Backpack helicopter
A backpack helicopter is a helicopter motor and rotor and controls assembly that can be strapped to a person's back, so that he can walk about on the ground wearing it, and can use it to fly. Its harness, like a parachute harness, should have a strap between the legs, so that the pilot does not fall out of the harness during flight.
Typically a backpack helicopter differs from a conventional helicopter in two ways. Firstly there is no tail rotor, and the main rotors are contra-rotating. Yaw is controlled by fine adjustment of a differential gear in the rotor drive transmission. When one rotor is adjusted to spin slightly faster than the other it induces yaw, or turning motion. Secondly, the rotors are fixed pitch, which assists with simplicity, however this means that in the event of engine failure autorotation is impossible. Usually a Ballistic parachute would be incorporated for safety.
Some designs may use ducted fan design to increase upward thrust.
Related are devices like a backpack helicopter which also include a seat and leg supports and are actually very small open-topped ordinary helicopters.
Several inventors have tried to make backpack helicopters, with mixed results.
In theory, a helicopter would be more efficient than a rocket/jet pack, possessing a greater specific impulse, and being more suited to hovering due to the smaller velocities of the propelled gases.
Examples
Pure backpacks
- http://english.pravda.ru/main/2002/06/11/30172.html describes a Russian backpack helicopter.
- The Heliofly was a make which was designed in Germany in 1941 onwards. See [1] and [2].
- Pentecost HX-1 Hoppi-Copter and here: Pentecost Hoppicopter
- Rhyme (made in Japan)
- Tecnologia Aeroespacial Mexicana (TAM): called Libelula (after the Libellula genus of dragonfly), with a 2-bladed rotor driven by a small rocket motor at the end of each rotor blade. Info. (They also make a jetpack.)
With a seat
- SoloTrek XFV (Exo-skeletal Flying Vehicle).
- See http://www.vortechonline.com for various models which have seats. They formerly also made a pure backpack model with two very long rotor blades driven by a little propane-powered jet motor at the end of each blade.
- GenH4
- The Aerospace Corporation's Springtail [3]
Pilot strapped on; too big to be a backpack
- Martin Jetpack, which, despite its name, is a small helicopter-like device, with two ducted fans that provide lift, powered by a gasoline-powered V-4 piston engine.
In popular culture
Backpack helicopters occur sometimes in fiction. All real backpack helicopters are flown with its pilot's body vertical, but there are some in fiction (for example, in Dan Dare comics and the video game H.E.R.O.) which are flown with its pilot's body horizontal.
Inspector Gadget used the "Gadget 'Copter" which opened a helicopter from his hat.
Backpack helicopters are considered to be relatively popular gadget. The Martin Jetpack (which is not a jetpack, despite its name) has appeared in spy films such as the 2003 film Agent Cody Banks.
Toy versions & Video Games
Another vertical example is the Turbo-Copter unit for the popular Action Man toy figure.
H.E.R.O. Helicopter Emergency Rescue Operation for the Commodore 64 programmed by John Van Ryzin and released in 1984 by Activision.
A motorised back-pack helicopter accessory was released as part of the GI Joe toyline for any figure to use.
The Annihilator figure had a helicopter back-pack as part of its accessories.