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Bomber Theory

Bomber Theory



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World War One

World War One saw the emergence of air power in the military field - initially as 'spotter' planes, then as fighters and finally bombers. The Zeppelins were used as 'strategic' bombers in 1915, and extended fighting to the Home Front for the first time. As speed and endurance increased, civilians became more and more in the forefront of war. You can find more detailed account of air power in World War One at The Aerodrome.

After the War

Once World War One ended, strategists were trying to find ways of avoiding the slaughter of the trenches, and re-introducing mobility onto the battlefield. The tank had been one attempt to do this (see Tanks). Other views developed the idea of air power as a way to defeat the enemy. Three people are perhaps best remembered for the new emphasis on air power.

Guilio Douhet's Theory of Air Power

Guilio Douhet was an Italian. He believed that the airplane had completely changed warfare and that airplanes would win wars quickly and decisively. The first priority was to gain command of the air. With command of the air, an air force would be free to operate whenever and wherever it desired. There was, as yet, no effective defence against air attacks. Having achieved command of the air, pilots would then destroy the enemy's will to resist by conducting aerial bombing on his cities, industrial centres and civilian population. It was thought that civilians were not prepared for the effects of war and the bombing of population centres would create panic among the people. People would then pressurize the government to negotiate for peace. Douhet believed the bomber could fight its way to and from the target, hence the origin of the phrase 'the bomber will always get through.' (see Air Power for a further discussion on Douhet's theories).

Sir Basil Henry Liddell Hart

Sir Basil Liddell Hart had fought in the war, and had supported the use and devlopment of tanks. Liddell Hart was also one of the most enthusiastic early supporters of air power. It was the virtually unlimited mobility of the airplane that appealed. The airplane - with its ability to bypass the trenches and strike directly at the heart of the enemy - seemed to offer the best way to quickly win wars. The debates on the proper way to use air power were rapidly coming down in favour of the long-range bomber offensive. A sudden, massive, devastating strike at the enemy's industrial centres seemed the best tactic to destroy his ability to resist.

William Mitchell

William Mitchell was an American. He also believed in the capability of the airplane. In 1930, Mitchell wrote: 'The advent of air power has put a completely new complexion on the old ways of fighting wars. We now realise that the hostile main army in the field is not the main target. Armies themselves can be disregarded by air power if a rapid strike is made against the opposing centres'. So, instead of concentrating air attacks on population centres (as Douhet argues) or the main army, airplanes should be used as strategic weapons to strike deep into the enemy's territory, targeting cities, military related industries and other vital areas. Unlike Douhet's idea of aerial bombing, Mitchell's aim was to be much more accurate and bomb specific targets.

All of these ideas developed because the Generals had not been able to find an effective means of winning the war quickly and cheaply. The idea rapidly spread that air power was the answer. This had two advantages - there was no need for a large (and expensive) army, and, as the bomber would always get through, there was no need to spend money on air defence, as there was no way of stopping a determined attack by enemy bombers. Lots of money was spent between the wars developing bomber fleets.

The Development of RAF Strategic Bombing Doctrine, 1919-1939

When World War Two started, in September 1939, the RAF was unable to deliver the long-promised `knock out blow' against Germany. The optimistic `Air Plans' were shelved, and Bomber Command spent the early months of the war showering German cities with nothing more destructive than leaflets. In its early years, the RAF faced persistent competition from the Navy and Army. To defend its independence, the Air Staff defended the idea that the bomber was a devastating and revolutionary weapon - a different method of waging war, which required a separate air service to wage it. Far too little thought was given to the practicalities of navigation, equipment and bomb-aiming, or to the possibilities of air defence. For example in 1939, despite arguing for twenty years in favour of the strategic air offensive, the Air Staff went to war with little idea about potential economic targets in Germany. It didn't have effective long-range powerful bombers, or accurate navigation aids. Early daylight bombing raids in WW2 were destroyed by German fighter planes, and night raids often failed to get anywhere near their targets. The Bomber Theory was shown up to be a myth. Why therefore had it taken such a hold on Britain's politicians?

The use of the RAF to defeat rebels in the Empire

After World War I Britain had to deal with disorders of all sorts in its empire. Uprisings against British rule, tribal warfare and border problems seemed widespread in the Middle East, Africa, and along India's northwest frontier. The expense of large ground-force expeditions to keep order was seen as a burden. During the early 1920s, the British began to look for alternative ways to control and administer the empire. The Royal Air Force needed to develop methods whereby its aircraft could be used as a cheap, effective force to control the empire.

In the 1920s Britain bombed Kurds and Arabs in Iraq when they rebelled against Britain's attempts to control them. By October 1922 the RAF had principal responsibility for the war, with British ground forces being reduced. In a single aerial sortie, in mid-May 1922, Suleymaniya was bombarded, causing the town's 7,000 residents to evacuate the town for the rest of the conflict. In fact, armed confrontations between Kurdish and Arab nationalists and British imperialism continued until the early 1930s.

Winston Churchill, the colonial secretary at the time, believed that gas could be used effectively against the Kurds and Iraqis (as well as against other peoples in the Empire): 'I do not understand this squeamishness about the use of gas. I am strongly in favour of using poison gas against uncivilised tribes.' Some shared Churchill's enthusiasm for gas as an instrument of colonial control but the British cabinet was reluctant to allow the use of a weapon that had caused such misery and revulsion in the First World War. In the event, gas was used against the Iraqi rebels though gas shells were not dropped from aircraft because of practical difficulties.

Wing-Commander Sir Arthur Harris, later Bomber Harris, head of wartime Bomber Command, was happy to emphasise that 'The Arab and Kurd now know what real bombing means in casualties and damage. Within forty-five minutes a full-size village can be practically wiped out and a third of its inhabitants killed or injured.' It was an easy matter to bomb and machine-gun the tribespeople, because they had no means of defence or retaliation. Iraq and Kurdistan were also used as testing grounds for new weapons; devices specifically developed by the Air Ministry for use against tribal villages.

Hugh Trenchard, the RAF chief of staff concluded "Air power is of vital concern to the Empire and in Iraq, and evidence is growing of its great potential. It may further reduce defence spending, not only in Iraq, but also in other Eastern territories where armed forces are needed to keep control".

Aerial bombardment had proven to be a satisfactory method of mass killing. Jonathan Glancey (The Guardian, 19 April 2003) recalls: "Winston Churchill, secretary of state for war and air, estimated that without the RAF, somewhere between 25,000 British and 80,000 Indian troops would be needed to control Iraq. Reliance on the airforce promised to cut these numbers to just 4,000 and 10,000. Churchill's confidence was soon repaid". Glancey reports that the RAF "flew missions totaling 4,008 hours, dropped 97 tons of bombs and fired 183,861 rounds for the loss of nine men killed, seven wounded and 11 aircraft destroyed behind rebel lines".

You can find out more about the RAF and inter-war operations in the Empire from the following websites: Terror Bombing and Air Power in Small Wars.

Abyssinia

During their invasion of Abyssinia in 1935-36 the Italians used poison gas and bombing against the poorly-equipped Abyssinian army and unarmed civilians. It shows how a developed country could use its technology and conquer a foe. Again aircraft played the key role. Without anti-aircraft guns, the Ethiopians could not defend themselves. James Ambrose Brown, wrote: "Abyssinia, primitive and inaccessible in 1935, had been largely conquered from the air. In the campaign Italian air-power had been used with ruthless ability against the massed armies of chieftains and feudal lords. It had attacked the miles-long processions of peasant foot soldiers, mule trains and camp followers, pursued armies broken in battle along the only escape routes, leaving corpses at every river crossing and mountain pass. It had laid waste the land with incendiary bomb and mustard gas. You can find more on the Italian conquest of Abyssinia at the Military History Department.

Guernica

The bombing and destruction of Guernica in 1937 had an enormous impact on opinion in Britain. Cinemas showed film of the German planes attacking the Basque town as part of the Spanish Civil War. This helped to reinforce the Bomber Theory and the fear of air attack. To find out more about Guernica go to these websites: Spanish Refugees and Guernica.

Appeasement

After Hitler came to power in 1933, Britain had to decide how best to respond to the threat he posed. Britain had a very small army. The Chancellor of Exchequer, Neville Chamberlain, opposed any funding for an army to fight overseas. Chamberlain wanted funding for air power which he considered a more effective deterrent against enemy attack. In the 1930s the theory was developed, as mentioned earlier, that nothing could stop modern bombers. The increased speeds of the bombers reduced the time taken to reach the target, and because they flew higher this made it impossible to send fighters in the air in time to intercept the bomber force. If the bombers were intercepted, their heavy armament would enable them to defeat the attackers. It was a convincing argument, especially because it coincided with the need to save money because of the Great Depression, and the difficulty Governments faced in paying for mass unemployment. This was also the time of the famous 'Peace Ballot' and the Oxford Union debate on not fighting for King and Country. People in Britain felt very strongly that anything was better than another war - and the Bomber Theory suggested that the bomber might prevent another war.

Many military thinkers believed that in any major conflict of the future vast fleets of bombers, pounding the enemy's capital to rubble, would decide the issue in a matter of hours. In 1932 Stanley Baldwin, then a prominent member of the government, gloomily told the House of Commons, 'I think it is well for the man in the street to realise that there is no power on earth that can protect him from being bombed. Whatever people may tell him, the bomber will always get through. The only defence is offence, which means that you have to kill more women and children more quickly than the enemy if you want to save yourself.'

In March 1935 Hitler proclaimed the existence of a new German air force, the Luftwaffe, boasting that it was already equal in size to the RAF. In the late 1930s British air planners anticipated that, if war came, the Luftwaffe would launch an overwhelming air attack on London, referred to as the 'knock-out blow'. It would be swift, sudden and shocking. The Air Staff calculated that the Luftwaffe could deliver 700 tons of bombs a day on London, each ton causing at least fifty casualties. Their heads filled with these doom-laden figures, the Home Office calculated that in the first three months of war 60,000,000 square feet of coffin timber would be required to bury the dead. The proposed expense resulted in the stockpiling of tens of thousands of collapsible papier-mâché and cardboard coffins.

Advised by leading experts, the government also planned for the psychological as well as the physical worst. The Ministry of Health joined the numbers game, estimating that it might have to deal with up to 4 000 000 mental cases in the first six months of war. In these circumstances it was assumed in government circles that civilian morale would crack under air bombardment. Panic-stricken hordes of Londoners would pour out of the shattered capital into the countryside, where the government had plans to turn them back, with machine-gun fire if necessary. People, especially in high places, were scared of the Bomber! For more on this subject see Appeasement and An Appeasement History.

Conclusion

We are used to hearing the arguments about the 'Guilty Men' of Munich, about Appeasement right from 1919 when some thought the Treaty of Versailles too harsh on Germany, about the strong desire not to repeat history and the blood-bath of the First World War. What we don't think about quite so often is the role the Bomber Theory played in all this. Perhaps it was fear of the bomber - as Baldwin said, 'The Bomber will always get through,' that was the driving force behind Appeasement. What do you think?


Why the Hunt for the Real Atlanta Bomber Took Nearly 7 Years

Midway through the 1996 Summer Olympics in Atlanta, Georgia, three pipe bombs went off in the Centennial Olympic Park, killing two people and injuring 111. The man behind the bombing was 29-year-old Eric Rudolph, a terrorist who went on to carry out three more bombings over the next year and a half. But in order to catch him, the federal government and local law enforcement had to change how they worked. It wasn&apost until they increased collaboration on domestic terrorism that Rudolph was finally captured—nearly seven years later.

