The proposed effort directly responds to NASA's SBIR solicitation goal to "develop and validate tools, technologies and concepts to overcome key barriers for rotary wing vehicles" citing in particular an objective to "develop design and analysis tools for the prediction of acoustics for small vertical lift UAVs." The proposed effort will provide valuable test data characterizing the acoustics generated by small VTOL UAVs an area where current test data is sparse. The proposed effort will also see the enhancement of existing analysis methods to allow accurate prediction of small VTOL UAV noise. These advancements will support future NASA applications developing, designing and operating small VTOL UAVs in the civilian airspace an area that NASA anticipates will grow significantly in the near future. The new test database and the enhanced analysis tools for small VTOL UAV acoustics will be of great use to rotorcraft manufacturers, DoD agencies and private industry as well as NASA in the coming years. The DoD is seeing a growing use of small VTOL UAV aircraft in surveillance and tactical urban warfare. In these applications, stealth can be critical, and the ability to accurately characterize and predict the UAV noise will be invaluable. The analysis tools developed in this effort will be needed by manufacturers of small VTOL UAVs wishing to include acoustic analysis in their design work. Since the forecast for the implementation of these types of aircraft is burgeoning, not just for NASA and DoD but also for private industry, the market for analysis software and engineering services in this area has a tremendous upside for growth, leading to great potential for commercial applications beyond NASA's needs.