Determination of sound power levels of a small UAS during flight operations

Unmanned Aircraft Systems (UASs), also called Unmanned Aerial Vehicles (UAVs), have mostly found military applications, but also are increasingly finding uses in civil applications, such as search and rescue operations, 3D mapping, environments monitoring, industrial applications (inspection of power plants or pipelines), TV Entertainment. The UASs are often preferred for missions that are very difficult or dangerous for manned aircraft or for men in general. The use, in everyday life, of this type of vehicles further increase the total acoustic pollution. It is necessary to evaluate the Small UAS noise, in manner to determine its contribution to total acoustic pollution. Goal of this work is to evaluate the acoustic emissions of some small UASs during normal flight operations (e.g. take off, landing, turning, hovering, etc.), related to electric engines and propellers. The acoustic measurements are carried out in an anechoic room. Data collection of small UASs noise, at low altitude and velocity, were made. Investigation on sound power levels is based on EN ISO 3745, which specifies measurement method. The results of each UAS have been presented and discussed.