Pentecost E-III Hoppicopter
The Hoppicopter is a part of the long quest for a truly low-cost personal flying machine. It was designed by Horace Pentecost of Seattle, Washington during World War II. He marketed it to the U.S. military as a replacement for the parachutes used by paratroops. The design consists of a small 20 horsepower motor powering two counter-rotating sets of rotor blades, strapped to the back of the pilot. The greatest weakness of the design was its use of the pilot’s legs as landing gear. If he stumbled during landing or take-off the blades would quickly turn into thousands of potentially lethal splinters as they pounded themselves to bits on the ground. This was, quite correctly, seen as ridiculously hazardous and the idea was quickly abandoned.

Rotor Diameter12 ft
Weight88 lbs
EngineOne 2-cylinder piston engine with 20 horsepower
Crew1
ManufacturerPentecost
MarkingsHorace Pentecost, 1945
DesignationE-III
Serial Number1