Starfire is proposing to fabricate and do full scale dynamometer testing of single rotor, JSF lift fan clutch heat sinks, and fully characterize the wear debris layer. The testing will be compared to the baseline C/C lift fan clutch material. The dynamometer testing will be done at Refractory Composites Inc using the dynamometer designed and purchased under RCI's Phase II program to address the same application. CMC friction material is inherently less moisture sensitive than the Carbon/Carbon baseline material which has lead to instability of the clutch and excessive wear. The development of a stable wear debris layer with the addition of Starfire's FM-35 friction modifier to CMC clutch plates is expected to result in reduced wear and further improve stability of the friction couple. Two rounds of full scale testing are proposed with moisture exposure testing. The full scale testing will shorten the development cycle eliminating the potential scale-up discrepancies demonstrated on the CCAB program and prior Starfire JSF Lift Fan Clutch SBIR.