MANOEUVRES - an Effort Towards Quieter, Reliable Rotorcraft Terminal Procedures

The MANOEUVRES project concerns an innovative approach geared towards quieter rotorcraft manoeuvres, especially during terminal flight phases. Emitted noise strongly depends on the actual helicopter rotor dynamics, which is typically unsteady in terminal manoeuvres and difficult to estimate in real time. Therefore, a major topic in the project concerns the design, development and testing of a novel in-flight measurement system for rotor blade flapping. This system will be able to provide reliable rotor state information to feed an algorithm that, together with other data retrieved from the helicopter avionics, will enable the run-time estimation of the emitted noise. The noise estimation will exploit an acoustic data prediction process resulting from a dedicated study, which includes the analysis of unsteadiness effects and of trajectiory perturbations. Computed noise will then be synthesized into a suitable noise index, to be displayed onboard via a dedicated human-machine interface, in order to provide useful information to the pilot for flying low noise procedures with improved awareness and effectiveness.