2001-Future

In the beginning of the 21st century, subsonic aviation focused on eliminating the pilot in favor of remotely operated or completely autonomous vehicles. Several Unmanned aerial vehicles or UAVs have been developed. In April 2001 the unmanned aircraft Global Hawk flew from Edwards AFB in the US to Australia non-stop and unrefuelled. This is the longest point-to-point flight ever undertaken by an unmanned aircraft, and took 23 hours and 23 minutes. In October 2003 the first totally autonomous flight across the Atlantic by a computer-controlled model aircraft occurred.

In commercial aviation, the early 21st century saw the end of an era with the retirement of Concorde. Supersonic flight was not very commercially viable, as the planes were required to fly over the oceans if they wanted to break the sound barrier. Concorde also was fuel hungry and could carry a limited amount of passengers due to its highly streamlined design. Nevertherless, it seems to have made a significant operating profit for British Airways.

Despite this setback, and the general slowing of progress, it is generally agreed that the 21st century will be a bright one for aviation. Planes and rockets offer unique capabilities in terms of speed and carrying capacity that should not be underestimated. As long as there is a need for people to get to places quickly, there will be a need for aviation.

The U.S. Centennial of Flight Commission was established in 1999 to encourage the broadest national and international participation in the celebration of 100 years of powered flight.[10] It publicized and encouraged a number of programs, projects and events intended to educate people about the history of aviation.

1945 - 1991: The Cold War

Commercial Aviation took hold after World War II using mostly ex-military aircraft in the business of transporting people and goods. Within a few years many companies existed, with routes that criss-crossed North America, Europe and other parts of the world. This was accelerated due to the glut of heavy and super-heavy bomber airframes like the B-29 and Lancaster that could easily be converted into commercial aircraft. The DC-3 also made for easier and longer commercial flights. The first North American commercial jet airliner to fly was the Avro C102 Jetliner in September 1949, shortly after the British Comet. By 1952, the British state airline BOAC had introduced the De Havilland Comet into scheduled service. While a technical achievement, the plane suffered a series of highly public failures, as the shape of the windows led to cracks due to metal fatigue. The fatigue was caused by cycles of pressurization and depressurization of the cabin, and eventually led to catastrophic failure of the plane's fuselage. By the time the problems were overcome, other jet airliner designs had already taken to the skies. USSR's Aeroflot became the first airline in the world to operate sustained regular jet services on 15 September 1956 with the Tupolev Tu-104. Boeing 707, which established new levels of comfort, safety and passenger expectations, ushered in the age of mass commercial air travel as we enjoy it today.

Even with the end of World War II, there was still a need for advancement in aircraft and rocket technology. Not long after the war ended, in October of 1947, Chuck Yeager took the rocket powered Bell X-1 past the speed of sound. Although anecdotal evidence exists that some fighter pilots may have done so while divebombing ground targets during the war, this is the first controlled, level flight to cross the sound barrier. Further barriers of distance were eliminated in 1948 and 1952 as the first jet crossing of the Atlantic occurred and the first nonstop flight to Australia occurred.

During the 1950s, a new age of military aviation history would be written. When the Soviet Union developed long-range bombers that could deliver nuclear weapons to North America and Europe, Western countries responded with interceptor aircraft that could engage and destroy the bombers before they reached their destination. The "minister-of-everything" C.D. Howe in the Canadian government, was the key proponent of the Avro Arrow, designed as a high-speed interceptor, reputedly the fastest aircraft in its time. However, by 1955, most Western countries agreed that the interceptor age was replaced by guided missile age. Consequently, the Avro Arrow project was eventually cancelled in 1959 under Prime Minister John Diefenbaker. See Avro Arrow for more details.

In 1961, the sky was no longer the limit for manned flight, as Yuri Gagarin orbited once around the planet within 108 minutes. This action further heated up the space race that had started in 1957 with the launch of Sputnik 1 by the Soviet Union. The United States responded by launching Alan Shepard into space on a suborbital flight in a Mercury space capsule. With the launch of the Alouette I in 1963, Canada became the third country to send a satellite in space. The Space race between the United States and the Soviet Union would ultimately lead to the current pinnacle of human flight, the landing of men on the moon in 1969.

This historic achievement in space was not the only progress made in aviation at this time however. In 1967, the X-15 set the air speed record for an aircraft at 4,534 mph or Mach 6.1 (7,297 km/h). Aside from vehicles designed to fly in outer space, this record still stands as the air speed record for powered flight.

