A hybrid drone like HYBRiX has power redundancy. If the engine stops for some reason, it still has some minutes of endurance in electric-only mode, for an emerg

A hybrid drone like HYBRiX has power redundancy. If the engine stops for some reason, it still has some minutes of endurance in electric-only mode, for an emergency landing. With an unmanned helicopter, if the engine fails, the crash is mostly warranted, even with the autorotation function. Besides, the mechanics are simpler and therefore more reliable. And the propellers are smaller than a helicopter rotor, which is safer. Multirotors are also much simpler to operate than a helicopter. Most industrial customers do not want to operate unmanned helicopters because of their complexity.