TheHoppi-Copter was a functionalbackpack helicopter developed by the American companyHoppi-Copters Inc. founded byHorace T. Pentecost in the 1940s.[1] The original Hoppi-Copter consisted of twocontra-rotating rotors on a pole attached to a motorized backpack.[2] Although it was capable of flight, it was extremely hard to control.[3]
Later prototypes of the Hoppi-Copter included versions with the pilot in a sitting position, and were in effect miniature one-man helicopters of a more conventional design, though retaining the contra-rotating rotors and thus obviating atail rotor.[1][4] Despite interest from the BritishMinistry of Supply in the 102 and 104 models,[5] none were adopted commercially.[3]