The same year that Neil Armstrong and Buzz Aldrin set foot on the moon, 1969, Boeing came out with its vision for the future of air travel, unveiling the Boeing 747 for the first time. This plane is still one of the largest aircraft ever to fly, and it carries millions of passengers each year. Commercial aviation progressed even further in 1975, as Soviet Aeroflot started regular service on Tu-144 — the first supersonic passenger plane, and in 1976, as British Airways inaugurated supersonic service across the Atlantic, courtesy of the Concorde. A few years earlier the SR-71 Blackbird had set the record for crossing the Atlantic in under 2 hours, and Concorde followed in its footsteps with passengers in tow.

The last quarter of the 20th century saw a slowing of the pace of advancement seen in the first three quarters of the century. No longer was revolutionary progress made in flight speeds, distances and technology. This part of the century saw the steady improvement of flight avionics, and a few minor milestones in flight progress.

For example, in 1979 the Gossamer Albatross became the first human powered aircraft to cross the English channel. This achievement finally saw the realization of centuries of dreams of human flight, but this has not had any significant impact on either commercial or military aviation. In 1986 Dick Rutan and Jeana Yeager flew an aircraft around the world unrefuelled, and without landing. In 1999 Bertrand Piccard became the first person to circle the earth in a balloon. By the end of the 20th Century there were no major or minor accomplishments left to be made in subsonic aviation. Focus was turning to the ultimate conquest of space and flight at faster than the speed of sound. The ANSARI X PRIZE inspired entrepreneurs and space enthusiasts to build their own rocket ships to fly faster than sound and climb into the lowest reaches of space.

1939 - 1945: World War II

World War II saw a drastic increase in the pace of aircraft development and production. All countries involved in the war stepped up development and production of aircraft and flight based weapon delivery systems, such as the first long range bomber. Fighters were critical to the success of the heavy bombers, allowing much lower losses than would have been the case without fighter protection.

World War II saw a number of technological advances that were remarkable for its day: The first functional jetplane was the Heinkel He 178 (Germany), flown by Erich Warsitz in 1939 (a Coanda-1910 is said to have done a short involuntary flight on 16 December 1910). The first cruise missile (V-1), the first ballistic missile (V-2), and the first manned rocket Bachem Ba 349 were also developed by Germany. However, the small number of Jet fighters did not have significant impact, the V-1 was not very effective as it was slow and vulnerable, and the V-2 could not hit targets precisely enough.

The following table shows how aircraft production in the United States drastically increased over the course of the war.

Type 1940 1941 1942 1943 1944 1945 Total
Very Heavy Bombers 0 0 4 91 1,147 2,657 3,899
Heavy Bombers 19 181 2,241 8,695 3,6812 7,874 42,691
Medium Bombers 24 326 2,429 3,989 3,636 1,432 11,836
Light Bomber 16 373 1,153 2,247 2,276 1,720 7,785
Fighters 187 1,727 5,213 11,766 18,291 10,591 47,775
Reconnaissance 10 165 195 320 241 285 1,216
Transports 5 133 1,264 5,072 6,430 3,043 15,947
Trainers 948 5,585 11,004 11,246 4,861 825 34,469
Communication/ Liaison 0 233 2,945 2,463 1,608 2,020 9,269
Total by Year 1,209 8,723 26,448 45,889 51,547 26,254 160,070

1918 - 1939 (The "Golden Age")

The years between World War I and World War II saw a large advancement in aircraft technology.

Aircraft evolved from being constructed of mostly wood and canvas to being constructed almost entirely of aluminium. Engine development proceeded apace, with engines moving from in-line water cooled gasoline engines to rotary and radial air cooled engines, with a commensurate increase in propulsive power. Pushing all of this forward were prizes for distance and speed records. For example Charles Lindbergh took the Orteig Prize of $25,000 for his solo non-stop crossing of the Atlantic, the first person to achieve this, although not the first to carry out a non-stop crossing. That was achieved eight years earlier when Captain John Alcock and Lieutenant Arthur Brown co-piloted a Vickers Vimy nonstop from St. John's, Newfoundland to Clifden, Ireland on June 14, 1919, winning the £10,000 ($50,000) Northcliffe prize.

