Editing Aeronautics (section)

==History==

===Early ideas===
[[File:Leonardo da Vinci helicopter and lifting wing.jpg|thumb|right|Designs for flying machines by Leonardo da Vinci, {{circa|1490}}]]

Attempts  to fly without any real aeronautical understanding have been made from the earliest times, typically by constructing wings and jumping from a tower with crippling or lethal results.{{sfn|Wragg|1974}}

Wiser investigators sought to gain some rational understanding through the study of bird flight. Medieval [[Islamic Golden Age]] scientists such as [[Abbas ibn Firnas]] also made such studies.<ref name="EI2">{{Cite encyclopedia|title=ʿAbbās b. Firnās|volume=I|editor5-first=W.P.|publisher=[[Brill publishers]]|url=http://referenceworks.brillonline.com/entries/encyclopaedia-of-islam-2/abbas-b-firnas-SIM_0021|last=Lévi-Provençal|first=E.|author-link=Évariste Lévi-Provençal|edition=2nd|encyclopedia=Encyclopaedia of Islam|editor1-last=Bearman|page=11|editor1-first=P.|editor2-last=Bianquis|editor2-first=Th.|editor3-last=Bosworth|editor3-first=C.E.|editor4-last=van Donzel|editor4-first=E.|editor5-last=Heinrichs|year=1986}}</ref><ref>How Invention Begins: Echoes of Old Voices in the Rise of New Machines
By John H. Lienhard</ref><ref name="Lienhard">{{cite episode |transcript-url=http://www.uh.edu/engines/epi1910.htm |transcript=Transcript|title='Abbas Ibn Firnas |credits=John H. Lienhard |series=The Engines of Our Ingenuity |series-link=The Engines of Our Ingenuity |network=NPR |station=KUHF-FM Houston |airdate=2004 |number=1910 <!--access-date=2009-08-31-->}}</ref><ref name="Lynn White 1961, 100f.">[[Lynn Townsend White, Jr.]] (Spring, 1961). "Eilmer of Malmesbury, an Eleventh Century Aviator: A Case Study of Technological Innovation, Its Context and Tradition", ''Technology and Culture'' '''2''' (2), p.  97–111 [100f.]</ref> The founders of modern aeronautics, [[Leonardo da Vinci]] in the Renaissance and Cayley in 1799, both began their investigations with studies of bird flight.

Man-carrying kites are believed to have been used extensively in ancient China. In 1282 the Italian explorer [[Marco Polo]] described the Chinese techniques then current.<ref name="pelham">Pelham, D.; ''The Penguin book of kites'', Penguin (1976)</ref> The Chinese also constructed small hot air balloons, or lanterns, and rotary-wing toys.

An early European to provide any scientific discussion of flight was [[Roger Bacon]], who described principles of operation for the lighter-than-air [[Balloon (aircraft)|balloon]] and the flapping-wing [[ornithopter]], which he envisaged would be constructed in the future. The lifting medium for his balloon would be an "aether" whose composition he did not know.{{sfn|Wragg|1974|pp=10–11}}

In the late fifteenth century, Leonardo da Vinci followed up his study of birds with designs for some of the earliest flying machines, including the flapping-wing [[ornithopter]] and the rotating-wing [[helicopter]]. Although his designs were rational, they were not based on particularly good science.{{sfn|Wragg|1974|p=11}} Many of his designs, such as a four-person screw-type helicopter, have severe flaws. He did at least understand that "An object offers as much resistance to the air as the air does to the object."{{sfn|Fairlie|Cayley|1965|p=163}} ([[Isaac Newton|Newton]] would not publish the [[Newton's laws of motion#Newton.27s third law|Third law of motion]] until 1687.) His analysis led to the realisation that manpower alone was not sufficient for sustained flight, and his later designs included a mechanical power source such as a spring. Da Vinci's work was lost after his death and did not reappear until it had been overtaken by the work of [[George Cayley]].

===Balloon flight===
{{Main|History of ballooning}}
[[File:Flying boat.png|thumb|right|upright|[[Francesco Lana de Terzi]]'s flying boat concept {{circa|1670}}]]
The modern era of lighter-than-air flight began early in the 17th century with [[Galileo]]'s experiments in which he showed that air has weight. Around 1650 [[Cyrano de Bergerac]] wrote some fantasy novels in which he described the principle of ascent using a substance (dew) he supposed to be lighter than air, and descending by releasing a controlled amount of the substance.{{sfn|Ege|1973|p=6}} [[Francesco Lana de Terzi]] measured the pressure of air at sea level and in 1670 proposed the first scientifically credible lifting medium in the form of hollow metal spheres from which all the air had been pumped out. These would be lighter than the displaced air and able to lift an [[airship]]. His proposed methods of controlling height are still in use today; by carrying ballast which may be dropped overboard to gain height, and by venting the lifting containers to lose height.{{sfn|Ege|1973|p=7}} In practice de Terzi's spheres would have collapsed under air pressure, and further developments had to wait for more practicable lifting gases.

