute of Chicago. Chanute's trail blazing dual wing glider was a key influence on the work of the Wright Brothers of Dayton, Ohio who are generally credited with having the first controlled powered flight in a manned aircraft on Dec. 17, 1903 on the sand dunes near Kitty Hawk, North Carolina.
Augustus Moore Herring of Michigan also worked at developing models of gliders. In 1893 he had built and crashed a full sized glider that he constructed based on principles that he deduced by observing the flight of kites. Later he worked with Octave Chanute and employed much of what he learned from Chanute in the development of a biplane glider of his own design with a compressed air engine. He successfully flew his device in St. Joseph, Michigan on October 11, 1898 and there is some debate on the fact that he may have been first in powered flight.
In Europe, Otto Lilienthal of Germany made many successful flights in gliders and wrote extensively on the principles of flight that he derived from his experiments. His writings were much sought after by other pioneers who worked on powered flight. Lilienthal died in a glider crash near Berlin in August 1896.
Summary of the Times:
This was an era of much energy directed towards the issue and problems of flight. The scientific, technological, and manufacturing advancements of the turn into the Twentieth Century made the era ripe for solving the problems of controlled, powered flight once and for all.
Although communication was not instant and all pervasive as it is today, advances made by the telegraph, photography, news wire services, postal services, access to books and information and the increasing ease of travel by rail ensured that news of each advancement or report of experiments added to the energy and knowledge of the times.
Keen and dedicated pioneers were ready to push the frontiers of flight and make significant advancements in achieving safe powered aerial flight.
Next in the Aerial Experiment Association story:
Preliminary Work on Flight - A.G. Bell
1. Dee, Richard. The Man who Discovered Flight: George Cayley and the First Airplane. Toronto: McClelland and Stewart Ltd., 2007. (ISBN:978-0-7710-2971-4)
2. Dee, 302.