After WWI experienced fighter pilots were eager to show off their new skills. Many American pilots became barnstormers, flying into small towns across the country and showing off their flying abilities, as well as taking paying passengers for rides. Eventually the barnstormers grouped into more organized displays. Air shows sprang up around the country, with air races, acrobatic stunts, and feats of air superiority. The air races drove engine and airframe development - the Schneider Trophy for example led to a series of ever faster and sleeker monoplane designs culminating in the Supermarine S.6B, a direct forerunner of the Spitfire. With pilots competing for cash prizes, there was an incentive to go faster. Amelia Earhart was perhaps the most famous of those on the barnstorming/air show circuit. She was also the first female pilot to achieve records such as crossing of the Atlantic and English channels.
The first lighter-than-air crossings of the Atlantic were made by airship in July 1919 by His Majesty's Airship R34 and crew when they flew from East Lothian, Scotland to Long Island, New York and then back to Pulham, England. By 1929, airship technology had advanced to the point that the first round-the-world flight was completed by the Graf Zeppelin in September and in October, the same aircraft inaugurated the first commercial transatlantic service. However the age of the dirigible ended in 1937 with the terrible fire aboard the Zeppelin Hindenburg. After the now famous footage of the hydrogen-filled Hindenburg burning and crashing on the Lakehurst, New Jersey, landing field, people stopped using airships, despite the fact that most people on board survived. The Hindenburg, combined with the Winged Foot Express disaster that occurred on 21 July, 1919, in Chicago, Illinois, in which 12 civilians died, started the demise of the airship. Flammable gas dirigibles did not burn and crash often, but when they did crash they caused a disproportionate amount of destruction to the crash zone compared with the aeroplanes of the time. It was more shock value than the number of fatalities that caused the retirement of the world's airships. This may not have been the case had helium been available to the Zeppelin company. The United States, holder of the world's only reserves of helium at the time, was loathe to supply it to the company, which was based in Nazi Germany.

In 1929 Jimmy Doolittle developed instrument flight.

Flight instruments
Pitot-static instruments: Altimeter · Airspeed indicator · Machmeter · Vertical speed indicator
Gyroscopic instruments Attitude indicator · Heading indicator · Horizontal Situation Indicator · Turn and bank indicator · Turn coordinator
Navigation: Horizontal Situation Indicator · Course Deviation Indicator · Inertial Navigation System · GPS • SIGI
Other: Magnetic compass · Yaw string

In the 1930s development of the jet engine began in Germany and in England. In England Frank Whittle patented a design for a jet engine in 1930 and began developing an engine towards the end of the decade. In Germany Hans von Ohain patented his version of a jet engine in 1936 and began developing a similar engine. The two men were unaware of each others work, and both Germany and Britain had developed jet aircraft by the end of World War II.

1914 - 1918: World War I

Almost as soon as they were invented, planes were drafted for military service. The first country to use planes for military purposes was Bulgaria, whose planes attacked and reconnoitred the Ottoman positions during the First Balkan War 1912-13. The first war to see major use of planes in offensive, defensive and reconnaissance capabilities was World War I. The Allies and Central Powers both used planes extensively. The most famous plane of the war is the Sopwith Camel; it was credited with more aerial victories than any other Allied plane, but was also notorious for its awkward handling resulting in the death of many pilots.

While the concept of using the aeroplane as a weapon of war was generally laughed at before World War I, the idea of using it for photography was one that was not lost on any of the major forces. All of the major forces in Europe had light aircraft, typically derived from pre-war sporting designs, attached to their reconnaissance departments. While early efforts were hampered by the light loads carried, improved two-seat designs soon appeared that were entirely practical.

It was not long before aircraft were shooting at each other, but the lack of any sort of steady point for the gun was a problem. The French solved this problem when, in late 1914, Roland Garros attached a fixed machine gun to the front of his plane, but it was Adolphe Pegoud who would become known as the first "ace", getting credit for five victories, before also becoming the first ace to die in action.

Aviators were styled as modern day knights, doing individual combat with their enemies. Several pilots became famous for their air to air combats, the most well-known is Manfred von Richthofen, better known as the Red Baron, who shot down 80 planes in air to air combat with several different planes, the most celebrated of which was the Fokker Dr.I. On the allied side, René Paul Fonck is credited with the most victories at 75. For the Americans, the most successful ace was Eddie Rickenbacker with 26 victories.

