hundred-mile-an-hour tape n. a narrow roll of strong plastic, acrylic, or woven fiber backed with a strong adhesive; duct tape. Also two-hundred-mile-an-hour tape. Editorial Note: Duct tape is just one kind of adhesive tape that is called “hundred-mile-an-hour tape.” (source: Double-Tongued Dictionary)
It was called “hundred-mile-an-hour tape” initially by American helicopter crewmen during the Vietnam War, then the expression spread to other service members. The variety issued by the Army was medium green in color and two inches wide, and could be used on a helicopter to cover fuselage holes or hold down loose items (cables, equipment, torn metal, etc.) in flight. Like civilian duct tape, it was used for many other things as well, e.g. reinforcing book bindings or holding two M-16 magazines together so you could just flip the pair over to reload.