Current international guidance on aircraft noise modelling is limited to fixed-wing aircraft, thus not covering rotorcraft noise. In the NORAH2 project, rotorcraft noise modelling guidance was issued and implemented in a software prototype.
The hemisphere-based approach of the NORAH2 project is suitable for modelling rotorcraft noise of helicopters, as well as noise created by future transport modes such as drones and urban air mobility aircraft. The method was validated by comparison against benchmark data, such as EASA certification noise levels and the internationally established outdoor sound propagation method NORD2000.