“The Devil’s Hovercraft”
Another United States Army “invention” from the 1950s that should have been destroyed when it was first proposed for consideration in the design process. The Devil’s Hoverbike was designed to function as a one-person helicopter, allowing the operator to “hover” while on missions.
The most serious issue was that the rotator blades were located right beneath the user! For whoever was piloting the device, one minor blunder meant the end of the line. Someone found it out eventually and presumably said something like, “Hey, that’s probably not a smart idea.”