The Secret History of Drones

Pilotless aircraft have been around longer than you might think.  

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In , newspapers heralded the dawn of a new age with the invention of a device that would &#;render fleets and guns useless.&#; Physical distance was said to &#;have no effect on its magic results,&#; which could be controlled &#;with the touch of a switchboard key.&#; On top of that, the device didn&#;t cost much.

The invention that had inspired such glowing reviews was a four-foot-long model of a torpedo boat unveiled by Nikola Tesla&#;considered by some to be the world&#;s greatest inventor&#;at a press conference in New York City. When Tesla turned a switch on a small box at the other end of the laboratory he had set up, the boat&#;s propeller began to move, and when he gave the switch another turn, it sent the helm of the boat &#;sharp over&#; to starboard.

The Bug was launched from a four-wheeled dolly that ran on a portable track.

In truth, other engineers had already been working on the promising concept, pondering the potential battlefield applications of Guglielmo Marconi&#;s invention of the radio transmitter and receiver. Just one year prior to Tesla&#;s press conference, guns had been remotely fired at an electrical exhibition at Madison Square Garden in Manhattan. One journalist noted the gun firing, mocking Tesla&#;s &#;extravagant promises and meager performances.&#;

&#;Despite his reputation as a genius, there was nothing particularly novel about what Tesla was saying,&#; says Iwan Rhys Morus, author of the book Nikola Tesla and the Electrical Future. &#;He may have been surfing the wave of the zeitgeist. But he was a very, very good surfer.&#; 

The Bug relied on pneumatic and electrical controls to reach its target.

What Tesla may have lacked in originality, he made up for in showmanship and a keen ability to conceptualize the implications of new technologies. In a speech that today sounds markedly prescient about the destructive potential of mass-produced aerial drones, Tesla told the assembled journalists: &#;War will cease to be possible when all the world knows that the most feeble of nations can supply itself with a weapon which renders its coast secure, and its ports impregnable to the assaults of even the united armadas of the world.&#; By the time Orville Wright took off in his wood-and-fabric Flyer from Kitty Hawk, North Carolina, five years later, visions of pilotless aircraft had already taken hold within the fledgling aviation community. 

&#;The growth of unpiloted aviation and radio went hand in hand,&#; says Roger D. Connor, a curator in the National Air and Space Museum&#;s aeronautics department. &#;In World War I, the ability to direct artillery by radio drives the development of aircraft. The growth of unpiloted aviation is no different.&#;

Staff at the National Museum of the U.S. Air Force in Ohio built a full-size replica.

Dull, Dirty, and Dangerous

Elmer Sperry was an American inventor whose wide-ranging interests included the development of gyroscopic stabilizers to reduce the lurching of U.S. Navy ships at sea. He became intrigued with the idea of radio-controlled aircraft, but recognized that stabilization during flight would be essential to make it work. With the assistance of the Navy, Sperry and his son Lawrence developed an automatic gyrostabilizer in , which enabled a Curtiss flying boat to fly straight and level without input from the human pilot on board. On June 18, , Lawrence Sperry and his French assistant Emil Cachin demonstrated the invention at the Aero Club of France&#;s airplane safety competition. As Sperry stood on one wing of his pilotless flying craft, Cachin on the other, one of the judges on the ground cried out: &#;Mais, c&#;est inoui!&#; (&#;But that&#;s unheard of!&#;). Needless to say, Sperry won the competition&#;s first prize&#;50,000 francs ($10,000)&#;and became famous overnight. 

In the s, the British converted biplanes into radio-controlled target drones, beginning with the Fairey Queen IIIF Mk.IIIB (on the aft deck of a Royal Navy vessel).

Wars accelerate the development of technology, and the drone is no exception. After World War I erupted and the Western Front descended into stalemate, the British decided to take advantage of Sperry&#;s breakthrough and build a top-secret facility to design the first generation of drones. British engineer, inventor, and television pioneer Archibald Low was given the job, and the Germans considered him to be so capable, they attempted to kill him twice (the second time by a poisoned cigarette). 

Low entered the history books with his engineering project known as &#;Aerial Target.&#; Intended to be an aerial torpedo to be used against Zeppelin bombers and U-boats, it had been named Aerial Target to fool the Germans into thinking it was just fodder for testing anti-aircraft weapons. Low&#;s flying torpedo took off for the first time under radio control in March , a feat that later saw him recognized as the &#;father of radio guidance systems&#; and, more recently, &#;father of the drone.&#; The initial demonstration was far from perfect&#;it ended with a spectacular crash landing.

