#1330: ChopperSwopper

The twin-rotor Chinook helicopter is a remarkable design. If anyone suggested having two sets of counter-rotating interleaved rotor blades they might well be criticised for optimism bordering on naivete…my speciality, in fact.

Today’s invention is a Chinook upgrade in which each rotor blade engages its outer end with the distal rotor hub, driving that hub’s rotors around until it slows enough so that that end then becomes the inner end of the blade rotating about the distal hub.

This stresses each blade more evenly and lessens the overall sweep of the blades as shown in the diagram -in which the helicopter is flying up the page. The single blade shown swaps from hub to hub, providing drive for one rotor from the other without any need for a drive shaft (difficult, but not impossible to achieve).


  1. Sorry, your way off on this one. 1st, if anything like a wind turbine, the pitch of the blade varies as the distance from the hub, in order to optimize the pitch with the linear velocity. The further from the hub, the faster the blade travels through the air, demanding a different pitch. 2nd, it would destroy either the blade or the helicopter itself to stop and redirect the rotational momentum of the blade. Finally, only one blade is very unlikely to provide sufficient lift, at least on earth.

    • Yep, I stand corrected. Especially about the varying pitch. I thought for fully ten minutes about the change in momentum and there is just too much momentum exchange…I do think it might be possible to have the outer rim of one rotor drive the other (ie without a driveshaft between them) but it would be pretty pointless. Actually, I was planning on having many more than one blade per rotor, all swapping -quite mad.

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