Like Timothy McVeigh, who bombed Oklahoma City in 1995, Rudolph was a former military member and far-right extremist who turned to violence. Rudolph bombed the Olympics because, as he later said in a statement, he wanted to embarrass the United States on the world stage for legalizing abortion. In January and February 1997, he bombed an abortion clinic and a gay nightclub in the Atlanta area, injuring 11 people. In January 1998, he bombed another abortion clinic in Birmingham, Alabama, seriously injuring a nurse and killing a police officer—making it the first deadly abortion clinic bombing in U.S. history.

Although Rudolph acted alone, he was part of a growing trend of violent far-right extremism in the 1980s and �s. This type of extremism was on the federal government’s radar, but at the time, local law enforcement didn’t necessarily see attacks on abortion clinics and a major sporting event as part of a larger picture of domestic terrorism.

US soldiers inspect a vehicle on July 28, 1996 in downtown Atlanta. Security checks increased following the bomb blast at Centennial Park which killed two people and injured 111. 

Dimitri Messinis/AFP/Getty Images

“The entire mindset in the United States was terrorism was not terrorism unless it was foreign,” says Malcolm Nance, who has spent decades training local law enforcement in counterterrorism and is the executive director of TAPSTRI. “It was just sort of like domestic terrorism in the United States was so anecdotal that it was to be ignored.”


Officials investigate whether Nashville bomber believed in 'lizard people'

The world-ruled-by-lizard-people fantasy shot to prominence in recent years in part through the ramblings of David Icke, a popular British sports reporter-turned-conspiracy theorist known for his eccentric ideas.

Icke would have you believe that a race of reptilian beings not only invaded Earth, but that it also created a genetically modified lizard-human hybrid race called the "Babylonian Brotherhood," which, he maintains, is busy plotting a worldwide fascist state. This sinister cabal of global reptilian elites boasts a membership list including former President Barack Obama, Queen Elizabeth II of Great Britain, former Federal Reserve Chairman Alan Greenspan and Mick Jagger.

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This nonsense is espoused by a variety of internet conspiracy-mongers, including far-right, Trump-loving QAnon adherents, one of whom was accused in 2019 of murdering his own brother because he thought he was a lizard. As many as 12 million Americans believed in this lizard people conspiracy in a 2013 Public Policy Polling survey. It's safe to assume the number is higher today.

This nonsense is espoused by a variety of conspiracy-mongers, including one of whom was accused of murdering his own brother because he thought he was a lizard.

The outlandish trope has roots in the second half of the 19th century, when the Industrial Revolution, Darwin's theory of evolution and rapid scientific advances upended time-honored traditional ways of life, leaving people unsettled and unsure what to believe. It emerged more strongly toward the end of the century, when anxieties about perceived outsiders, especially Jewish ones, were fueled by waves of immigrants flooding urban centers in Great Britain and the United States in search of economic prosperity and religious freedom. The tide of immigrants ignited cultural conflicts, as well as health and sanitation crises, in cities that lacked adequate infrastructure for the millions of arrivals.

Amid this tumult, a colorful array of gurus and charismatic figures arrived on the scene claiming secret knowledge of world affairs and answers to burning questions. The writings of the Russian-born mystic Helena Blavatsky, the founder of Theosophy, bristle with cosmic energies and mysterious knowledge — including her claim of an ancient race of dragon men from a lost continent mentioned in her esoteric 1888 tome, "The Secret Doctrine."

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Blavatsky's florid imagination influenced a slew of artists and writers, including, as political scientist Michael Barkun notes, one Robert E. Howard. His widely popular "Conan the Barbarian" stories in the early 20th century featured reptilian humanoids who deploy their shape-changing and mind-control talents to dominate humanity.

Bram Stoker's "Dracula," the 1897 tale of a Romanian vampire who plans to take over London using his renowned shape-shifting abilities, also carries traces of this trope. The count possesses a number of reptilian qualities — from his association with the knightly Order of the Dragon, from which his name derives, to his cold-blooded nature and talent for shimmying down walls lizard-fashion.

Dracula's protruding teeth, pointed ears and blood-sucking habits mark him as a species apart, a motif of "othering" read by some critics as code for Jewishness. From this perspective, Stoker's book is part of the British response to the increasing numbers of Jewish immigrants arriving from Eastern Europe. The vampire is a stealthy invader, passing as a proper citizen but secretly plotting domination and destruction.

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Blood-sucking, as Stephanie Winkler observes, is a common metaphor for greed, a trait often linked to Anglo-Jews associated with banking and stock trading. This coupling of Jewishness and greedy blood-sucking gained momentum as wealthy British Jews — such as banker Baron Lionel de Rothschild, who was admitted to the House of Commons in 1858 — gained influence in society. Eventually, paranoia that Jews, through their financial power and connections to royalty, would seize the opportunity to take over an empire facing ever more complex challenges helped drive the mounting anti-Semitism.

Does any of this sound familiar? It should, because today's internet postings by conspiracy theorists often carry traces of just the sort of anti-immigrant and anti-Semitic tensions that show up in history whenever segments of the population feel betrayed by elites and fear loss of their own social and economic status.

It may not surprise you that Icke, who wrote a theosophical work about the origins of Earth, also endorses the infamous anti-Semitic forgery "The Protocols of the Elders of Zion," which appeared in 1903 and was likely created by the Russian czar's secret police. Henry Ford, for one, helped circulate the pamphlet, which purported to reveal a secret Jewish society conspiring to control the banks, the media and, ultimately, the entire Earth. Though it was quickly discredited, the Nazis used it as propaganda.

Icke denies animosity toward Jewish people. But whether he is or isn't deliberately using the notion of reptilian invaders as coded anti-Semitism, it is nonetheless the case that the idea tends to circulate, as writer Miikka Jaarte points out, among neo-Nazis, Illuminati conspiracy proponents and various other groups that insist that we are being manipulated by sinister "puppeteers" who often just happen to be Jewish. Billionaire George Soros is a frequent bête noire among this crowd, and he is often depicted as a world-dominating reptile.

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The lizard takeover, with its Jewish-cabal links, has, unfortunately, become so commonplace that it even made an appearance in Netflix's hit sci-fi series "The Umbrella Academy" — now taking some heat for its alleged use of anti-Semitic tropes in the form of a shadowy society of lizard people who run the world, complete with a Yiddish-speaking villain.

History shows that when panic is rising, institutions seem to be failing and the masses feel betrayed by wealthy elites, finding scapegoats can seem alluring. If charismatic influencers are able to channel the grievances toward secret cabals, immigrants and religious groups, eventually, something terrible is likely to happen.

The real problems, however, won't change.

Lynn Stuart Parramore is a cultural historian who studies the intersection of culture, psychology and economics. Her work has appeared in Reuters, Lapham's Quarterly, Salon, Quartz, Vice, HuffPost and others. She is the author of "Reading the Sphinx: Ancient Egypt in 19th Century Literary Culture."


Bomber Theory - History

A Brief History of Aircraft Carburetors and Fuel Systems

by Terry Welshans
Bardstown, Kentucky
for the Aircraft Engine Historical Society
August 2013

The AEHS is pleased to present Terry Welshans' groundbreaking account of aircraft carburetor and fuel system history.

Terry Welshans grew up in Burbank, California, in the shadow of Lockheed Aircraft's plant B-1, Lockheed's original factory and home of the P-38. Terry began working as a "swamper" on a Bell 47G3B helicopter after graduating high school. The helicopter was leased to a US Forestry fire fighting crew that operated all over southern California.
From there, he worked in the tool room at Weber Aircraft, a manufacturer of ejection seats for Boeing B-52s, Cessna T-37s, and General Dynamics
F-106s. Weber also built seats for Gemini and Apollo spacecraft, along with tons of commercial airline seats, overhead storage, galleys and lavatories.
Terry was the 1967 Honor Graduate of the US Army's Fuel and Electrical Systems School. He received his private pilot certificate in 1968, and his commercial pilot certificate in 1974. Terry worked at Aircraft Carburetor in Burbank, where he overhauled almost every model of Bendix Stromberg and Marvel aircraft carburetors. Terry worked on a number of ADI regulators and carburetors for National Air Race competitors flying Vought F4U Corsairs, North American T-28s and P-51s, and Grumman F8Fs and F7Fs. The largest carburetor he worked on was a Bendix Stromberg PR100B4 for a Pratt & Whitney R-4360 engine used on a Boeing 377 being modified as the "Pregnant Guppy."
Terry attended classes at night, fitting them in between work and a growing family. He graduated in 1985, with a degree in workplace psychology. After retiring in 2006, Terry and his wife Carolyn moved to Bardstown, Kentucky. Terry and Carolyn recently purchased a Cessna 172, and plan on taking many trips across the United States.

This work is a brief history of aircraft carburetors and fuel systems, beginning with a study of carburetor theory and design, as it existed in 1917. It was a time when inventors filed carburetor patents for every conceivable combination of designs, some of which were tested and others were not. Aircraft engines were also undergoing great changes in design, as were the aircraft themselves. To meet the changing needs peculiar to aviation, fuels, fuel systems, air induction systems and carburetors, a U. S. Government agency formed to test and evaluate aircraft, engines and all other components, eventually testing and evaluating all aspects of aviation. Originally named National Advisory Committee for Aeronautics (NACA), in 1958 it became the National Aeronautics and Space Administration (NASA), the agency that oversees aircraft and aerospace vehicles to this day. Great use of the early NACA reports along with several books published prior to 1930 provided a basis from which the study of aircraft carburetors and fuel systems could begin. It is obvious by reviewing those reports that the understanding of engines, fuels, altitude and temperature was in the early stage of development. Much work was ahead in setting standards to insure safe designs and operational procedures.

A carburetor (American and Canadian spelling), carburator, carburettor, or carburetter (Commonwealth spelling) is a device that blends air and fuel for an internal combustion engine. It is sometimes, but not always, shortened to carb in North America and the United Kingdom. The word carburetor comes from the French carbure meaning "carbide" Carburer is to combine with carbon. In fuel chemistry, the term has the more specific meaning of increasing the carbon (and therefore energy) content of a fluid by mixing it within a volatile hydrocarbon. Development continues for fuels built from these hydrocarbons, and will continue to do so until the discovery of a suitable alternative fuel.

In the opening days of the internal combustion engine, it was also necessary to design a carburetor for the engine, as none existed. Early attempts to supply fuel to a gasoline engine included a drip feed of fuel into the air intake pipe, or cotton wicks immersed in a pool of fuel with their tops exposed the airflow in the intake pipe.[1]

These inefficient methods of controlling the fuel mixture ended with the invention of a basic carburetor in 1863, attributed to Jean Joseph Étienne Lenoir (12 January 1822 &ndash 4 August 1900. In 1863, Lenoir demonstrated a three-wheeled carriage, little more than a wagon body set atop a tricycle platform. Powered by a 2,543cc (155 in³ 180 mm x 100 mm, 7.1" x 3.9") 1.5 hp "liquid hydrocarbon" (petroleum) engine with a primitive carburettor, patented in 1886.[2] The patent for Lenoir&rsquos carburetor description states:

&lsquoThis carburetor consists of a cylinder provided at opposite ends with hollow journals, adapted to suitable bearings. The interior of the cylinder is provided with a series of perforated diaphragms and intermediate layers of sponge or similar absorbent material, and contains a hydrocarbon liquid. On one ratchet-wheel, n, with which engages a pawl on an arm, L, Figures 1 and 2. To this a vibrating motion is imparted from some moving part of the engine to impart a slow rotary motion to the cylinder to keep the sponge uniformly saturated with the hydrocarbon liquid, so that the air will also be uniformly saturated as it passes through the cylinder from the pipe J to the exit-pipe h and reservoir H. From thence the carbureted air passes through the tubes h to the gas-bag Q, Figs. 1 and 2, and thence to the gas-valve D, above the valve-chest D.&rsquo[3]

Lenior's carburetor, in other words, was a rotating hollow cylinder containing layers of an absorbent material. Air flowing to the engine absorbed this fuel as it passed through the cylinder. As the cylinder rotated, the absorbent material picked up more fuel from the fuel supply.

