View source for Engineering:Backpack helicopter

{{short description|Helicopter system designed to be worn on a person's back}}
[[Image:Pentecost Backpack Helicopter.JPG|thumb|right|The Pentecost HX-1 Hoppi-Copter, a functional backpack helicopter]]

A '''backpack helicopter''' is a [[Engineering:Helicopter|helicopter]] motor and [[Engineering:Helicopter rotor|rotor]] 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 [[Engineering:Safety harness|harness]] like a [[Engineering:Parachute|parachute]] 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 [[Engineering:Ducted fan|ducted fan]] design to increase upward [[Thrust|thrust]]. 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 [[Engineering:Contra-rotating|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 (turning motion).

Second, the rotors are fixed pitch, which assists with simplicity; this means, however, that in the event of engine failure autorotation is impossible. Usually, a [[Engineering:Ballistic parachute|ballistic parachute]] would be incorporated for safety.

An edition of ''Popular Science'' magazine in 1969 featured a backpack helicopter that used small jet engines in a [[Engineering:Tip jet|tip jet]] configuration instead of [[Engineering:Contra-rotating|contra-rotating]] 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, possessing a greater [[Physics:Specific impulse|specific impulse]], 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",<ref>{{cite web |url=https://copterpack.com.au/ |title=About CopterPack |website=copterpack.com }}</ref> and released test videos in June 2021.<ref>{{cite web |url=https://futurism.com/the-byte/copterpack-helicopter-backpack |title=Watch a Man Soar Into the Sky With a Helicopter Backpack |website=Futurism |date=2 June 2021 }}</ref> However, the device consists of two rotors with diameters around {{convert|3|ft}} connected via carbon fiber tubes to a backpack with battery packs, and a pair of armrests with hand controls on them.<ref>{{cite web |url=https://newatlas.com/aircraft/copterpack-electric-jetpack/ |title=Aussie electric Copterpack makes sensational first manned flight |website=New Atlas |date=6 June 2021 }}</ref> Later video analysis revealed operator and equipment were at the end of a drop cable that was edited out using post-production software. <ref>{{cite web |url=https://newatlas.com/aircraft/copterpack-fake-video/ |title=Internet sleuths find evidence of Copterpack video tampering |website=New Atlas |date=8 June 2021 }}</ref>

==Examples==
[[Image:Aa helibackpack.jpg|thumb|right|A possible design for a helibackpack with contra-rotating twin rotors]]

===Pure backpacks===
* The Heliofly was a make which was designed in {{wipe|Germany}} in 1941 onwards.<ref>{{cite web|url=http://www.geocities.com/unicraftmodels/germ/heliofly/heliofly.htm |title=Heliofly |publisher=Geocities.com |access-date=2009-07-26|archive-url=https://web.archive.org/web/20091022171438/http://geocities.com/unicraftmodels/germ/heliofly/heliofly.htm|archive-date=2009-10-22}}</ref>
* The Pentecost HX-1 Hoppi-Copter was developed by Horace T. Pentecost, an independent inventor and demonstrated to the military in 1945.<ref>{{cite web|url=http://www.pimaair.org/collection-detail.php?cid=220&pn=1 |title=Pima Air Museum - Pentecost Hoppicopter |publisher=Pimaair.org |access-date=2013-06-18}}</ref>
* Rhyme (made in Japan)<ref>{{cite web|url=http://www.rhyme-japan.com/ |title=RHYME Strap-on Helicopter |publisher=Web.archive.org |access-date=2013-06-18 |url-status=dead |archive-url=https://web.archive.org/web/20090328115907/http://www.rhyme-japan.com/ |archive-date=March 28, 2009 }}</ref>
* 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.<ref>{{cite web |author=Juan Manuel Lozano Gallegos |url=http://www.tecaeromex.com/ingles/libe-i.htm |title=Backpack helicopter from Tecnología Aeroespacial Mexicana |publisher=Tecaeromex.com |access-date=2013-06-18 |archive-date=2009-11-28 |archive-url=https://web.archive.org/web/20091128084726/http://www.tecaeromex.com/ingles/libe-i.htm |url-status=dead }}</ref><ref>{{cite web |author=Juan Manuel Lozano Gallegos |url=http://www.tecaeromex.com/ingles/RH-i.htm |title=Rocket Helicopter Tecnología Aeroespacial Mexicana |publisher=Tecaeromex.com |date=1954-05-13 |access-date=2013-06-18 |archive-date=2006-03-11 |archive-url=https://web.archive.org/web/20060311024606/http://www.tecaeromex.com/ingles/RH-i.htm |url-status=dead }}</ref> The company also manufactures a jetpack.

===With a seat===
* [[Engineering:SoloTrek XFV|SoloTrek XFV]] (Exo-skeletal Flying Vehicle).
* Martin Jetpack
* Vortech designed various models which have seats.<ref>{{cite web|url=http://www.vortechonline.com |title=Aircraft and Jet books and videos |publisher=Vortechonline.com |access-date=2009-07-26| archive-url= https://web.archive.org/web/20090627090547/http://www.vortechonline.com/| archive-date= 27 June 2009 | url-status= live}}</ref> 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<ref>[http://www.ultralightflyer.com/genH4/index.htm ] {{webarchive |url=https://web.archive.org/web/20051217064748/http://www.ultralightflyer.com/genH4/index.htm |date=December 17, 2005 }}</ref>
* Trek Aerospace's Springtail <ref>{{cite web|author=MyFreeTemplates.com |url=http://www.trekaero.com/Trek_VTOL_Springtail_Vehicles.htm |title=PAV Springtail EFV |publisher=Trekaero.com |date=2003-11-05 |access-date=2009-07-26 |url-status=dead |archive-url=https://web.archive.org/web/20080511180102/http://www.trekaero.com/Trek_VTOL_Springtail_Vehicles.htm |archive-date=2008-05-11 }}</ref> 

==See also==
* [[Engineering:Baumgärtl Heliofly III|Baumgärtl Heliofly III]]
* [[Engineering:Jet pack|Jet pack]]
* Hovercar
* Ultralight aircraft
* [[Engineering:Gyrodyne RON Rotorcycle|Gyrodyne RON Rotorcycle]]
* Hiller ROE-1 / YROE-1 "Rotorcycle"

==References==
{{reflist}}

{{Emerging technologies|transport=yes}}

[[Category:Aircraft configurations]]
[[Category:Ultralight aircraft]]

{{Sourceattribution|Backpack helicopter}}