When blade 2 is in {HEAD ~ the upwind} or in {TAIL ~ the downwind sectors} of the cylindrical path it creates mainly drag and drive component forces 
When blade 2 is in { HEAD ~ the upwind } or in { TAIL ~ the downwind sectors } of the cylindrical path it creates mainly drag and drive component forces
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH