From Academic Kids
Humanity's desire to fly probably dates back to the first time prehistoric man observed birds. Through all of recorded history aspects of this desire have surfaced from time to time. The most well known is the legendary story of Daedalus and Icarus. Daedalus was trapped on the island of Minos, and so built wings out of feathers and wax for himself and his son. His son Icarus flew too close to the sun and the wax melted, destroying the wings and causing Icarus to fall into the sea, killing him. The legend was designed to be a cautionary tale about attempting to reach heaven, similar to the Tower of Babel story in The Bible. Nevertheless, it exemplifies man's desire to fly.
The modern history of aviation has had several broad trends. Aircraft designers have struggled to make their planes go faster, fly higher, and be controlled more easily. To that effect, engine designs have moved towards more compact, more powerful designs, beginning with steam engines and ending with jet and rocket engines. Planes have become more streamlined and made of stronger and lighter materials. Initially airplanes were made of canvas and wood. Today airplanes are made of aluminium, and increasingly, carbon fiber, which is prized for its lightness and strength. The methods used to control planes have advanced significantly as well. Initially planes were controlled by moving your entire body (gliders) or warping the planes' wings (Wright brothers). Modern planes are controlled by computers, which can make planes that were otherwise unflyable able to fly, such as the F-117.
Before the 20th century
There were many early attempts to fly, covering the full range of legend to fact. See List of early flying machines for a list of these. Note that there are many claims and counter-claims how successful these were. See First flying machine for a review of such claims.
Leonardo da Vinci was the first person to seriously design an aircraft, designing a glider in the 15th century. While this glider was never built by Leonardo, its plans were preserved and it was constructed in the late 20th century from materials that would have been available to da Vinci. The design was deemed flightworthy and the prototype actually flew. However, a considerable amount of interpretation of his design, with modern knowledge of aerodynamic principles in mind, was made. Leonardo also sketched designs for a helicopter, but this design would not have flown.
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, and so arranged that the upstroke met with no resistance while the downstroke provided the 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 was prescient in his observation that powering the aircraft through the air was the crux of flying. Sufficiently light and powerful engines would not be available for powered flight until the gasoline engine designed by the Wright Brothers.
The first known human flight ever took place in Paris in 1783. Francois Pilatre de Rozier and Francois d'Arlandes went 5 miles (8 km) in a hot air balloon invented by the Montgolfier brothers. The balloon was powered by a wood fire, and was uncontrolled, that is, it flew wherever the wind took it. For the first flight, the balloon was tethered, and ultimately reached a height of 26 m. Ballooning became a major "rage" in Europe in the late 18th century, providing the first detailed understanding of the relationship between altitude and the atmosphere.
The first powered, controlled, sustained lighter-than-air flight took place in 1852. Henri Giffard flew 15 miles (24 km) in France, with a steam engine mounted on a dirigible. Throughout the latter half of the 19th century and the first half of the 20th century, the airship was considered to be a serious option for air transport.
During the last years of the 18th century, Sir George Cayley became interested in aircraft and started the first rigorous study of the physics involved in 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. Later he 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.
Another person who continually but slowly advanced the state of the art was Frank 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 were surprised, and delighted, to learn that cambered wings generated considerably more lift than expected by Cayley's Newtonian reasoning, with lift-to-drag ratios of about 5 to one 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.
The 1880s became a period of "intense" study, characterized by the "gentleman scientists" that represented most research efforts until the 20th century. Starting in the 1880s a number of advancements were made in construction that led to the first truly practical gliders. Three names in particular remain well known in the aviation world; Otto Lilienthal, Percy Pilcher and Octave Chanute. One of the first truly modern glider appears to have been built by John J. Montgomery, which 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 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.
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, but no one took up his work on the engine and gliders until the Wright brothers.
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 surprising modern. Like Lilienthal he heavily documented his work while photographing it, and was busy corresponding to like-minded hobbyists around the world. Canute 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 airplane. However the majority of these were of somewhat laughable quality, built by interested hobbyists who did not have a full understanding of the problems being discussed by Lilienthal and Chanute. In France Cl魥nt Ader successfully launched his steam powered Eole for a short hop near Paris in 1890. 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 never able to leave the ground.
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 at any altitude, he instead had a 1,800 foot track constructed for test runs. After a number of test runs working out bugs, on July 31st, 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 (183 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 (61 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 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, his Aerodrome No. 5 made the first fully successful flight of a powered heavier-than-air craft of substantial size, flying twice with one flight of 3,300 ft (1,000 m) and a second of 2,300 ft (700 m), at about 25 mph (40 km/h). On November 28, another successful flight was made with a similar model, the Aerodrome No.6. It flew a distance of approximately 1,460 m (4,790 ft).
In the United Kingdom a close-run 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 for many years forgotten.
1900 to 1914
At the same time that fixed wing aircraft were advancing, rigid body dirigibles 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 facilitate the difficult 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. See the zeppelin page for more history.
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 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. Following Lilienthal's principles of jumping before flying, the brothers built and tested a series of improving glider designs from 1900 to 1902, before attempting to build a powered design. The Wrights appear to be the first design team to make serious studied attempts to solve both the power and control problems at the same time. Both proved difficult, but they never lost interest and eventually delivered an engine of their own design with the needed performance, as well as solving 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.
