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Heavier than air

Italian inventor, Tito Livio Burattini, invited by the Polish King WBadysBaw IV to his court in Warsaw, built a model aircraft with four fixed glider wings in 1647. Described as “four pairs of wings attached to an elaborate ‘dragon'”, it was said to have successfully lifted a cat in 1648 but not Burattini himself. He promised that “only the most minor injuries” would result from landing the craft. His “Dragon Volant” is considered “the most elaborate and sophisticated airplane to be built before the 19th Century”.

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 wrote: “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 a method of powering of an aircraft was one of the critical problems to be overcome.

Throughout the 19th century, tower jumping was replaced by the equally fatal but equally popular balloon jumping as a way to demonstrate the continued uselessness of man-power and flapping wings. Meanwhile, the scientific study of heavier-than-air flight began in earnest.

Sir George Cayley was first called the “father of the airplane” in 1846. During the last years of the previous century, he had begun the first rigorous study of the physics of flight and would later design the first modern heavier-than-air craft. Among his many achievements, his most important contributions to aeronautics include:

Clarifying our ideas and laying down the principles of heavier-than-air flight.

Reaching a scientific understanding of the principles of bird flight.

Conducting scientific aerodynamic experiments demonstrating drag and streamlining the movement of the center of pressure, and the increase in lift from curving the wing surface.

Defining the modern airplane configuration comprising a fixed wing, fuselage, and tail assembly.

Demonstrations of manned, gliding flight.

Setting out the principles of the power-to-weight ratio in sustaining flight.

Cayley’s first innovation was to study the basic science of lift by adopting the whirling arm test rig for use in aircraft research and using simple aerodynamic models on the arm, rather than attempting to fly a model of a complete design.

In 1799 he set down the concept of the modern airplane as a fixed-wing flying machine with separate systems for lift, propulsion, and control.

In 1804 Cayley constructed a model glider which was the first modern heavier-than-air flying machine, having the layout of a conventional modern aircraft with an inclined wing towards the front and adjustable tail at the back with both tailplane and fin. A movable weight allowed adjustment of the model’s center of gravity.

In 1809, goaded by the farcical antics of his contemporaries (see above), he began the publication of a landmark three-part treatise titled “On Aerial Navigation” (1809–1810). In it he wrote the first scientific statement of the problem, “The whole problem is confined within these limits, viz. to make a surface support a given weight by the application of power to the resistance of air.” He identified the four vector forces that influence an aircraft: thrust, lift, drag and weight and distinguished stability and control in his designs. He also identified and described the importance of the cambered aerofoil, dihedral, diagonal bracing, and drag reduction, and contributed to the understanding and design of ornithopters and parachutes.

In 1848 he had progressed far enough to construct a glider in the form of a triplane large and safe enough to carry a child. A local boy was chosen but his name is not known.

He went on to publish in 1852 the design for a full-size manned glider or “governable parachute” to be launched from a balloon and then to construct a version capable of launching from the top of a hill, which carried the first adult aviator across Brompton Dale in 1853.

Minor inventions included the rubber-powered motor, which provided a reliable power source for research models. By 1808 he had even re-invented the wheel, devising the tension-spoked wheel in which all compression loads are carried by the rim, allowing a lightweight undercarriage.

Drawing directly from Cayley’s work, Henson’s 1842 design for an aerial steam carriage broke new ground. Although only a design, it was the first in history for a propeller-driven fixed-wing aircraft.

1866 saw the founding of the Aeronautical Society of Great Britain and two years later the world’s first aeronautical exhibition was held at the Crystal Palace, London, where John Stringfellow was awarded a 100 prize for the steam engine with the best power-to-weight ratio. Francis Herbert Wenham presented the first paper to the newly formed Aeronautical Society (later the Royal Aeronautical Society), On Aerial Locomotion. He advanced Cayley’s work on cambered wings, making important findings. To test his ideas, from 1858 he had constructed several gliders, both manned and unmanned, and with up to five stacked wings. He realized that long, thin wings are better than bat-like ones because they have more leading edge for their area. Today this relationship is known as the aspect ratio of a wing.

The latter part of the 19th century became a period of intense study, characterized by the “gentleman scientists” who represented most research efforts until the 20th century. Among them was the British scientist-philosopher and inventor Matthew Piers Watt Boulton, who studied lateral flight control and was the first to patent an aileron control system in 1868.

In 1871 Wenham and Browning made the first wind tunnel.

Meanwhile, the British advances had galvanized French researchers. In 1857 Flix du Temple proposed a monoplane with a tail plane and retractable undercarriage. Developing his ideas with a model powered first by clockwork and later by steam, he eventually achieved a short hop with a full-size manned craft in 1874. It achieved lift-off under its own power after launching from a ramp, glided for a short time and returned safely to the ground, making it the first successful powered glide in history.

In 1865 Louis Pierre Mouillard published an influential book The Empire Of The Air (l’Empire de l’Air).

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.

Alphonse Pnaud, a Frenchman, advanced the theory of wing contours and aerodynamics and constructed successful models of aeroplanes, helicopters and ornithopters. In 1871 he flew the first aerodynamically stable fixed-wing aeroplane, a model monoplane he called the “Planophore”, a distance of 40 m (130 ft). Pnaud’s model incorporated several of Cayley’s discoveries, including the use of a tail, wing dihedral for inherent stability, and rubber power. The planophore also had longitudinal stability, being trimmed such that the tailplane was set at a smaller angle of incidence than the wings, an original and important contribution to the theory of aeronautics. Pnaud’s later project for an amphibian airplane, although never built, incorporated other modern features. A tailless monoplane with a single vertical fin and twin tractor propellers, it also featured hinged rear elevator and rudder surfaces, retractable undercarriage and a fully enclosed, instrumented cockpit.

Equally authoritative as a theorist was Pnaud’s fellow countryman Victor Tatin. In 1879 he flew a model which, like Pnaud’s project, was a monoplane with twin tractor propellers but also had a separate horizontal tail. It was powered by compressed air. Flown tethered to a pole, this was the first model to take off under its own power.

In 1884 Alexandre Goupil published his work La Locomotion Arienne (Aerial Locomotion), although the flying machine he later constructed failed to fly.

