Wizard: The Life and Times of Nikola Tesla (46 page)

June 8, 1908

My dear Colonel,

I am now ready to take an order from you for a self-propelled flying machine, either of the lighter or heavier-than-air type.

Yours sincerely,
Nikola Tesla
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Astor was particularly interested in flying machines, but as would become his habit, Tesla would be working at cross-purposes. He wanted the good colonel to fund this work in aeronautics, but, in actuality, his ultimate goal was to earn enough money so that he could return to Long Island and reopen his world telegraphy plant. Thus, any potential profits were always threatened by the greater plan. This problem would continue to encumber
any possible deal, especially with someone like Astor, who knew full well the inventor’s primary intentions.

One of Tesla’s most confounding prognostications came at the onset of 1908. Having finally located a new work space at 165 Broadway, Tesla felt that he was getting back on track. Shortly after he moved in, he received an invitation to speak at a Waldorf-Astoria dinner in honor of himself and Rear Adm. Charles Sigsbee. “Th[is] coming year will dispel [one]…error which has greatly retarded aerial navigation,” Tesla prophesied. “The aeronaut will soon satisfy himself that an aeroplane…is altogether too heavy to soar, and that such a machine, while it will have some use, can never fly as fast as a dirigible balloon…In strong contrast with these unnecessarily hazardous trials are the serious and dignified efforts of Count Zeppelin, who is building a real flying machine, safe and reliable, to carry a dozen men and provisions, and with a speed far in excess of those obtained with aeroplanes.”
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Assuming that the viscosity of the atmosphere exceeded that of water, Tesla had calculated that an airplane could never fly much faster than “an aqueous craft.” The inventor further reasoned that for highest velocities “the propeller is doomed.” Not only was its rotational speed restrictive, it was also subject to easy breakage. The prop plane, according to calculations, would have to be replaced by “a reactive jet.”
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In the short run, that is, for the next thirty years, the airship was the preferred method of passenger travel.

BERLIN, May 30 [1908]. Count Zeppelin, whose remarkable performances in his first airship brought such signal honors, today accomplished the most striking feat in his career so far. He guided his Zeppelin II, with two engineers and a crew of seven aboard, a distance of more than 400 miles, without landing…

All through the night the vessel…sped over Wertenberg and Bavaria, passing over sleeping countryside and villages and cities hardly less asleep…

It was announced and widely published…that the Count would come to Berlin and land at the…parade ground. In expectation of the event…the Emperor and Empress…and hundreds of thousands gathered there.
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It would be two decades before Lindbergh would capture the imagination of the public by flying solo in a propeller-driven airplane across the high seas, but airships were already close to accomplishing that feat. In 1911, Joseph Brucker formed the Transatlantic Airship Expedition, but he was beaten in the quest by the British air force, which succeeded in crossing the Atlantic eight years later.
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During World War I, the zeppelin ran frequent bombing missions from Berlin to London; Robert Underwood
Johnson flew with fifty other passengers in a similar “leviathan” over Rome just two years later, in 1919.
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However, by the late 1920s this infamous legacy was all but forgotten, as these great airships were flying regularly across the Atlantic from Europe to both North and South America, and Germany was enjoying a reputation as the new leader in futuristic technology.

One curious and unfortunate footnote to history was the senseless choice to fill those blimps with hydrogen, a highly explosive gas, instead of nonflammable helium. Had engineers insisted on the much safer medium by heeding Tesla’s 1915 warning, the great
Hindenburg
disaster of 1937 would never have taken place, and the use of zeppelins would probably have continued for many more years to come. The problem stemmed all the way back to the late 1700s, when Jacques Charles, a French scientist, discovered that hydrogen was fourteen times lighter than air and filled a balloon with it. Monsieur Charles, like Count Zeppelin of Tesla’s time, gained great notoriety by traveling in his balloon fifteen or twenty miles at a stretch.

