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E-volvo, a German firm, has totally redesigned the helicopter. Its multicopter boasts 16 electrically powered propellers divided into four groups of four. Power for up to 20 min of flight comes from a lithium battery pack.
The 175-lb manned prototype measures about 16 × 16 ft and can carry a payload equal to its own weight. Unlike conventional helicopters, the multicopter rotors are permanently positioned. They do not move or change pitch, which should greatly reduce wear compared to conventional helicopter rotors. Instead, each set of rotors has its own motor and the amount of lift each rotor generates depends on how much electricity it receives. Several onboard computers take pilot inputs from a throttle and joystick to calculate power signals for each of the 16 rotors that, in turn, change their speed to carry out the commands. The computers also continually strive to keep the copter upright. This relieves the pilot of having to think about minimum speed, stalling, gas mixtures, pitch control, and the other issues that complicate helicopter flight.
The aircraft also has a few safety features designed in. For example, because there are no overhead rotors, the multicopter can be outfitted with a parachute that could bring a failed multicopter safely to the ground. Plus, the multicopter can safely land with up to four of its rotors totally disabled.