In 1890 the French engineer Clment Ader completed the first of three steam-driven flying machines, the ole. On October 9, 1890, Ader made an uncontrolled hop of around 50 m (165 ft); this was the first manned airplane to take off under its own power. His Avion III of 1897, notable only for having twin steam engines, failed to fly: Ader would later claim success and was not debunked until 1910 when the French Army published its report on his attempt.

Sir Hiram Maxim was an American engineer who had moved to England. He built his own whirling arm rig and wind tunnel and constructed a large machine with a wingspan of 105 feet (32 m), a length of 145 feet (44 m), fore and aft horizontal surfaces and a crew of three. Twin propellers were powered by two lightweight compound steam engines each delivering 180 hp (130 kW). Overall weight was 8,000 pounds (3,600 kg). It was intended as a test rig to investigate aerodynamic lift: lacking flight controls it ran on rails, with a second set of rails above the wheels to restrain it. Completed in 1894, on its third run it broke from the rail, became airborne for several hundred feet at two to three feet altitude and was badly damaged upon falling back to the ground. It was subsequently repaired, but Maxim abandoned his experiments shortly afterward.

n the last decade or so of the 19th century, a number of key figures were refining and defining the modern aeroplane. Lacking a suitable engine, aircraft work focused on stability and control in gliding flight. In 1879 Biot constructed a bird-like glider with the help of Massia and flew in it briefly. It is preserved in the Musee de l’Air, France, and is claimed to be the earliest man-carrying flying machine still in existence.

The Englishman Horatio Phillips made key contributions to aerodynamics. He conducted extensive wind tunnel research on aerofoil sections, proving the principles of aerodynamic lift foreseen by Cayley and Wenham. His findings underpin all modern aerofoil design.

Otto Lilienthal became known as the “Glider King” or “Flying Man” of Germany. He duplicated Wenham’s work and greatly expanded on it in 1884, publishing his research in 1889 as Birdflight as the Basis of Aviation (Der Vogelflug als Grundlage der Fliegekunst). He also produced a series of hang gliders, including bat-wing, monoplane and biplane forms, such as the Derwitzer Glider and Normal soaring apparatus. Starting in 1891 he became the first person to make controlled untethered glides routinely, and the first to be photographed flying a heavier-than-air machine, stimulating interest around the world. He rigorously documented his work, including photographs, and for this reason is one of the best known of the early pioneers. Lilienthal made over 2,000 glides until his death in 1896 from injuries sustained in a glider crash.

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 team flew several of their designs eventually deciding that the best was a biplane design. Like Lilienthal, he documented and photographed his work.

In Britain Percy Pilcher, who had worked for Maxim, built and successfully flew several gliders during the mid to late 1890s.

The invention of the box kite during this period by the Australian Lawrence Hargrave would lead to the development of the practical biplane. In 1894 Hargrave linked four of his kites together, added a sling seat, and flew 16 feet (4.9 m). Later pioneers of manned kite flying included Samuel Franklin Cody in England and Captain Gnie Saconney in France.

After a distinguished career in astronomy and shortly before becoming Secretary of the Smithsonian Institution, Samuel Pierpont 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. He hoped to achieve automatic aerodynamic stability, so he gave little consideration to in-flight control. On May 6, 1896, Langley’s Aerodrome No. 5 made the first successful sustained 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 meters (3,297 ft) and a second of 700 meters (2,300 ft), at a speed of approximately 25 miles per hour (40 km/h). 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, of 1,460 meters (4,790 ft), was witnessed and photographed by Alexander Graham Bell. The Aerodrome No. 6 was actually Aerodrome No. 4 greatly modified. So little remained of the original aircraft that it was given a new designation.

With the successes of the Aerodrome No. 5 and No. 6, Langley started looking for funding to build a full-scale man-carrying version of his designs. Spurred by the Spanish–American War, the U.S. government granted him $50,000 to develop a man-carrying flying machine for aerial reconnaissance. 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 one but was disappointed when it delivered only 8 hp (6.0 kW) instead of 12 hp (8.9 kW) he expected. Langley’s assistant, Charles M. Manly, then reworked the design into a five-cylinder water-cooled radial that delivered 52 hp (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. Simply scaling up the original small models resulted in a design that was too weak to hold itself together. Two launches in late 1903 both ended with the Aerodrome immediately crashing into the water. The pilot, Manly, was rescued each time. Also, the aircraft’s control system was inadequate to allow quick pilot responses, and it had no method of lateral control, and the Aerodrome’s aerial stability was marginal.

Langley’s attempts to gain further funding failed, and his efforts ended. Nine days after his second abortive launch on December 8, the Wright brothers successfully flew their Flyer. Glenn Curtiss made 93 modifications to the Aerodrome and flew this very different aircraft in 1914. Without acknowledging the modifications, the Smithsonian Institution asserted that Langley’s Aerodrome was the first machine “capable of flight”.

Gustave Weikopf was a German who emigrated to the U.S., where he soon changed his name to Whitehead. From 1897 to 1915 he designed and built early flying machines and engines. On August 14, 1901, two and a half years before the Wright Brothers’ flight, he claimed to have carried out a controlled, powered flight in his Number 21 monoplane at Fairfield, Connecticut. The flight was reported in the Bridgeport Sunday Herald local newspaper. About 30 years later, several people questioned by a researcher claimed to have seen that or other Whitehead flights.

In March 2013 Jane’s All the World’s Aircraft, an authoritative source for contemporary aviation, published an editorial which accepted Whitehead’s flight as the first manned, powered, controlled flight of a heavier-than-air craft. The Smithsonian Institution (custodians of the original Wright Flyer) and many aviation historians continue to maintain that Whitehead did not fly as suggested.

Using a methodological approach and concentrating on the controllability of the aircraft, 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. Their testing and calculating produced the third glider with a higher aspect ratio and true three-axis control. They flew it successfully hundreds of times in 1902, and it performed far better than the previous models. By using a rigorous system of experimentation, involving wind-tunnel testing of airfoils and flight testing of full-size prototypes, the Wrights not only built a working aircraft, the Wright Flyer but also helped advance the science of aeronautical engineering.

