US Patent 7712701 Unmanned aerial vehicle with electrically powered, counterrotating ducted rotors

An unmanned aerial vehicle having counterrotating ducted rotors that are driven by electric motors. The vehicle has a low weight and a small profile. The unmanned aerial vehicle is suitable for a number of different tasks, including control, surveillance and reconnaissance, communication, and other tasks without exposing personnel to dangerous situations. The vehicle is particularly suited for entering buildings and other enclosed structures and spaces such as caves. The unmanned aerial vehicle can also be equipped for potential offensive actions.