Today airships create stable platforms for TV sports cameras, advertisers use them because of their unique ability to generate “brand-name recognition,” and the military likes them because they offer singular advantages over the helicopter. They can be used for low-flying rescue missions without creating hazardous turbulence; they can be used to detect the submarine launching of cruise missiles by positioning themselves in a single area for hours or days on end; and they are extremely difficult to locate by ground surveillance. “Why don’t they show on radar?” a recent
Popular Mechanics
article asks. “Because the Skyship’s gondola is made of Kevlar, the envelope is of polyurethane fiber and it’s filled with helium.

They all have little or no radar register…The next-generation [air] ships would sip fuel. And they would stay operational for months at a time. As these are developed for military use, it is not too farfetched to predict that airships of the [21st century] may even be used for trans-Atlantic passenger service.”
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Tesla reveals in his Waldorf-Astoria speech his prophecy of the inevitable development of the jet plane, which would be about as close as he would come to explaining his highly novel and still obscure invention of an airplane that operated much like today’s VTOL “vectored thrust” aircraft. Tesla had played with a number of airship designs since his college days. One of his models, drawn up in 1894, was a traditionally shaped hot air balloon. Inspired by those he had seen at the World Fairs in Paris and Chicago, this dirigible received its continuing supply of heat from a gigantic induction coil that was placed high above the gondola, in the center of the hot-air container.
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The more recent model, which resembled a gigantic teardrop, took into consideration aerodynamic principles uncovered by such researchers
as Leonardo da Vinci, Count von Zeppelin and Lawrence Hargrave, an Australian who, in 1890, fashioned rubber-band powered prop planes which traveled through the air over distances exceeding a hundred yards. This design was schematically prepared in the shape of a conventional airfoil by one of Tesla’s draftsmen in 1908.
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My airship will have neither gas bag, wings nor propellers…You might see it on the ground and you would never guess that it was a flying machine. Yet it will be able to move at will through the air in any direction with perfect safety, higher speeds than have yet been reached, regardless of weather and obvious “holes in the air” or downward currents. It will ascend in such currents if desired. It can remain absolutely stationary in the air even in a wind for a great length of time. Its lifting power will not depend on any such delicate devices as the bird has to employ, but upon positive mechanical action…[Stability will be achieved] through gyroscopic action of my engine…It is the child of my dreams, the product of years of intense and painful toil and research.
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Tesla’s vehicle had the “reactive jet” placed at its “leading edge,” or bulky end, and the fifty steering escape valves placed at the opposite, “trailing edge,” or tapered end. If fashioned as a lighter-than-air dirigible, the ship would have been modeled, in part, after the work of Henri Giffard, a Frenchman who invented the first dirigible in 1852, as well as Count von Zeppelin, the inventor who had been the first to construct a successful prototype with a rigid metal framework “within the bag.”
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Zeppelin was also one of the first to take into consideration wind resistance; his ships could travel at speeds of more than forty miles per hour.

A well-designed airfoil can develop “a lift force many times its drag. This allows the wing of an airplane to serve as a thrust amplifier…[If] the thrust is directed horizontally, a vertical lift force large enough to overcome the vehicle’s weight can be developed.”
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Thus, it appears that Tesla’s reactive-jet prototype could have also been fabricated in a heavier-than-air design. Oliver Chanute, M. Goupil, and O. Lilienthal were other Gay Nineties aeronauts whose patented works Tesla had studied. Naturally, he was also influenced by Samuel Langley and the Wright brothers, both of whom had produced heavier-than-air models that had actually flown.
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Another horseshoe crab-shaped VTOL designed by Tesla was called a hovercraft. This vehicle, which resembled a Corvette, placed the powerful
turbine horizontally within its center. Operating much like a great fan, the engine created a heavy downdraft which caused the vehicle to rise up and ride along the ground on a layer of air.
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This invention, which apparently worked much like the hovercraft depicted in the original
Star Wars
film, was the early precursor of the army’s car-sized “aerial jeep,” which “derive[d] its thrust from ducted fans mounted rigidly in the airframe. To fly horizontally, the entire craft [was] tilted slightly [by the leaning motion of the driver].” In 1960,
Scientific American
could write that “this design is being explored because of its simplicity and…adaptability for flying at very low altitudes.”
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It is doubtful that Tesla ever constructed any of the heavier-than-air hovercrafts, although he may have built a hydrofoil model to skim over the Hudson. There is no doubt that he also constructed “lighter-than-air” vessels which could be operated by means of remote control.