Lenoir's 1886 U.S. Gas Engine Patent No. 335,462
Fig. 1. Vehicle Fig. 2. Engine Fig. 4. Carburetor

In 1876, Luigi De Cristoforis made the first carburetor in Italy. Enrico Bernardi at the University of Padua developed a carburetor for his "Motrice Pia," his first "petrol combustion engine." His one cylinder, 1,225 cc engine was prototyped on 5 August 1882.

In 1885, German inventors Wilhelm Maybach and Gottlieb Daimler developed a float type carburetor for their engine, based on the atomizer nozzle. A carburetor design was among Karl Benz's early patents as he developed his internal combustion engines and components.[4]

The Hungarian engineers János Csonka and Donát Bánki invented the world&rsquos first carburetor for a stationary engine in 1893. At about the same time, the Austrian automobile pioneer Siegfried Marcus invented the rotating brush type carburetor.

By 1894, the German engineer Wilhelm Maybach developed a carburetor with the now familiar float-and-needle-valve arrangement. The float type carburetor maintains a reliable supply of fuel at a constant height. Karl Benz's "Patentwagen" of 1897 was equipped with one of Maybach's float-equipped carburetors.[5]

Some early carburetors were the evaporator type in which the air absorbs fuel as it passes over, bubbles up through the surface of gasoline or drawn through gauze that wicks the fuel up from its container.

Frederick William Lanchester of Birmingham, England, experimented with the wick type carburetor for cars. In 1896, Frederick and his brother built the first gasoline driven car in England, a single cylinder 5 hp (3.7 kW) internal combustion engine with chain drive. Unhappy with the performance and power they re-built the engine into a two cylinder horizontally opposed version with his new wick type carburetor design.

Other early types of jet carburetors had a fuel supply to the engine that was more or less controlled by the size or number of the jet orifices. This type of carburetor was fitted either with a choke tube, of one constant diameter located round the jet orifice, or with a cone shaped tube, the position of which could be varied with regard to the jet.

The Longuemare carburetor of 1901 was first one of this type. In this design, a hand-controlled device admitted supplementary air. The arrangement was crude, as it was only capable of giving a correct mixture automatically for the one speed for which the choke tube was suited. As the speed increased so did the suction. The admission of air from an external source balanced the suction. In these early devices, extra air valves working against springs reduced the amount of hand manipulation necessary with such a device.

The early Krebs carburetor combined the extra air valve with the carburetor by means of air pressure actuating a diaphragm against the resistance of a spring, and in such an arrangement, it is possible to design the ports so that constant pressure difference with regard to the external atmosphere surrounds the jet.

The Kingston carburetor admitted the extra air needed as the load demanded it through a number of chambers, each with a ball and seat. Suction from the airflow lifts the balls from their seats in sequence, until the lifted balls provide extra air through the valve seats as needed. George Kingston invented this carburetor in 1902, and was standard on the Ford Model T automobile. Several large agricultural tractors used a larger version.

A further development of this principle, as claimed in the Gillet-Lehmann carburetor, a small pipe made a direct connection between the float chamber and the induction pipe at one or more points. Assuming that the restricting screw or screws were set properly, with a device of this nature it was possible to regulate the pressure difference under which the instrument worked with some degree of finesse. Devices of this nature were the forerunners of modern constant vacuum carburetors.

Another line of development aimed at restricting the flow of the liquid fuel as the engine suction increased. Such devices took the form of spirals of metal in the jet orifice. Obviously, arrangements of this sort could not give any great accuracy, and it was very difficult to obtain uniform carburetion at all speeds.

These devices were undoubtedly the forerunners of some of the later carburetors, in which the main feature was the variation of jet orifice in accordance with the demands of the engine. In several designs, the orifice consisted of at least two parts, which rotate relatively to each other, and in which the holes or orifices are circular, segmental, triangular or any other suitable shape, and which give an orifice opening in proportion to the air and throttle opening.

Carburetors of this type possessed a great degree of accuracy, and required very little final adjustment. There were further carburetor developments where additional air devices, some with either pneumatically or hydraulically controls, gave excellent results. In such a combination, however, more than one type of adjustment was required, and the carburetor immediately became liable to derangement and erratic working when in the hands of an inexperienced user.

Furthermore, the air-controlling arrangement was liable to suffer as the operating mechanism wears, the spring control loses its original liveliness or the moving parts stick or become loose.

Carburetors were the usual method of fuel delivery for most gasoline-fueled automobile engines until the late 1980s, when fuel injection became the preferred method of delivering fuel. Fuel injection systems that include an electronic integrated engine control systems such as the &lsquofull authority digital engine control&rsquo (FADEC) systems are beyond the scope of this article, and will be the subject of future articles.

A discussion about aircraft carburetors is not complete unless a discussion of engines and fuels are included, as the development and improvement of any one of the three calls for experimentation, development and testing of the others, as all three must work together as a single power system.

Air: Air is a breathable, non-toxic mixture of four parts nitrogen and one part oxygen, with an umber of other gasses in very small quantities. In combustion, the oxygen unites with the hydrogen and carbon parts in the hydrocarbon fuel, producing a hot gas made from the reconstituted hydrocarbon, nitrogen and oxygen atoms combined in new configurations. Air expands when heated, and when it is contained, its pressure increases. Under high-heat combustion, nitrogen in the air combines with surplus oxygen to form oxides of nitrogen (NOX), a component of photo-reactive smog.

Air-Fuel Ratio: See Fuel&ndashair ratio.

Atom: In chemistry, an atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The outermost electron shell of an atom in its uncombined state known as the valence shell. The electrons in that shell are called valence electrons. The number of valence electrons determines the bonding behavior with other atoms. Atoms tend to chemically react with each other in a manner that fills (or empties) their outer valence shells. Hydrocarbon molecules form when hydrogen and carbon atoms join.

Atomize: Reducing a liquid into very small droplets to assist in its evaporation.

Autoignition: The spontaneous ignition that results when the heated fuel&ndashair mixture reaches the point where it ignites with no external ignition source. Diesel engines use the principle of autoignition. In a diesel engine, fuel injected into the highly compressed high-temperature air within the engine cylinder ignites as it mixes with the heated air.

Aviation Fuel: A mixture of various hydrocarbons that has specific combustion characteristics. Aviation fuel must meet pressure and temperatures found at high altitude as well as at the earth&rsquos surface. A basic aviation fuel usually has three primary hydrocarbons and an untold number of other hydrocarbons or other chemicals.

BMEP: ( Brake Mean Effective Pressure) - The mean effective pressure calculated from brake power, abbreviated as MEP.The mean effective pressure is a quantity relating to the operation of a reciprocating engine and is a valuable measure of an engine's capacity to do work that is independent of engine displacement. A torque meter instrument indicates BMEP engine output.

Combustion: The common name for the reduction and reaction within a fuel&ndashair mixture where the fuel and air are ignited and broken down to their atomic constituents and then reformed into the gases that flow through the exhaust system. Heat released in this reaction expands the gases created.

Carburetor: A carburetor (American and Canadian spelling), carburator, carburettor, or carburetter (Commonwealth spelling) is a device that blends air and fuel for an internal combustion engine. It is sometimes, but not always, shortened to carb in North America and the United Kingdom. The word carburetor comes from the French carbure meaning "carbide".[1] Carburer means to combine with carbon. In fuel chemistry, the term has the more specific meaning of increasing the carbon (and therefore energy) content of a fluid by mixing it with a volatile hydrocarbon.

Detonation: The uncontrolled autoignition of the fuel&ndashair mixture after the normal ignition has occurred. The combustion pressure and radiated infrared energy building within the cylinder compresses the unburned mixture, bringing it to the temperature where it spontaneously ignites. The ignition results in a dramatic pressure increase within the cylinder, creating a number of high velocity pressure waves. The resulting temperature may be high enough to burn or melt pistons and damage valves.

Engine: A device engineered to accept a combustible mixture, compress it, ignite it, and use the increased gas volume caused by the temperature increase to provide thrust, which moves the aircraft.

Evaporate: As heat is absorbed into a liquid, the liquid temperature will rise to its vapor pressure threshold, where liquid fuel is gasified into a vapor. This change of state from a liquid to a gas removes heat from the remaining liquid, cooling it. This process is similar to refrigeration, in that it cools water vapor within the airflow to its saturation point, causing the water vapor to condense into a liquid, freezing any moisture within the vapor if cooled below the freezing point.

Evaporative Carburetor: A type of carburetor that incorporates fuel vapors into the air flowing through it by passing the air across the fuel surface, through a wick that is suspended in the fuel, or by bubbling the air through the fuel. This is a non-proportioning carburetor and is best for use on an engine that operates at a steady load and speed, as it cannot provide a correct fuel&ndashair ratio except for that one operating condition.

Float-Type Carburetor: A type of carburetor that reduces fuel pressure to atmospheric pressure by a valve that is operated by a float. This type of carburetor is sensitive to the forces of gravity, acceleration, and aircraft attitude. A float-type carburetor works poorly or not at all when the aircraft is inverted, and under certain conditions is plagued by ice formation that chokes airflow, reducing engine performance.

Floatless Carburetor: This carburetor design eliminates the fuel-level set by a float in a typical carburetor by replacing it with a diaphragm-operated valve. The valve operates to reduce the fuel pressure to atmospheric pressure, which is modifiable to include altitude and temperature compensation.

Formula: A method of expressing the chemical reactions under a given condition. Formulas are the numeric representation of molecules, with the number of elemental atoms shown as a subscript number following the element name. For example, water results when two hydrogen atoms combine with one oxygen atom. The formula for water is H2O.

Fuel: An internal combustion engine burns a mixture of fuel and air to produce useful work. The amount of heat released by a given fuel, mixed at the correct fuel&ndashair ratio, varies with the molecular construction of the hydrogen, carbon, and other elements within the molecule. In a piston engine, fuels that contain high hydrogen levels are the most energetic, and those molecules with complex internal structures burn slowly, preventing detonation at high compression ratios.

Fuel&ndashAir Ratio: The number of parts of fuel (in pounds) compared to parts of air (in pounds). For example, a 1:8 fuel to air ratio is one pound of fuel mixed with eight pounds of air. Fuel&ndashair ratio is equivalent to air-fuel ratio, worded in the reverse. For example, the 1:8 fuel to air ratio can also be expressed as being an 8:1 air to fuel ratio as eight pounds of air is mixed with one pound of fuel. In either case, about 12.5% of the mixture is fuel and the remainder is air.

Fuel Injection: A method of providing a precise amount of fuel under sufficient pressure, spraying the fuel either into the air flowing into an engine, or directly into the combustion chamber. Fuel injection delivers the same fuel charge to every cylinder, resulting in consistent temperature and pressure within all of the cylinders.

Hydrocarbon A number of hydrogen and carbon atoms combined into a molecule with a specific configuration that is limited to the arrangements permitted by the bonds between the atoms in the mix. A hydrocarbon can be a gas, liquid, semi-solid or solid, as determined by the number of carbon atoms in a single molecule. The fuel molecule can be in a number of configurations, those with the most complex configuration release more energy when ignited in a high compression engine. Hydrocarbons vary in arrangement, and are found as a simple endless "straight chains", more compact, complex branching chain arrangements that incorporate branches of additional carbon atoms (which allow additional hydrogen atoms to join in the arrangement), or in rings where the ends of the straight chain are joined to one another.

