Community noise contributions from flight path sections of different transitional air-taxi flight conditions

Previous UAM noise studies showed already that most of the aircraft noise will occur close to the vertiports and therefore is requiring a careful selection of observer positions for community noise studies and noise impact testing, depending mainly on the aircrafts' changing operational conditions during take-off and approach. While vertiports can be situated close to the next residential areas of a community, the noise, generated during take-off and landing is playing an important role. Especially before and short after take-off, as well as short before or after landing, most air-taxis' operational parameters, such as rotor rpm, velocity and in some cases tilt-angle of wing/engines, can vary significantly in a very short time, sometimes only within seconds. This so-called transition phase is of high importance to describe the aircraft's acoustics during its specific flight phases before reaching the final flight conditions for cruise, or the landing process is completed. The work presented here was performed in the frame of the research project PAULA and is showing for the first time, how different sections of the air-taxis' trajectory are differently contributing to community noise during take-off and approach.