The story of the Kettering Bug, the World’s First Aerial Drone

2. Delco invented the electrical system for automobiles in 1911

Kettering and his team attacked the problem of electrical distribution in automobiles, and by 1911 developed the system still more or less in use in the 21^st century. To the Delco team, the electrical system had three roles to play in conjunction with the internal combustion engine. It needed to produce the spark necessary for ignition. It needed to start the engine. And a supply of current for lighting was another necessary function of the system. Kettering and Delco developed the first automobile electric starter, the generator (later alternator), and the necessary adjuncts for the electrical distribution system.

When the system was presented to Henry Leland in 1911, Cadillac ordered 12,000 units for inclusion in its automobiles. Delco had no means of producing them. The company was what in a later day would be called a think tank, not a manufacturing facility. Delco purchased land in Moraine (south of Dayton) to build an assembly facility, and electric starters and distribution systems for Cadillac were installed on 1912 models of their car. Delco became widely known in the fledgling automotive industry. By 1918, Delco (and Cadillac) was part of General Motors, with Kettering serving as the vice-president of General Motors Research Corporation and Delco Electronics.

3. Elmer Sperry developed gyroscopic stabilizers in the early 20^th century

Elmer Ambrose Sperry was interested in electrical power from an early age, and founded the Sperry Electric Company in Chicago in the 1880s. He developed electrified mines, to which he sold specially designed electric mining equipment. He then developed electrified trolley systems and inclines, an electric automobile (the first American car to appear in Paris, France) and was awarded numerous patents. Eventually, he sold his electric railway businesses and patents to General Electric. In 1898 Sperry began work on gyroscopic stabilizers for ships, designed to counteract the rolling they encountered in heavy seas. His work with gyroscopes led him to design a gyrocompass. By 1913 Sperry’s gyrocompass was reduced in size, allowing it to be used in airplanes.

Sperry’s innovations were in use by the major navies of the world when World War I began in 1914. During the war years, Sperry continued to develop gyrocompasses for airplanes, and began work on both remote control and self-guided airplanes. In 1916 he began work on his own on a flying bomb. During the war years, he developed instrumentation for aircraft, including a gyro-controlled horizon indicator. By the time the United States entered World War I, Sperry was widely considered the world’s foremost authority on navigational instruments and control systems which used servo motors to respond to signals from gyroscopic sensors.

4. The Sperry-Hewitt flying torpedo

In 1916 Elmer Sperry, his son Lawrence, and their business partner Peter Hewitt, began work on an unmanned flying torpedo, controlled by Sperry’s gyroscopic automatic pilot. The elder Sperry worked with Hewitt on the US Navy’s Naval Consulting Board. The Navy expressed some interest in the idea of an unmanned aerial torpedo, but did not commit itself to explore the concept. After the United States entered World War I, Sperry succeeded in convincing the Navy to revisit the idea as a possible counter to the German U-Boat threat. By early autumn, 1917, Sperry-Hewitt was ready to present their flying torpedo for evaluation by the Navy.

The Naval Board of Ordnance was responsible for the evaluation of the potential weapon. It took the highly unusual step of inviting the Army to send a representative to witness the tests. The Army sent Lieutenant Colonel George Squier. Squier was the first officer of the United States Army to have earned a doctorate in electrical engineering, and the second military officer to ride in an airplane. In his case, Orville Wright flew the airplane. Squier was an enthusiastic supporter of military aviation. After witnessing the tests of the Sperry-Hewitt aerial torpedo, which the Navy rejected, Squier decided the concept was workable for the army.

5. Squier and Deeds developed the concept of a flying bomb

Edward Deeds volunteered as an Army officer with the rank of Colonel. In 1917 he was assigned as the head of the Army’s Aircraft Production Board. At the time the only viable aircraft constructors in the United States were the Curtiss Company and the Dayton Wright Company. Deeds also had a long-standing relationship with Charles Kettering. Squier was promoted to General as the United States mobilized for war in 1917, tasked with procuring aircraft for the Army. After viewing the demonstration of the Sperry torpedo, he discussed the possibility of obtaining a similar device for the Army, creating what was in essence airborne heavy artillery. Deeds recommended Kettering to supervise the project.