Jet: In reciprocating engine carburetors, a jet is a replaceable orifice that causes a precise pressure drop as a fluid flows through it. A jet is an accurately made precision part constructed to retain its flow characteristics. The internal diameter of the jet and the length of the reduced diameter combine to produce a given pressure drop as the fuel flows through the jet. This pressure drop through a jet is constant, and remains unchanged when the rate of flow through the jet changes.

Molecule: The smallest part of matter that retains the characteristics of the whole, and is further divisible only into individual atoms. Hydrocarbon molecules are the building blocks that combine for their specific characteristics to produce fuel with a given resistance to autoignition.

Nozzle: A part of the fuel system that sprays fuel into the air flowing into the engine. It may be inside the carburetor venturi, below the throttle plates, at the air inlet to the supercharger, at the intake valve, in the cylinder head or any other place determined to be suitable for its intended purpose.

Preignition: The autoignition of the fuel&ndashair mixture within the engine cylinder before normal ignition occurs. The ignition results when the fuel&ndashair mixture temperature reaches the autoignition point as it is compressed. Preignition results from very high inlet air temperatures or high compression ratios.

Pressure Carburetor: A carburetor design where the fuel within the carburetor is pressurized to a point where it is ejected from the discharge nozzle as a spray. A pressure carburetor typically has a regulator section that senses pressures at specific points within the airflow and fuel flow to constantly adjust the amount of fuel flowing to a prescribed amount, over the entire engine operating range.

Proportioning carburetor: This type of carburetor measures the air flowing through it, and adjusts the fuel flow accordingly, to provide the correct fuel&ndashair ratio under all operating conditions.

Stochiometric Point: In the combustion reaction, oxygen reacts with the fuel, and the point where exactly all oxygen is consumed and all fuel burned is defined as the stoichiometric point. With more oxygen, some of it stays unreacted. Likewise, if the combustion is incomplete due to lack of sufficient oxygen, fuel remains unreacted. Different hydrocarbon fuels have a different contents of carbon, hydrogen and other elements, thus their stoichiometry varies.

Suction: The correct term for any relatively low-pressure area within an engine intake system. Air flows from high-pressure areas to low-pressure areas. In a normally aspirated engine, that is, one without a turbocharger or supercharger, air can leak into the system due to the suction created by the engine drawing air into the intake manifold, leaning the mixture. On engines with boost pressure greater than atmospheric, the fuel&ndashair mixture will leak out, reducing engine power.

Supercharger: A mechanically driven air compressor. High-power aircraft engines typically have a centrifugal supercharger built into the crankcase. The supercharger impellers driven by a series of gears to a speed greater than the speed of the crankshaft, and may consume considerable power at full speed. Superchargers may have up to three gear ratios that provide optimum manifold pressure at various altitudes, and may have a turbocharger or a second supercharger to create a two-stage induction system.

Throttle: A valve that opens and closes to control the volume of air entering the engine induction system.The shape and number of parts varies by the design of the carburetor. The throttle plate is designed to precisely fit the shape of the air passage. A carburetor with a round air passage will have a single plate on a rotating shaft, while a carburetor with a rectangular air passage could have two or more flat or other shaped plates that operate in unison to control the airflow.

Turbo(super)charger: An exhaust gas turbine-driven centrifugal air compressor. A turbine wheel that is coupled to a compressor wheel absorbs energy from the expansion of exhaust gases after combustion. The compressor provides compressed air to the engine supercharger. A turbocharger restricts the engine exhaust, thereby raising the pressure in the exhaust manifold, reducing the exhaust to intake pressure ratio, and slightly reducing engine horsepower. Advantages of using a turbocharger far outweighs its disadvantages.

Vacuum: Used in the context of this article, vacuum refers to a pressure that is lower than atmospheric. One vacuum may have less pressure than another vacuum. The term suction is more correct, as a true vacuum is the result of the complete evacuation of all gas, a condition that does not exist within an engine or carburetor. In an engine, suction is created in the intake manifold as the piston is moved toward the crankshaft. The intake manifold suction is controlled by the position of the throttle. When a supercharger is installed, intake manifold suction may be eliminated and a positive manifold pressure developed as more air is admitted to the intake manifold than is drawn in by the piston movement.

Venturi: A restriction within a tube where fluid flow velocity is increased and the pressure is reduced at its narrowest place, as described by Bernoulli. The shape of a round venturi is similar to two smoothed, truncated cones that join their smaller ends at the venturi&rsquos narrowest point. In a rectangular venturi, only two sides will have the tapered shape, the others remaining flat. To avoid undue drag, a venturi typically has an entry cone of 30° and an exit cone of 5°. According to the laws governing fluid dynamics, a fluid's velocity must increase as it passes through a constriction to satisfy the principle of continuity, while its pressure must decrease to satisfy the principle of conservation of mechanical energy. Thus, a drop in pressure negates any gain in kinetic energy that a fluid may accrue due to its increased velocity through a constriction. An equation for the drop in pressure due to the venturi effect derives from a combination of Bernoulli's equation and the continuity equation. The low pressure created within a venturi is determined by the velocity and density of the fluid flowing through it. The venturi effect is a jet effect the velocity of the fluid increases as the cross sectional area decreases, with the static pressure correspondingly decreasing. The venturi is named for Giovanni Battista Venturi, an Italian physicist. Bernoulli's equation is named for Swiss scientist Daniel Bernoulli, who published his principle in the 1738 book, Hydrodynamica.

Aird, Forbes. Bosch Fuel Injection Systems. HP Books, 2001.
Baukal Jr., Charles E., editor. The John Zink Combustion Handbook. John Zink Company, 2012.
Cessna 152 Information Manual. Cessna Aircraft Company, 1 July 1979.
Dickey III, Philip S. &ldquoThe Liberty Engine 1918-1942.&rdquo Smithsonian Annals of Flight Volume 1 Number 3. Smithsonian Institution Press, National Air and Space Museum, Washington, D.C. 1968.
Dyke, A. L. "Zenith Carburetors." Dyke's Automobile and Gasoline Engine Encyclopedia, 12th edition,. 1922.
Engine Conditioning For Reciprocating Engines. Department of the Air Force Manual 52-9. Washington, March 1953.
Fernandez, Ronald. Excess Profits: The Rise of United Technologies. Boston, Massachusetts, Addison-Wesley, 1983.
Flight Manual USAF Series A-26A Aircraft (On Mark). Department of the Air Force Technical Order TO 1A-26A-1 (Formerly TO 1B-26K-1). Washington, 1 September 1969
Heron S. D. Development of Aviation Fuels. Harvard University, 1950.
Holley Aircraft Carburetors Instruction Manual, Third Edition. Holley Carburetor Company, January 1941.
Manual of Stromberg Aircraft Carburetors, Edition II. Stromberg Motor Devices Co., 1927.
NACA Technical Report No. 11. Carburetor Design: a Preliminary Study of the State of the Art. Lucke, Charles Edward and Willhofft, Friederich Otto. 1917.
NACA Technical Report No. 48. Carbureting Conditions Characteristics of Aircraft Engines. Tice, Percival S. 1920.
NACA Technical Report No. 49. Discharge Characteristics of Fuel Metering Nozzles in Carburetors. Tice, Percival S. 1920.
NACA Technical Report No. 102. Performance of a Liberty 12 Engine . Sparrow S.W. and White, H.S. 1920.
NACA Technical Report No. 189. Relation of Fuel&ndashair Ratio to Engine Performance. Sparrow, Stanwood W. 1925.
NACA Report No. 250. The NACA Universal Test Engine and Some Test Results. Ware, Marsden. 1938.
NACA Technical Note No. 647. Engine Performance and Knock Rating of Fuels for High-Output Aircraft Engines. Rothbrock, A.M. and Biermann, Arnold E. April 1938.
NACA Technical Memorandum No. 853. Effect of Air-Fuel Ratio on Detonation in Gasoline Engines. Peletier, L.A.1938.
NACA Technical Report No. 655. The Knocking Characteristics of Fuels in Relation to Maximum Permissible Performance of Aircraft Engines. Rothcock, A.M. and Biermann, Arnold E. 1939.
NACA Advance Restricted Report No. 3H13. Deicing of an Aircraft-engine Induction System. Essex, Henry A. National Bureau of Standards, August 1943.
NACA Memorandum Report No. L4L18. Flight Tests of the High Speed Performance of a P-51B Airplane (AAF43-12105). Vogelwede, T.J.and Danforth, E.C.B. Dec 18, 1944.
NACA Memorandum Report No. E5D24. Effect of Fuel Volatility and Mixture Temperature on the Knocking Characteristics of a Liquid-cooled Single-Cylinder Test Engine. Tauschek, Max J. and Lietzke, A.F. April 1945.
NACA Advance Restricted Report No. E4J05, The Knock-Limited Performance of Fuel Blends Containing Aromatics Part I: Toluene, Ethyl Benzene and p-Xylene. Meyer, Carl L. and Branstetter, J. Robert. October 1944.
NACA Advance Restricted Report No. E5A20. The Knock-Limited Performance of Fuel Blends Containing Aromatics Part II: Isopropylbenzene, Benzene, and o-Xylene. Meyer, Carl L. and Branstetter, J. Robert. January 1945.
NACA Advance Restricted Report No. E5D16. The Knock-Limited Performance of Fuel Blends Containing Aromatics Part III: 1,3,5-trimethylbenzene, tert-butylbenzene and 1,2,4-trimmethylbenzene. Meyer, Carl L. and Branstetter, J. Robert. 6 April 1945.
NACA Advance Restricted Report No.E5D16a. The Knock-Limited Performance of Fuel Blends Containing Aromatics Part IV: Data for m-diemethylbenzene, 1-ethyl-4-methylbenzene and sec-butylbenzene. Together with a Summarization of Data for 12 Aromatic Hydrocarbons. Meyer, Carl L. and Branstetter, J. Robert. April 1945.
NACA Advance Restricted Report No. E6C05. The Knock-Limited Performance of Fuel Blends Containing Aromatics Part V n-propelbenzene, n-butylbenzene, isobutylbenzene, m-xylene, and 1-isopropyl-4-methylbenzene. Meyer, Carl L. and Branstetter, J. Robert. 1946.
NACA Memorandum Report No. E6C25. Hydraulic Characteristics of the NACA Injection Impeller. Ritter, William K. , Johnsen, Irving A. and Lieblein, Seymour. May 1946.
Pollard, Harol. Aero Engines, Magnetos and Carburetors. The MacMillan Company, 1918.
Powerplant Handbook. US Department of Commerce Civil Aeronautics Administration Technical Manual No.107. January 1949.
Powerplant Maintenance for Reciprocating Engines. Department of the Air Force Air Force Manual Number 52-12. Washington, May 1953.
Publication AN 03-108F-1. Handbook of Instructions with Parts Catalog: Hydro-Metering Carburetor Model 58-4. Commanding General, Army Air Forces, the Chief of the Bureau of Aeronautics, and the Air Council of the United Kingdom. 5 July 1944.
Publication AN 03-10C8-1. Operation, Service, and Overhaul Instructions with Parts Catalog for Gasoline Injection System Model 58-18-A2B. Commanding General, Army Air Forces, and the Chief of the Bureau of Aeronautics. 30 January 1946.
Publication AN 03-CA-1. Operation, Service, and Overhaul Instructions with Parts Catalog for Direct Fuel Injection System Models 58-18-A1A, 58-18-B1A and 58-18-C1A. Commanding General, Army Air Forces, and theChief of the Bureau of Aeronautics. 7 December 1945.
Schlaifer, Robert. Development of Aircraft Engines. Harvard University, 1950.
Sherbondy, E.H. and Wardrop, G. Douglas.Textbook of Aero Engines. Fredrick A. Stokes Company, 1920.
The Aircraft Engine and its Operation. United Aircraft Corporation, Pratt & Whitney Aircraft Division, 1952.
The Claudel-Hobson Carburettor Models R. A. F., Z & HC7, for Aero Engines: Instruction Manual. Technical Information Section, T.3.F., Air Board, 1918.
Thirty-fifth Annual Report. National Advisory Committee for Aeronautics, 1949.
Thorner, Robert H. Aircraft Carburetion. John Wiley & Sons, Inc., 1949.
Whitney, Daniel D. Vee&rsquos For Victory. Schiffer Military History, 1998.
Wise, David Burgess. "Lenoir: The Motoring Pioneer." The World of Automobiles. Orbis Publishing, 1974.
Zhao, F., Lai, M., Harrington, D. l, Editors. &ldquoAutomotive Spark-Ignited Direct-Injection Gasoline Engines.&rdquo International Journal Progress in Energy and Combustion Science, Volume 25:5. 1999.
Investigation Report 200002157 by Department of Transport and Regional Services Australian Transport Safety Bureau Re: Piper PA31-350 Chieftain VH-MZK at Spencer Gulf SA on 31 May 2000
CFR Title 14 Para 33.47. Detonation Test and EASA CS-E 360 Detonation Tests.
Dowling, Brian. The Hartford Courant.
IUPAC Compendium of Chemical Terminology Gold Book, International Union of Pure and Applied Chemistry Version 2. 3. 2. 2012.
Note 1: The NACA issued reports in a number of different series, some as part of their annual report, which are &ldquoTechnical Reports&rdquo and &ldquoTechnical Notes&rdquo. Others were issued as Advance Restricted&rdquo Reports, &ldquoMemorandum Reports&rdquo, &ldquoRestricted Bulletins&rdquo, &ldquoTechnical Memorandums&rdquo under the general category of &ldquoWar Reports&rdquo. Many of the documents have the same number, resulting in confusion if consulting the wrong series of reports, as the report titles are different, yet have the same number.
Note 2: All NACA files used in this publication are downloadable at: University of North Texas UNT Digital Library

