A. Developments before the Wright Brothers
Men had always wondered why it was impossible for them to attain the art of flying. They questioned the ability of birds to fly. As a result of their fascination for flying, stories of man’s ability to fly have been embedded in the Greek myths of Daedalus and his son, Icarus.
The stories were centered around his escape from the island of Crete where he was imprisoned. They described how they fastened wings with wax to their bodies and flew through the air; Icarus flew too near the sun, the wax melted and he fell to his death in the sea.
Man’s idea about flying was thus centered on the imitation of birds; as a result various medieval people fastened wings to their bodies and tried to fly, many fell to their most unfortunate fates.
Finally men gave up the idea of strapping a pair of wings to their bodies to enable them to fly. It was replaced by the concept of wings which were flapped up and down by some mechanical mechanism. powered by some type of human arm, leg or some other body movement. These were the ornithopters.
Leonardo da Vinci designed a number of these. Below is a sketch of his ornithopter
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(figure available in print form)
Ornithopters did not accomplish any successful flight; therefore they made no contribution to the advancement of flight.
It was not until November 21, 1783 that human efforts to fly were accomplished. This was done when the balloon flown by the Marquis d’Ariandes went up in the air and flew 5 miles to Paris. This balloon was inflated and buoyed up by hot air coming from a fire beneath it.
(figure available in print form)
The Montgolfier brothers thought of the lifting power of hot air and its ability to lift a person from the earth. They experimented with different materials (bags made with linen in which hot air was trapped), they had several public demonstrations and finally the flight of November 1783.
The flight served its purpose by triggering the public’s interest in the ability of man to fly.
It was not until the advent of Sir George Cayley (1773-1857) that the concept to include a fixed wing for generating lift and a separate mechanism for propulsion was originated. He envisioned paddles and a horizontal and vertical tail for stability. These ideas were inscribed on a silver disc.
(figure available in print form)
(figure available in print form)
With these ideas Cayley introduced the concept that lift was different from propulsion and therefore set the stage for the developments that took place later.
He devoted a life of study to aerodynamics. In 1804 he built a whirling arm apparatus for testing airfoils; this was a lifting surface mounted on the end of a long rod, which was rotated at some speed to generate a flow of air over the airfoils. This is synonymous to the wind tunnels today. It was an important development because it allowed the measurement of aerodynamic forces and the center of pressure on the lifting surface, these developments can be considered the first step in aerodynamic testing.
In 1804 he designed, built and flew a small model glider.
(figure available in print form)
He documented his developments in a paper entitled “ On Aerial Navigation.” This was published in 1809. In 1849 he built and tested a full size airplane by which a ten year old boy was carried along and lifted several meters from the ground.
He had the concept of stacking several wings on top of each other (biplanes and triplanes); he had the fear that a single wing would fail. This idea was carried down into the twentieth century. It was only in the 1930s that the monoplane became the dominant airplane configuration.
(figure available in print form)
It was sometime in 1853 that Cayley built and flew the world’s first human carrying glider. The configuration is unknown; it could have been a triplane and looked like the boy carrier.
After Cayley’s death in 1857, not many inventions took place for the next fifty years.
Other landmark discoveries
William Samuel Henson (1812-1888): he published a design for a fixed wing airplane powered by a steam engine driving two propellers. This was called the aerial steam carriage.
This design was a direct result of Cayley’s ideas and research in aeronautics.
John Stringfellow, a friend of Henson, built several small steam engines and attempted to power some model monoplanes off the ground. He was not very successful. His most recognized work appeared in the form of a steam powered triplane. His triplane was the main bridge between Cayley’s work and modern aeronautics.
Felix Du Temple (1857-1858) flew the first successful powered model airplane. It was a monoplane; it had wings and was powered by clockwork.
The second airplane (1874) had the first powered take off by a piloted full sized airplane. It had wings and was powered by hot air engine.
The machine was launched down an inclined plane.
Alexander F. Mozhaiski was a Russian; in July 1884 he designed an aerial steam carriage.It was launched down a ski ramp and flew for a few seconds.
These attempts did not satisfy the criteria of sustained flight, but could be considered assisted powered takeoffs.
B. The age of the glider
Otto Lilienthal was one of the giants in aeronautical engineering. He designed and flew the first successful controlled glider in history.
Because of his interest in flight, he studied the structure and types of birds’ wings and applied this information to the design of mechanical flight.
In 1889 and again in 1890, he designed and flew gliders, but both were unsuccessful. In 1891 he had his first successful glider flight from a hill in Germany.
