The picture shows a pylon-mounted version of the aeroelastic model X-DIA develop by POLIMI used as a testbench to develop and validate active flutter suppression technologies. In this FAA-sponsored joint project with the University of Washington, the researchers investigated the impact of free play on aeroelastic stability and active flutter suppression. The test configuration with a pylon allowed researchers to accurately control incidence and sideslip angles, which strongly impact limit-cycle oscillations.