1900 to 1914 (The "Pioneer Era") 6

Seaplane

The first seaplane was invented in March 1910 by the French engineer Henri Fabre. Its name was Le Canard ('the duck'), and took off from the water and flew 800 meters on its first flight on March 28, 1910. These experiments were closely followed by the aircraft pioneers Gabriel and Charles Voisin, who purchased several of the Fabre floats and fitted them to their Canard Voisin airplane. In October 1910, the Canard Voisin became the first seaplane to fly over the river Seine, and in March 1912, the first seaplane to be used militarily from a seaplane carrier, La Foudre ('the lightning').

1900 to 1914 (The "Pioneer Era") 5

Helicopter

In 1877 Enrico Forlanini developed an early unmanned helicopter powered by a steam engine. It was the first of its type that rose to a height of 13 meters, where it remained for some 20 seconds, after a vertical take-off from a park in Milan.

The first manned helicopter known to have risen off the ground took place in 1907 (Cornu, France) though the first practical helicopter was the Focke FA-61 (Germany, 1936).

1900 to 1914 (The "Pioneer Era") 4

Other early flights

At the time, a number of other inventors had made (or claimed to have made) short flights. Gustave Whitehead reported that he had flown a powered aircraft on 14 August, 1901. He failed to document the flight, but a later replica of his Number 21 was flown successfully. Lyman Gilmore also claimed to have achieved success on 15 May, 1902. In New Zealand, South Canterbury farmer and inventor Richard Pearse constructed a monoplane aircraft that he reputedly flew on March 31 1903. However, even Pearse himself admitted the flight was uncontrolled and ended in a crash-landing on a hedge without having gained any altitude.

Karl Jatho from Hanover conducted a short motorized flight in August 1903, just a few months after Pearse. Jatho's wing design and airspeed did not allow his control surfaces to act properly to control the aircraft.

Also in the summer of 1903, eyewitnesses claimed to have seen Preston Watson make his initial flights at Errol, near Dundee in the east of Scotland. Once again, however, lack of photographic or documentary evidence makes the claim difficult to verify. Many claims of flight are complicated by the fact that many early flights were done at such low altitude that they did not clear the ground effect, and by the complexities involved in the differences between unpowered and powered aircraft.

The Wright Brothers conducted numerous additional flights (about 150) in 1904 and 1905 from Huffman Prairie in Dayton, Ohio and invited friends and relatives. Newspaper reporters did not pay attention after seeing an unsuccessful flight attempt in May 1904.

Public exhibitions of high altitude flights were made by Daniel Maloney in the John Montgomery tandem-wing glider in March and April of 1905 in the Santa Clara, California area. These flights received national media attention and demonstrated superior control of the design, with launches as high as 4,000 feet and landings made at predetermined locations.

Alberto Santos-Dumont made a public flight in Europe on September 13, 1906 in Paris. He used a canard elevator and pronounced wing dihedral, and covered a distance of 221 m (725 ft). Since the plane did not need headwinds or catapults to take off, this flight is considered by some as the first true powered flight. Also, since the earlier attempts of Pearse, Jatho, Watson, and the Wright brothers received less attention from the popular press than Santos-Dumont's flight, its importance to society, especially in Europe and Brazil, is often considered to be greater despite occurring some years later.

Two English inventors Henry Farman and John William Dunne were also working separately on powered flying machines. In January 1908, Farman won the Grand Prix d'Aviation with a machine which flew for 1 km, though by this time many longer flights had already been done.

For example, the Wright Brothers had made flights over 39 km long by 1905. Dunne's early work was sponsored by the British military, and tested in great secrecy in Glen Tilt in the Scottish Highlands. His best early design, the D4, flew in December 1908 near Blair Atholl in Perthshire. Dunne's main contribution to early aviation was stability, which was a key problem with the planes designed by the Wright brothers and Samuel Cody.

On May 14, 1908 the Wright Brothers made what is accepted to be the first two-person aircraft flight, with Charlie Furnas as a passenger.

On 8 July 1908, Thérèse Peltier became the first woman to fly as a passenger in an airplane when she made a flight of 656 feet with Léon Delagrange in Milan, Italy.

Thomas Selfridge became the first person killed in a powered aircraft on September 17, 1908, when Orville crashed his two-passenger plane during military tests at Fort Myer in Virginia.
In late 1908, Mrs Hart O. Berg became the first American woman to fly as a passenger in an airplane when she flew with Wilbur Wright in Le Mans, France.

