In the framework of the Large Passenger Aircraft ITD of Clean Sky 2, the industrial partners Airbus & Safran will push the CROR and UHBR low fuel burn propulsion concepts to TRL6 with a flight test demonstration program on the A340-300 MSN001 aircraft. The activities proposed in this document will make a valuable contribution to this program. The activities comprise: CROR&UHBR numerical aero-acoustic characterisation, CROR blade aero-elastic deformation, innovative acoustic measurement techniques, acoustic chase aircraft flight testing, and blade impact numerical simulation.In Clean Sky’s Smart Fixed Wing Aircraft, NLR supported Airbus & Safran with manufacturing the highly complex wind tunnel test rigs that laid the basis for the technical dossiers available today on CROR. Accurate numerical aero-acoustic simulations techniques were developed at NLR. In close collaboration with Airbus, these were subsequently applied to CROR which led to a deep physical understanding of this innovative propulsion concept. The current proposal builds on the success story of Clean Sky. It ensures a head start on pushing the frontiers of our current knowledge on novel CROR & UHBR propulsion concepts.In conclusion, NLR holds an impressive track record on engine integration support and is well equipped to carry out the proposed research.