Ideas inherent in Tesla’s hovercraft and paramecium-shaped reactive-jet dirigibles evolved into today’s Harrier fighter plane, a supersonic aircraft considered one of the military’s “most potent fighting machines,” and the new, yet-to-be-built Lockheed Martin X-33, which is a lightweight VTOL replacement of the space shuttle having a new experimental engine, the plane itself being shaped like a “flat-flying wing.”
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The seeds of this technology can also be traced to the work of “A. F. Zahm, a prominent aeronautical engineer who patented [in 1921] an airplane with a wing that would deflect the propeller slipstream to provide lift for hovering.” Although Zahm did not actually construct his plane, his concept, which may have been influenced by Tesla’s work, evolved into the English Hawker, a British fighter developed in the 1960s. This airplane utilized nozzles to deflect a slipstream downward for vertical takeoff or for hovering and horizontally for normal flight. Utilizing “thrust vectoring,” this apparatus became more workable with the development of the Pegasus engine, an extremely powerful turbojet found in the Harrier, which was unyeiled in 1969.
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“From the pilot’s point of view, there is only one extra control in the cockpit: a single [lever] to select the nozzle angle.”
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“AV-8B Harrier: The U.S. Marines’ ground-support jet can take off vertically, hover close to a battlefield and let loose missiles, cluster bombs or smart bombs.”
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Whether or not Tesla was able to perfect his design for aircraft that operated without any fuel—by deriving energy from wireless transmitters—is unknown. This concept, however, has been adopted by the military. In 1987, the
New York Times
and also
Newsweek
reported large glider planes “powered without fuel.” Their energy is derived from
microwaves beamed up from ground transmitters to large, flat panels of “rectennae” on each wing’s underbelly. These “special antennas, laced with tiny rectifiers that turn alternating current into direct current, power an electric motor to run the craft’s propeller.”
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This concept is also utilized as solar panels onboard spacecraft as well as on solar-powered automobiles.

The Flivver Plane

Tesla Designs Weird Craft to Fly Up, Down, Sideways
Craft Combines Qualities of Helicopter & Plane

Detailed descriptions were available yesterday of the helicopter airplane, the latest creation of Nikola Tesla, inventor, electrical wizard, experimenter and dreamer.

It is a tiny combination plane, which, its inventor asserts, will rise and descend vertically and fly horizontally at great speed, much faster than the speed of the planes of today. But despite the feats which he credits to his invention, Tesla says it will sell for something less than $1000.
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Although this article was written in 1928, Tesla first applied for patents on his new “method of aerial transportation” in 1921.
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Nevertheless, designs for propeller-driven VTOL aircraft dated back even before the turn of the century. One of Tesla’s earliest and most primitive helicopters looked much like a washbasin, with vertical shaft rising from its center. Flailing out, like the skeletons of two umbrellas stacked above one another, were its dual horizontal propellers. This vehicle evolved into the flivver plane, which took off vertically like a helicopter and then flew like a normal airplane, when the propeller and craft were rotated 90 degrees into the horizontal position. The concepts found in Tesla’s flivver plane can be found in another advanced military VTOL aircraft called the V-22 Osprey. In this design, the body of the vehicle resembles a normal military transport plane. It is the propellers, at the ends of each wing, which rotate ninety degrees from the helicopter position, for vertical takeoff, into the normal airplane position for forward flight. Used in the recent war with Iraq (February 1990), this vehicle, like the aerial jeep and VTOL Harrier fighter jet, evolved directly out of Tesla’s designs. As Tesla’s work in aeronautics has never received much publicity, it is quite possible that the military adopted it in secret.