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Rudolph has been described as a terrorist of the "lone wolf" type. As the name implies, they operate alone and act without a leader or group, though they may adhere to a specific ideology or religion of another movement or organization. Their beliefs are often rooted in extreme right-wing ideologies. Rudolph personally was extremely pro-life and also anti-gay.

Rudolph's design of his 1996 bomb included a steel plate that functioned as a directional device, similar to a Claymore mine. This told investigators the suspect was either in the military or had previously served. Rudolph's deployment of secondary bomb devices meant to target first responders also reinforced the theory of the bomber having previous military experience.


The lizard-people conspiracy theory was popularized by conspiracy theorist David Icke

Contemporary belief in reptilians is mostly linked to British conspiracy theorist David Icke, who first published his book "The Biggest Secret" in 1998. Icke alleged that "the same interconnecting bloodlines have controlled the planet for thousands of years," as the book's Amazon description says. The book suggests that blood-drinking reptilians of extraterrestrial origin had been controlling the world for centuries, and even originated the Illuminati - a fictitious group of world leaders that conspiracy theorists say control the world.

Icke has long been accused of anti-Semitism, as his writings on the reptilian conspiracy theory are clearly evocative of the centuries-old blood-libel conspiracy theory, which alleged that a cabal of Jews were controlling the world and drinking the blood of Christian children. He has denied being anti-Semitic, The Guardian reported in 2001. Insider sent a message to Icke via the media-request contact form on his website, but had not heard back at press time.

Like many conspiracy theories, this one has been popularized at various points in history. Most recently, it resurfaced when former President Barack Obama was in office. A 2013 poll about conspiracy theories conducted by Public Policy Polling, a left-leaning polling firm, found that 12 million Americans believed that "lizard people control politics," or 4% of respondents.

A March 2013 YouTube video claiming that the president had a "Reptilian Secret Service" has been viewed more than 3 million times. YouTube affixed a label to the video that leads to a Wikipedia page about the fictional reptilian humanoids.

Such claims have often been dismissed and responded to in jest. Caitlin Hayden, then the chief spokeswoman for the National Security Council, told Wired in 2013 that "any alleged program to guard the president with aliens or robots would likely have to be scaled back or eliminated in the sequester," referencing a congressional plan to cut defense funding.


History of Aviation - First Flights

On December 17, 1903, Orville and Wilbur Wright capped four years of research and design efforts with a 120-foot, 12-second flight at Kitty Hawk, North Carolina - the first powered flight in a heavier-than-air machine. Prior to that, people had flown only in balloons and gliders. The first person to fly as a passenger was Leon Delagrange, who rode with French pilot Henri Farman from a meadow outside of Paris in 1908. Charles Furnas became the first American airplane passenger when he flew with Orville Wright at Kitty Hawk later that year.

First Flights

On December 17, 1903, Orville and Wilbur Wright capped four years of research and design efforts with a 120-foot, 12-second flight at Kitty Hawk, North Carolina - the first powered flight in a heavier-than-air machine. Prior to that, people had flown only in balloons and gliders.

The first person to fly as a passenger was Leon Delagrange, who rode with French pilot Henri Farman from a meadow outside of Paris in 1908. Charles Furnas became the first American airplane passenger when he flew with Orville Wright at Kitty Hawk later that year.

The first scheduled air service began in Florida on January 1, 1914. Glenn Curtiss had designed a plane that could take off and land on water and thus could be built larger than any plane to date, because it did not need the heavy undercarriage required for landing on hard ground. Thomas Benoist, an auto parts maker, decided to build such a flying boat, or seaplane, for a service across Tampa Bay called the St. Petersburg - Tampa Air Boat Line. His first passenger was ex-St. Petersburg Mayor A.C. Pheil, who made the 18-mile trip in 23 minutes, a considerable improvement over the two-hour trip by boat. The single-plane service accommodated one passenger at a time, and the company charged a one-way fare of $5. After operating two flights a day for four months, the company folded with the end of the winter tourist season.

World War I

These and other early flights were headline events, but commercial aviation was very slow to catch on with the general public, most of whom were afraid to ride in the new flying machines. Improvements in aircraft design also were slow. However, with the advent of World War I, the military value of aircraft was quickly recognized and production increased significantly to meet the soaring demand for planes from governments on both sides of the Atlantic. Most significant was the development of more powerful motors, enabling aircraft to reach speeds of up to 130 miles per hour, more than twice the speed of pre-war aircraft. Increased power also made larger aircraft possible.

At the same time, the war was bad for commercial aviation in several respects. It focused all design and production efforts on building military aircraft. In the public's mind, flying became associated with bombing runs, surveillance and aerial dogfights. In addition, there was such a large surplus of planes at the end of the war that the demand for new production was almost nonexistent for several years - and many aircraft builders went bankrupt. Some European countries, such as Great Britain and France, nurtured commercial aviation by starting air service over the English Channel. However, nothing similar occurred in the United States, where there were no such natural obstacles isolating major cities and where railroads could transport people almost as fast as an airplane, and in considerably more comfort. The salvation of the U.S. commercial aviation industry following World War I was a government program, but one that had nothing to do with the transportation of people.

Airmail

By 1917, the U.S. government felt enough progress had been made in the development of planes to warrant something totally new - the transport of mail by air. That year, Congress appropriated $100,000 for an experimental airmail service to be conducted jointly by the Army and the Post Office between Washington and New York, with an intermediate stop in Philadelphia. The first flight left Belmont Park, Long Island for Philadelphia on May 14, 1918 and the next day continued on to Washington, where it was met by President Woodrow Wilson.

With a large number of war-surplus aircraft in hand, the Post Office set its sights on a far more ambitious goal - transcontinental air service. It opened the first segment, between Chicago and Cleveland, on May 15, 1919 and completed the air route on September 8, 1920, when the most difficult part of the route, the Rocky Mountains, was spanned. Airplanes still could not fly at night when the service first began, so the mail was handed off to trains at the end of each day. Nonetheless, by using airplanes the Post Office was able to shave 22 hours off coast-to-coast mail deliveries.

Beacons

In 1921, the Army deployed rotating beacons in a line between Columbus and Dayton, Ohio, a distance of about 80 miles. The beacons, visible to pilots at 10-second intervals, made it possible to fly the route at night.

The Post Office took over the operation of the guidance system the following year, and by the end of 1923, constructed similar beacons between Chicago and Cheyenne, Wyoming, a line later extended coast-to-coast at a cost of $550,000. Mail then could be delivered across the continent in as little as 29 hours eastbound and 34 hours westbound - prevailing winds from west to east accounted for the difference which was at least two days less than it took by train.

The Contract Air Mail Act of 1925

By the mid-1920s, the Post Office mail fleet was flying 2.5 million miles and delivering 14 million letters annually. However, the government had no intention of continuing airmail service on its own. Traditionally, the Post Office had used private companies for the transportation of mail. So, once the feasibility of airmail was firmly established and airline facilities were in place, the government moved to transfer airmail service to the private sector, by way of competitive bids. The legislative authority for the move was the Contract Air Mail Act of 1925, commonly referred to as the Kelly Act after its chief sponsor, Rep. Clyde Kelly of Pennsylvania. This was the first major step toward the creation of a private U.S. airline industry. Winners of the initial five contracts were National Air Transport (owned by the Curtiss Aeroplane Co.), Varney Air Lines, Western Air Express, Colonial Air Transport and Robertson Aircraft Corporation. National and Varney would later become important parts of United Air Lines (originally a joint venture of the Boeing Airplane Company and Pratt & Whitney). Western would merge with Transcontinental Air Transport (TAT), another Curtiss subsidiary, to form Transcontinental and Western Air (TWA). Robertson would become part of the Universal Aviation Corporation, which in turn would merge with Colonial, Southern Air Transport and others, to form American Airways, predecessor of American Airlines. Juan Trippe, one of the original partners in Colonial, later pioneered international air travel with Pan Am - a carrier he founded in 1927 to transport mail between Key West, Florida, and Havana, Cuba. Pitcairn Aviation, yet another Curtiss subsidiary that got its start transporting mail, would become Eastern Air Transport, predecessor of Eastern Air Lines.

The Morrow Board

The same year Congress passed the Contract Air Mail Act, President Calvin Coolidge appointed a board to recommend a national aviation policy (a much-sought-after goal of then Secretary of Commerce Herbert Hoover). Dwight Morrow, a senior partner in J.P. Morgan's bank, and later the father-in-law of Charles Lindbergh, was named chairman. The board heard testimony from 99 people, and on November 30, 1925, submitted its report to President Coolidge. The report was wide-ranging, but its key recommendation was that the government should set standards for civil aviation and that the standards should be set outside of the military.

The Air Commerce Act of 1926

Congress adopted the recommendations of the Morrow Board almost to the letter in the Air Commerce Act of 1926. The legislation authorized the Secretary of Commerce to designate air routes, to develop air navigation systems, to license pilots and aircraft, and to investigate accidents. The act brought the government into commercial aviation as regulator of the private airlines spawned by the Kelly Act of the previous year.

Congress also adopted the board's recommendation for airmail contracting, by amending the Kelly Act to change the method of compensation for airmail services. Instead of paying carriers a percentage of the postage paid, the government would pay them according to the weight of the mail. This simplified payments, and proved highly advantageous to the carriers, which collected $48 million from the government for the carriage of mail between 1926 and 1931.