Kettering was recommended for reasons other than his long business relationship with Deeds. Both men were well acquainted with Orville Wright, and the Dayton Wright Company was a potential builder of the flying bomb. Squier also had worked extensively with the surviving Wright Brothers. It is also true however that Dayton Wright Company was established by Deeds, Kettering, and associates as the successor of the Wright Company established by Wilbur and Orville. Orville Wright served as a director of the new company. When Deeds accepted his commission into the army, he divested his shares in Dayton Wright, to avoid accusations of steering profitable work into his own company.

6. Kettering was hired to develop a flying bomb for the army

In November 1917, after meeting extensively with Squier and Deeds, Kettering agreed to take on the project of developing a self-guided flying bomb for the Army. The effort was named Project Liberty Eagle. In January, 1918, two contracts were awarded as part of the project, one to Dayton Wright and the other to Dayton Metal Products Company. Since neither was considered the prime contractor, the Army assumed the role, filled by General Squier. Kettering was a major investor in both companies. The project was highly classified, and the contracts did not specify deliverables. Instead, they were to be identified verbally by the “account manager”, in the form of General Squier or his designated representative.

Prior to the contract awards, Kettering traveled to Amityville, New York, where he viewed the Sperry Aerial Torpedo and met with Elmer Sperry. There he learned of the workings of Sperry’s gyroscopic control system, which became a critical component of the Army’s weapon. It has been speculated that it was the trip to Amityville which convinced Kettering the Army’s idea was workable. Back in Dayton, Kettering met with his team on Christmas Eve, where he described the Navy’s version and his vision of the small aircraft they would build. One member of his team was Thomas Midgley, who became famous, or perhaps infamous, as the man who developed leaded gasoline as well as Freon.

7. Kettering rejected the idea of a remotely controlled airplane

Kettering’s vision for the aircraft was an expendable bomb, to be used once, rather than a device for delivering a bomb and returning to from whence it came. In his opinion, landing such an aircraft with existing technology was impossible, and there were time constraints to consider. He proposed the aircraft carry fuel and explosives, and little else. Since it wasn’t going to land at the end of its mission it would have no undercarriage. It could be launched from reusable sleds. His team agreed with the proposals, as did the Army when he relayed his concerns to Squier. Squier used Kettering’s recommendations when he wrote the contract specifications.

Cost was another concern. Kettering recognized each unit produced would be used but once, and accordingly they should be as cheap as possible. Essentially, they were engineering a giant artillery shell, and the costs of the deliverable were to be in line with those. The airframe itself was built of wood and fabric, but the guidance components were costly. Kettering also feared the costs of the engines for his aerial weapons would be prohibitive. To ensure they weren’t, yet another American industrialist needed to be brought aboard the program, one able to mass-produce the engines reliably and affordably. Charles Kettering knew who that person should be, and contacted him. His name was Henry Ford.

8. Building the engine affordably was a serious problem for the designers

In 1918, aircraft engines were large, heavy, expensive, and temperamental. Kettering needed an engine which was small, inexpensive, and reliable. It also had to be simple to install, given that the weapon would need to be assembled in the field just prior to launch. Kettering was well known in the automotive industry, and through his contacts, he reached Ralph DePalma, the winner of the 1915 Indianapolis 500, and the owner of DePalma Manufacturing Company. DePalma designed a lightweight, two-stroke motor, four cylinders and air-cooled, which was perfect for Kettering’s needs. However, DePalma was unable to manufacture the motor in numbers sufficient to meet demand in full production, at least not affordably.

Ford was. After his engineers studied the design and components of the engine, which proved to be difficult during development, the Ford Motor Company proposed mass production of the motor at a cost of $50 per unit. Kettering’s flying bomb had thus before it had ever flown, involved the considerable talents of Orville Wright, Elmer Sperry, Henry Ford, and Charles F. Kettering. These men had decided to build an airframe which was little more than an enlarged box kite, capable of flying on its own a specified distance, in an assigned direction, hitting a selected target. There were still numerous technical issues to resolve, but Kettering had assembled the talent necessary.

9. The airframe was built of wood and cloth

Kettering envisioned the aircraft which came to be known as the Kettering Bug as a simple and inexpensive container for high explosives. He assigned one of his team, Jay Schoonmaker, to design the vehicle. Schoonmaker worked in harness with Orville Wright, probably the foremost authority in aerodynamics at the time. They designed an airframe which was blunt-nosed to accommodate the DePalma engine, about twelve feet in length. The wings were designed to be attached in the field, making shipping easier. Overall, the wing span was about fifteen feet. The airframe could hold sufficient fuel for a range of about fifty miles.

The materials used to construct the Bug were wood, cloth, paper, and papier-mache. It was simple in appearance and assembly, deliberately designed as components that troops could easily assemble in the field who were neither aviators nor aircraft mechanics. The entire Bug could be put together using common hand tools, wrenches, pliers, hammers, and screwdrivers, with written instructions provided. The only technically challenging component of the assembly was the guidance mechanism, which though complex in design was made to be installed as easily as possible. Kettering’s Bug was designed as a kit to be put together in adverse circumstances by men who had no idea of the complexities of the device, yet operated reliably.

10. Getting the Bug to the target was a problem to be solved

For the Kettering Bug to work as planned, two problems had to be resolved. It had to “know” where it needed to go, and it had to also know how to get there. Level flight at a pre-planned altitude was relatively easy to achieve, or so its designers thought. Measuring the distance to the target was another problem posed to the designers. How could the machine know how far it had traveled? To resolve the problems of altitude, distance, and course of flight, Kettering and his team relied on the abilities of Elmer Sperry and his associates. The gyrocompass was reliable enough to ensure the flight would be on course. Altitude and distance were other issues.

An aneroid barometer – measuring air pressure – was developed by the engineers and technicians at Sperry. It was sensitive to the point that it could detect differences in air pressure from just a few feet. Sperry demonstrated it registering changes between the floor and the surface of Kettering’s desk. Detecting the change was not enough. The information needed to be transferred to the control surfaces, ensuring the Bug attained and remained at the desired altitude. Both Kettering and Midgley applied their talents to the problem of controls. Their first system used servos, which added weight to the aircraft and failed to respond rapidly enough to the input from the sensors. It was Midgley who came up with the idea of using the medium through which the Bug operated – air – to control its flight.

11. Flight control was achieved pneumatically

Kettering sacrificed his personal player piano and pipe organ – both of which were in his home – to craft a compressed air system which operated the control surfaces of the Bug. When Midgley and Kettering were convinced the system, which used suction from the crankcase of the DePalma engine to operate a bellows, worked sufficiently he sought a subcontractor to manufacture it. He found one in the Aeolian Company of New York City. Aeolian was not involved in the aircraft industry, nor weapons for the military. They were the nation’s largest manufacturer of pump organs and player pianos for the home. In 1916 they also began manufacturing phonographs and records.

By late summer, 1918, Kettering and the Army were at odds with one another, the latter demanding a flying prototype, the former concerned with reimbursement for expenses. General Squier, through Army representatives dispatched to Dayton, began to take control over the project, much to the annoyance of the Dayton inventor and businessman. Squier wanted Kettering to give his full attention to Project Liberty Eagle, to the detriment of the many other projects which occupied the inventor’s mind and time. In late summer the general’s personal aide began to appear in Dayton, to discuss the Bug and the problems surrounding the project. He was Lieutenant Colonel Henry Arnold, known to all as “Hap”.

12. The Kettering Bug was tested in September, 1918

The Wright Brothers first flew at Kitty Hawk, in North Carolina, but it was at Huffman Prairie, east of Dayton, Ohio, where they learned to fly. There the brothers learned to control their aircraft, take off and land, and the rudiments of extended flight. The flights conducted near Dayton were launched using a rail and counterweight system to accelerate the Wright Flyer into the air. Orville Wright developed a similar system for launching the Kettering Bug. In the fall of 1918, the launch rail was assembled at McCook Field, just south of Dayton, on the banks of the Great Miami River. The Kettering Bug was ready for its first flight.

After postponements due to contrary weather, the Bug was launched into the air on Saturday, September 14, 1918. It crashed after a flight of about 300 feet. Engine problems were determined to be the culprit. In early October another test resulted in a flight of less than fifteen seconds, with the Bug circling after launch and diving upon the launchers. Modifications were made to the control system, and about two dozen Bugs were ordered by the Army, for the purpose of testing and evaluation. DePalma (which was still manufacturing the engines) produced an engine capable of higher revolutions per minute, and it was installed in future prototypes of the aircraft. Meanwhile, World War One dragged on in Europe.

13. The first successful test of the Kettering Bug occurred in October, 1918

On October 4, 1918, the Bug flew an extended distance for the first time, though not in the direction intended, nor at the preset altitude. After launch, the aircraft circled McCook Field several times before heading off to the northeast. It eventually crashed in a farmer’s field near Xenia, Ohio. Army officers, including Hap Arnold, heard reports of the crash and traveled by automobile to the site. They immediately quelled rumors of a pilotless airplane, with Arnold claiming to have parachuted from the stricken craft to a local newspaper reporter. At the time, the United States Army possessed no parachutes, though that information was not available to the reporter. The Bug was deliberately burned where it lay in the field, though the guidance system was recovered.

Despite the guidance failures, the Bug had otherwise performed as designed. One of the features of the Bug was how it measured the distance it traveled. A counter was designed to number the revolutions of the DePalma engine. Before launch, technicians computed the distance to be traveled, as well as wind direction and speed. The correct number of revolutions at a preset speed to cover the distance was calculated. In flight, when the counter reached the set number of revolutions it engaged a cam, which cut off fuel to the engine, and also operated a device to detach the wings. Without power or the means to glide, the Bug plummeted to the ground.

14. Despite the failures development on the Bug continued

Upon learning of the semi-successful flight of the Bud, General Squier sent a report to the Army’s Chief of Staff, evidently the first acknowledgment of the project’s existence. On October 22, another test of the aircraft was conducted. That time the Bug achieved its programmed altitude, flew its programmed distance, and descended on its preselected target. An ecstatic Squier so informed his superiors, and with their approval dispatched Hap Arnold to Europe to brief General John J. Pershing. The latter was the commander of the American Expeditionary Force in Europe. He was at the time planning a major offensive for the spring of 1919, and Squier wanted him to be aware of the availability of the new weapon and its potential use.

Arnold was stricken with the Spanish Flu during his journey to Europe, and Pershing was not informed of the existence of the Bug until after the armistice was declared on November 11, 1918. When he was informed of the Bug’s existence he was impressed, and supported further development of the weapon for use in future wars. Great Britain’s military leaders were also briefed on the device and requested an opportunity to have a representative inspect the weapon. The US Army declined, having not yet accepted the Bug as a deliverable. The weapon was not yet in full production, and testing and evaluation continued. The Army Air Service wanted the weapon, though senior officers of the infantry and artillery opposed its acquisition.

15. The Kettering Bug continued to be built and wrecked during flight testing

Through the rest of October and into November Kettering and his team built and flew Bugs in a test and evaluation program, assisted by Army personnel. On November 11, the war in Europe ended. All testing of the Bug was immediately halted. Construction of new Bugs was also stopped. Existing planes and components were gathered at McCook Field, and all design drawings, research papers, reports, subcontracts, and remaining bills and expense accounts were prepared for delivery to Washington. In late November General Squier requested Kettering and Orville Wright come to Washington for a meeting with the Secretary of War.

Secretary of War Newton Baker needed to advise the President, Woodrow Wilson, on weapons and potential weapons which were subject to discussion at the upcoming peace conference. Wilson intended to recommend all nations impose a ban on some of the weapons introduced during the war, which included submarines and gas weapons. Baker had been briefed on the aerial bomb, and its potential destructive power. Though the Bug was still a secret program, he made several oblique references to its existence in public speeches, calling it one of the most “destructive” weapons yet devised by the military for use in war.

