The reciprocating mechanism undergoes generally free flight with energy being supplied only as required to maintain {HEAD ~ the nominal speed} in {TAIL ~ the face} of minor friction losses and the like 
in
The reciprocating mechanism undergoes generally free flight with energy being supplied only as required to maintain { HEAD ~ the nominal speed } in { TAIL ~ the face } of minor friction losses and the like
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH