The use of virtual flight testing to support the Certification Process of civil helicopters

The work carried out in this thesis consists in the development and testing of two helicopter mathematical models, with the aim of trying to understand if it’s possible to support the certification process of changes with virtual simulators. The first model is Michele Arra's model, which studies the helicopter’s trim conditions while the second one is a 10 degrees of freedom simulator, developed by Peter Talbot et al. The validation of the two models has been performed by comparing the results obtained with data published in the book from M. Arra, where the Agusta Westland AW109 helicopter is used as a case study. The two models were then compared with each other to verify the reliability of the results. After that, comparisons were made also with real flight data. The real flight data were taken from a report published by NASA, and from recent flights tests on the AW109 helicopter. The change in commands due to the introduction of items such as external mirrors, basket, or cameras has been investigated as well. In particular, both the models have been modified to better keep into consideration the centre of gravity position, and the installation of external items. The judgment on the reliability of the results has been given following the metric adopted by Leonardo Helicopters (LH),that will be shown in the following chapters. The models developed have given satisfactory results, as they are not much far from the results reported in the NASA report. As for the comparison made with the addition of the mirror in real flights, the models are still far from predicting the exact variation of the controls. However, the trends of the results of the two models are very similar to those of the real data.