{HEAD ~ A trailing surface} aft of the maximum radius has {TAIL ~ a radius} at all points therealong less than the maximum radius 
has
{ HEAD ~ A trailing surface } aft of the maximum radius has { TAIL ~ a radius } at all points therealong less than the maximum radius
HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH