Interest in civilian use of small Unmanned Aerial Vehicles (UAVs) with Vertical Takeoff and Landing (VTOL) capability has increased greatly in recent years, and is expected to grow significantly in the future. Research to date has focused on propulsion, batteries, sensors and autonomous control laws, but little attention has been paid to acoustic characteristics. The generation and propagation of noise associated with small VTOL UAVs are not well understood and prediction tools have not been developed or validated for this class of vehicles. Since public acceptance of these vehicles is crucial to their future in civilian roles, it is imperative that NASA acquire the analysis tools and an adequate understanding of the acoustic characteristics associated with these aircraft. The objective of the proposed effort is to create a base of experimental data to characterize the noise generated by this class of vehicle and then to use this data to evaluate and enhance existing rotary-wing design and analysis tools in this area.