A gas turbine engine acoustic noise damping mount on a helicopter airframe includes a first outboard washer assembly with metallic inner and outer washers having a thin layer of elastomer bonded therebetween; an inboard bushing assembly has telescoped inner and outer metallic bushings with a thin layer of elastomer bonded therebetween; an engine trunnion is supported by the inner bushing; and flat inboard faces on the washer assembly and inboard bushing assembly are held against either side of an airframe strut by a nut threaded to the trunnion. The inboard bushing assembly includes a tubular extension pilot guided within an engine strut whereby the thin layers of elastomer serve to interrupt transmission of structure borne sound from engine to airframe.