The Wrights made the first controlled powered heavier-than-air flight at Kitty Hawk, North Carolina on December 17, 1903. The first flight by Orville Wright, of 120 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 arguably the first public flight and certainly the first well documented one.
Although his attempts failed, the Smithsonian Institution continued to boast that Langley's Aerodrome was the first machine "capable of flight", due to Glenn Curtiss making several modifications to the Aerodrome and successfully flying it in 1914.
At the time, a number of other inventors had made (or claimed to) short flights. Gustave Whitehead claimed to have flown a powered aircraft on August 14, 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 May 15, 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 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 allow him to control the design very well.
Also some time 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. However once again 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 the complexities involved in the differences between unpowered and powered aircraft.
The Wright Brothers conducted numerous additional public flights (over 80) in 1904 and 1905 from Huffman Prairie in Dayton, Ohio and invited friends, neighbors and newspaper reporters to them although few came.
Alberto Santos-Dumont made a public flight in Europe on September 13, 1906 in Paris. His design, like the Wright brothers', used a canard elevator and wing-warping, 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 then Santos-Dumont's flight its importance to society, especially in Europe, 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.
In late 1908, Madame Hart O. Berg became the first woman to fly when she flew with Wilbur Wright in Le Mans, France.
Controversy in the credit for invention of the airplane 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) also has been claimed to have been first self-propelled, heavier-than-air aircraft, able to take off autonomously, without a headwind, and entirely driven by its on-board installations, throughout its evolution. Vuia piloted the airplane 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, by the end of 1904, the Wright brothers had sustained flights up to 39 minutes and 24.5 miles (39 km) in 1905, circling over Huffman Prairie.
The early history of flight and credit for various accomplishments is often highly contested. See First flying machine.
1914 - 1918: World War I
Main article: World War I Aviation
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 ackward handling resulting in the death of many rookie pilots. 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 today 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. His record of air to air kills still stands today. On the allied side, Ren預aul Fonck is credited with the most victories.
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.
And with the arrival of practical reconnaissance aircraft came the problem of the enemy's practical reconnaissance aircraft. It was not long before aircraft were shooting at each other, but the lack of any sort of steady point to aim from made such efforts comical. The French made a more serious effort to solve this problem, and in late 1914 Roland Garros had attached a fixed machine gun to the front of his plane, allowing him to aim and fly with the same actions. Although he was shot down and captured, he became the first "ace", and succeeded in starting the air war.
1918 - 1939
Airplanes went 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 air cooled engines, with a commensurate increase in propulsive power. Pushing all of this forward were a series of prizes for various 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 in the process.
After WWI there were many experienced fighter pilots who 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 skills, as well as taking paying passengers for rides. Eventually the barnstormers grouped into more organized displays of their prowess. A series of air shows sprang up around the country, with air races, acrobatic stunts, and feats of air superiority being the main attraction. 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 more incentive to go faster than just personal prestige. Amelia Earhart was perhaps the most famous of those on the barnstorming/air show circuit. She was also the first female pilot to achieve many records such as crossing of the Atlantic, English channel, etc.
On the lighter-than-air front, the first 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 Hindenburg crashing and burning on the Lakehurst, New Jersey, landing field, people simply stopped using airships, despite the fact that most people on board survived, and the Hindenburg disaster was the only such disaster with a lighter-than-air ship to claim civilian lives.
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 a workable 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.
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 production and development of aircraft and flight based weapon delivery systems, such as the German V-2 missile, and World War two saw the development of the first long range bomber, and the first jet fighter. The first functional jetplane which was the Heinkel He 178 (Germany), flown by Erich Warsitz in 1939. An earlier prototype was the Coanda-1910 that did a short flight in December 16, 1910. The first cruise missile (V-1), and the first ballistic missile (V-2) were also developed by Germany. Long range bombers made the bigger difference in the war of those technologies. Jet fighters did not have significant impact, nor cruise and ballistic missiles in part because the V-1 was not very effective and the V-2 was never produced in useful numbers. The P-51 Mustang was critical to the success of the heavy bomber, allowing much lower losses then otherwise. The following table shows Aircraft production in the United States, and how it drastically increased over the course of the war.
|Very Heavy Bombers||0||0||4||91||1,147||2,657||3,899|
|Total by Year||1,209||8,723||26,448||45,889||51,547||26,254||160,070|
1945 - 1991: The Cold War
Commercial Aviation really 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. By 1952, the British state airline BOAC introduced into service the first jet airliner, the De Havilland Comet. 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, including the Boeing 707, which established new levels of comfort, safety and passenger expectations. The 707 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 airplane 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.
In 1961, ths sky was literally 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. The Space race would ultimately lead to the current pinacle 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 airplane 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 to ever fly, and it carries millions of passengers each year. Commercial aviation progressed even further in 1976 as British Airways inagurated 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 revoloutionary 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 airplane to cross the English channel. This achievement finally saw the realization of centuries of dreams of human flight, but it ultimately did not have an impact on either commercial or military aviation. In 1986 Dick Rutan and Jeana Yeager flew an airplane around the world unrefueled, 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.
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 the Concorde. Supersonic flight was not very commercial, as the planes were required to fly over the oceans if they wanted to break the sound barier. The Concorde also was fuel hungry and could carry a limited amount of passengers due to its highly streamlined design.
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 cannot be underestimated. As long as there is a need for people to get to places quickly, there will be a need for aviation.