On 25 July 1909 Louis Blériot flew the Blériot XI monoplane across the English Channel winning the Daily Mail aviation prize. His flight from Calais to Dover lasted 37 minutes.

On 22 October 1909 Raymonde de Laroche became the first woman to pilot and solo in a powered heavier than air craft. She was also the first woman in the world to receive a pilot's licence.

Controversy over who gets credit for invention of the aircraft has been fuelled by Pearse's and Jatho's essentially non-existent efforts to inform the popular press, by the Wrights' secrecy while their patent was prepared, by the pride of nations, and by the number of firsts made possible by the basic invention. For example, the Romanian engineer Traian Vuia (1872 - 1950) has also been claimed to have built the first self-propelled, heavier-than-air aircraft able to take off autonomously, without a headwind and entirely driven by its own power. Vuia piloted the aircraft he designed and built on March 18, 1906, at Montesson, near Paris. None of his flights were longer than 100 feet (30 m) in length. In comparison, in October 1905, the Wright brothers had a sustained flight of 39 minutes and 24.5 miles (39 km), circling over Huffman Prairie.

1900 to 1914 (The "Pioneer Era") 3

The Wright Brothers

Following Lilienthal's principles of jumping before flying, the brothers built and tested a series of kite and glider designs from 1900 to 1902 before attempting to build a powered design. The gliders worked, but not as well as the Wrights had expected based on the experiments and writings of their 19th century predecessors. Their first glider, launched in 1900, had only about half the lift they anticipated. Their second glider, built the following year, performed even more poorly. Rather than giving up, the Wrights constructed their own wind tunnel and created a number of sophisticated devices to measure lift and drag on the 200 wing designs they tested. As a result, the Wrights corrected earlier mistakes in calculations regarding drag and lift, though they missed the effect of Reynolds number (known since 1883), which would have given them an even bigger advantage. Their testing and calculating produced a third glider design, which they flew in 1902. It performed far better than the previous models. In the end, by establishing their rigorous system of designing, wind-tunnel testing of models and flight testing of full-size prototypes, the Wrights not only built a working aircraft but also helped advance the modern science of aeronautical engineering.

The Wrights appear to be the first design team to make serious studied attempts to simultaneously solve the power and control problems. Both problems proved difficult, but they never lost interest. Eventually, they designed and built an engine that could provide the needed power, and solved the control problem through a system known as "wing warping". Although this method was used only briefly during the history of aviation, it worked at the low airspeeds their designs would fly at, and proved to be a key advance, leading directly to modern ailerons. While many aviation pioneers appeared to leave safety largely to chance, the Wrights' design was greatly influenced by the need to teach themselves to fly without unreasonable risk to life and limb, by surviving crashes. This, not lack of power, was the reason for the low speed and for taking off in a head wind. It was also the reason for the rear-heavy design, for the canard, and for the anhedral wings.

The Wrights made the first sustained, controlled and powered heavier-than-air flight at Kill Devil Hills, North Carolina, a town five miles down the road from Kitty Hawk, North Carolina on December 17, 1903

The first flight by Orville Wright, of 121 feet (37 m) in 12 seconds, was recorded in a famous photograph. In the fourth flight of the same day, Wilbur Wright flew 852 feet (260 m) in 59 seconds. The flights were witnessed by 4 lifesavers and a boy from the village, making them the first public flights and certainly the first well-documented ones.

The telegram station the Wright Brothers used to send their message of successful, sustained, powered flight is now a restaurant named "The Black Pelican."

1900 to 1914 (The "Pioneer Era") 2

Langley

On May 6, 1896, Langley's Aerodrome No.5 made the first successful flight of an unpiloted, engine-driven heavier-than-air craft of substantial size. It was launched from a spring-actuated catapult mounted on top of a houseboat on the Potomac River near Quantico, Virginia. Two flights were made that afternoon, one of 1,005 m (3,300 ft) and a second of 700 m (2,300 ft), at a speed of approximately 25 miles per hour. On both occasions, the Aerodrome No.5 landed in the water, as planned, because, in order to save weight, it was not equipped with landing gear.

On November 28, 1896, another successful flight was made with the Aerodrome No.6. This flight was witnessed and photographed by Alexander Graham Bell. It was flown a distance of approximately 1,460 m (4,790 ft). The Aerodrome No.6 was actually Aerodrome No.4 greatly modified. So little remained of the original aircraft that it was given the new designation of Aerodrome No.6.

