Unpowered Aircraft


An ornithopter (from Greek ornithos "bird" and pteron "wing") is an aircraft that flies by flapping its wings. Designers seek to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, they are usually built on the same scale as these flying creatures. Manned ornithopters have also been built, and some have been successful. The machines are of two general types: those with engines, and those powered by the muscles of the pilot.

*how it begun ?

Some early manned flight attempts may have been intended to achieve flapping-wing flight though probably only a glide was actually achieved. These include the flights of the 11th-century monk Eilmer of Malmesbury (recorded in the 12th century) and the 9th-century poet Abbas Ibn Firnas (recorded in the 17th century). Roger Bacon, writing in 1260, was also among the first to consider a technological means of flight. In 1485, Leonardo da Vinci began to study the flight of birds. He grasped that humans are too heavy, and not strong enough, to fly using wings simply attached to the arms. Therefore he sketched a device in which the aviator lies down on a plank and works two large, membranous wings using hand levers, foot pedals, and a system of pulleys.

The first ornithopters capable of flight were constructed in France. Jobert in 1871 used a rubber band to power a small model bird. Alphonse Pénaud, Abel Hureau de Villeneuve, and Victor Tatin, also made rubber-powered ornithopters during the 1870s. Tatin's ornithopter (now in the US Air & Space Museum) was perhaps the first to use active torsion of the wings, and apparently it served as the basis for a commercial toy offered by Pichancourt c. 1889. Gustave Trouvé was the first to use internal combustion and his 1890 model flew a distance of 70 metres in a demonstration for the French Academy of Sciences. The wings were flapped by gunpowder charges activating a bourdon tube.
From 1884 on, Lawrence Hargrave built scores of ornithopters powered by rubber bands, springs, steam, or compressed air. He introduced the use of small flapping wings providing the thrust for a larger fixed wing. This eliminated the need for gear reduction, thereby simplifying the construction.

E.P. Frost made ornithopters starting in the 1870s, first models power by steam engines then in the 1900s an internal combustion one large enough for a person but which did not fly.

In the 1930s, Alexander Lippisch and the NSFK in Germany constructed and successfully flew a series of internal combustion powered ornithopters, using Hargrave's concept of small flapping wings, but with aerodynamic improvements resulting from methodical study.
Erich von Holst also working in the 1930s, achieved great efficiency and realism in his work with ornithopters powered by rubber band. This includes perhaps the first success of an ornithopter with a bending wing, intended to more closely imitate the folding wing action of birds although it was not a true variable span wing like birds have.


Around 1960, Percival Spencer successfully flew a series of unmanned ornithopters using internal combustion engines ranging from 0.020-to-0.80-cubic-inch (0.33 to 13.11 cm3) displacement, and having wingspans up to 8 feet (2.4 m). In 1961, Percival Spencer and Jack Stephenson flew the first successful engine-powered, remotely piloted ornithopter, known as the Spencer Orniplane. The Orniplane had a 90.7 inches (2,300 mm) wingspan, weighed 7.5 pounds (3.4 kg), and was powered by a 0.35-cubic-inch (5.7 cm3) displacement 2-stroke engine. It has a biplane configuration, to reduce oscillation of the fuselage.

To sum up

Ornithoper is not really usefull for transportation nowdays. But people still use it for hobby because it is reaiiu fun to play with it or when you become expert on it you can make your own ornithoper model. My writing is now finished but to add  more fun I will show you some video about ornithoper.




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The hot air balloon is the oldest successful human-carrying flight technology. It is part of a class of aircraft known as balloon aircraft. On November 21, 1783, in Paris, France, the first untethered manned flight was performed by Jean-François Pilâtre de Rozier and François Laurent d'Arlandes in a hot air balloon created on December 14, 1782, by the Montgolfier brothers. Hot air balloons that can be propelled through the air rather than just being pushed along by the wind are known as airships or, more specifically, thermal airships.

A hot air balloon consists of a bag called the envelope that is capable of containing heated air. Suspended beneath is a gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule), which carries passengers and (usually) a source of heat, in most cases an open flame. The heated air inside the envelope makes it buoyant since it has a lower density than the relatively cold air outside the envelope. As with all aircraft, hot air balloons cannot fly beyond the atmosphere. Unlike gas balloons, the envelope does not have to be sealed at the bottom since the air near the bottom of the envelope is at the same pressure as the air surrounding. For modern sport balloons, the envelope is generally made from nylon fabric and the inlet of the balloon (closest to the burner flame) is made from fire resistant material such as Nomex. Beginning during the mid-1970s, balloon envelopes have been made in all kinds of shapes, such as rocket ships and the shapes of various commercial products, though the traditional shape remains popular for most non-commercial, and many commercial, applications


