trogador writes to mention that a group of researchers is taking another swing at the idea of a cyclogyro design for a UAV. Even though the cyclogyro design was invented in the 1930's there are no records of a successful flight. "Cyclogyros have the potential to be highly maneuverable flying robots due to their method of operation, making them potentially more suitable for complex tasks than helicopters and other micro air vehicles (MAVs) with less maneuverability. The biggest challenge in designing the cyclogyros is varying the angle of attack of the rotating wings. This ability would enable the plan to change altitude, hover, and fly in reverse. To achieve this quick angle variation, the researchers introduced an eccentric (rotational) point in addition to a rotational point connected to a motor."