To: Dave Jackson
Regarding Newton’s law that deals with action and reaction there is a lot of action but due to the lack of a ducting and adequate power to spin the screw there is minimal reaction. The law applies but the design was lacking. Helicopters don’t require a duct because of the amount of air that they can displace resulting in aerodynamic lift or, if you subscribe to the application of that same Newton’s law the reaction of the blade impacting the air results in a vertical component referred to as lift. Also for maximum effect with a duct the screw should be reversed so the pointy end is down thus allowing the air to be compressed but then again that is a gas turbine engine as I previously indicated or possibly an Atlas Copco axial compressor..