With the success of the Aerodrome No. 5 and its follow-on No. 6, Langley started looking for funding to build a full-scale man-carrying version of his designs. He succeeded in winning $50,000 in funding from the government, perhaps spurred on by the recent opening of the Spanish-American War. Langley planned on building a scaled-up version known as the Aerodrome A, and started with the smaller Quarter-scale Aerodrome, which flew twice on June 18, 1901, and then again with a newer and more powerful engine in 1903.

With the basic design apparently successfully tested, he then turned to the problem of a suitable engine. He contracted Stephen Balzer to build him one, but was disappointed when it delivered only 8 horsepower (6 kW) instead of 12 hp (9 kW) as he expected. Langley's assistant, Charles M. Manly, then reworked the design into a five-cylinder water-cooled radial that delivered 52 horsepower (39 kW) at 950 rpm, a feat that took years to duplicate. Now with both power and a design, Langley put the two together with great hopes.

To his dismay, the resulting aircraft proved to be too fragile. He had apparently overlooked the effects of minimum gauge, and simply scaling up the original small models resulted in a design that was too heavy to hold itself up. Two launches in late 1903 both ended with the Aerodrome crashing into the water almost immediately after launch.

His attempts to gain further funding failed, and his efforts ended -- only weeks later the Wright brothers successfully flew their aptly-named Flyer.

(Glenn Curtiss made several modifications to the Aerodrome and successfully flew it in 1914 -- the Smithsonian Institution thus continued to boast that Langley's Aerodrome was the first machine "capable of flight".)

1900 to 1914 (The "Pioneer Era") 1

Lighter than air

The first aircraft to make routine controlled flights were non-rigid airships (later called "blimps".) The most successful early pioneer of this type of aircraft was the Brazilian Alberto Santos-Dumont. Santos-Dumont effectively combined a balloon with an internal combustion engine. On October 19, 1901 he became world famous when he flew his airship "Number 6" over Paris from the Parc Saint Cloud around the Eiffel Tower and back in under thirty minutes to win the Deutsch de la Meurthe prize. After this triumph in airships, Santos-Dumont would go on to design and build several aircraft. The subsequent controversy surrounding his and others' competing claims with regard to aircraft would come to overshadow and obscure his unparalleled contributions to the development of airships.

At the same time that non-rigid airships were starting to have some success, rigid airships were also becoming more advanced. Indeed, rigid body dirigibles would be far more capable than fixed wing aircraft in terms of pure cargo carrying capacity for decades. Dirigible design and advancement was brought about by the German count, Ferdinand von Zeppelin.

Construction of the first Zeppelin airship began in 1899 in a floating assembly hall on Lake Constance in the Bay of Manzell, Friedrichshafen. This was intended to ease the starting procedure, as the hall could easily be aligned with the wind. The prototype airship LZ 1 (LZ for "Luftschiff Zeppelin") had a length of 128 m, was driven by two 14.2 ps (10.6 kW) Daimler engines and balanced by moving a weight between its two nacelles.

The first Zeppelin flight occurred on July 2, 1900. It lasted for only 18 minutes, as LZ 1 was forced to land on the lake after the winding mechanism for the balancing weight had broken. Upon repair, the technology proved its potential in subsequent flights, beating the 6 m/s velocity record of French airship La France by 3 m/s, but could not yet convince possible investors. It would be several years before the Count was able to raise enough funds for another try.

Modern Flight 3

Picking up the pace

The 1880s became a period of intense study, characterized by the "gentleman scientists" who represented most research efforts until the 20th century. Starting in the 1880s advancements were made in construction that led to the first truly practical gliders. Three people in particular were active: Otto Lilienthal, Percy Pilcher and Octave Chanute. One of the first truly modern gliders appears to have been built by John J. Montgomery; it flew in a controlled manner outside of San Diego on August 28, 1883. It was not until many years later that his efforts became well known. Another delta hang-glider had been constructed by Wilhelm Kress as early as 1877 near Vienna.

Otto Lilienthal of Germany duplicated Wenham's work and greatly expanded on it in 1874, publishing all of his research in 1889. He also produced a series of ever-better gliders, and in 1891 was able to make flights of 25 meters or more routinely. He rigorously documented his work, including photographs, and for this reason is one of the best known of the early pioneers. He also promoted the idea of "jumping before you fly", suggesting that researchers should start with gliders and work their way up, instead of simply designing a powered machine on paper and hoping it would work. His type of aircraft is now know as a hang glider.