The general configuration of this monoplane glider was one of a bird-like platform of the wing. He used chambered airfoil shape on the wing and used vertical and horizontal tail planes in the back for stability. These machines are the forerunners of the hangliders today. flight control was exercised by shifting one’s center of gravity.
Lilienthal can be classified as an airman in contrast to those who were called chauffeurs. The distinction was drawn between those who were concerned with thrust and lift, and the air men who were concerned with flight in the air.
Lilienthal made about 2000 successful glider flights. His aerodynamic data were widely read. He died during a glider flight in Germany on August 9, 1896.
Percy Pilcher studied with Lilienthal and under his guidance made several glides. He could be classified as an airman; he understood the need for understanding natural flight, before engaging in machine powered flights. He built a machine called the Hawk in 1896. It was powered by a 4 hp engine weighing 40 lbs. He died while flying this machine.
C. Aeronautics in the United States
Most of the advances that had been made in heavier than air flying machines were made in Britain and in Europe. These developments were taking place during the time when the United States was more concerned with land expansion and the consolidation of a new government; aeronautical developments had no impact.
This interest in flying was taken by Octave Chanute (1832-1910). He collected and studied all the aeronautical information available. He later published his book Progress in Flying Machines. In his book he summarized all the important progress in aviation. He could be considered the first aviation historian.
He designed hang gliders and produced a biplane glider. He bridged the gap between Stringfellow’s triplane and the successful powered flights of 1903.
Samuel Pierpont Langley (1834-1906) designed and built a series of powered aircrafts, that resulted in piloted flights in 1903.
Langley followed in the tradition of Cayley and therefore built a large whirling arm, powered by a steam engine, this he used to make tests on steam airfoils.
In 1896 Langley was successful when one of powered models made a free flight of 3300 ft and later another flew over 3/4 mile. These “Aerodromes,” as he called them, were tandem winged vehicles, driven by two propellers between the wings that were powered by a 1 hp steam engine.
After studying Stringfellow’s work he set out to design a better engine. In 1898, the war department commissioned him to build a machine for passengers. He decided that a gasoline fueled engine would be best for use on an aircraft. A 52.4 hp engine resulted from his efforts. He used a 3.2 hp gasoline fueled engine to have a successful flight with a 1/4 scale model. With this encouragement he started to design a full scale airplane. He mounted this aircraft on a catapult in order to provide an assisted take off; this contraption was placed on top of a houseboat on the Potomac River.
On October of 1903, with his companion Charles Manley at the controls, he made his first attempt at flying. The aircraft fell into the water soon after launch. They tried again on December 8, 1903 but had the same consequences.
Langley abandoned his attempt at human flight after his failures and the criticisms from the press.
Critics of Langley classified him as a chauffeur because he had not paid much attention to the aspect of flight control; he did, however, leave a legacy by the contributions he made to aeronautics.
D. The Wright Brothers
The Wright brothers drew on the rich heritage in aeronautical experiences left them by their predecessors. They became interested in aviation after the flight of Otto Lilienthal in 1896. They took up the study of bird as a guide to mechanical flight; from their study they concluded that birds regain their lateral balance when partly overturned by a gust of wind. This emerged as the single most important development in aviation history, the use of wings’ twist to control airplane in rolling motion. They coined the phase “wing warping.”
They read all the available literature on the advancements in aeronautics, then set out to experiment with wing warping. To test this concept they built a bi-plane with a wing span of 5 ft that was controlled from the ground with strings. This concept worked. Encouraged, the Wright brothers decided to test this concept, but not before gaining experience as “airmen”. They made their first 17 ft wing span by September 1900 and flew it from Kitty Hawk on October of that year.
With this success they proceeded to build a second glider from their new headquarters at Kill Devil Hills 4 miles to the south of Kitty Hawk; it was tested in July and August of 1901. This new glider was larger than the previous one. It had a wing span of 22 ft.
The Wrights were very suspicious of the existing data from the literature, especially those generated by Lilienthal and Langley. They built their own wind tunnel and did their own investigations. From these researches they built the number three glider. This was flown in December 1902 and provided much information on the impact of wind tunnels.
During 1902, they made more than 1000 perfect flights and set a distance record of 26 seconds. The brothers had become experienced and skillful pilots, and with all the theoretical and practical problems solved, they felt that they could construct a machine whose stability and control in the air depended on the pilot’s skill. The only difficulty was to find an existing engine capable of powering the aircraft. They could not find such an engine; therefore they designed and built their own. It was 12 hp, water cooled, and weighed only 200 lbs. They also built their own propeller ; thus they produced their first powered machine the “ Flyer” in the summer of 1903.