16. The Army continued to evaluate the Bug after the war

When World War I ended in November, about two dozen completed Bugs were on hand, with sufficient parts available to assemble several more. Though several tests had been completed, only one had generated results in which all components of the aircraft performed as designed. The Army decided to use the remaining Bugs for further evaluation of the concept and its potential. Officially the existence of the aircraft – indeed the entire project – was still secret. Unofficially it was known throughout the army that the weapon had been developed, and its use was the subject of debate among professional officers.

In the Dayton community, it was also the subject of rumor and conjecture. The crash in the farmer’s field near Xenia was the source of much speculation among the community. Kettering was also ready to wash his hands of the whole project, since the end of the war meant the large profits anticipated from supplying completed Bugs to the Army would not materialize. Without Kettering’s involvement, there was no longer the need to perform the testing in Dayton, and more rural sites were considered to complete the program. While they were sought, four Bugs were sent to the Navy’s test site at Amityville, New York.

17. The Bug was the Army’s first black program

The plan to rapidly develop and deploy a new type of weapon, designed and built jointly and in secrecy between a small Army team and civilian engineers and scientists, can rightly be called America’s first black program. It remained classified after the war, but the Bug’s existence was known to a greatly expanded community. Army personnel were assigned to the program, assisted by engineers and technicians from Dayton. Kettering’s lack of interest in continuing the project was discouraging to the Army proponents of the Bug, but Midgley remained with the program, the only engineer who fully understood the sensitive flight control system.

Engine problems continued, mostly based on lack of quality control when the engines were built at DePalma. Ford assembly line construction likely would have resolved the engine problems, but the Army had no reason to order a large quantity of Bugs, thereby justifying Ford’s involvement. Ford could deliver the engine at significant cost savings per unit, but it was not to be. The Bugs flew four times at Amityville. Three of the flights were failures, and only one was deemed to be a partial success. Problems with the launching rail, engine control, and flight control haunted the Bugs, and the Army canceled further testing at Amityville. Further tests, if any, were determined to be better conducted away from the inquisitive eyes of the Navy, with whom the Army competed for post-war budgets.

18. There was another Colonel Arnold involved in the Bug program

Besides Colonel Hap Arnold, who commanded the US Army Air Corps during World War II, there was another Colonel Arnold in the Bug program, Lt. Col. Bion Arnold. Bion Arnold was an engineer with a career building urban transit systems when the Army called him to duty in World War One. Arnold specialized in the electrification of urban and interurban railways, and was experienced working with both contractors and government bureaucracies, which he brought with him to the Bug project. His role in the development phase was what in later times be considered a program manager, and he was actively involved with developers, manufacturers, and the Army as an eventual customer.

Following the November Armistice, Arnold asked for quick release from the Army, eager to return to his lucrative career. The Army accommodated him in December, 1918. With Arnold gone, and with Kettering no longer particularly interested in the Bug as a potentially profitable pursuit, the program all but collapsed. A dozen or so Bugs remained, and there were parts scavenged from failed flights which were usable. A decision was made within the Army’s hierarchy to use the remaining Bugs for test flights, since they had been bought and paid for with taxpayer money. A remote location was considered ideal, keeping the project secret.

19. Several test sites had already been considered in the South

Following the Xenia crash and the publicity which had been attendant with it, the Army searched for more remote test locations. The end of the war meant the end of urgency in developing the Bug, and concerns over security became less pressing. Colonel Bion Arnold left the program and the Army. The Bugs sat in Dayton, with little to nothing being done on them, even after the test flights and failures at Amityville. A small Army contingent remained involved in the program, and Midgley offered it his continued support, but Kettering soon had him involved in other projects at Delco. Orville Wright’s involvement with the program was over. Elmer Sperry concentrated his efforts on Navy projects.