&#;A great number of the pieces are in place for remotely piloted aircraft pretty early, by the beginning of World War I,&#; says Connor. &#;But what was really lacking was the ability to control the drones effectively, and this was down to the reliability of the radio signals. In so many cases, like the United States&#; Kettering aerial torpedo, these projects just devolve into what might be considered a flying bomb. Even Low demonstrated only a degree of control with his Aerial Target: He nearly killed observers on the ground when it crashed during its demonstration flight.&#;

Indeed, a similar misfortune befell the aforementioned Kettering aerial torpedo&#;known as the &#;Bug&#;&#;during its demonstration flight at a secluded airfield near Dayton, Ohio, where a group of U.S. Army VIPs had gathered to see the first U.S. &#;guided missile&#; in action. The miniature wood biplane&#;named for its inventor Charles F. Kettering&#;was packed with explosives. A gyro helped maintain the stability of the craft, and a barometer sent signals to small flight controls that were moved by a system of cranks and a bellows (from a player piano) for altitude control. But after taking off, the Bug pivoted off course, at which point it swooped down and headed straight for the reviewing stands, causing officials to dive for cover under the bleachers. Fewer than 50 Bugs were manufactured, and they never saw combat.

Despite these somewhat disappointing initial outcomes, the development of drones continued after the war, while tech nerds of the era remained captivated by radio&#;s potential. In , Hugo Gernsback, editor of the first science fiction magazine, Amazing Stories, published a book, Radio for All, which had a &#;really amazing frontispiece,&#; says Rhys Morus. &#;It&#;s a picture of a man of the future, sitting in the future office&#;and through the window, there is a flying machine in the sky labeled &#;radio-controlled aeroplane.&#; &#; 

Prior to the end of World War I, French engineers had succeeded in launching a radio-controlled Voisin biplane that stayed aloft for 51 minutes, traveling more than 60 miles. The tricky business of takeoff and landing, however, was still handled by pilots on board. That changed in , when engineer Maurice Percheron and pilot Captain Max Boucher designed, built, and remotely piloted a Voisin Type 10&#;a two-seat bomber&#;from takeoff to landing. The feat had been made possible through the ongoing augmentation of Sperry&#;s autopilot design and the introduction of a tactile land sensor to flatten out the rate of descent. Despite this accomplishment, the French canceled the project.

The Curtiss-built Hewitt-Sperry automatic airplane (&#;Flying Bomb&#;) sits on its launch catapult in . The aircraft crashed after flying only 100 yards, and the design was discontinued.

Pilotless aircraft, flying slow and straight, hardly seemed like a viable weapon. It would fall to Great Britain in the ensuing decade to figure out a practical military application for the technology. In the s, British military leaders realized that naval anti-aircraft gunners were having a tough time hitting fast-turning aircraft from a warship that was also maneuvering. The solution was the de Havilland Queen Bee drone. &#;It&#;s this requirement for anti-aircraft training that really drives the drone industry and establishes it as a viable aerospace niche during the &#;30s,&#; says Connor.

Researchers at Britain&#;s Royal Aircraft Establishment had continued Low&#;s work after the war, culminating in the development of the Queen Bee, which resembled the legendary de Havilland Tiger Moth trainer, albeit without a pilot. The enclosed rear cockpit was fitted with radio-control gear that included pneumatically operated servo units linked to the elevator controls and rudder. Engineers also replaced the Tiger Moth&#;s metal-frame fuselage with a less expensive one made of spruce and plywood, which also made the drone buoyant if it had to ditch in the ocean.

The McDonnell Aircraft TD2D Katydid target drone had a similar configuration. During the war, Germany used pulse jets to power V-1 flying bombs.

After World War II, the Radioplane Company began experimenting with pulse jets, mounting them on the backs of drones to replace propellers.

&#;Projects like the Queen Bee should get the credit for being the first viable application of drones, which up to that point had been more or less laboratory work,&#; says Connor. Drones had begun to develop the reputation&#;repeated as a mantra throughout the 20th century&#;as the workhorses for missions that were too dull, dirty, and dangerous for piloted aircraft.

The U.S. Chief of Naval Operations, William Standley, saw the Queen Bee drone at work and concluded there was an &#;urgent need in the fleet&#; to have one of their own. It was Commander Delmer Fahrney&#;s job to get them one, even if the British refused to share their remote-control technology with their overseas cousins.

A TDR-1 is prepped for an attack against an enemy target in Rabaul during World War II. Controlled from a TBM-1C Avenger aircraft, the Edna III carried a 1,000-pound bomb.

Fahrney turned full-scale obsolete aircraft like the Curtiss N2C Fledgling trainers into drones for aerial targets, controlled by pilots in other airplanes. In , one squadron was deployed for the Navy on the West Coast, and two years later on the East.

But there were complications. &#;Many of these aerial targets were unreliable because they were obsolete and poorly maintained,&#; says Connor. &#;They would make a pass of a battleship during gunnery practice and sustain damage but remain in the air.&#; If this happened, the crew of the control airplane had Tommy guns, and they were expected to fly alongside the compromised drone and shoot it down.

Norma Jeane Dougherty&#;later known as Marilyn Monroe&#;was discovered by a photographer while she worked at Radioplane (seen here assembling an OQ-3 drone).

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Army anti-aircraft gunnery was less complex than the Navy&#;s in that the gunners were stationary when they were shooting. Army gunners wanted their own smaller target drones, and at that time, there was only one man to talk to about this in the U.S. Reginald Denny had been a Royal Air Force pilot at the end of World War I, when he emigrated to the U.S. and became a successful Hollywood actor. But he continued to be fascinated with aviation, and he went into business manufacturing model aircraft for the hobbyist market.

In , Denny decided to add radio control to his model aircraft despite the challenge of finding equipment light and small enough to fit on his airplanes. His success in doing so soon attracted the attention of the Army. By , Denny was developing his Radioplane for them, and two years later, the Radioplane OQ-2 became the first mass-produced UAV (unmanned aerial vehicle) in the U.S. The next model, the OQ-3, became the most widely used target drone by U.S. forces, with more than 9,400 built during World War II. 

But the existence of drones was still a secret and would remain so for a few more years. &#;It had not filtered into public consciousness  because its potential as a weapon system was still driving a high level of secrecy, and the fear that the Germans might employ this technology against us,&#; says Connor.

As part of Operation Crossroads, Grumman F6F Hellcats were converted to drones to gather data from atomic tests at Bikini Atoll in July . The tail colors on the brightly painted aircraft indicate different radio guidance frequencies. (Guided by period color photos of the F6Fs, color has been added to this archival black-and-white image.)

Meanwhile, the U.S. had made progress militarizing the technology against Germany. The Anvil and Aphrodite projects turned war-weary Boeing B-17 Flying Fortresses (for the Army) and Consolidated B-24s (for the Navy) into flying bombs by filling them with 20,000 pounds of explosives and then flying into heavily defended or very hard targets, such as Germany&#;s U-boat pens and long-range artillery sites. At the start of these programs, a human pilot had to do the hazardous job of flying these lumbering machines off the runway, and then parachute out. By the end, a pilot could perform the whole operation remotely.

Boeing B-17 drones flew via remote control, such as this one coming in for a landing, while other drones are parked, prior to taking part in the first atomic bomb test.

Ground-based military personnel flew Boeing B-17 drones via remote control.

The U.S. Navy then planned to build 5,000 of their own kamikaze drones. The TDR-1 was a large, modern-looking, twin-engine wood-and-metal unpiloted aircraft capable of carrying a 2,000-pound bomb or torpedo and hitting a target 425 miles away. It was controlled from a Grumman Avenger torpedo bomber flying nearby. Around 190 TDR-1s were built and, before the project was cancelled, 50 of the drones saw action, with 31 hits on ships, airfields, and bridges. &#;They may sound impressive, but they were largely unsuccessful,&#; says Connor. &#;They didn&#;t cause much damage, and the results were pretty disappointing for most of these programs compared to the amount of resources put into them.&#; However, one of the really important things about these drone programs is the development of television to fly them. The controller of the TDR-1 had a five-inch screen to guide the aircraft to its target.

