Abackpack helicopter /helipack is ahelicopter motor androtor 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 aharness like aparachute 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 aducted fan design to increase upwardthrust. 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 arecontra-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 failureautorotation is impossible. Usually, aballistic parachute would be incorporated for safety.
An edition ofPopular Science magazine in 1969 featured a backpack helicopter that used small jet engines in atip jet configuration instead ofcontra-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-poweredjetpack, possessing a greaterspecific 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",[1] and released test videos in June 2021.[2] However, the device consists of two rotors with diameters around 3 feet (0.91 m) connected viacarbon fiber tubes to a backpack with battery packs, and a pair of armrests with hand controls on them.[3] Later video analysis revealed operator and equipment were at the end of a drop cable that was edited out using post-production software.[4]
