Dedicated in loving memory to my mother, Dorothy M. Segal, for her service to the Navy Department, Bureau of Aeronautics, Naval Air Experimental Engineering Command, in Philadelphia, Pa., as a civilian during World War II. Her work involved assisting in the preparation of confidential reports on radar, loran and sonar.

INTRODUCTION
Unmanned aerial vehicles (UAVs) have been known by a variety of names – drones, robot planes, pilotless aircraft, remotely piloted vehicles (RPVs) and remotely piloted aircraft (RPA).[1]

HISTORY
Early unmanned aerial vehicles took the form of balloons.[2] During the American Civil War (1861-1865) an unmanned balloon carried a basket of explosives. The explosives could be dropped after a time-delay fuse mechanism triggered the basket to overturn its contents. The balloons were not successful because it was difficult to estimate how long to set the fuse due to air currents and weather conditions.[3]

WWI
Around the time the United States was becoming involved in WWI, a group of individuals teamed to provide the Navy with its first unmanned aircraft — the aerial torpedo. This team was comprised of Elmer Sperry, inventor of the gyroscope, and Dr. Peter Cooper Hewitt, who was known for his work in radio. Both were appointed members of the Aeronautical Committee of the Naval Consulting Board, which was established by Secretary of the Navy, Josephus Daniels. Thomas A. Edison advised Daniels on scientific and technical matters. Carl Norden, developer of the Norden bombsight of WWII, also joined the team. Glenn Curtiss, inventor of the flying boat, delivered an airframe designed to carry 1,000 pounds of ordnance a distance of 50 miles at 90 mph. A successful demonstration of the Navy’s aerial torpedo was conducted.

Rear Adm. Ralph Earle suggested the aerial torpedo could be carried on ships stationed offshore from German submarine bases and defeat the U-boat threat.

In 1918 the Curtiss-Sperry aerial torpedo made its longest successful flight, flying a distance of 1,000 yards. Also in 1918, the pilotless N-9 aircraft was successfully launched but it failed to land on the target at the range of 14,500 yards and crashed at sea. Additional tests were conducted. However, on November 11, 1918, the Armistice was signed and the aerial torpedo never saw wartime service and further development was canceled.

Between the Wars
In September 1924, for the first time in history, a radiocontrolled Curtiss F5L was flown remotely through all phases of flight – takeoff, maneuver and landing.[4] A similarly modified Curtiss N-9H Navy seaplane remained aloft for about . . .