That&#;s why, despite their underwhelming performance in the field, &#;drones and their ever-improving supporting technology continued to show great promise&#;and the knowledge that other nations were also in the hunt was a further motivation,&#; says H.R Everett, author of Unmanned Systems of World War I and II. &#;The message was don&#;t get left behind.&#;

This is only a test

In July , the U.S. military conducted a pair of nuclear weapons tests at Bikini Atoll in Operation Crossroads. A large press corps witnessed the devastation, including Philip Porter, who wrote in the Cleveland Plain Dealer: &#;A gigantic dome of water, white, beautiful, terror inspiring, at least a mile across, rose nearly a mile in the air immediately. It blanketed the entire target fleet. It left me staring open mouthed. The dome of water surged into the air, seemed to settle down into a doughnut-like circle. It hid everything.&#;

Newsreels showed a single-engine fighter aircraft flying over the bombing site. But the airplane didn&#;t have a pilot, and off camera there were others like it. After the end of World War II, Grumman Hellcats and B-17s had been converted into remote-controlled drones, equipped with air scoops, collection bags, and recording instruments to measure the radioactivity in the mushroom cloud that had enveloped Bikini.

Pre-flight tests are made on the MX&#;873 Guided Missile XQ-2 aerial target at Holloman Air Force Base, New Mexico, in May .

&#;It was the dirty part of the dull, dirty, dangerous moniker,&#; says Roger Connor. &#;You can&#;t expose humans to radiation. You use remotely piloted aircraft from an airborne mother ship.&#; By demonstrating that drones could operate in &#;very hazardous conditions,&#; says Connor, the Operation Crossroads drones served as a &#;bridge between the development of the drone in World War II and their Cold War applications.&#;

One of the most prominent Cold War drones, the Gyrodyne QH-50, was the first drone helicopter put into operation and one of the first armed unpiloted aerial vehicles. The introduction of Soviet nuclear-powered submarines in the early s created a pressing demand for a remotely piloted helicopter that could operate from smaller, older destroyers and carry a Mark 57 nuclear depth bomb&#;or two torpedoes. Some QH-50 drones were also deployed during the Vietnam War, where they were used primarily for spotting naval gunfire.

A more common presence over the skies of Vietnam was the AQM-34 Ryan Firebee. Originally designated the Q-2, the Firebee began its illustrious career as a jet-powered target drone for both surface-to-air and air-to-air missiles. In the s, the U.S. Air Force modified the Firebee for stealth surveillance missions, adding innovations such as radar-absorbing paint. Between and , some 1,000 AQM-34s&#;which were launched and controlled from Lockheed DC-130s&#;flew more than 34,000 operational surveillance missions over southeast Asia, with 83 percent of them returning home to fly further missions.

&#;We were flying hundreds of drones over North Vietnam during the war, and there was little publicity about it for obvious reasons,&#; says Russ Lee, a curator in the aeronautics department at the National Air and Space Museum. &#;But [drone technology] is no longer classified to the same extent.&#;

The Gyrodyne QH-50C drone, used for anti-submarine patrols, could carry a Mark 57 nuclear depth bomb.

&#;Until recently, drones were simply regarded as something not serious, like a toy, even when they were seen in action,&#; says Connor. &#;There&#;s always been this kind of weird perception of drones as this strange little corner of aviation by the community as a whole. It&#;s an issue that persists to the present day, as a drone operator is not seen in many cases as a proper pilot.&#;

In the end, would Tesla see these drones and think his prediction had come true? &#;It has a kind of family resemblance to the kind of future Tesla imagined,&#; says Rhys Morus. &#;It&#;s not his world, but if Tesla suddenly appeared and saw the world around him, I have no doubt at all he would try and sell himself as the progenitor.&#; 

Mark Piesing is an aviation journalist and frequent contributor to Air & Space Quarterly. He is the author of N-4 Down: The Hunt for the Arctic Airship Italia (Custom House, ).

This article is from the Fall issue of Air & Space Quarterly, the National Air and Space Museum's signature magazine that explores topics in aviation and space, from the earliest moments of flight to today. Explore the full issue.

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The Case:

Working beside a rural airstrip, an Illinois man dug up an intriguing find:  an eight-foot long wooden airplane propellor. A little research online made him believe that his propeller might be from a TDR-1 plane, a pioneering U.S. drone plane from World War II.

Various websites say the TDR-1 were the first drones used in combat, the prototype of the unmanned assault planes used today in Afghanistan and Iraq.

History Detectives investigates whether this propellor is an important piece of American military history or simply fell off a local prop plane.

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