Hoppi-Copter
| Hoppi-Copter | |
|---|---|
| Pentecost HX-1 Hoppi-Copter on display at Pima Air & Space Museum, in Arizona, U.S. | |
| Role | Backpack helicopter | 
| National origin | United States | 
| Manufacturer | Hoppi-Copters Inc. | 
| First flight | c. 1940 | 
The Hoppi-Copter was a functional backpack helicopter developed by the American company Hoppi-Copters Inc. founded by Horace T. Pentecost in the 1940s.[1] The original Hoppi-Copter consisted of two contra-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 a tail rotor.[1][4] Despite interest from the British Ministry of Supply in the 102 and 104 models,[5] none were adopted commercially.[3]
Variants
- Pentecost HX-1 Hoppi-Copter (Hoppi-Copter 100)
 - original back-pack version.
 - Hoppi-Copter 101
 - equipped with a seat and landing gear, proved that more development was necessary.[6]
 - Hoppi-Copter 102
 - framed, with seat for pilot.[4]
 - Hoppi-Copter 103
 - as the 102, but lighter with a more powerful engine and slightly greater rotor diameter
 - Hoppi-Copter 104
 - as the 103, with even greater rotor diameter[5]
 - Hoppi-Copter Firefly
 
Specifications (Hoppi-Copter 102)
Data from Jane's All the World's Aircraft 1948[4]
General characteristics
- Crew: One
 - Empty weight: 173 lb (78 kg)
 - Gross weight: 363 lb (165 kg)
 - Powerplant: 1 × Unknown 750 cm3 (46 cu in) two stroke flat twin, 35 hp (26 kW) at 4,500 rpm; 9.1:1 reduction gearing to rotors
 - Main rotor diameter: 2 × 16 ft (4.9 m)
 - Main rotor area: 402 sq ft (37.3 m2) total
 
Performance
- Maximum speed: 96 mph (154 km/h, 83 kn) all performance figures estimated
 - Endurance: 1 hr at cruising speed
 - Service ceiling: 12,000 ft (3,700 m) hover
 - Disk loading: 1.8 lb/sq ft (8.8 kg/m2)
 
See also
References
- ^ a b "The Hoppi-Copter" (PDF). Flight. October 14, 1948. Retrieved January 7, 2016.
 - ^ Pentecost, Horace T. (17 Oct 1945), US2461347 A, Helicopter adapted to be attached to a pilot, retrieved 2016-01-07
 - ^ a b "Pentecost HX-1 (Model 100) Hoppi-Copter". Smithsonian National Air and Space Museum. Retrieved 2016-01-07.
 - ^ a b c Bridgman, Leonard (1948). Jane's All the World's Aircraft 1948. London: Sampson, Low, Marston and Co. Ltd. p. 271c.
 - ^ a b Bridgman, Leonard (1949). Jane's All the World's Aircraft 1949. London: Samson, Low, Marston and Co. Ltd. p. 234c.
 - ^ Bridgman, Leonard (1951). Jane's All the World's Aircraft 1951. London: Samson, Low, Marston and Co. Ltd. p. 248c.