SBb1 DEFIANT JMR Technology Demonstrator Aircraft Main Rotor Gearbox Technology Insertions & Teardown Results

The Sikorsky Boeing SB>1 DEFIANT is a technology demonstrator aircraft that was built under the Joint Multi-Role Technology Demonstrator (JMR TD) program to address the next generation performance requirements of the US Army Future Vertical Lift (FVL) initiative. The Main Rotor Gearbox (MRGB) incorporated several low Technology Readiness Level (TRL) technologies to improve power density and meet challenging program requirements for gearbox empty weight fraction. After the conclusion of the flight test program the ground test Main Rotor Gearbox was disassembled and evaluated to raise the TRL level of these technologies. The technology insertions, teardown observations, and laboratory test results are discussed.