prop thing..

Since the ellipse prop as 4 blader has been found out as the most efficient one....OTOH there are other kinda developements:



Like the infamous BALONEY SLICER....




Look at the blades only not the governor. Looks pretty slick and efficient to me.

Some wise words about a prop from Sikorsky; Quote: "I don't quite know how to build it and don't quite know how to fly it, but I will."