Lilienthal knew that once an engine was attached to the plane it would be nearly impossible to further study the laws of aviation. The finding and describing of many of those laws were his greatest heritage to his successors, as they were able to construct their planes accordingly and thereby save themselves years of trial and error.

By the time of his death in 1896 he had made 2500 flights on a number of designs, when a gust of wind broke the wing of his latest design, causing him to fall from a height of roughly 56 ft (17 m), fracturing his spine. He died the next day, with his last words being "sacrifices must be made". Lilienthal had been working on small engines suitable for powering his designs at the time of his death.

Picking up where Lilienthal left off, Octave Chanute took up aircraft design after an early retirement, and funded the development of several gliders. In the summer of 1896 his troop flew several of their designs many times at Miller Beach, Indiana, eventually deciding that the best was a biplane design that looks surprisingly modern. Like Lilienthal, he heavily documented his work while photographing it, and was busy corresponding with like-minded hobbyists around the world. Chanute was particularly interested in solving the problem of natural stability of the aircraft in flight, one which birds corrected for by instinct, but one that humans would have to do manually. The most disconcerting problem was longitudinal stability, because as the angle of attack of a wing increased, the center of pressure moved forward and made the angle increase more. Without immediate correction, the craft would pitch up and stall.

Throughout this period, a number of attempts were made to produce a true powered aircraft. However the majority of these efforts were doomed to failure, being designed by hobbyists who did not have a full understanding of the problems being discussed by Lilienthal and Chanute.
In France Clément Ader successfully launched his steam powered Eole for a short 50 meter flight near Paris in 1890, making it the first self-propelled "long distance" flight in history. After this test he immediately turned to a larger design, which took five years to build. However, this design, the Avion III, was too heavy and was barely able to leave the ground. The plane reportedly managed to fly a distance of 300 meters, at a small height.

In 1884, Alexander Mozhaysky's monoplane design made what is now considered to be a power assisted take off or 'hop' of 60-100 feet (20-30 meters) near Krasnoye Selo, Russia.

Sir Hiram Maxim studied a series of designs in England, eventually building a monstrous 7,000 lb (3,175 kg) design with a wingspan of 105 feet (32 m), powered by two advanced low-weight steam engines which delivered 180 hp (134 kW) each. Maxim built it to study the basic problems of construction and power and it remained without controls, and, realizing that it would be unsafe to fly, he instead had a 1,800 foot (550 m) track constructed for test runs. After a number of test runs working out problems, on July 31, 1894 they started a series of runs at increasing power settings. The first two were successful, with the craft "flying" on the rails. In the afternoon the crew of three fired the boilers to full power, and after reaching over 42 mph (68 km/h) about 600 ft (180 m) down the track the machine produced so much lift it pulled itself free of the track and crashed after flying at low altitudes for about 200 feet (60 m). Declining fortunes left him unable to continue his work until the 1900s, when he was able to test a number of smaller designs powered by gasoline.

Another less successful early experimenter was Samuel Pierpont Langley. After a distinguished career in astronomy and a tenure at the Smithsonian Institution, Langley started a serious investigation into aerodynamics at what is today the University of Pittsburgh. In 1891 he published Experiments in Aerodynamics detailing his research, and then turned to building his designs. On May 6, 1896, Langley's Aerodrome No.5 made the first successful flight of an unpiloted, engine-driven heavier-than-air craft of substantial size. It was launched from a spring-actuated catapult mounted on top of a houseboat on the Potomac River near Quantico, Virginia. Two flights were made that afternoon, one of 1,005 m (3,300 ft) and a second of 700 m (2,300 ft), at a speed of approximately 25 miles per hour.

On November 28, 1896, another successful flight was made with the Aerodrome No.6. This flight was witnessed and photographed by Alexander Graham Bell. It was flown a distance of approximately 1,460 m (4,790 ft).

In the United Kingdom an attempt at heavier-than-air flight was made by the aviation pioneer Percy Pilcher. Pilcher had built several working gliders, The Bat, The Beetle, The Gull and The Hawk, which he flew successfully during the mid to late 1890s. In 1899 he constructed a prototype powered aircraft which, recent research has shown, would have been capable of flight. However, he died in a glider accident before he was able to test it, and his plans were forgotten for many years.

