Examples of unmanned air vehicles
Between August and November of 1903, Karl Jatho demonstrated a gasoline-fueled pilot-less biplane that covered a distance of 196 feet at a height of 11 feet near Hannover, Germany. 
In 1917, Dr. Peter Cooper and Elmer A. Sperry invented the automatic gyroscopic stabilizer, which helps to keep an aircraft flying straight and level. Cooper and Sperry used their technological breakthrough to convert a U.S. Navy Curtiss N-9 trainer aircraft into the first radio-controlled UAV. The Sperry Aerial Torpedo flew 50 miles carrying a 300-pound bomb in several test flights, but it never saw combat. 
Made of wood and canvas for $400 each, the "Kettering Bug" was a small biplane equipped to carry a bomb load equal to its own weight—300 pounds. Charles F. Kettering of General Motors designed the Bug to take off from a wheeled trolley and then detach its wings, allowing its fuselage to dive vertically towards a pre-programmed target. The U.S. military ordered large quantities of the Bug during the last months of World War I, but when the war ended the orders were cancelled. 
The Queen Bee (UK), the first returnable and reusable UAV, was designed for use as an aerial target during training missions. The spruce-and-plywood biplanes first flew in 1935 and bore wheels or floats. The Queen Bee was radio-controlled and could fly as high as 17,000 feet and travel a maximum distance of 300 miles at over 100 mph. A total of 380 Queen Bees served as target drones in the Royal Air Force and the Royal Navy until they were retired in 1947. 
In 1939, Englishman and Hollywood actor Reginald Denny formed Radioplane Company (Northrop / Grumman today) Denny used a team of engineers and radio experts from Lockheed Company, and developed a large, remote-controlled airplane called OQ Targets. The U.S. Air Force ordered thousands of OQ drones, which took off via a large slingshot and landed with the aid of a 24-foot parachute. The U.S. Army and Navy used OQ Targets, which cost about $600 each, to train a whole generation of anti-aircraft gunners.
