The wood or wind turbine markets, to name two examples, are confronted to the obstacle of having to transport heavy loads to and from areas that are accessible with difficulty. Airborne transportation is a solution. In this frame, a new generation aerostat is being developed, in partnership with Flying Whales. In order to make possible a commercial success of this kind of vehicle, the increasing sensitivity of people to aircraft noise has to be taken into consideration. In order to comply with future noise regulation applicable to this kind of aerostats, the noise impact for different operating conditions has to be estimated. Classic procedures like cruise, take-off and landing, as well as stationary flights are considered and evaluated. The aerostat is equipped with two propulsive propellers, four hovering propellers and two additional propellers for lateral control. The propulsive and control propellers are mounted vertically, the hovering propellers horizontally. Operating conditions will lead to flights above grounds with steep slopes and possibly dense vegetation. In this paper noise evaluations are presented for the most standard operating points that should occur. Given the sources' characteristic noise directivity, the vertically mounted propellers radiate directly into the field below the aerostat, where, in case of a stationary flight, people will be at work, loading the aerostat. The hovering propellers however radiate away from the aerostat, reaching maximum levels on the ground several hundreds of meters away from the aerostat itself, depending on the emission altitude and the ground slope. The rank of each source depends on the operating condition. A parametric study helps to identify leads for noise reduction at the ground.