They returned to their camp to find it in disarray. They repaired the number 3 glider and practiced. Finally overcoming all setbacks (weather, mechanical breakdowns) they were ready to test the Flyer. It was a biplane of 40 ft with a wing area of 510 square feet and used a double rudder behind the wings and a double elevator in front of the wings.
With conditions favorable, they called five witnesses, and with a camera set up for pictures the Flyer made its first historic flight. (Orville was at the controls.)
They did not stop with Flyer 1. In May 1904 they flew their second powered machine Flyer 2. They made improvements with a smaller wing chamber. By 1905 Flyer 3 was ready. It was described as the world’s first practical powered aeroplane, justified by the sturdiness of its structure. With their combined contribution, research and inventions the world was on the threshold to a new form of vehicle for public transportation.
E. The emergence of the aircraft as a valuable means of transportation
During 1909 the aeroplane had become accepted as the world’s new practical vehicle. Louis Bleriot’s crossing of the Channel on July 25, and the first air meeting at Rheims in August were significant signs.
With the Wrights’ achievements and techniques to follow, European airmen came into their own; so during the first half of the 1900s there was a growing number of aviators, designers and amateurs, and the forms of their aircraft began to multiply. The dominant types of aircraft became more efficient and reliable. The message of powered flying began spreading over the world and the beginnings of an aircraft industry, as well as governments’ concerns with aviation, became evident.
There were some difficulties to be overcome to make the aeroplane more efficient.
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1. The development of an engine with enough horse power to lift an aircraft off the ground. This was solved with the development of gasoline fueled internal combustion engine (the Wright brothers were pioneers in this area). The automobile industry then led the development of new engines.
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2. The development and the search for aeroplanes that could fly faster and higher. This problem was solved partly by the introduction of competitions; this prompted and advanced development of high speed aircraft. One notable competition was the Schneider race.
Military aviation became a serious concern of leading European nations. As a result military and naval flying schools were established.
When the first world war was declared the aeroplane’s duties were as aerial intelligence agents or scouts, for visual and photographic reconnaissance. During the war years the aircraft industry in Europe and the United States expanded from a handful of machines in 1914 to 3300 in use by 1918. It also provided many jobs from a few hundreds in 1914, to nearly 350,000 workers in 1918.
After the war there was more technical progress made and the acceptance of the importance of flying was extended in the public’s mind; and air transport became a means of public transportation. As Cayley predicted, “We shall be able to transport ourselves and our families and their goods and chattels, more securely by air than by water.”
With the far reaching developments of combat aircraft, and the various equipment for flying and communicating, comparable developments were taking place in the aircraft for civil transport.
After the war years, the non-military sphere of flying saw the most dramatic developments. In 1919, the first air transport with scheduled airlines started in Europe. The first civil airline for passengers began in Germany February 8, 1919 with service between Berlin, Leipzig and Vienna.
The machines used in France, England and America as transport planes were wartime bombers adapted to passenger planes.
One important landmark in the air transport and private flying was the solo flight direct from New York to Paris on May 20-21. It helped to transform the entire travel industry and made the public more air minded.
It was in the United States that the first modern type airliner was the Boeing 247, flown in February 1933. The second was Douglas DC-1 flown in July 1933.
These are a few of the airlines that emerged as a result of the developments in aerodynamics and the demand for passenger planes.
With the advent of the Second World War, there were enormous developments in aviation and in aeroplane engines and all the types of equipment used in flying. This period saw the jet propelled aeroplane; the production of helicopters and long ranged rockets. After the war the industry turned its attention to transport production.
The leader in developing light and medium transports was the United States. Aircraft were developed that set the style for modern heavy transports with the Douglas Dakota (DC-3). This aircraft monopolized the traffic on the world’s long haul airlines after the war.
Following is a list the aircrafts that were developed and their passenger capabilities.
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1. Douglas Dakota (DC-3), USA
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2. Junkers Ja 52, Germany
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3. Douglas DC-4 Skymaster (Military C-54): February 1942. It had a crew of six and 42 passengers. 4. Douglas DC-6: February 1946, into airline service 1947.
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5. Lockheed 049 (C-69): Jan 1943, carried 52 passengers.
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6. Stratocruiser: November 1944.
The preceding pages do not cover all the developments of the types of aircraft that came into existence, but they do show that the stage was set for the use of the aircraft as a public transport system. The need was met as a result of the inventions that arose, so that the aircraft could be viable in the war years. After that, technology was directed towards passenger travel.
The years after the wars also saw the research in aerodynamics directed to rocketry and the aerospace industry.
From the developments described in the previous pages, one can point to many fruitful instances of applied mathematics. The following sections will attempt to present some of the existing mathematical topics that can be brought to bear on the history of flight.