The Army decided to disassemble and create a dozen or so Bugs, along with spare parts and other components, ship them to Carlstrom Field in Florida, and continue testing the concept there. Carlstrom was remote, located in terrain which was mostly level. Construction of the launch rail system there promised to be simple. There were also sufficient aircraft there for the Bug to be pursued in flight, if necessary. In late summer of 1919, members of the team, including Midgley, and Army personnel assigned to the project relocated to Carlstrom Field. One of the Army pilots who would observe some tests was a flight instructor by the name of Jimmy Doolittle.

20. The launch rail was problematic in Florida

In September, 1919, the remaining Kettering Bugs arrived in Florida and preparations to evaluate their performance began. The launch rail was assembled in a remote area of Carlstrom Field. Midgley was on hand to coax an improved performance from the problematic flight control system. By then nearly a year had gone by since the only fully successful flight of the Kettering Bug, and that flight had only been for a few hundred feet near Dayton. Early attempts to launch the Bug in Florida failed. The launch rail failed to generate enough speed to allow the Bug to generate enough lift to become airborne. Materials were scavenged from the damaged Bugs to attempt to reuse them as much as possible.

Orville Wright had devised the launch rail. He and his brother Wilbur had used a similar system when evaluating the Wright Flyers at Huffman Prairie. It consisted of a tower erected perpendicular to the rail on which the Bug sat. A cable was connected to the Bug, ran along the rail and then back toward the tower, where it was connected to a counterweight at the top. When the weight was dropped the Bug, its engine running at a preset speed was pulled along the rail by the cable until the latter was dropped and the aircraft lifted into the air. Several failures resulted in wrecked Bugs. The launch system was discarded in favor of a sled in which the Bug would travel under its own power over rails. Other problems were encountered, chiefly with the DePalma Engines. Results were discouraging, but the team persisted in its attempts as the number of available Kettering Bugs dwindled.

21. Development continued in late 1919

By the end of October, the only Kettering Bugs remaining were assembled from parts scavenged from the wrecks of previous tests. That in itself wasn’t indicative of complete failure, since the Bug was designed to crash at the end of its flight. Successful controlled and level flight for a distance beyond several hundred feet remained elusive. Problems with the engines were predominant; springs broke, there were problems with carburetion, excessive vibration, and other issues generally attributed to what was then called workmanship. On a later day, it would be called quality control. Problems remained in the flight control system as well.

Army mechanics tinkered with the remaining engines, adjusting settings and when necessary machining new parts on-site. Propeller pitch was adjusted. Midgley and his assistants continued to make minute adjustments to the flight control system, noting that once the proper settings were achieved, they would be standard for every flight. The only modification required of technicians who launched the Kettering Bug in combat conditions would be to the range – the number of engine revolutions necessary to reach the target. By late October Midgley found the desired setup of the flight control system and had fine-tuned its performance in the air. Launch rail flaws were resolved. The engine was ready, and so was the tired team of developers.

22. The Kettering Bug flew successfully on October 28, 1919

On October 28, the last remaining Kettering Bug was placed on its sled on the launch rails. It had been built from the parts left over from the failures of its predecessors. The rev counter was set for the desired distance of the flight. The engine was started, revved to the correct speed and the Bug shuttled down the rails. A moment later it was aloft. The technicians watched it climb to its assigned altitude, level off, and head into the distance on a straight line in the direction of its target. The aircraft flew in a line for just over 16 miles, maintaining its settings. Then the rev count was reached. The cam rolled as designed, the fuel supply was cut off, and the engine died.

As its engine sputtered to a halt the Bug’s wings were released, folding backward, and the fuselage began its dive to the ground. It crashed more or less, upon its intended target, well within the designed margin of error. In other words, it was a complete and unqualified success. No remaining Kettering Bugs were available, and the Army had no intention of purchasing more, given the restricted budgets of peacetime and the general demobilization still underway at the time. It had been the best performance yet achieved by the Kettering Bug in flight. It was also the last. The idea remained alive in the minds of many involved in its development.

