Applicability of ISO standard 3744 to UA

Abstract

Unmanned Aircraft Systems (UAS) are used for a variety of purposes. Especially the industrial or professional use of unmanned aircraft (UA) will lead to an increasing number of possible applications. The steadily rising number of UA raise the question of noise impact from these air traffic users. For the first time, an EU regulation provides a uniform noise rating for UA. It involves the introduction of a label for the guaranteed sound power level. This level is to be determined via EN ISO 3744:2010 by means of an enveloping surface method. Manufacturers are required to document the guaranteed sound power level as part of their CE marking. In addition, the EU regulation specifies a maximum permissible sound power level. The permitted level depends on the weight of the UA. Therefore, the German Environment Agency has started with acoustic investigations of UA. Various small UA models (i.e. multicopter) were used in the measurements in accordance with the EU regulation. This paper presents the results of the measurements and shows whether the requirements of the EU regulation are to be complied with. The challenges for users of the applicable measurement standard are also highlighted.