The Wrights appear to be the first to make serious studied attempts to simultaneously solve the power and control problems. Both problems proved difficult, but they never lost interest. They solved the control problem by inventing wing warping for roll control, combined with simultaneous yaw control with a steerable rear rudder. Almost as an afterthought, they designed and built a low-powered internal combustion engine. They also designed and carved wooden propellers that were more efficient than any before, enabling them to gain adequate performance from their low engine power. Although wing-warping as a means of lateral control was used only briefly during the early history of aviation, the principle of combining lateral control in combination with a rudder was a key advance in aircraft control. 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 emphasis, as well as low engine power, was the reason for low flying speed and for taking off in a head wind. Performance, rather than safety, was the reason for the rear-heavy design because the canard could not be highly loaded; anhedral wings were less affected by crosswinds and were consistent with the low yaw stability.

According to the Smithsonian Institution and Fdration Aronautique Internationale (FAI), the Wrights made the first sustained, controlled, powered heavier-than-air manned flight at Kill Devil Hills, North Carolina, four miles (8 km) south of 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 three coastal life-saving crewmen, a local businessman, and a boy from the village, making these the first public flights and the first well-documented ones.

Orville described the final flight of the day: “The first few hundred feet were up and down, as before, but by the time three hundred feet had been covered, the machine was under much better control. The course for the next four or five hundred feet had but little undulation. However, when out about eight hundred feet the machine began pitching again, and, in one of its darts downward, struck the ground. The distance over the ground was measured to be 852 feet (260 m); the time of the flight was 59 seconds. The frame supporting the front rudder was badly broken, but the main part of the machine was not injured at all. We estimated that the machine could be put in condition for flight again in about a day or two.” They flew only about ten feet above the ground as a safety precaution, so they had little room to maneuver, and all four flights in the gusty winds ended in a bumpy and unintended “landing”. Modern analysis by Professor Fred E. C. Culick and Henry R. Rex (1985) has demonstrated that the 1903 Wright Flyer was so unstable as to be almost unmanageable by anyone but the Wrights, who had trained themselves in the 1902 glider.

The Wrights continued flying at Huffman Prairie near Dayton, Ohio in 1904–05. In May 1904 they introduced the Flyer II, a heavier and improved version of the original Flyer. On June 23, 1905, they first flew a third machine, the Flyer III. After a severe crash on 14 July 1905, they rebuilt the Flyer III and made important design changes. They almost doubled the size of the elevator and rudder and moved them about twice the distance from the wings. They added two fixed vertical vanes (called “blinkers”) between the elevators and gave the wings a very slight dihedral. They disconnected the rudder from the wing-warping control, and as in all future aircraft, placed it on a separate control handle. When flights resumed the results were immediate. The serious pitch instability that hampered Flyers I and II were significantly reduced, so repeated minor crashes were eliminated. Flights with the redesigned Flyer III started lasting over 10 minutes, then 20, then 30. Flyer III became the first practical aircraft (though without wheels and needing a launching device), flying consistently under full control and bringing its pilot back to the starting point safely and landing without damage. On 5 October 1905, Wilbur flew 24 miles (39 km) in 39 minutes 23 seconds.”

According to the April 1907 issue of the Scientific American magazine, the Wright brothers seemed to have the most advanced knowledge of heavier-than-air navigation at the time. However, the same magazine issue also claimed that no public flight had been made in the United States before its April 1907 issue. Hence, they devised the Scientific American Aeronautic Trophy in order to encourage the development of a heavier-than-air flying machine.

Although full details of the Wright Brothers’ system of flight control had been published in l’Aerophile in January 1906 the importance of this advance was not recognized, and European experimenters generally concentrated on attempting to produce inherently stable machines.

Short powered flights were performed in France by Romanian engineer Traian Vuia on March 18 and August 19, 1906, when he flew 12 and 24 meters, respectively, in a self-designed, fully self-propelled, fixed-wing aircraft, that possessed a fully wheeled undercarriage. He was followed by Jacob Ellehammer who built a monoplane which he tested with a tether in Denmark on September 12, 1906, flying 42 meters.

On September 13, 1906, a day after Ellehammer’s tethered flight and three years after the Wright Brothers’ flight, the Brazilian Alberto Santos-Dumont made a public flight in Paris with the 14-bis, also known as Oiseau de proie (French for “bird of prey”). This was of canard configuration with pronounced wing dihedral and covered a distance of 60 m (200 ft) on the grounds of the Chateau de Bagatelle in Paris’ Bois de Boulogne before a large crowd of witnesses. This well-documented event was the first flight verified by the Aro-Club de France of a powered heavier-than-air machine in Europe and won the Deutsch-Archdeacon Prize for the first officially observed flight greater than 25 m (82 ft). On November 12, 1906, Santos-Dumont set the first world record recognized by the Federation Aeronautique Internationale by flying 220 m (720 ft) in 21.5 seconds. Only one more brief flight was made by the 14bis in March 1907, after which it was abandoned.

In March 1907 Gabriel Voisin flew the first example of his Voisin biplane. On 13 January 1908, a second example of the type was flown by Henri Farman to win the Deutsch-Archdeacon Grand Prix d’Aviation prize for a flight in which the aircraft flew a distance of more than a kilometer and landed at the point where it had taken off. The flight lasted 1 minute and 28 seconds.

In 1914, just before the start of World War I, Romania completed the world’s first metal-built aircraft, Vlaicu III. It was captured by the Germans in 1916 and last seen at a 1942 aviation exhibition in Berlin.

Santos-Dumont later added ailerons, between the wings in an effort to gain more lateral stability. His final design, first flown in 1907, was the series of Demoiselle monoplanes (Nos. 19 to 22). The Demoiselle No 19 could be constructed in only 15 days and became the world’s first series production aircraft. The Demoiselle achieved 120 km/h. The fuselage consisted of three specially reinforced bamboo booms: the pilot sat a seat between the main wheels of a conventional landing gear whose pair of wire-spoked main wheels were located at the lower front of the airframe, with a tail skid half-way back beneath the rear fuselage structure. The Demoiselle was controlled in flight by a cruciform tail unit hinged on a form of the universal joint at the aft end of the fuselage structure to function as elevator and rudder, with roll control provided through wing warping (No. 20), with the wings only warping “down”.