[[File:Montgolfier brothers flight.jpg|thumb|Montgolfier brothers flight, 1784]]
From the mid-18th century the [[Montgolfier brothers]] in France began experimenting with balloons. Their balloons were made of paper, and early experiments using steam as the lifting gas were short-lived due to its effect on the paper as it condensed. Mistaking smoke for a kind of steam, they began filling their balloons with hot smoky air which they called "electric smoke" and, despite not fully understanding the principles at work, made some successful launches and in 1783 were invited to give a demonstration to the French ''Académie des Sciences''.

Meanwhile, the discovery of [[hydrogen]] led [[Joseph Black]] in {{circa|1780}} to propose its use as a lifting gas, though practical demonstration awaited a gas-tight balloon material. On hearing of the Montgolfier Brothers' invitation, the French Academy member [[Jacques Charles]] offered a similar demonstration of a hydrogen balloon. Charles and two craftsmen, the Robert brothers, developed a gas-tight material of rubberised silk for the envelope. The hydrogen gas was to be generated by chemical reaction during the filling process.

The Montgolfier designs had several shortcomings, not least the need for dry weather and a tendency for sparks from the fire to set light to the paper balloon. The manned design had a gallery around the base of the balloon rather than the hanging basket of the first, unmanned design, which brought the paper closer to the fire. On their free flight, [[Jean-François Pilâtre de Rozier|De Rozier]] and [[François Laurent d'Arlandes|d'Arlandes]] took buckets of water and sponges to douse these fires as they arose. On the other hand, the manned design of Charles was essentially modern.{{sfn|Ege|1973|pp=97–100}} As a result of these exploits, the [[hot air balloon]] became known as the ''Montgolfière'' type and the [[gas balloon]] the ''Charlière''.

Charles and the Robert brothers' next balloon, ''[[Robert brothers#Attempted dirigible: the elongated balloon|La Caroline]]'', was a Charlière that followed [[Jean Baptiste Meusnier]]'s proposals for an elongated dirigible balloon, and was notable for having an outer envelope with the gas contained in a second, inner ballonet. On 19 September 1784, it completed the first flight of over {{convert|100|km}}, between Paris and [[Beuvry]], despite the man-powered propulsive devices proving useless.

In an attempt the next year to provide both endurance and controllability, de Rozier developed a balloon having both hot air and hydrogen gas bags, a design which was soon named after him as the ''Rozière.'' The principle was to use the hydrogen section for constant lift and to navigate vertically by heating and allowing to cool the hot air section, in order to catch the most favourable wind at whatever altitude it was blowing. The balloon envelope was made of [[goldbeaters skin|goldbeater's skin]]. The first flight ended in disaster and the approach has seldom been used since.{{sfn|Ege|1973|p=105}}

===Cayley and the foundation of modern aeronautics===
[[Sir George Cayley]] (1773–1857) is widely acknowledged as the founder of modern aeronautics. He was first called the "father of the aeroplane" in 1846{{sfn|Fairlie|Cayley|1965}} and Henson called him the "father of aerial navigation."{{sfn|Wragg|1974}} He was the first true scientific aerial investigator to publish his work, which included for the first time the underlying principles and forces of flight.<ref>{{cite web| title = Sir George Carley| url = http://www.flyingmachines.org/cayl.html| publisher = Flyingmachines.org| access-date = 2009-07-26| quote = Sir George Cayley is one of the most important people in the history of aeronautics. Many consider him the first true scientific aerial investigator and the first person to understand the underlying principles and forces of flight.| url-status = live| archive-url = https://web.archive.org/web/20090211164945/http://flyingmachines.org/cayl.html| archive-date = 2009-02-11}}</ref>

In 1809 he began the publication of a landmark three-part treatise titled "On Aerial Navigation" (1809–1810).<ref name="AerNav123">''Cayley, George''. "On Aerial Navigation" [http://www.aeronautics.nasa.gov/fap/OnAerialNavigationPt1.pdf Part 1]  {{webarchive|url=https://web.archive.org/web/20130511071413/http://www.aeronautics.nasa.gov/fap/OnAerialNavigationPt1.pdf |date=2013-05-11 }}, [http://www.aeronautics.nasa.gov/fap/OnAerialNavigationPt2.pdf Part 2]  {{webarchive|url=https://web.archive.org/web/20130511041814/http://www.aeronautics.nasa.gov/fap/OnAerialNavigationPt2.pdf |date=2013-05-11 }}, [http://www.aeronautics.nasa.gov/fap/OnAerialNavigationPt3.pdf Part 3]  {{webarchive|url=https://web.archive.org/web/20130511052409/http://www.aeronautics.nasa.gov/fap/OnAerialNavigationPt3.pdf |date=2013-05-11 }} ''Nicholson's Journal of Natural Philosophy'', 1809–1810. (Via [[NASA]]). [http://invention.psychology.msstate.edu/i/Cayley/Cayley.html Raw text] {{webarchive|url=https://web.archive.org/web/20160303193751/http://invention.psychology.msstate.edu/i/Cayley/Cayley.html |date=2016-03-03 }}. Retrieved: 30 May 2010.</ref> 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 (force)|lift]]'', ''[[Aerodynamic drag|drag]]'' and ''[[weight]]'' and distinguished stability and control in his designs.