History 

Early unmanned hot air balloons were used in China. Zhuge Liang of the Shu Han kingdom, during the Three Kingdoms era (220–280 AD), used airborne lanterns for military signaling. These lanterns are known as Kongming lanterns. There is also some speculation, from a demonstration directed by British modern hot air balloonist Julian Nott during the late 1970s, and again in 2003, that hot air balloons could have been used as an aid for designing the famous Nazca ground figures and lines which were created by the Nazca culture of Peru between 400 and 650 AD. The first documented balloon flight in Europe was demonstrated by Bartolomeu de Gusmão. On August 8, 1709, in Lisbon, he managed to lift a balloon full of hot air about 4.5 meters in front of King John V and the Portuguese court.


Today

Modern hot air balloons, with an onboard heat source, were developed by Ed Yost, beginning during the 1950s; his work resulted in his first successful flight, on October 22, 1960. The first modern hot air balloon to be made in the United Kingdom (UK) was the Bristol Belle during 1967. Presently, hot air balloons are used primarily for recreation.
Hot air balloons are able to fly to extremely high altitudes. On November 26, 2005, Vijaypat Singhania set the world altitude record for highest hot air balloon flight, reaching 21,027 m (68,986 ft). He took off from downtown Mumbai, India, and landed 240 km (150 mi) south in Panchale.The previous record of 19,811 m (64,997 ft) had been set by Per Lindstrand on June 6, 1988, in Plano, Texas.
On January 15, 1991, the 'Virgin Pacific Flyer' balloon completed the longest flight in a hot air balloon when Per Lindstrand (born in Sweden, but resident in the UK) and Richard Branson of the UK flew 7,671.91 km (4,767.10 mi) from Japan to Northern Canada. With a volume of 74 thousand cubic meters (2.6 million cubic feet), the balloon envelope was the largest ever built for a hot air craft. Designed to fly in the trans-oceanic jet streams, the Pacific Flyer recorded the fastest ground speed for a manned balloon at 245 mph (394 km/h). The longest duration record was set by Swiss psychiatrist Bertrand Piccard, Auguste Piccard's grandson; and Briton Brian Jones, flying in the Breitling Orbiter 3. It was the first nonstop trip around the world by balloon. The balloon left Château-d'Oex, Switzerland, on March 1, 1999, and landed at 1:02 a.m. on March 21 in the Egyptian desert 300 miles (480 km) south of Cairo. The two men exceeded distance, endurance, and time records, traveling 19 days, 21 hours, and 55 minutes. Steve Fossett exceeded the record for briefest time traveling around the world on 3 July 2002. The new record is 320 h 33 min.


That's all from me. I hope you enjoyed reading my short writting. Here is a video to lit some funs up.








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Hi everyone I am Nazlı. I choose Kite option for this presentation. I think, this topic really colorful and so funny. I will write about kites.


A kite is an aircraft consisting of one or more wings tethered to an anchor system. Frequently a wing of a kite is referenced as "kite". The necessary lift that sustains the kite in flight is generated when air flows above the kite's surface, producing low pressure above and high pressure below the wings. The interaction with the wind also generates horizontal drag along the direction of the wind. The resultant force vector from the lift and drag force components is opposed by the tension of one or more of the lines or tethers to which the kite is attached. The anchor point of the kite line may be static or moving (e.g., the towing of a kite by a running person, boat, free-falling anchors as in paragliders and fugitive parakites or vehicle).
The same principles can be used in water and experiments have also been made with lighter-than-air kites (kytoons)



History

Kites were invented in China where materials ideal for kite building were readily available: silk fabric for sail material; fine, high-tensile-strength silk for flying line; and resilient bamboo for a strong, lightweight framework.
The kite has been claimed as the invention of the 5th-century BC Chinese philosophers Mozi (also Mo Di) and Lu Ban (also Gongshu Ban). By AD 549 paper kites were certainly being flown, as it was recorded that in that year a paper kite was used as a message for a rescue mission. Ancient and medieval Chinese sources describe kites being used for measuring distances, testing the wind, lifting men, signaling, and communication for military operations. The earliest known Chinese kites were flat (not bowed) and often rectangular. Later, tailless kites incorporated a stabilizing bowline. Kites were decorated with mythological motifs and legendary figures; some were fitted with strings and whistles to make musical sounds while flying. From China, kite was introduced to Cambodia, India, Japan, Korea and western world


After its introduction into India, the kite further evolved into the fighter kite, known as the patang in India, where thousands are flown every year on festivals such as Makar Sankranti.
Kites were known throughout Polynesia, as far as New Zealand, with the assumption being that the knowledge diffused from China along with the people. Anthropomorphic kites made from cloth and wood were used in religious ceremonies to send prayers to the gods. Polynesian kite traditions are used by anthropologists get an idea of early "primitive" Asian traditions that are believed to have at one time existed in Asia.