In 1908 Wilbur Wright traveled to Europe and starting in August gave a series of flight demonstrations at Le Mans in France. The first demonstration, made on 8 August, attracted an audience including most of the major French aviation experimenters, who were astonished by the clear superiority of the Wright Brothers’ aircraft, particularly its ability to make tight controlled turns. The importance of using roll control in making turns was recognized by almost all the European experimenters: Henri Farman fitted ailerons to his Voisin biplane and shortly afterward set up his own aircraft construction business, whose first product was the influential Farman III biplane.

The following year saw the widespread recognition of powered flight as something other than the preserve of dreamers and eccentrics. On 25 July Louis Blriot won worldwide fame by winning a 1,000 prize offered by the British Daily Mail newspaper for a flight across the English Channel, and in August around half a million people, including the President of France Armand Fallires and David Lloyd George, attended one of the first aviation meetings, the Grande Semaine d’Aviation at Reims.

In 1877, Enrico Forlanini developed an unmanned helicopter powered by a steam engine. It rose to a height of 13 meters, where it remained for some 20 seconds, after a vertical take-off The first time a manned helicopter is known to have risen off the ground was on a tethered flight in 1907 by the Breguet-Richet Gyroplane. Later the same year the Cornu helicopter, also French, made the first rotary-winged free flight at Lisenux, France. However, these were not practical designs.from a park in Milan.

Almost as soon as they were invented, airplanes were used for military purposes. The first country to use them for military purposes was Italy, whose aircraft made reconnaissance, bombing and artillery correction flights in Libya during the Italian-Turkish war (September 1911 – October 1912). The first mission (a reconnaissance) occurred on 23 October 1911. The first bombing mission was flown on 1 November 1911. Then Bulgaria followed this example. Its airplanes attacked and reconnoitered the Ottoman positions during the First Balkan War 1912–13. The first war to see major use of airplanes in offensive, defensive and reconnaissance capabilities was World War I. The Allies and Central Powers both used airplanes and airships extensively.

While the concept of using the airplane as an offensive weapon was generally discounted 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. Radiotelephones were also being explored on airplanes, notably the SCR-68, as communication between pilots and ground commander grew more and more important.

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 while Adolphe Pegoud would become known as the first “ace”, getting credit for five victories, before also becoming the first ace to die in action, it was German Luftstreitkrfte Leutnant Kurt Wintgens, who, on July 1, 1915, scored the very first aerial victory by a purpose-built fighter plane, with a synchronized machine gun.

Aviators were styled as modern-day knights, doing individual combat with their enemies. Several pilots became famous for their air-to-air combat; 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, Ren Paul Fonck is credited with the most all-time victories at 75, even when later wars are considered.

France, Britain, Germany, and Italy were the leading manufacturers of fighter planes that saw action during the war, with German aviation technologist Hugo Junkers showing the way to the future through his pioneering use of all-metal aircraft from late 1915.

The years between World War I and World War II saw great advancements in aircraft technology. Airplanes evolved from low-powered biplanes made from wood and fabric to sleek, high-powered monoplanes made of aluminum, based primarily on the founding work of Hugo Junkers during the World War I period and its adoption by American designer William Bushnell Stout and Soviet designer Andrei Tupolev. The age of the great rigid airships came and went. The first successful rotorcraft appeared in the form of the autogyro, invented by Spanish engineer Juan de la Cierva and first flown in 1919. In this design, the rotor is not powered but is spun like a windmill by its passage through the air. A separate powerplant is used to propel the aircraft forwards.

After World War I, experienced fighter pilots were eager to show off their 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. 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 Pacific Oceans.

Other prizes, for distance and speed records, also drove development forwards. For example, on June 14, 1919, Captain John Alcock and Lieutenant Arthur Brown co-piloted a Vickers Vimy non-stop from St. John’s, Newfoundland to Clifden, Ireland, winning the 13,000 ($65,000) Northcliffe prize. The first flight across the South Atlantic and the first aerial crossing using astronomical navigation, was made by the naval aviators Gago Coutinho and Sacadura Cabral in 1922, from Lisbon, Portugal, to Rio de Janeiro, Brazil, with only internal means of navigation, in an aircraft specifically fitted for himself with an artificial horizon for aeronautical use, an invention that revolutionized air navigation at the time (Gago Coutinho invented a type of sextant incorporating two spirit levels to provide an artificial horizon). Five years later Charles Lindbergh took the Orteig Prize of $25,000 for the first solo non-stop crossing of the Atlantic. Months after Lindbergh, Paul Redfern was the first to solo the Caribbean Sea and was last seen flying over Venezuela.

Australian Sir Charles Kingsford Smith was the first to fly across the larger Pacific Ocean in the Southern Cross. His crew left Oakland, California to make the first trans-Pacific flight to Australia in three stages. The first (from Oakland to Hawaii) was 2,400 miles, took 27 hours 25 minutes and was uneventful. They then flew to Suva, Fiji 3,100 miles away, taking 34 hours 30 minutes. This was the toughest part of the journey as they flew through a massive lightning storm near the equator. They then flew on to Brisbane in 20 hours, where they landed on 9 June 1928 after approximately 7,400 miles total flight. On arrival, Kingsford Smith was met by a huge crowd of 25,000 at Eagle Farm Airport in his hometown of Brisbane. Accompanying him were Australian aviator Charles Ulm as the relief pilot, and the Americans James Warner and Captain Harry Lyon (who were the radio operator, navigator, and engineer). A week after they landed, Kingsford Smith and Ulm recorded a disc for Columbia talking about their trip. With Ulm, Kingsford Smith later continued his journey being the first in 1929 to circumnavigate the world, crossing the equator twice.

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 rigid airship ended following the destruction by fire of the Zeppelin LZ 129 Hindenburg just before landing at Lakehurst, New Jersey on May 6, 1937, killing 35 of the 97 people aboard. Previous spectacular airship accidents, from the Wingfoot Express disaster (1919) to the loss of the R101 (1930), the Akron (1933) and the Macon (1935) had already cast doubt on airship safety, but with the disasters of the U.S. Navy’s rigid showing the importance of solely using helium as the lifting medium; following the destruction of the Hindenburg, the remaining airship making international flights, the Graf Zeppelin was retired (June 1937). Its replacement, the rigid airship Graf Zeppelin II, made a number of flights, primarily over Germany, from 1938 to 1939, but was grounded when Germany began World War II. Both remaining German zeppelins were scrapped in 1940 to supply metal for the German Luftwaffe; the last American rigid airship, the Los Angeles, which had not flown since 1932, was dismantled in late 1939.

Meanwhile, Germany, which was restricted by the Treaty of Versailles in its development of powered aircraft, developed gliding as a sport, especially at the Wasserkuppe, during the 1920s. In its various forms, in the 21st-century sailplane aviation now has over 400,000 participants.

In 1929 Jimmy Doolittle developed instrument flight.

1929 also saw the first flight of by far the largest plane ever built until then: the Dornier Do X with a wing span of 48 m. On its 70th test flight on October 21 there were 169 people on board, a record that was not broken for 20 years.

Less than a decade after the development of the first practical rotorcraft of any type with the autogyro, in the Soviet Union, Boris N. Yuriev and Alexei M. Cheremukhin, two aeronautical engineers working at the Tsentralniy Aerogidrodinamicheskiy Institut, constructed and flew the TsAGI 1-EA single rotor helicopter, which used an open tubing framework, a four blade main rotor, and twin sets of 1.8-meter (5.9 ft) diameter anti-torque rotors; one set of two at the nose and one set of two at the tail. Powered by two M-2 power plants, up-rated copies of the Gnome Monosoupape rotary radial engine of World War I, the TsAGI 1-EA made several successful low altitude flights. By 14 August 1932, Cheremukhin managed to get the 1-EA up to an unofficial altitude of 605 meters (1,985 feet) with what is likely to be the first successful single-lift rotor helicopter design ever tested and flown.

Only five years after the German Dornier Do-X had flown, Tupolev designed the largest aircraft of the 1930s era, the Maksim Gorky in the Soviet Union by 1934, as the largest aircraft ever built using the Junkers methods of metal aircraft construction.

In the 1930s development of the jet engine began in Germany and in Britain – both countries would go on to develop jet aircraft by the end of World War II.

World War II saw a great increase in the pace of development and production, not only of aircraft but also the associated flight-based weapon delivery systems. Air combat tactics and doctrines took advantage. Large-scale strategic bombing campaigns were launched, fighter escorts introduced and the more flexible aircraft and weapons allowed precise attacks on small targets with dive bombers, fighter-bombers, and ground-attack aircraft. New technologies like radar also allowed more coordinated and controlled deployment of air defense.

The first jet aircraft to fly was the Heinkel He 178 (Germany), flown by Erich Warsitz in 1939, followed by the world’s first operational jet aircraft, the Me 262, in July 1942 and world’s first jet-powered bomber, the Arado Ar 234, in June 1943. British developments, like the Gloster Meteor, followed afterward but saw only brief use in World War II. The first cruise missile (V-1), the first ballistic missile (V-2), the first (and to date only) operational rocket-powered combat aircraft Me 163 — with attained velocities of up to 1,130 km/h (700 mph) in test flights — and the first vertical take-off manned point-defense interceptor, the Bachem Ba 349 Natter, were also developed by Germany. However, jet and rocket aircraft had an only limited impact due to their late introduction, fuel shortages, the lack of experienced pilots and the declining war industry of Germany.

Not only airplanes but also helicopters saw rapid development in the Second World War, with the introduction of the Focke Achgelis Fa 223, the Flettner Fl 282 synchropter in 1941 in Germany and the Sikorsky R-4 in 1942 in the USA.

After World War II, commercial aviation grew rapidly, using mostly ex-military aircraft to transport people and cargo. This growth was accelerated by the glut of heavy and super-heavy bomber airframes like the B-29 and Lancaster that could be converted into commercial aircraft. The DC-3 also made for easier and longer commercial flights. The first commercial jet airliner to fly was the British de Havilland Comet. By 1952, the British state airline BOAC had introduced the 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 September 15, 1956, with the Tupolev Tu-104. The Boeing 707 and DC-8 which established new levels of comfort, safety, and passenger expectations, ushered in the age of mass commercial air travel, dubbed the Jet Age.

In October 1947 Chuck Yeager took the rocket-powered Bell X-1 through the sound barrier. Although anecdotal evidence exists that some fighter pilots may have done so while dive bombing ground targets during the war, this was the first controlled, level flight to exceed the speed of sound. Further barriers of distance fell in 1948 and 1952 with the first jet crossing of the Atlantic and the first nonstop flight to Australia.

The 1945 invention of nuclear bombs briefly increased the strategic importance of military aircraft in the Cold War between East and West. Even a moderate fleet of long-range bombers could deliver a deadly blow to the enemy, so great efforts were made to develop countermeasures. At first, the supersonic interceptor aircraft were produced in considerable numbers. By 1955 most development efforts shifted to guided surface-to-air missiles. However, the approach diametrically changed when a new type of nuclear-carrying platform appeared that could not be stopped in any feasible way: intercontinental ballistic missiles. The possibility of these was demonstrated in 1957 with the launch of Sputnik 1 by the Soviet Union. This action started the Space Race between the nations.

In 1961, the sky was no longer the limit for manned flight, as Yuri Gagarin orbited once around the planet within 108 minutes, and then used the descent module of Vostok I to safely reenter the atmosphere and reduce speed from Mach 25 using friction and converting the kinetic energy of the velocity into heat. 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 into space. The space race between the United States and the Soviet Union would ultimately lead to the landing of men on the moon in 1969.

In 1967, the X-15 set the air speed record for an aircraft at 4,534 mph (7,297 km/h) or Mach 6.1. Aside from vehicles designed to fly in outer space, this record was renewed by X-43 in the 21st century.

The Harrier Jump Jet often referred to as just “Harrier” or “the Jump Jet”, is a British designed military jet aircraft capable of Vertical/Short Takeoff and Landing (V/STOL) via thrust vectoring. It first flew in 1969, the same year that Neil Armstrong and Buzz Aldrin set foot on the moon, and Boeing unveiled the Boeing 747 and the Arospatiale-BAC Concorde supersonic passenger airliner had its maiden flight. The Boeing 747 was the largest commercial passenger aircraft ever to fly, and still carries millions of passengers each year, though it has been superseded by the Airbus A380, which is capable of carrying up to 853 passengers. In 1975 Aeroflot started regular service on the Tu-144—the first supersonic passenger plane. In 1976 British Airways and Air France began supersonic service across the Atlantic, with 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.

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.

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Aversa, R., D. Parcesepe, R.V.V. Petrescu, F. Berto and G. Chen et al., 2017d. Process ability of bulk metallic glasses. Am. J. Applied Sci., 14: 294-301.

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Aversa, R., D. Parcesepe, R.V. Petrescu, G. Chen and F.I.T. Petrescu et al., 2016b. Glassy amorphous metal injection molded induced morphological defects. Am. J. Applied Sci., 13: 1476-1482.

Aversa, R., R.V. Petrescu, F.I.T. Petrescu and A. Apicella, 2016c. Smart-factory: Optimization and process control of composite centrifuged pipes. Am. J. Applied Sci., 13: 1330-1341.

Aversa, R., F. Tamburrino, R.V. Petrescu, F.I.T. Petrescu and M. Artur et al., 2016d. Biomechanically inspired shape memory effect machines driven by muscle like acting NiTi alloys. Am. J. Applied Sci., 13: 1264-1271.

Aversa, R., E.M. Buzea, R.V. Petrescu, A. Apicella and M. Neacsa et al., 2016e. Present a mechatronic system having able to determine the concentration of carotenoids. Am. J. Eng. Applied Sci., 9: 1106-1111.

Aversa, R., R.V. Petrescu, R. Sorrentino, F.I.T. Petrescu and A. Apicella, 2016f. Hybrid ceramo-polymeric nanocomposite for biomimetic scaffolds design and preparation. Am. J. Eng. Applied Sci., 9: 1096-1105.

Aversa, R., V. Perrotta, R.V. Petrescu, C. Misiano and F.I.T. Petrescu et al., 2016g. From structural colors to super-hydrophobicity and achromatic transparent protective coatings: Ion plating plasma assisted TiO2 and SiO2 Nano-film deposition. Am. J. Eng. Applied Sci., 9: 1037-1045.

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Aversa, R., R.V. Petrescu, A. Apicella and F.I.T. Petrescu, 2016l. One can slow down the aging through antioxidants. Am. J. Eng. Applied Sci., 9: 1112-1126.

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Mirsayar, M.M., V.A. Joneidi, R.V.V. Petrescu, F.I.T. Petrescu and F. Berto, 2017 Extended MTSN criterion for fracture analysis of soda lime glass. Eng. Fracture Mechanics 178: 50-59. DOI: 10.1016/j.engfracmech.2017.04.018

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Petrescu, F.I., Petrescu, R.V., 2016b Dynamic Cinematic to a Structure 2R, GEINTEC-GESTAO INOVACAO E TECNOLOGIAS, 6(2):3143-3154.

Petrescu, F.I., Petrescu, R.V., 2014a Cam Gears Dynamics in the Classic Distribution, Independent Journal of Management & Production, 5(1):166-185.

Petrescu, F.I., Petrescu, R.V., 2014b High Efficiency Gears Synthesis by Avoid the Interferences, Independent Journal of Management & Production, 5(2):275-298.

Petrescu, F.I., Petrescu R.V., 2014c Gear Design, ENGEVISTA, 16(4):313-328.

Petrescu, F.I., Petrescu, R.V., 2014d Balancing Otto Engines, International Review of Mechanical Engineering 8(3):473-480.

Petrescu, F.I., Petrescu, R.V., 2014e Machine Equations to the Classical Distribution, International Review of Mechanical Engineering 8(2):309-316.

Petrescu, F.I., Petrescu, R.V., 2014f Forces of Internal Combustion Heat Engines, International Review on Modelling and Simulations 7(1):206-212.

Petrescu, F.I., Petrescu, R.V., 2014g Determination of the Yield of Internal Combustion Thermal Engines, International Review of Mechanical Engineering 8(1):62-67.

Petrescu, F.I., Petrescu, R.V., 2014h Cam Dynamic Synthesis, Al-Khwarizmi Engineering Journal, 10(1):1-23.

Petrescu, F.I., Petrescu R.V., 2013a Dynamic Synthesis of the Rotary Cam and Translated Tappet with Roll, ENGEVISTA 15(3):325-332.

Petrescu, F.I., Petrescu, R.V., 2013b Cams with High Efficiency, International Review of Mechanical Engineering 7(4):599-606.

Petrescu, F.I., Petrescu, R.V., 2013c An Algorithm for Setting the Dynamic Parameters of the Classic Distribution Mechanism, International Review on Modelling and Simulations 6(5B):1637-1641.

Petrescu, F.I., Petrescu, R.V., 2013d Dynamic Synthesis of the Rotary Cam and Translated Tappet with Roll, International Review on Modelling and Simulations 6(2B):600-607.

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Petrescu, F.I., Petrescu, R.V., 2012c Motoare termice, Create Space publisher, USA, October 2012, ISBN 978-1-4802-0488-1, 164 pages, Romanian edition.

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Petrescu, F.I., Petrescu, R.V., 2011b Trenuri planetare, Create Space publisher, USA, December 2011, ISBN 978-1-4680-3041-9, 204 pages, Romanian version.

Petrescu, F.I., Petrescu, R.V., 2011c Gear Solutions, Create Space publisher, USA, November 2011, ISBN 978-1-4679-8764-6, 72 pages, English version.

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Petrescu, FIT., 2015a Geometrical Synthesis of the Distribution Mechanisms, American Journal of Engineering and Applied Sciences, 8(1):63-81. DOI: 10.3844/ajeassp.2015.63.81

Petrescu, FIT., 2015b Machine Motion Equations at the Internal Combustion Heat Engines, American Journal of Engineering and Applied Sciences, 8(1):127-137. DOI: 10.3844/ajeassp.2015.127.137

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Petrescu, FIT.; Calautit, JK.; Mirsayar, M.; Marinkovic, D.; 2015 Structural Dynamics of the Distribution Mechanism with Rocking Tappet with Roll, American Journal of Engineering and Applied Sciences, 8(4):589-601. DOI: 10.3844/ajeassp.2015.589.601

Petrescu, FIT.; Calautit, JK.; 2016 About Nano Fusion and Dynamic Fusion, American Journal of Applied Sciences, 13(3):261-266.

Petrescu, R.V.V., R. Aversa, A. Apicella, F. Berto and S. Li et al., 2016a. Ecosphere protection through green energy. Am. J. Applied Sci., 13: 1027-1032. DOI: 10.3844/ajassp.2016.1027.1032

Petrescu, F.I.T., A. Apicella, R.V.V. Petrescu, S.P. Kozaitis and R.B. Bucinell et al., 2016b. Environmental protection through nuclear energy. Am. J. Applied Sci., 13: 941-946.

Petrescu, F.I., Petrescu R.V., 2017 Velocities and accelerations at the 3R robots, ENGEVISTA 19(1):202-216.

Petrescu, RV., Petrescu, FIT., Aversa, R., Apicella, A., 2017 Nano Energy, Engevista, 19(2):267-292.

Petrescu, RV., Aversa, R., Apicella, A., Petrescu, FIT., 2017 ENERGIA VERDE PARA PROTEGER O MEIO AMBIENTE, Geintec, 7(1):3722-3743.

Aversa, R., Petrescu, RV., Apicella, A., Petrescu, FIT., 2017 Under Water, OnLine Journal of Biological Sciences, 17(2): 70-87.

Aversa, R., Petrescu, RV., Apicella, A., Petrescu, Fit., 2017 Nano-Diamond Hybrid Materials for Structural Biomedical Application, American Journal of Biochemistry and Biotechnology, 13(1): 34-41.

Syed, J., Dharrab, AA., Zafa, MS., Khand, E., Aversa, R., Petrescu, RV., Apicella, A., Petrescu, FIT., 2017 Influence of Curing Light Type and Staining Medium on the Discoloring Stability of Dental Restorative Composite, American Journal of Biochemistry and Biotechnology 13(1): 42-50.

Aversa, R., Petrescu, RV., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Chen, G., Li, S., Apicella, A., Petrescu, FIT., 2017 Kinematics and Forces to a New Model Forging Manipulator, American Journal of Applied Sciences 14(1):60-80.

Aversa, R., Petrescu, RV., Apicella, A., Petrescu, FIT., Calautit, JK., Mirsayar, MM., Bucinell, R., Berto, F., Akash, B., 2017 Something about the V Engines Design, American Journal of Applied Sciences 14(1):34-52.

Aversa, R., Parcesepe, D., Petrescu, RV., Berto, F., Chen, G., Petrescu, FIT., Tamburrino, F., Apicella, A., 2017 Processability of Bulk Metallic Glasses, American Journal of Applied Sciences 14(2): 294-301.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Calautit, JK., Apicella, A., Petrescu, FIT., 2017 Yield at Thermal Engines Internal Combustion, American Journal of Engineering and Applied Sciences 10(1): 243-251.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Apicella, A., Petrescu, FIT., 2017 Velocities and Accelerations at the 3R Mechatronic Systems, American Journal of Engineering and Applied Sciences 10(1): 252-263.

Berto, F., Gagani, A., Petrescu, RV., Petrescu, FIT., 2017 A Review of the Fatigue Strength of Load Carrying Shear Welded Joints, American Journal of Engineering and Applied Sciences 10(1):1-12.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Apicella, A., Petrescu, FIT., 2017 Anthropomorphic Solid Structures n-R Kinematics, American Journal of Engineering and Applied Sciences 10(1): 279-291.

Aversa, R., Petrescu, RV., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Chen, G., Li, S., Apicella, A., Petrescu, FIT., 2017 Something about the Balancing of Thermal Motors, American Journal of Engineering and Applied Sciences 10(1):200-217.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Apicella, A., Petrescu, FIT., 2017 Inverse Kinematics at the Anthropomorphic Robots, by a Trigonometric Method, American Journal of Engineering and Applied Sciences, 10(2): 394-411.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Calautit, JK., Apicella, A., Petrescu, FIT., 2017 Forces at Internal Combustion Engines, American Journal of Engineering and Applied Sciences, 10(2): 382-393.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Apicella, A., Petrescu, FIT., 2017 Gears-Part I, American Journal of Engineering and Applied Sciences, 10(2): 457-472.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Apicella, A., Petrescu, FIT., 2017 Gears-Part II, American Journal of Engineering and Applied Sciences, 10(2): 473-483.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Apicella, A., Petrescu, FIT., 2017 Cam-Gears Forces, Velocities, Powers and Efficiency, American Journal of Engineering and Applied Sciences, 10(2): 491-505.

Aversa, R., Petrescu, RV., Apicella, A., Petrescu, FIT., 2017 A Dynamic Model for Gears, American Journal of Engineering and Applied Sciences, 10(2): 484-490.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Kosaitis, S., Abu-Lebdeh, T., Apicella, A., Petrescu, FIT., 2017 Dynamics of Mechanisms with Cams Illustrated in the Classical Distribution, American Journal of Engineering and Applied Sciences, 10(2): 551-567.

Petrescu, RV., Aversa, R., Akash, B., Bucinell, R., Corchado, J., Berto, F., Mirsayar, MM., Kosaitis, S., Abu-Lebdeh, T., Apicella, A., Petrescu, FIT., 2017 Testing by Non-Destructive Control, American Journal of Engineering and Applied Sciences, 10(2): 568-583.

Petrescu, RV., Aversa, R., Li, S., Mirsayar, MM., Bucinell, R., Kosaitis, S., Abu-Lebdeh, T., Apicella, A., Petrescu, FIT., 2017 Electron Dimensions, American Journal of Engineering and Applied Sciences, 10(2): 584-602.

Petrescu, RV., Aversa, R., Kozaitis, S., Apicella, A., Petrescu, FIT., 2017 Deuteron Dimensions, American Journal of Engineering and Applied Sciences, 10(3).

