Development of Drones During WWI and WWII

It was in the mid-19th century that the first UAV was deployed in combat. That distinction belongs to the Austrians, who in 1849 bombed Venice, Italy, using explosive-laden balloons. Unsurprisingly, they weren’t very effective—many of them even blew back toward Austria due to wind.

Before long, engineers were looking at a new application for UAVs: aerial photography.

The first surveillance drones didn’t emerge until the Vietnam War. But in 1858, French photographer Nadar was credited with taking the first photos from a balloon. A few decades later, William Abner Eddy took photos from a flying kite, some of which survived. And around the same time, Alfred Nobel was thought to have taken photos from a “rocket camera,” though the history is disputed.

Yet all of these aircraft had a big problem: They were difficult or impossible to control. Nikola Tesla began laying the foundation for radio-controlled vehicles with his “robot-boat” in 1898. A technological marvel for its time, Tesla reportedly fooled a crowd at New York City’s Madison Square Garden into thinking they could control the vehicle by shouting.

Tesla never built a remote-control system for flight. But leading up to WWI, Britain’s Royal Aircraft Factory recognized the potential for radio-guided combat aircraft—and got to work.

WWI and the 1st UAV

The task of developing a radio-controlled airplane was left up to A.M. Low, an English engineer, physicist, and inventor commissioned by Britain’s Royal Flying Corps in 1914, just more than a decade after the Wright Brothers’ first flight.

Considered by some to be “the father of radio guidance systems,” Low in 1916 developed a design called the Aerial Target (AT) that laid the foundation for drones as we know them today. The following year, a monoplane made by Geoffrey de Havilland—who would go on to found the aircraft manufacturer sharing his last name—became the first AT model to fly under radio control. It was considered the first UAV flight.

While working on AT, Low survived two assassination attempts by the Germans, who saw the danger in his invention. The British military, however, eventually scrapped the program. Low later developed remote-controlled boats to counter submarines, though they were never deployed in war.

The U.S. also took notice of Low. In 1917, at the behest of scientist-inventors Peter Hewitt and Elmer Sperry, the Navy began developing the Hewitt-Sperry Automatic Airplane, or “Flying Bomb,” considered to be the earliest iteration of the modern cruise missile. It was made by attaching automatic control gear to the Curtiss N-9 seaplane and eventually, after failed tests, a custom Curtiss airframe.

Launched from a catapult—and later a car—and controlled through gyro-stabilization technology created by Sperry, the aircraft never saw battle. But the U.S. military now had UAVs on its mind.

Around the time the Flying Bomb was undergoing flight testing, the U.S. Army asked inventor and engineer Charles Kettering to design a “flying machine” that could hit targets from 40 miles away.

His design, the Kettering Aerial Torpedo—better known as the “Kettering Bug”—was groundbreaking despite never seeing combat. It was capable of carrying 180 pounds of explosives over 75 miles at a speed of 50 mph, making it an enigma of its time.

Using a guidance and control system developed by Sperry, the Bug was programmed to turn off its engine after a specified number of revolutions corresponding to the distance it needed to travel, improving its accuracy. That resulted in several successful flight tests in 1918, and the U.S. government would ultimately spend $275,000 (or about $4 million today) developing it.

The Bug and its predecessors ultimately never saw battle. But Kettering’s design and others would later inspire the UAVs deployed during WWII.

The Interwar Period

The Allies didn’t need drones to win World War I. But the early glimpses of UAV technology were too tantalizing to ignore, and the interwar period brought plenty of new innovations that have stuck around.

One is the quadcopter design, a common feature of modern drones. The first practical quadcopter design arrived in 1924, when French engineer Étienne Oehmichen flew his Oehmichen 2. Around the same time, George de Bothezat successfully flew a quadrotor helicopter for the U.S. Army.

But the bulk of UAV innovation at this time came from the British and American militaries.

Drawing upon Kettering’s Bug and Low’s radio-control technology, the British Royal Aircraft Establishment began building the Larynx autopilot cruise missile in 1925, conducting test flights between 1927 and 1929. Britain also developed the Fairey Queen, a radio-controlled target drone constructed from a Fairey IIIF floatplane, in 1931. Only three were ever flown.

