EASA has released its NORAH2 prototype software and database developed to support industry efforts to reduce the noise impact of rotorcraft. The new tools—recently published for download—are intended to provide a reliable estimate of noise levels on the ground and are the result of a four-year research project funded by the European Union’s Horizon 2020 program.

The NORAH2 software and database have been developed to support the noise-monitoring activities the rotorcraft industry is required to conduct under the European Noise Directive 2002/49/EC legislation. This project was led by Dutch aerospace research agency NLR, and NORAH stands for Noise of Rotorcraft Assessed by a Hemisphere approach.

According to EASA, the new tools are intended to track noise from existing helicopters, as well as drones and eVTOL aircraft. They have been developed to take account of varied operating conditions, including urban environments, weather, and other operating conditions.

The NORAH2 development team has built an extensive database of rotorcraft to establish baseline noise data. The system also provides a new noise-modeling method that EASA hopes will be more accurate for assessing the local impact of ground noise to match provisions already made for airplanes.