A friction damper provides {HEAD ~ friction damping} for {TAIL ~ gas turbine engine airfoils} to reduce vibrations thereto 
for
A friction damper provides { HEAD ~ friction damping } for { TAIL ~ gas turbine engine airfoils } to reduce vibrations thereto
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH