Helicopter. Autogyro. Cyclogyro

I've always thought autogyros were fairly clever contraptions, and I find their "Frankenstein's Airplane" look amusing. Well, they may have been topped. Engineers in Singapore have built a functioning cyclogyro.

The concept is similar to cycloidal propellers sometimes used on ships. A set of blades is arranged to revolve around an axis that parallels their length. The pitches of the blades are varied as they revolve, adjusting the net thrust. So the same blades can provide lift and thrust. With two sets, one on each side of the craft, the thrust differentials can be used to spin the around the vertical or longitudinal axis.

Cycloidal propellers on ships have always interested me - they are often used for vessels that need extreme manueverablity. I remember learning about them while reading about the exploration of the Titanic wreck. The ship that supported the first exploration dives was equipped with them, allowing for precise station-keeping while controlling the ROV at the end of a 5 mile long cable. I never considered the possibility the same concept would be viable for aircraft.