UAV (Drones) Inquiry Unit
The United States was not the only nation to employ aerial balloons for reconnaissance. Even after airplanes were in use during World War I, all participating nations used reconnaissance balloons. These hydrogen-filled balloons were not free-flying like the Goodyear Blimp, but were tethered by long ropes to a drum on a large truck that could reel in the balloon after the observers on board were finished, or in case they saw that they were going to be attacked.