He developed the modern conventional form of the fixed-wing aeroplane having a stabilising tail with both horizontal and vertical surfaces, flying gliders both unmanned and manned.

He introduced the use of the whirling arm test rig to investigate the aerodynamics of flight, using it to discover the benefits of the curved or [[camber (aerodynamics)|cambered]] [[aerofoil]] over the flat wing he had used for his first glider. He also identified and described the importance of [[Dihedral (aircraft)|dihedral]], diagonal bracing and drag reduction, and contributed to the understanding and design of [[ornithopter]]s and [[parachute]]s.{{sfn|Wragg|1974}}

Another significant invention was the tension-spoked wheel, which he devised in order to create a light, strong wheel for aircraft undercarriage.

===The 19th century: Otto Lilienthal and the first human flights===
[[File:Otto Lilienthal gliding experiment ppmsca.02546.jpg|thumb|Lilienthal in mid-flight, Berlin c. 1895]]

During the 19th century Cayley's ideas were refined, proved and expanded on, culminating in the works of [[Otto Lilienthal]].

Lilienthal was a German engineer and businessman who became known as the "flying man".<ref>{{citation |url=https://lilienthal-museum.museumnet.eu/archiv/objekt/15851 |title=Killed In Trying To Fly |work=New York Herald |date=August 12, 1896|access-date=11 June 2019}}</ref> He was the first person to make well-documented, repeated, successful flights with [[Glider (aircraft)|glider]]s,<ref>[http://www.dlr.de/dlr/desktopdefault.aspx/tabid-10280/385_read-16705/year-all/#/gallery/21944 ''DLR baut das erste Serien-Flugzeug der Welt nach''] 2017. Retrieved: 3 March 2017.</ref> therefore making the idea of "[[heavier than air]]" a reality. Newspapers and magazines published photographs of Lilienthal gliding, favourably influencing public and scientific opinion about the possibility of flying machines becoming practical.

His work led to the development of the modern wing.<ref>{{Cite web|url=http://www.lilienthal-museum.de/olma/eotto.htm|title = Otto-Lilienthal-Museum Anklam}}</ref><ref>{{Cite web|url=https://www.dlr.de/content/en/dossiers/2019/lilienthal-glider-project.html|title=The Lilienthal glider project|access-date=2022-02-26|archive-date=2022-03-07|archive-url=https://web.archive.org/web/20220307224806/https://www.dlr.de/content/en/dossiers/2019/lilienthal-glider-project.html|url-status=dead}}</ref> His flight attempts in [[Berlin]] in the year 1891 are seen as the beginning of human flight<ref>{{Cite web|url=http://www.lilienthal-museum.de/olma/e34.htm|title = Otto-Lilienthal-Museum Anklam}}</ref> and the "[[Lilienthal Normalsegelapparat]]" is considered to be the first air plane in series production, making the ''Maschinenfabrik Otto Lilienthal'' in [[Berlin]] the first air plane production company in the world.<ref>{{Cite web|url=https://aeroreport.de/en/good-to-know/like-a-bird|title = Like a bird}}</ref>

[[Otto Lilienthal]] is often referred to as either the "father of aviation"<ref>{{Cite web|url=https://www.dpma.de/english/our_office/publications/milestones/airandspacepioneers/ottolilienthal/index.html|title=DPMA &#124; Otto Lilienthal}}</ref><ref>{{Cite web|url=https://www.cobaltrecruitment.co.uk/blog/2017/11/in-perspective-otto-lilienthal|title = In perspective: Otto Lilienthal}}</ref><ref>{{Cite news|url=https://www.economist.com/prospero/2011/09/20/remembering-germanys-first-flying-man|title = Remembering Germany's first "flying man"|newspaper = The Economist|date = 20 September 2011}}</ref> or "father of flight".<ref>{{Cite web|url=http://scihi.org/otto-lilienthal-glider-king/|title=Otto Lilienthal, the Glider King|date=23 May 2020}}</ref>

Other important investigators included [[Horatio Phillips]].