A backpack helicopter is a

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

motor and

rotor Rotor may refer to: Science and technology Engineering *Rotor (electric), the non-stationary part of an alternator or electric motor, operating with a stationary element so called the stator * Helicopter rotor, the rotary wing(s) of a rotorcraft ...

and controls assembly that can be strapped to a person's back, so they can walk about on the ground wearing it, and can use it to fly. It uses a

harness A harness is a looped restraint or support. Specifically, it may refer to one of the following harness types: * Bondage harness * Child harness * Climbing harness * Dog harness * Pet harness * Five-point harness * Horse harness * Parrot harness * ...

like a

parachute A parachute is a device used to slow the motion of an object through an atmosphere by creating drag or, in a ram-air parachute, aerodynamic lift. A major application is to support people, for recreation or as a safety device for aviators, who ...

harness and should have a strap between the legs (so the pilot does not fall out of the harness during flight). Some designs may use a

ducted fan In aeronautics, a ducted fan is a thrust-generating mechanical fan or propeller mounted within a cylindrical duct or shroud. Other terms include ducted propeller or shrouded propeller. When used in vertical takeoff and landing (VTOL) applicatio ...

design to increase upward

thrust Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that syst ...

. Several inventors have tried to make backpack helicopters, with mixed results. Typically, a backpack helicopter differs from a conventional helicopter in two main ways: First, there is no tail rotor, and the main rotors are

contra-rotating Contra-rotating, also referred to as coaxial contra-rotating, is a technique whereby parts of a mechanism rotate in opposite directions about a common axis, usually to minimise the effect of torque. Examples include some aircraft propellers, res ...

. 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 (turning motion). Second, the rotors are fixed pitch, which assists with simplicity; this means, however, that in the event of engine failure

autorotation Autorotation is a state of flight in which the main rotor system of a helicopter or other rotary-wing aircraft turns by the action of air moving up through the rotor, as with an autogyro, rather than engine power driving the rotor. Bensen, Igor ...

is impossible. Usually, a

ballistic parachute A ballistic parachute, ballistic reserve parachute, or emergency ballistic reserve parachute, is a parachute ejected from its casing by a small explosion, much like that used in an ejection seat. The advantage of the ballistic parachute over a co ...

would be incorporated for safety. An edition of ''

Popular Science ''Popular Science'' (also known as ''PopSci'') is an American digital magazine carrying popular science content, which refers to articles for the general reader on science and technology subjects. ''Popular Science'' has won over 58 awards, incl ...

'' magazine in 1969 featured a backpack helicopter that used small jet engines in a

tip jet A tip jet is a jet nozzle at the tip of some helicopter rotor blades, used to spin the rotor, much like a Catherine wheel firework. Tip jets replace the normal shaft drive and have the advantage of placing no torque on the airframe, thus not r ...

configuration instead of

rotors. This design could function in autorotation. Related are devices like a backpack helicopter which also include a seat and leg supports, which are small, open-topped helicopters. In theory, a helicopter would be more efficient than a rocket-powered

jetpack A jet pack, rocket belt, or rocket pack is a device worn on the back which uses jets of gas or liquid to propel the wearer through the air. The concept has been present in science fiction for almost a century and became widespread in the 1960s. ...

, possessing a greater

specific impulse Specific impulse (usually abbreviated ) is a measure of how efficiently a reaction mass engine (a rocket using propellant or a jet engine using fuel) creates thrust. For engines whose reaction mass is only the fuel they carry, specific impulse i ...

, and being more suited to hovering, due to the lower velocities of the propelled gases. Australian electric company CopterPack had developed "an electric backpack helicopter with a self-levelling autopilot", and released test videos in June 2021. However, the device consists of two rotors with diameters around connected via

carbon fiber Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon compo ...

tubes to a backpack with battery packs, and a pair of armrests with hand controls on them. Later video analysis revealed operator and equipment were at the end of a drop cable that was edited out using post-production software.

Examples

Pure backpacks

* The Heliofly was a make which was designed in

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

in 1941 onwards. * The Pentecost HX-1 Hoppi-Copter was developed by Horace T. Pentecost, an independent inventor and demonstrated to the military in 1945. * Rhyme (made in Japan) * The Libelula ("dragonfly") from Tecnologia Aeroespacial Mexicana has a 2-bladed rotor driven by a small rocket motor at the end of each rotor blade. The company also manufactures a

With a seat

SoloTrek XFV The SoloTrek XFV (Exo-skeletal Flying Vehicle) was a single-person VTOL aircraft. It was first flown in December 2001 by Millennium Jet Inc, a private company run by Michael Moshier. Millennium Jet subsequently changed its name to Trek Aerospac ...

(Exo-skeletal Flying Vehicle). *

Martin Jetpack The Martin Jetpack was a single-person aircraft under development. Despite its name, it did not use a jet pack as such, but ducted fans for lift. Martin Aircraft Company of New Zealand (not related to Glenn L. Martin Company, the US company als ...

* Vortech designed 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 * Trek Aerospace's Springtail

References

{{Emerging technologies, transport=yes Aircraft configurations Helicopters Ultralight aircraft Emerging technologies

Examples

Pure backpacks

With a seat

See also

References