Ford's Tin Goose

Henry Ford, the automobile manufacturer, was also among the early successful bidders for airmail contracts, winning the right, in 1925, to carry mail from Chicago to Detroit and Cleveland aboard planes his company already was using to transport spare parts for his automobile assembly plants. More importantly, he jumped into aircraft manufacturing, and in 1927, produced the Ford Trimotor, commonly referred to as the Tin Goose. It was one of the first all-metal planes, made of a new material, duralumin, which was almost as light as aluminum but twice as strong. It also was the first plane designed primarily to carry passengers rather than mail. The Ford Trimotor had 12 passenger seats a cabin high enough for a passenger to walk down the aisle without stooping and room for a "stewardess," or flight attendant, the first of whom were nurses, hired by United in 1930 to serve meals and assist airsick passengers. The Tin Goose's three engines made it possible to fly higher and faster (up to 130 miles per hour), and its sturdy appearance, combined with the Ford name, had a reassuring effect on the public's perception of flying. However, it was another event, in 1927, that brought unprecedented public attention to aviation and helped secure the industry's future as a major mode of transportation.

Charles Lindbergh

At 7:52 a.m. on May 20, 1927, a young pilot named Charles Lindbergh set out on an historic flight across the Atlantic Ocean, from New York to Paris. It was the first trans-Atlantic non-stop flight in an airplane, and its effect on both Lindbergh and aviation was enormous. Lindbergh became an instant American hero. Aviation became a more established industry, attracting millions of private investment dollars almost overnight, as well as the support of millions of Americans.

The pilot who sparked all of this attention had dropped out of engineering school at the University of Wisconsin to learn how to fly. He became a barnstormer, doing aerial shows across the country, and eventually joined the Robertson Aircraft Corporation, to transport mail between St. Louis and Chicago.

In planning his trans-Atlantic voyage, Lindbergh daringly decided to fly by himself, without a navigator, so he could carry more fuel. His plane, the Spirit of St. Louis, was slightly less than 28 feet in length, with a wingspan of 46 feet. It carried 450 gallons of gasoline, which comprised half its takeoff weight. There was too little room in the cramped cockpit for navigating by the stars, so Lindbergh flew by dead reckoning. He divided maps from his local library into thirty-three 100-mile segments, noting the heading he would follow as he flew each segment. When he first sighted the coast of Ireland, he was almost exactly on the route he had plotted, and he landed several hours later, with 80 gallons of fuel to spare.

Lindbergh's greatest enemy on his journey was fatigue. The trip took an exhausting 33 hours, 29 minutes and 30 seconds, but he managed to keep awake by sticking his head out the window to inhale cold air, by holding his eyelids open, and by constantly reminding himself that if he fell asleep he would perish. In addition, he had a slight instability built into his airplane that helped keep him focused and awake.

Lindbergh landed at Le Bourget Field, outside of Paris, at 10:24 p.m. Paris time on May 21. Word of his flight preceded him and a large crowd of Parisians rushed out to the airfield to see him and his little plane. There was no question about the magnitude of what he had accomplished. The Air Age had arrived.

The Watres Act and the Spoils Conference

In 1930, Postmaster General Walter Brown pushed for legislation that would have another major impact on the development of commercial aviation. Known as the Watres Act (after one of its chief sponsors, Rep. Laurence H. Watres of Pennsylvania), it authorized the Post Office to enter into longer-term contracts for airmail, with rates based on space or volume, rather than weight. In addition, the act authorized the Post Office to consolidate airmail routes, where it was in the national interest to do so. Brown believed the changes would promote larger, stronger airlines, as well as more coast-to-coast and nighttime service.

Immediately after Congress approved the act, Brown held a series of meetings in Washington to discuss the new contracts. The meetings were later dubbed the Spoils Conference because Brown gave them little publicity and directly invited only a handful of people from the larger airlines. He designated three transcontinental mail routes and made it clear that he wanted only one company operating each service rather than a number of small airlines handing the mail off to one another. His actions brought political trouble that resulted in major changes to the system two years later.

Scandal and the Air Mail Act of 1934

Following the Democratic landslide in the election of 1932, some of the smaller airlines began complaining to news reporters and politicians that they had been unfairly denied airmail contracts by Brown. One reporter discovered that a major contract had been awarded to an airline whose bid was three times higher than a rival bid from a smaller airline. Congressional hearings followed, chaired by Sen. Hugo Black of Alabama, and by 1934 the scandal had reached such proportions as to prompt President Franklin Roosevelt to cancel all mail contracts and turn mail deliveries over to the Army.

The decision was a mistake. The Army pilots were unfamiliar with the mail routes, and the weather at the time they took over the deliveries, February 1934, was terrible. There were a number of accidents as the pilots flew practice runs and began carrying the mail, leading to newspaper headlines that forced President Roosevelt to retreat from his plan only a month after he had turned the mail over to the Army

By means of the Air Mail Act of 1934, the government once again returned airmail transportation to the private sector, but it did so under a new set of rules that would have a significant impact on the industry. Bidding was structured to be more competitive, and former contract holders were not allowed to bid at all, so many companies were reorganized. The result was a more even distribution of the government's mail business and lower mail rates that forced airlines and aircraft manufacturers to pay more attention to the development of the passenger side of the business.

In another major change, the government forced the dismantling of the vertical holding companies common up to that time in the industry, sending aircraft manufacturers and airline operators (most notably Boeing, Pratt & Whitney, and United Air Lines) their separate ways. The entire industry was now reorganized and refocused.

Aircraft Innovations

For the airlines to attract passengers away from the railroads, they needed both larger and faster airplanes. They also needed safer airplanes. Accidents, such as the one in 1931 that killed Notre Dame Football Coach Knute Rockne along with six others, kept people from flying

Aircraft manufacturers responded to the challenge. There were so many improvements to aircraft in the 1930s that many believe it was the most innovative period in aviation history. Air-cooled engines replaced water-cooled engines, reducing weight and making larger and faster planes possible. Cockpit instruments also improved, with better altimeters, airspeed indicators, rate-of-climb indicators, compasses, and the introduction of artificial horizon, which showed pilots the attitude of the aircraft relative to the ground - important for flying in reduced visibility

Radio

Another development of enormous importance to aviation was radio. Aviation and radio developed almost in lock step. Marconi sent his first message across the Atlantic on the airwaves just two years before the Wright Brothers? first flight at Kitty Hawk. By World War I, some pilots were taking radios up in the air with them so they could communicate with people on the ground. The airlines followed suit after the war, using radio to transmit weather information from the ground to their pilots, so they could avoid storms

An even more significant development, however, was the realization that radio could be used as an aid to navigation when visibility was poor and visual navigation aids, such as beacons, were useless. Once technical problems were worked out, the Department of Commerce constructed 83 radio beacons across the country. They became fully operational in 1932, automatically transmitting directional beams, or tracks, that pilots could follow to their destination. Marker beacons came next, allowing pilots to locate airports in poor visibility. The first air traffic control tower was established in 1935 at what is now Newark International Airport in New Jersey

The First Modern Airliners

Boeing built what generally is considered the first modern passenger airliner, the Boeing 247. It was unveiled in 1933, and United Air Lines promptly bought 60 of them. Based on a low-wing, twin-engine bomber with retractable landing gear built for the military, the 247 accommodated 10 passengers and cruised at 155 miles per hour. Its cabin was insulated, to reduce engine noise levels inside the plane, and it featured such amenities as upholstered seats and a hot water heater to make flying more comfortable to passengers. Eventually, Boeing also gave the 247 variable-pitch propellers, that reduced takeoff distances, increased the rate of climb, and boosted cruising speeds

Not to be outdone by United, TWA went searching for an alternative to the 247 and eventually found what it wanted from the Douglas Aircraft Company. Its DC-1 incorporated Boeing's innovations and improved upon many of them. The DC-1 had a more powerful engine and accommodations for two more passengers than did the 247. More importantly, the airframe was designed so that the skin of the aircraft bore most of the stress on the plane during flight. There was no interior skeleton of metal spars, thus giving passengers more room than they had in the 247.The DC-1 also was easier to fly. It was equipped with the first automatic pilot and the first efficient wing flaps, for added lift during takeoff. However, for all its advancements, only one DC-1 was ever built. Douglas decided almost immediately to alter its design, adding 18 inches to its length so it could accommodate two more passengers. The new, longer version was called the DC-2 and it was a big success, but the best was still to come

The DC-3

Called the plane that changed the world, the DC-3 was the first aircraft to enable airlines to make money carrying passengers. As a result, it quickly became the dominant aircraft in the United States, following its debut in 1936 with American Airlines (which played a key role in its design).

The DC-3 had 50 percent greater passenger capacity than the DC-2 (21 seats versus 14), yet cost only ten percent more to operate. It also was considered a safer plane, built of an aluminum alloy stronger than materials previously used in aircraft construction. It had more powerful engines (1,000 horsepower versus 710 horsepower for the DC-2), and it could travel coast to coast in only 16 hours - a fast trip for that time.

Another important improvement was the use of a hydraulic pump to lower and raise the landing gear. This freed pilots from having to crank the gear up and down during takeoffs and landings. For greater passenger comfort, the DC-3 had a noise-deadening plastic insulation, and seats set in rubber to minimize vibrations. It was a fantastically popular airplane, and it helped attract many new travelers to flying.

Pressurized Cabins

Although planes such as the Boeing 247 and the DC-3 represented significant advances in aircraft design, they had a major drawback. They could fly no higher than 10,000 feet, because people became dizzy and even fainted, due to the reduced levels of oxygen at higher altitudes.

The airlines wanted to fly higher, to get above the air turbulence and storms common at lower altitudes. Motion sickness was a problem for many airline passengers, and an inhibiting factor to the industry's growth.

The breakthrough came at Boeing with the Stratoliner, a derivation of the B-17 bomber introduced in 1940 and first flown by TWA. It was the first pressurized aircraft, meaning that air was pumped into the aircraft as it gained altitude to maintain an atmosphere inside the cabin similar to the atmosphere that occurs naturally at lower altitudes. With its regulated air compressor, the 33-seat Stratoliner could fly as high as 20,000 feet and reach speeds of 200 miles per hour.

The Civil Aeronautics Act of 1938

Government decisions continued to prove as important to aviation's future as technological breakthroughs, and one of the most important aviation bills ever enacted by Congress was the Civil Aeronautics Act of 1938. Until that time, numerous government agencies and departments had a hand in aviation policy. Airlines sometimes were pushed and pulled in several directions, and there was no central agency working for the long-term development of the industry. All the airlines had been losing money, since the postal reforms in 1934 significantly reduced the amount they were paid for carrying the mail.

The airlines wanted more rationalized government regulation, through an independent agency, and the Civil Aeronautics Act gave them what they needed. It created the Civil Aeronautics Authority (CAA) and gave the new agency power to regulate airline fares, airmail rates, interline agreements, mergers and routes. Its mission was to preserve order in the industry, holding rates to reasonable levels while, at the same time nurturing the still financially-shaky airline industry, thereby encouraging the development of commercial air transportation.

Congress created a separate agency - the Air Safety Board - to investigate accidents. In 1940, however, President Roosevelt convinced Congress to transfer the accident investigation function to the CAA, which was then renamed the Civil Aeronautics Board (CAB). These moves, coupled with the tremendous progress made on the technological side, put the industry on the road to success.

World War II

Aviation had an enormous impact on the course of World War II and the war had just as significant an impact on aviation. There were fewer than 300 air transport aircraft in the United States when Hitler marched into Poland in 1939. By the end of the war, U.S. aircraft manufacturers were producing 50,000 planes a year.

Most of the planes, of course, were fighters and bombers, but the importance of air transports to the war effort quickly became apparent as well. Throughout the war, the airlines provided much needed airlift to keep troops and supplies moving, to the front and throughout the production chain back home. For the first time in their history, the airlines had far more business - for passengers as well as freight - than they could handle. Many of them also had opportunities to pioneer new routes, gaining an exposure that would give them a decidedly broader outlook at war's end.

While there were numerous advances in U.S. aircraft design during the war, that enabled planes to go faster, higher, and farther than ever before, mass production was the chief goal of the United States. The major innovations of the wartime period - radar and jet engines - occurred in Europe.