Kites were late to arrive in Europe, although windsock-like banners were known and used by the Romans. Stories of kites were first brought to Europe by Marco Polo towards the end of the 13th century, and kites were brought back by sailors from Japan and Malaysia in the 16th and 17th centuries. Although they were initially regarded as mere curiosities, by the 18th and 19th centuries kites were being used as vehicles for scientific research.

In 1750 Benjamin Franklin published a proposal for an experiment to prove that lightning was caused by electricity by flying a kite in a storm that appeared capable of becoming a lightning storm. It is not known whether Franklin ever performed his experiment, but on May 10, 1752, Thomas-François Dalibard of France conducted a similar experiment (using a 40-foot (12 m) iron rod instead of a kite) and extracted electrical sparks from a cloud.

Kites were also instrumental in the research of the Wright brothers when developing the first airplane in the late 1800s. Over the next 70 years, many new kite designs were developed, and often patented. These included Eddy's tail-less diamond kite, the tetrahedral kite, the flexible kite, the sled kite, and the parafoil kite, which helped to develop the modern hang-gliders. In fact, the period from 1860 to about 1910 became the "golden age of kiting". Kites started to be used for scientific purposes, especially in meteorology, aeronautics, wireless communications and photography; many different designs of man-lifting kite were developed as well as power kites.
The development of mechanically powered airplane diminished interest in kites. World War II saw a limited use of kites for military purposes (see Focke Achgelis Fa 330 for an example). Since then they are used mainly for recreation



General safety issues

There are safety issues involved in kite-flying, more so with power kites. Kite lines can strike and tangle on electrical power lines, causing power blackouts and running the risk of electrocuting the kite flier. Wet kite lines or wire can act as a conductor for static electricity and lightning when the weather is stormy. Kites with large surface area or powerful lift can lift kite fliers off the ground or drag them into other objects. In urban areas there is usually a ceiling on how high a kite can be flown, to prevent the kite and line infringing on the airspace of helicopters and light aircraft.



To sum up; I tried to tell kites, kites histories, and kites general safety issues. 
 



I hope you like my blog.








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 Propeller
Aircraft propellers or airscrews convert rotary motion from piston engines, turboprops or electric motors to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal. The most modern propeller designs use high-technology composite materials.
The propeller is usually attached to the crankshaft of a piston engine, either directly or through a reduction unit. Light aircraft engines often do not require the complexity of gearing but on larger engines and turboprop aircraft it is essential.

Hıstory

The twisted airfoil (aerofoil) shape of
modern aircraft propellers was pioneered by the Wright brothers. While some earlier engineers had attempted to model air propellers on marine propellers, the Wrights realized that a propeller is essentially the same as a wing, and were able to use data from their earlier wind tunnel experiments on wings. They also introduced a twist along the length of the blades. This was necessary to ensure the angle of attack of the blades was kept relatively constant along their length. Their original propeller blades had an efficiency of about 82%, compared to the 90% of modern propellers. Mahogany was the preferred wood for propellers through World War I, but wartime shortages encouraged use of walnut, oak, cherry and ash.
Alberto Santos Dumont was another early pioneer, having designed propellers before the Wright Brothers (albeit not as efficient) for his airships. He applied the knowledge he gained from experiences with airships to make a propeller with a steel shaft and aluminium blades for his 14 bis biplane. Some of his designs used a bent aluminium sheet for blades, thus creating an airfoil shape. They were heavily undercambered, and this plus the absence of lengthwise twist made them less efficient than the Wright propellers. Even so, this was perhaps the first use of aluminium in the construction of an airscrew.
Originally, a rotating airfoil behind the aircraft, which pushes it, was called a propeller, while one which pulled from the front was a tractor. Later the term 'pusher' became adopted for the rear-mounted device in contrast to the tractor configuration and both became referred to as 'propellers' or 'airscrews'.
The understanding of low speed propeller aerodynamics was fairly complete by the 1920s, but later requirements to handle more power in a smaller diameter have made the problem more complex.
Propeller control