But one British innovation from this period had staying power. In 1933, the country started building the DH.82B Queen Bee, a pilotless variant of de Havilland’s Tiger Moth biplane that revolutionized military target practice. The Queen Bee began flying remotely in 1935 and was in service with the Royal Air Force and Navy until 1947. Remarkably, it could fly as high as 17,000 feet and as fast as 100 mph, and it could be recovered after flight. More than 400 were built over a decade.

But perhaps the Queen Bee’s longest-lasting impact comes from its name. Historians believe that when the British demonstrated it for the U.S. military, officials began using the word drone—a term for worker bees—to refer to UAVs as a tip of the hat. But more importantly, Queen Bee is thought to have inspired the first American drone program.

U.S. experiments eventually produced the Curtiss N2C-2 antiaircraft target drone in 1937. Controlled remotely from a TG-2 “mothership,” the N2C-2 entered Navy service in 1938, and the Air Force adopted the concept the following year. The technology was ideal for target practice, but the requirement of a mothership limited its range and applications.

The Queen Bee and N2C-2 were the first UAVs to see extensive military use. And they arrived just in time for World War II, when drones really started to take off.

WWII and the First Mass-Produced UAVs

A couple hundred Queen Bees and a few thousand N2C-2 variants flew as target drones during World War II. But the conflict, the largest the world had ever seen, triggered the proliferation of UAVs.

The first mass-produced drone emerged from an unlikely source: actor Reginald Denny, a successful Hollywood leading man who experimented with radio-controlled aviation in the 1930s. Throughout the decade, Denny’s Radioplane Co. demonstrated several target drones for the U.S. Army.

In 1940, Denny’s persistence won Radioplane an Army contract to mass-produce the Radioplane OQ-2 and its successor, the OQ-3. The company would go on to build an astounding 15,000 target drones for the Army during WWII, marking the beginning of heavy military drone use. And in 1941, a patent filed by engineer Edward M. Sorensen allowed the aircraft to complete the first beyond visual line of sight (BVLOS) flights.

If Britain was the driving force behind UAV innovation during WWI, it was the U.S. in WWII.

In 1942, the U.S. military developed an early assault drone, the Naval Aircraft Factory TDN-1, which did not see operation but is credited as the first drone to take off from an aircraft carrier. Shortly after, it devised the Interstate TDR-1 assault drone, which saw about a month of deployment in the Pacific Theater before being retired in 1944.

The U.S. also experimented with applying radio control to out-of-service aircraft. In 1944, Operation Aphrodite saw the Army Air Forces repurpose the Boeing B-17 Flying Fortress and Consolidated B-24 Liberator for remote flight. These designs were also the first UAVs equipped with cameras for first-person-view flights.

Despite flying 14 missions, Aphrodite was considered a failure. The drones were essentially torpedoes equipped with explosives, requiring the pilot to jump from the aircraft before impact. One mission led to the death of Joseph P. Kennedy, the older brother of John F. Kennedy.

However, the U.S. did find success with one of the earliest combat drones, the GB-1 glide bomb. Also known as the “grapefruit bomb,” the aircraft’s wings allowed it to glide farther than a torpedo, which allowed bombers to release it from outside enemy lines. More than 1,000 GB-1s flew during WWII in 1944 and 1945.

But ironically, a U.S. invention inspired the Germans to build the most devastating UAV of the time. Remember that old Kettering Bug? Well, the Germans certainly did, adapting the model into what would become the V-1 flying bomb, commonly known as the “doodlebug” or “buzz bomb.”

The V-1 is considered to be the first operational cruise missile, and it was unlike anything the world had ever seen. It was a true monstrosity of its time, capable of traveling more than 150 miles at speeds approaching 400 mph—not far off from modern passenger airliners.

At the height of the V-1’s deployment in 1944, Germany riddled London with bombs, launching more than 100 drones per day, before switching its sights to Belgium. The flying bomb was remarkably effective for its time, so much so that it inspired the British to produce some of the earliest counter-UAV technology.

Near the end of the war, the Germans also introduced the world’s first long-range guided ballistic missile, the V-2 rocket. Amazingly, the V-2 traveled close to the speed of sound, making it stealthier and even more dangerous than the V-1. More than 3,000 were launched between 1943 and 1945.

The vast majority of these aircraft were retired in the years after the war. But the damage was already done—the Germans had just provided the first glimpse into the power of combat drones, and there was no turning back.

Through decades of trial and error and the modern-day equivalent of billions of dollars, WWI and WWII produced most of the foundational concepts of drones as we know them today, from remote-control to BVLOS operations.

Source: Flying