The Jet Engine

Isaac Newton was the first to theorize, in the 18th century, that a rearward-channeled explosion could propel a machine forward at a great rate of speed. However, no one found a practical application for the theory until Frank Whittle, a British pilot, designed the first jet engine in 1930. Even then, widespread skepticism about the commercial viability of a jet prevented Whittle's design from being tested for several years.

The Germans were the first to build and test a jet aircraft. Based on a design by Hans von Ohain, a student whose work was independent of Whittle's, it flew in 1939, although not as well as the Germans had hoped. It would take another five years for German scientists to perfect the design, by which time it was, fortunately, too late to affect the outcome of the war.

Whittle also improved his jet engine during the war, and in 1942 he shipped an engine prototype to General Electric in the United States. America's first jet plane - the Bell P-59 - was built the following year.

Radar

Another technological development with a much greater impact on the war's outcome (and later on commercial aviation) was radar. British scientists had been working on a device that could give them early warning of approaching enemy aircraft even before the war began, and by 1940 Britain had a line of radar transceivers along its east coast that could detect German aircraft the moment they took off from the Continent. British scientists also perfected the cathode ray oscilloscope, which produced map-type outlines of surrounding countryside and showed aircraft as a pulsing light. Americans, meanwhile, found a way to distinguish between enemy aircraft and allied aircraft by installing transponders aboard the latter that signaled their identity to radar operators.

Dawn of the Jet Age

Aviation was poised to advance rapidly following the war, in large part because of the development of jets, but there still were significant problems to overcome. In 1952, a 36-seat British-made jet, the Comet, flew from London to Johannesburg, South Africa, at speeds as high as 500 miles per hour. Two years later, the Comet's career ended abruptly following two back-to-back accidents in which the fuselage burst apart during flight - the result of metal fatigue.

The Cold War between the Soviet Union and the United States, following World War II, helped secure the funding needed to solve such problems and advance the jet's development. Most of the breakthroughs related to military aircraft that later were applied to the commercial sector. For example, Boeing employed a swept-back wing design for its B-47 and B-52 bombers to reduce drag and increase speed. Later, the design was incorporated into commercial jets, making them faster and thus more attractive to passengers. The best example of military - civilian technology transfer was the jet tanker Boeing designed for the Air Force to refuel bombers in flight. The tanker, the KC-135, was a huge success as a military plane, but even more successful when revamped and introduced, in 1958, as the first U.S. passenger jet, the Boeing 707. With a length of 125 feet and four engines with 17,000 pounds of thrust each, the 707 could carry up to 181 passengers and travel at speeds of 550 miles per hour. Its engines proved more reliable than piston-driven engines - producing less vibration, putting less stress on the plane's airframe and reducing maintenance expenses. They also burned kerosene, which cost half as much as the high-octane gasoline used in more traditional planes. With the 707, first ordered and operated by Pan Am, all questions about the commercial feasibility of jets were answered. The Jet Age had arrived, and other airlines soon were lining up to buy the new aircraft.

The Federal Aviation Act of 1958

Following World War II, air travel soared, but with the industry's growth came new problems. In 1956 two aircraft collided over the Grand Canyon, killing 128 people. The skies were getting too crowded for existing systems of aircraft separation, and Congress responded by passing the Federal Aviation Act of 1958.

The legislation created a new safety regulatory agency, the Federal Aviation Agency, later called the Federal Aviation Administration (FAA) when Congress created the Department of Transportation (DOT) in 1967. The agency was charged with establishing and running a broad air traffic control system, to maintain safe separation of all commercial aircraft through all phases of flight. In addition, it assumed jurisdiction over all other aviation safety matters, such as the certification of aircraft designs, and airline training and maintenance programs. The Civil Aeronautics Board retained jurisdiction over economic matters, such as airline routes and rates.

Wide-bodies and Supersonics

1969 marked the debut of another revolutionary aircraft, the Boeing 747, which, again, Pan Am was the first to purchase and fly in commercial service. It was the first wide-body jet, with two aisles, a distinctive upper deck over the front section of the fuselage, and four engines. With seating for as many as 450 passengers, it was twice as big as any other Boeing jet and 80 percent bigger than the largest jet up until that time, the DC-8.

Recognizing the economies of scale to be gained from larger jets, other aircraft manufacturers quickly followed suit. Douglas built its first wide-body, the DC-10, in 1970, and only a month later, Lockheed flew its contender in the wide-body market, the L-1011. Both of these jets had three engines (one under each wing and one on the tail) and were smaller than the 747, seating about 250 passengers.


Bomber Theory - History

For a long time, the struggle for supremacy in the air has been fought for in the field of radio electronics. This contest may be an invisible battle of electromagnetic rays over a distance of hundreds of kilometers, but it still operates according to the old rule of fighting favors the element of surprise. Stealth technology is reviving this basic principle of warfare.

To understand how this technology works it is necessary to decipher the principles of radars.

As is known, radar is a means to ascertain the approximate location of an object in a given space. The operating principle of radar is based on the fact that radio signals reflect off of metal surfaces, such as the body of an aircraft.

As an aircraft fuselage is aerodynamically shaped with a generally round form, a radio signal reflected off it will go in all directions, including back toward the radar. Once the radar receives the signal, it determines the distance of the plane based on the time it took for the signal to return to the source.

Combining this information with the direction from which the signal is received, the radar determines the location of the object. Additionally, modern radars such as Irbis or Zhuk, developed by KRET, can identify targets by type, whether a helicopter, cruise missile, or fighter jet.

Thus, the more a plane reflects radio waves, the better it can be detected over a long distance. Engineers are striving to reduce this reflective capacity, also called a radar signature.

Stealth technology, the principle of reducing radar visibility, strives to use a plane’s body structure to direct signals away from the radar receiver. Currently there are two main ways to achieve this goal, either making the fuselage with an angular shape of straight faces and sharp angles, or covering the body of the plane with special material that absorbs radio signals.

In addition, the thermal signature of an aircraft is often reduced by placing the nozzle motor on the upper surface of the aircraft, or by installing cooling systems around heated areas. All of this facilitates maximum invisibility from enemy radar.

American invisibility, developed by a Russian physicist

The history of stealth technology began in 1966, when radar specialists at Lockheed came across an article written by physicist Peter Ufimtsev in a popular Soviet scientific and technical journal. The article said that a certain type of aircraft made of particular materials and with a specific angular shape and paint could be almost invisible to radar. This article piqued the interest of American military experts, who decided to build and test such an aircraft.

In the mid-1970s, the American Air Force introduced the SR-71 spy plane, characterized by an unusual shape and a special paint job based on the ideas from Ufimtsev. The SR-71 was the first aircraft created with radar stealth capabilities.

Despite its shape, and a special coating of cesium that was added to the fuel to reduce exhaust temperature, the SR-71 could easily be detected due to its stream of heated exhaust gas and the aircraft’s significant body heat at high speeds.

Invisibility in the sky

American specialists moved on and began to develop new types of stealth aircraft, still based on the ideas of the Russian physicist. The project was called stealth.

In the early 1990s, the United States introduced two unusual kinds of stealth aircraft: the F-117 fighter-bomber and the B-2 strategic bomber.

Incidentally, Peter Ufimtsev participated in the creation of the latter aircraft. When the Soviet Union gave up work on stealth technology in the 1980s based on his ideas, the resentful designer immigrated to the United States.

Russian stealth technology

One might wonder why, if it had long known about stealth technology, why the Soviet Union did not surpass the Americans with its own stealth systems?

The Soviet Union was known for spending enormous resources to develop the most modern defense apparatus, and this was no exception.

As recalled by Victor Chepkin, general designer for Lyulka-Saturn, stealth technology was well known to Soviet designers. “Together with various institutions we carefully analyzed stealth technology and the general principles of invisibility in combat and other contexts. We came to the conclusion, that the hyper-development of stealth – using stealth for stealth’s sake – greatly narrowed the range of an aircraft’s combat potential. Purely stealth aircraft could be used only in a specific set of combat operations and for a particular purpose, and this technology is very expensive,” he explained.

Stealth aircraft of different types were built and tested in at least two Soviet design bureaus. An authoritative commission decided against the use of the stealth technology.

First, the stealth aircraft built according to Ufimtsev’s ideas was poorly suited for combat maneuvering, as its shape resulted in low speed and maneuverability.

Second, the plane could still be identified visually and with special high-frequency radar. Furthermore, when opening the bombing bay, and in some particular flight conditions, the plane could even be seen on conventional radar, allowing it to be easily targeted. Serbian air defense experts discovered this in 1999 when a Yugoslavian MiG-20 shot down an American F-117A over Belgrade. Today, defense experts say that even the F-35 stealth aircraft is visible to Chinese and Russian radars.

Third, stealth aircraft are very expensive. As a reference, the B-2 bomber is the most expensive aircraft in aviation history, costing $1.157 billion.

Still, not a single side is giving up on stealth technology. A number of stealth technologies were incorporated into the design of the last Soviet fighter jets, the MiG-29 and MiG-27. New Russian aircraft, including the Su-34 fighter-bomber, the MiG-35 light frontline fighter, and the Su-35S heavy fighter utilize technology that reduces their visibility. The future fifth-generation Russian aircraft, such as the PAK FA heavy multipurpose fighter jet and the PAK DA long-range strategic bomber, are being designed as stealth aircraft.

Incidentally, the PAK FA, which is currently undergoing state testing, will be equipped with active phased array radar developed by KRET. The angled plane of the antenna significantly reduces the aircrafts’ electron paramagnetic resonance, making it less visible to radar.

In spite of practically identical design requirements for both fifth-generation Russian and American fighters, there is a basic difference, as the Americans favor stealth over agility.

According to Russian specialists, maneuverability is becoming increasingly important in military aviation, not only because of the development of radar, including new high-frequency radar, but the gradual decrease of the American monopoly on fifth-generation fighter technology. But only when the two stealth fighters meet will combat tactics return to the past.


The Mysterious Disappearance of Flight 19

It began as nothing more than a routine training flight. At 2:10 p.m. on December 5, 1945, five TBM Avenger torpedo bombers took off from a Naval Air Station in Ft. Lauderdale, Florida. The planes𠅌ollectively known as 𠇏light 19”—were scheduled to tackle a three-hour exercise known as “Navigation Problem Number One.” Their triangular flight plan called for them to head east from the Florida coast and conduct bombing runs at a place called Hens and Chickens Shoals. They would then turn north and proceed over Grand Bahama Island before changing course a third time and flying southwest back to base. Save for one plane that only carried two men, each of the Avengers was crewed by three Navy men or Marines, most of whom had logged around 300 hours in the air. The flight’s leader was Lieutenant Charles C. Taylor, an experienced pilot and veteran of several combat missions in World War II’s Pacific Theater.

At first, Flight 19’s hop proceeded just as smoothly as the previous 18 that day. Taylor and his pilots buzzed over Hens and Chickens Shoals around 2:30 p.m. and dropped their practice bombs without incident. But shortly after the patrol turned north for the second leg of its journey, something very strange happened. For reasons that are still unclear, Taylor became convinced that his Avenger’s compass was malfunctioning and that his planes had been flying in the wrong direction. The troubles only mounted after a front blew in and brought rain, gusting winds and heavy cloud cover. Flight 19 became hopelessly disoriented. “I don’t know where we are,” one of the pilots said over the radio. “We must have got lost after that last turn.”

Overal aerial view of Fort Lauderdale Naval Air Station the origin of 𠇏light 19.” (Credit: Acey Harper/Getty Images)

Lieutenant Robert F. Cox, another Navy flight instructor who was flying near the Florida coast, was the first to overhear the patrol’s radio communications. He immediately informed the Air Station of the situation and then contacted the Avengers to ask if they needed assistance. 𠇋oth my compasses are out and I’m trying to find Ft. Lauderdale, Florida,” Taylor said, his voice sounding anxious. “I’m over land, but it’s broken. I’m sure I’m in the Keys, but I don’t know how far down.”

