forming {HEAD ~ a cavity} in {TAIL ~ the root portion} of at least one single crystal superalloy blade 
in
forming { HEAD ~ a cavity } in { TAIL ~ the root portion } of at least one single crystal superalloy blade
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH