Ul
Utralight helicopters will not fall down suddenly when their engine fails. The big rotor will keep turning for a while more allowing the helicopter to come down softly. But piloting one of them is not easy and takes a lot of skills and training. Also helicopters are a bit louder. While these multicopters rely on propeller redundancy asserting that even when one or two propellers stop the remaining propeller will enable the vehicle to come down softly. Also these multicopters can not be made to run on gasoline, their flight times are limited by the energy stored in electric batteries which is much smaller than the energy stored in fossil fuel. They will arguably typically run for around 6 minutes while it is common for a single person ultralight helicopter to run for more than an hour.What's the difference between this and any ultralight helicopter?