23. Lieutenant Doolittle argued for further development using radio control

The Army’s final report on the test and evaluation of the Kettering Bug was written by James Doolittle, eight years after testing halted. The report contained several recommendations which stressed the desirability of continuing research into unmanned flying vehicles, using radio signals to control the flight from the ground. Doolittle rose to prominence in the Army Air Service and in the public mind between the World Wars. He set several flying records, earned the first Ph.D. in Aeronautics (Massachusetts Institute of Technology) ever awarded in the United States, and rose to the rank of Lt. Colonel before leading the famous Doolittle Raid. His recommendations for the Kettering Bug were lost in the Army’s bureaucratic maze.

Charles Kettering recommended a revised version of the Bug in 1939. The Army Air Corps and General Hap Arnold expressed interest, and several test versions were built by General Motors in the days leading up to World War II. It was capable of delivering a 500-pound bomb to a target and was flown by radio control, but its range was limited to 400 miles. In 1942 General Arnold canceled the program. By then he was forced to operate bombing missions from bases in England, and the limited range of the GM flying bomb was of no service. He did note that the Germans could make use of such a device, using bases in Belgium and France to launch raids against Great Britain.

24. Germans launched unmanned flying bombs 1944

On June 13, 1944, the Germans sent unmanned aerial vehicles on bombing missions to London. The vehicle was launched from a rail system. It was not guided by radio, instead, it relied on a flight control system which was based on gyrocompass-controlled servo-motors. Contrary to popular belief, it did not fly until it ran out of fuel. It flew a specified distance, measured by the means of an odometer. A vane-driven anemometer measured wind speed, drove the odometer, which subtracted revolutions from a preset count until it reached zero. When it did it sent signals which cut off the fuel supply and altered the control surfaces, pushing the weapon into a dive.

The V-1, the first of Hitler’s “Vengeance Weapons” borrowed many of its features from the Kettering Bug, which preceded it by more than two decades. Hitler’s weapon was powered by a pulse jet, rather than a two-stroke engine, and it carried considerably more explosives than its wood and fabric predecessor. The two unmanned aerial vehicles shared many basic functions, which included gyrocompass control and rev counters for distance measurements. As Hap Arnold predicted, the Germans launched them from the northern European coast at British targets. The British citizens they victimized gave them several names, one of which was “Doodlebugs”.

Where do we find this stuff? Here are our sources:

“Case Files: Charles F. Kettering”. Article, The Franklin Institute Awards. Online

“Case Files: Elmer A. Sperry (Gyroscopic Compass)”. Article, The Franklin Institute Awards. Online

“An Early Pilotless Aircraft”. Norman Polmar, Naval History Magazine. August, 2019

“From the Barn Gang to Industrial Empires”. Article, Engineers Club of Dayton. Online

“George Owen Squier: US Army Major General, Inventor”. Paul W. Clark, Laurence A. Lyons. 2014

“Ford’s Forgotten Aviation Legacy”. C.V. Glines, Aviation History Magazine. May, 2008

“DePalma, V-4 engine”. Article, National Air and Space Museum. Online

“Kettering Aerial Torpedo ‘Bug'”. Article, National Museum of the United States Air Force. Online

“Biographical Memoir of Thomas Midgley Jr.” Charles F. Kettering. 1947. Online

“Global Mission”. Henry A. “Hap” Arnold. 1949

“The Army and its Air Corps: Army Policy Toward Aviation 1919-1941”. James P. Tate. 1998

“Unmanned Drones Have Been Around Since World War I”. Jimmy Stamp, Smithsonian.com. February 12, 2013

“Spotlight on the Dayton-Wright Airplane Company”. Lisa Rickey, Out of the Box, Wright State University Libraries. May 30, 2014

“Unmanned Systems of World Wars I and II”. H. R. Everett. 2015

“General James Harold Doolittle”, Biography, United States Air Force. Online

“Case Files” Orville Wright (Cresson Medal)”. The Franklin Institute Awards. Online

“Twenty-Five Years Ahead of its Time: The American Aerial Torpedo in World War I”. Michael H. Taint, Ohio Academy of History. Online