Modern Flight 2

Toward better understanding

The first published paper on aviation was "Sketch of a Machine for Flying in the Air" by Emanuel Swedenborg published in 1716. This flying machine consisted of a light frame covered with strong canvas and provided with two large oars or wings moving on a horizontal axis, arranged so that the upstroke met with no resistance while the downstroke provided lifting power. Swedenborg knew that the machine would not fly, but suggested it as a start and was confident that the problem would be solved. He said, "It seems easier to talk of such a machine than to put it into actuality, for it requires greater force and less weight than exists in a human body. The science of mechanics might perhaps suggest a means, namely, a strong spiral spring. If these advantages and requisites are observed, perhaps in time to come some one might know how better to utilize our sketch and cause some addition to be made so as to accomplish that which we can only suggest. Yet there are sufficient proofs and examples from nature that such flights can take place without danger, although when the first trials are made you may have to pay for the experience, and not mind an arm or leg." Swedenborg would prove prescient in his observation that powering the aircraft through the air was the crux of flying.

During the last years of the 18th century, Sir George Cayley started the first rigorous study of the physics of flight. In 1799 he exhibited a plan for a glider, which except for planform was completely modern in having a separate tail for control and having the pilot suspended below the center of gravity to provide stability, and flew it as a model in 1804. Over the next five decades Cayley worked on and off on the problem, during which he invented most of basic aerodynamics and introduced such terms as lift and drag. He used both internal and external combustion engines, fueled by gunpowder, but it was left to Alphonse Penaud to make powering models simple, with rubber power. Later Cayley turned his research to building a full-scale version of his design, first flying it unmanned in 1849, and in 1853 his coachman made a short flight at Brompton, near Scarborough in Yorkshire.

In 1848, John Stringfellow had a successful test flight of a steam-powered model, in Chard, Somerset, England. This was 'unmanned'.

In 1866 a Polish peasant, sculptor and carpenter by the name of Jan Wnęk built and flew a controllable glider. Wnęk was illiterate and self-taught, and could only count on his knowledge about nature based on observation of birds' flight and on his own builder and carver skills. Jan Wnęk was firmly strapped to his glider by the chest and hips and controlled his glider by twisting the wing's trailing edge via strings attached to stirrups at his feet. Church records indicate that Jan Wnęk launched from a special ramp on top of the Odporyszów church tower; The tower stood 45 m high and was located on top of a 50 m hill, making a 95 m (311 ft) high launch above the valley below. Jan Wnęk made several public flights of substantial distances between 1866 - 1869, especially during religious festivals, carnivals and New Year celebrations. Wnęk left no known written records or drawings, thus having no impact on aviation progress. Recently, Professor Tadeusz Seweryn, director of the Kraków Museum of Ethnography, has unearthed church records with descriptions of Jan Wnęk's activities.

In 1856, Frenchman Jean-Marie Le Bris made the first flight higher than his point of departure, by having his glider "L'Albatros artificiel" pulled by a horse on a beach. He reportedly achieved a height of 100 meters, over a distance of 200 meters.

In 1874, Félix du Temple built the "Monoplane", a large plane made of aluminium in Brest, France, with a wingspan of 13 meters and a weight of only 80 kilograms (without the driver). Several trials were made with the plane, and it is generally recognized that it achieved lift off under its own power after a ski-jump run, glided for a short time and returned safely to the ground, making it the first successful powered flight in history, although the flight was only a short distance and a short time.

Another person who advanced the art of flying was Francis Herbert Wenham, who unsuccessfully attempted to build a series of unmanned gliders. During his work he found that the majority of the lift from a bird-like wing appeared to be generated at the front, and concluded that long, thin wings would be better than the bat-like ones suggested by many, because they would have more leading edge for their weight. Today this measure is known as aspect ratio. He presented a paper on his work to the newly formed Royal Aeronautical Society of Great Britain in 1866, and decided to prove it by building the world's first wind tunnel in 1871. Members of the Society used the tunnel and learned that cambered wings generated considerably more lift than expected by Cayley's Newtonian reasoning, with lift-to-drag ratios of about 5:1 at 15 degrees. This clearly demonstrated the ability to build practical heavier-than-air flying machines; what remained was the problem of powering them, and controlling the flight.