The ATTILA Team presented a paper at the 47th European Rotorcraft Forum, recently held online (September 7-9, 2021) by ERF’s UK representatives.  The paper illustrates the results of the whirl flutter simulations performed so far by NLR and POLIMI in support of the development of the wind tunnel model.  Two independent multibody dynamics solvers, FlightLab and MBDyn, are used, with sophisticated stability analysis techniques like Matrix Pencil Estimation (MPE) and Periodic Operational Modal Analysis (POMA).  Results show good correlation with the expected stability characteristics, suggesting that the project is on the right track for obtaining a wind tunnel model that meets the expectations.