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