Petrescu RV., Aversa R., Apicella A., Petrescu FIT., 2017 Transportation Engineering, American Journal of Engineering and Applied Sciences, 10(3).

Petrescu RV., Aversa R., Kozaitis S., Apicella A., Petrescu FIT., 2017 Some Proposed Solutions to Achieve Nuclear Fusion, American Journal of Engineering and Applied Sciences, 10(3).

Petrescu RV., Aversa R., Kozaitis S., Apicella A., Petrescu FIT., 2017 Some Basic Reactions in Nuclear Fusion, American Journal of Engineering and Applied Sciences, 10(3).

Petrescu, Relly Victoria; Aversa, Raffaella; Akash, Bilal; Bucinell, Ronald; Corchado, Juan; Berto, Filippo; Mirsayar, MirMilad; Apicella, Antonio; Petrescu, Florian Ion Tiberiu; 2017a Modern Propulsions for Aerospace-A Review, Journal of Aircraft and Spacecraft Technology, 1(1).

Petrescu, Relly Victoria; Aversa, Raffaella; Akash, Bilal; Bucinell, Ronald; Corchado, Juan; Berto, Filippo; Mirsayar, MirMilad; Apicella, Antonio; Petrescu, Florian Ion Tiberiu; 2017b Modern Propulsions for Aerospace-Part II, Journal of Aircraft and Spacecraft Technology, 1(1).

Petrescu, Relly Victoria; Aversa, Raffaella; Akash, Bilal; Bucinell, Ronald; Corchado, Juan; Berto, Filippo; Mirsayar, MirMilad; Apicella, Antonio; Petrescu, Florian Ion Tiberiu; 2017c History of Aviation-A Short Review, Journal of Aircraft and Spacecraft Technology, 1(1).

Petrescu, Relly Victoria; Aversa, Raffaella; Akash, Bilal; Bucinell, Ronald; Corchado, Juan; Berto, Filippo; Mirsayar, MirMilad; Apicella, Antonio; Petrescu, Florian Ion Tiberiu; 2017d Lockheed Martin-A Short Review, Journal of Aircraft and Spacecraft Technology, 1(1).

Petrescu, Relly Victoria; Aversa, Raffaella; Akash, Bilal; Corchado, Juan; Berto, Filippo; Mirsayar, MirMilad; Apicella, Antonio; Petrescu, Florian Ion Tiberiu; 2017e Our Universe, Journal of Aircraft and Spacecraft Technology, 1(1).

Petrescu, Relly Victoria; Aversa, Raffaella; Akash, Bilal; Corchado, Juan; Berto, Filippo; Mirsayar, MirMilad; Apicella, Antonio; Petrescu, Florian Ion Tiberiu; 2017f What is a UFO?, Journal of Aircraft and Spacecraft Technology, 1(1).

Petrescu, RV., Aversa, R., Akash, B., Corchado, J., Berto, F., Mirsayar, MM., Apicella, A., Petrescu, FIT., 2017 About Bell Helicopter FCX-001 Concept Aircraft-A Short Review, Journal of Aircraft and Spacecraft Technology, 1(1).

Petrescu, RV., Aversa, R., Akash, B., Corchado, J., Berto, F., Mirsayar, MM., Apicella, A., Petrescu, FIT., 2017 Home at Airbus, Journal of Aircraft and Spacecraft Technology, 1(1).

Petrescu, RV., Aversa, R., Akash, B., Corchado, J., Berto, F., Mirsayar, MM., Kozaitis, S., Abu-Lebdeh, T., Apicella, A., Petrescu, FIT., 2017 Airlander, Journal of Aircraft and Spacecraft Technology, 1(1).

Petrescu, RV., Aversa, R., Akash, B., Corchado, J., Berto, F., Apicella, A., Petrescu, FIT., 2017 When Boeing is Dreaming – a Review, Journal of Aircraft and Spacecraft Technology, 1(1).

History of aviation, From Wikipedia, the free encyclopedia. Retrieved from: https://en.wikipedia.org/wiki/History_of_aviation

History of ballooning, From Wikipedia, the free encyclopedia. Retrieved from: https://en.wikipedia.org/wiki/History_of_ballooning

Airship, From Wikipedia, the free encyclopedia. Retrieved from: https://en.wikipedia.org/wiki/Airship

High-altitude platform station, From Wikipedia, the free encyclopedia. Retrieved from: https://en.wikipedia.org/wiki/High-altitude_platform_station

Integrated Sensor is Structure, From Wikipedia, the free encyclopedia. Retrieved from: https://en.wikipedia.org/wiki/Integrated_Sensor_is_Structure

Mystery airship, From Wikipedia, the free encyclopedia. Retrieved from: https://en.wikipedia.org/wiki/Mystery_airship

Petrescu RVV., Petrescu FIT., July 28, 2017 Seaplane, Part I, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/seaplane-part-i.html

Petrescu RVV., Petrescu FIT., July 28, 2017 Seaplane, Part II, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/seaplane-part-ii.html

Petrescu RVV., Petrescu FIT., July 28, 2017 Seaplane, Part III, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/seaplane-part-iii.html

Petrescu RVV., Petrescu FIT., July 28, 2017 Seaplane, Part IV, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/seaplane-part-iv.html

Petrescu RVV., Petrescu FIT., July 28, 2017 Seaplane, Part V, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/seaplane-part-v.html

Petrescu RVV., Petrescu FIT., July 28, 2017 Aircraft Carriers, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/aircraft-carriers.html

Petrescu RVV., Petrescu FIT., July 28, 2017 The Battle of MIDWAY, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/the-battle-of-midway.html

Petrescu RVV., Petrescu FIT., July 24, 2017 Ships STOVL, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/ships-stovl.html

Petrescu RVV., Petrescu FIT., July 24, 2017 Invisible Aircraft, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/invisible-aircraft.html

Petrescu RVV., Petrescu FIT., July 24, 2017 Planes which have made History, Part I, Articles Factory. Retrieved from: http://www.articlesfactory.com/articles/technology/planes-which-have-made-history-part-i.html

Petrescu RVV., Petrescu FIT., July 24, 2017 Planes which have made History, Part II, Articles