Variable pitch

The purpose of varying pitch angle with a variable-pitch propeller is to maintain an optimal angle of attack (maximum lift to drag ratio) on the propeller blades as aircraft speed varies. Early pitch control settings were pilot operated, either two-position or manually variable. Following World War I, automatic propellers were developed to maintain an optimum angle of attack. This was done by balancing the centripetal twisting moment on the blades and a set of counterweights against a spring and the aerodynamic forces on the blade. Automatic props had the advantage of being simple, lightweight, and requiring no external control, but a particular propeller's performance was difficult to match with that of the aircraft's powerplant. An improvement on the automatic type was the constant-speed propeller. Constant-speed propellers allow the pilot to select a rotational speed for maximum engine power or maximum efficiency, and a propeller governor acts as a closed-loop controller to vary propeller pitch angle as required to maintain the selected engine speed. In most aircraft this system is hydraulic, with engine oil serving as the hydraulic fluid. However, electrically controlled propellers were developed during World War II and saw extensive use on military aircraft, and have recently seen a revival in use on homebuilt aircraft.

Fetahering

On some variable-pitch propellers, the blades can be rotated parallel to the airflow to reduce drag in case of an engine failure. This uses the term feathering, loaned from rowing. On single-engined aircraft, whether a powered glider or turbine powered aircraft, the effect is to increase the gliding distance. On a multi-engine aircraft, feathering the propeller on a failed engine allows the aircraft to maintain altitude with the reduced power from the remaining engines.
Most feathering systems for reciprocating engines sense a drop in oil pressure and move the blades toward the feather position, and require the pilot to pull the propeller control back to disengage the high-pitch stop pins before the engine reaches idle RPM. Turboprop control systems usually utilize a negative torque sensor in the reduction gearbox which moves the blades toward feather when the engine is no longer providing power to the propeller. Depending on design, the pilot may have to push a button to override the high-pitch stops and complete the feathering process, or the feathering process may be totally automatic.

Reverse pitch

In some aircraft, such as the C-130 Hercules, the pilot can manually override the constant-speed mechanism to reverse the blade pitch angle, and thus the thrust of the engine (although the rotation of the engine itself does not reverse). This is used to help slow the plane down after landing in order to save wear on the brakes and tires, but in some cases also allows the aircraft to back up on its own - this is particularly useful for getting floatplanes out of confined docks. See also Thrust reversal.


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Glider


A glider is a heavier-than-air aircraft that is supported in flight by the dynamic reaction of the air against its lifting surfaces, and whose free flight does not depend on an engine. Most gliders do not have an engine, although motor-gliders have small engines for extending their flight when necessary and some are even powerful enough to take off.
There is a wide variety of types differing in the construction of their wings, aerodynamic efficiency, location of the pilot, controls and intended purpose. Most exploit meteorological phenomena to maintain or even gain height. Gliders are principally used for the air sports of gliding, hang gliding and paragliding. However some spacecraft have been designed to descend as gliders and in the past military gliders have been used in warfare. Perhaps the simplest and most familiar types are toys such as the paper plane and balsa wood glider.




History of gliders

 

Main article: Early flying machines
Early pre-modern accounts of flight are in most cases difficult to verify and it is unclear whether each craft was a glider, kite or parachute and to what degree they were truly controllable. Often the event is only recorded a long time after it allegedly took place. A 17th-century account reports an attempt at flight by the 9th-century poet Abbas Ibn Firnas near Cordoba, Spain which ended in heavy back injuries. The monk Eilmer of Malmesbury is reported by William of Malmesbury (c. 1080–1143), a fellow monk and historian, to have flown off the roof of his Abbey in Malmesbury, England, sometime between 1000 and 1010 AD, gliding about 200 metres (220 yd) before crashing and breaking his legs. According to these reports, both used a set of (feathery) wings, and both blamed their crash on the lack of a tail.


Development of gliders

 

Main article: Glider (sailplane)
After World War I recreational gliders were built in Germany (see link to Rhön-Rossitten Gesellschaft) and in the United States (Schweizer brothers). The sporting use of gliders rapidly evolved in the 1930s and is now the main application. As their performance improved gliders began to be used to fly cross-country and now regularly fly hundreds or even thousands of kilometers in a day, if the weather is suitable.
Military gliders were developed during World War II by a number of countries for landing troops. A glider – the Colditz Cock – was even built secretly by POWs as a potential escape method at Oflag IV-C near the end of the war in 1944.

Etymology; 


Glider is the noun form of the verb to glide. It derives from Middle English gliden, which in turn derived from Old English glīdan. The oldest meaning of glide may have denoted a precipitous running or jumping, as opposed to a smooth motion. Scholars are uncertain as to its original derivation, with possible connections to "slide", and "light" having been advanced





Pre-flight preparation



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 Ooh I wanna touch the sky, I wanna fly so high....



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