Taylor’s claim didn’t seem to make sense. He𠆝 made his scheduled pass over Hens and Chicken Shoals in the Bahamas less than an hour earlier, but he now believed his planes had somehow drifted hundreds of miles off course and ended up in the Florida Keys. The 27-year-old had just transferred to Fort Lauderdale from Miami, and many have since speculated that he may have confused some of the islands of the Bahamas for the Keys. Under normal circumstances, pilots lost in the Atlantic were supposed to point their planes toward the setting sun and fly west toward the mainland, but Taylor had become convinced that he might be over the Gulf of Mexico. Hoping to locate the Florida peninsula, he made a fateful decision to steer Flight 19 northeast𠅊 course that would only take them even farther out to sea. Some of his pilots seemed to have recognized that he was making a mistake. �mmit,” one man griped over the radio. “If we would just fly west, we would get home.”

Taylor was eventually persuaded to turn around and head west, but shortly after 6 p.m., he seems to have cancelled the order and once again changed direction. “We didn’t go far enough east,” he said, still worried that he might be in the Gulf. “We may as well just turn around and go east again.” His pilots probably argued against the decision—some investigators even believe that one plane broke off and flew in a different direction𠅋ut most followed their commander’s lead. Flight 19’s radio transmissions soon became increasingly faint as it meandered out to sea. When fuel began to run low, Taylor was heard prepping his men for a potential crash landing in the ocean. 𠇊ll planes close up tight,” he said. “We’ll have to ditch unless landfall…when the first plane drops below ten gallons, we all go down together.” A few minutes later, the Avengers’ last radio communications were replaced by an eerie buzz of static.

A Martin PBM Mariner suspended from a ship’s stern crane. (Credit: PhotoQuest/Getty Images)

The Navy immediately scrambled search planes to hunt for the missing patrol. Around 7:30 p.m., a pair of PBM Mariner flying boats took off from an air station north of Ft. Lauderdale. Just 20 minutes later, however, one of them seemed to follow Flight 19’s lead by suddenly vanishing off radar. The remains of the Mariner and its 13 crewmen were never recovered, but it’s commonly believed that the seaplane exploded shortly after takeoff. Flying boats were notoriously accident-prone, and were even nicknamed 𠇏lying gas tanks” for their propensity for catching fire. Suspicions that the seaplane may have gone up in flames were all but confirmed by a passing merchant ship, which spotted a fireball and found evidence of an oil slick in the ocean.

At first light the next day, the Navy dispatched more than 300 boats and aircraft to look for Flight 19 and the missing Mariner. The search party spent five days combing through more than 300,000 square miles of territory, to no avail. “They just vanished,” Navy Lieutenant David White later recalled. “We had hundreds of planes out looking, and we searched over land and water for days, and nobody ever found the bodies or any debris.” A Navy board of investigation was also left scratching its head. While it argued that Taylor might have confused the Bahamas for the Florida Keys after his compasses malfunctioned, it could find no clear explanation for why Flight 19 had become so disoriented. Its members eventually attributed the loss to �uses or reasons unknown.”

The strange events of December 5, 1945 have since become fodder for all manner of wild theories and speculation. In the 1960s and 70s, pulp magazines and writers such as Vincent Gaddis and Charles Berlitz helped popularize the idea that Flight 19 had been gobbled up by the �rmuda Triangle,” a section of the Atlantic supposedly known for its high volume of freak disappearances and mechanical failures. Other books and fictional portrayals have suggested that magnetic anomalies, parallel dimensions and alien abductions might have all played a role in the tragedy. In 1977, the film 𠇌lose Encounters of the Third Kind” famously depicted Flight 19 as having been whisked away by flying saucers and later deposited in the deserts of Mexico.

Even if the “Lost Patrol” didn’t fall victim to the supernatural, there’s no denying that its disappearance was accompanied by many oddities and unanswered questions. Perhaps the strangest of all concerns Lieutenant Taylor. Witnesses later claimed that he arrived to Flight 19’s pre-exercise briefing several minutes late and requested to be excused from leading the mission. “I just don’t want to take this one out,” he supposedly said. Just why Taylor tried to get out of flying remains a mystery, but it has led many to suggest that he may have not been fit for duty. Also unexplained is why none of the members of Flight 19 made use of the rescue radio frequency or their planes’ ZBX receivers, which could have helped lead them toward Navy radio towers on land. The pilots were told to switch the devices on, but they either didn’t hear the message or didn’t acknowledge it.

What really happened to Flight 19? The most likely scenario is that the planes eventually ran out of gas and ditched in the ocean somewhere off the coast of Florida, leaving any survivors at the mercy of rough seas and deep water. In 1991, a group of treasure hunters seemed to have finally solved the puzzle when they stumbled upon the watery graves of five World War II-era Avengers near Fort Lauderdale. Unfortunately, it was later found that the hulks belonged to a different group of Navy planes whose serial numbers didn’t match those of the fabled “Lost Patrol.” Many believe the wrecks of Flight 19 and its doomed rescue plane may still lurk somewhere in the Bermuda Triangle, but while the search continues to this day, no definitive signs of the six aircraft or their 27 crewmen have ever been found.


Theory

Bernoulli's Theory of Flight

The Theory of Flight is often explained in terms Bernoulli's Equation which is a statement of the Conservation of Energy. It states that:

  • For a non-viscous, incompressible fluid in steady flow, the sum of pressure, potential and kinetic energies per unit volume is constant at any point.

In other words, ignoring the potential energy due to altitude:

  • When the velocity of a fluid increases, its pressure decreases by an equivalent amount to maintain the overall energy. This is known as Bernoulli's Principle

According to Bernoulli's Principle, the air passing over the top of an aerofoil or wing must travel further and hence faster that air the travelling the shorter distance under the wing in the same period but the energy associated with the air must remain the constant at all times. The consequence of this is that the air above the wing has a lower pressure than the air below below the wing and this pressure difference creates the lift.

Unfortunately Bernoulli's Principle does not explain how an aeroplane can fly upside down. Nor does it explain how aircraft and other structures with flat plate wings or even kites and paper aeroplanes can fly or remain airborne. This is where Newton's Laws come to the rescue. See below.

Newton's Theory of Flight

Isaac Newton did not propose a theory of flight but he did provide Newton's Laws of Motion the physical laws which can be used to explain aerodynamic lift.

Newton's Second Law states that:

  • The force on an object is equal to its mass times its acceleration or equivalently to its rate of change of momentum

F = M a = d/dt (M v)

In other words, whenever there is a change of momentum, there must be a force causing it. In this case, since momentum is a vector quantity, the change in direction of the airflow around the wing must be associated with a force on the volume of air involved.

Newton's Third Laws states that:

This means that the force of the aerofoil pushing the air downwards, creating the downwash, is accompanied by an equal and opposite force from the air pushing the aerofoil upwards and hence providing the aerodynamic lift.

It is thus the turning of the air flow which creates the lift.

Aircraft Wings

Aircraft are kept in the air by the forward thrust of the wings or aerofoils, through the air. The thrust driving the wing forward is provided by an external source, in this case by propellers or jet engines.

The result of the movement of the wing through stationary air is a lift force perpendicular to the motion of the wing, which is greater than the downwards gravitational force on the wing and so keeps the aircraft airborne. The lift is accompanied by drag which represents the air resistance against the wing as it forces its way through the air. The drag is dependent on the effective area of the wing facing directly into the airflow as well as the shape of the aerofoil.

The magnitudes of the lift and drag are dependent on the angle of attack between the direction of the motion of the wing through the air and the chord line of the wing.

See more about the angle of attack and the theories of aerodynamic lift below.

Wind Turbine Blades

Wind Turbines extract energy from the force of the wind on an aerofoil, in this case a turbine blade. The relative motion between the air flow and the turbine blade, is the same as for the aircraft wing, but in this case the wind is in motion towards the turbine blades and the blades are passive so that the external thrust provided by the moving air flow is in the opposite direction to the thrust provided by the aircraft wing. The turbine blades thus experience lift and drag forces, similar to the aircraft wing, which set the blades in motion transferring the wind energy into the kinetic energy of the blades

The turbine blades are connected to a single rotor shaft and the force of the wind along the length of the blades creates a torque which turns the rotor.

As with aircraft wings, the magnitudes of the lift and drag on the turbine blade are dependent on the angle of attack between the apparent wind direction and the chord line of the blade.

The dynamics of wind turbines is however slightly more complex than the dynamics of a simple wing because the direction of the gravitational force on the turbine blade changes with the rotation of the turbine rotor.

In a "theoretical" turbine with a single blade operating with a constant wind force, the magnitude and direction of the lift and drag with respect to the aerofoil profile will be constant throughout the full 360° rotation of the turbine rotor but the direction of the lift with respect to the ground will depend on the position of the rotor. The magnitude of the gravitational force on the blade will also be constant for any position of the rotor but the horizontal position of the centre of gravity of the blade with respect to the centre of the rotor will vary as the rotor turns. The net effect of these forces on the rotor torque depends on the position of the rotor.

  • When the blade is horizontal and moving upwards it is moving against the force of gravity which is pulling the blade downwards so that the net lifting force on the blade and the resulting torque on the rotor is reduced.
  • After 180° rotation of the rotor, the blade is once more horizontal but upside down and moving downwards so that the "lifting force" due to the wind is in the opposite direction and reinforces the downwards gravitational force so that the torque on the rotor is increased.
  • When the blade is vertical, either at the top or the bottom of its cycle, the gravitational force is perpendicular to the lifting force and passes through the centre of the rotor shaft and hence has no effect on the torque which is purely due to lift.

Practical turbines however have multiple blades which balance each other, so that the gravitational effects cancel out and the torque on the rotor is constant.

The magnitude of the gravitational force on the aerofoil depends on the position and orientation of the turbine blade at any point during its 360° rotation and either augments or opposes the lift force. (See opposite)

Angle of Attack

The angle of attack of a turbine blade is the angle between the direction of the apparent or relative wind and the chord line of the blade. For an aircraft wing, it is the angle between the direction of motion of the wing and the chord line of the wing.

At very low angles of attack, the airflow over the aerofoil is essentially smooth and laminar with perhaps a small amount of turbulence occuring at the trailing edge of the aerofoil. The point at which laminar flow ceases and turbulence begins is known as the separation point.

Increasing the angle of attack increases the area of the aerofoil facing directly into the wind. This increases the lift but it also moves the separation point of laminar flow of the air above the aerofoil part way up towards the leading edge and the result of the increased turbulent flow above the aerofoil is an increase in the drag.

Maximum lift typically occurs when the angle of attack is around 15 degrees but this could be higher for specially designed aerofoils.

Above 15 degrees, the separation point moves right up to the leading edge of the aerofoil and laminar flow above the aerofoil is destroyed. The increased turbulence causes the rapid deterioration of the lift force while at the same time it dramatically increases the drag, resulting in a stall.

The graph opposite shows the lift and drag at different angles of attack experienced by a Clark Y aerofoil, a type widely used in general purpose aircraft designs. When moving through the air at constant speed, as the angle of attack is increased, both the lift and the drag increase until the aerofoil reaches a critical angle when the lift suddenly falls away and the aerofoil begins to stall, in this case, as the angle of attack approaches 20 degrees.

Since the lift generated by an aircraft wing is proportional to the angle of attack and also to the square of the aircraft speed, the same lift can be accomplished by flying at a higher speed with a lower angle of attack. Reducing the angle of attack also reduces the induced drag due to turbulence thus enabling greater aerodynamic efficiency. (See next)