Cool. Can that adequately rule out flutter? it seems that flutter would be complex interaction with the airflow. Is it just a matter of having a high enough resonance frequency?
Of course, the purpose of this test is to meet the regulatory requirements, which are: For aircraft having a VD of more than 200 km/h a ground vibration test including flutter calculation must be performed prior to airborne flutter testing proofing the aircraft being flutter free up to 1,2 VD. The principle of the method consists in creating elastic FEM model and the mass FEM model and put these models together and compared with the ground vibration test. Implementation of aerodynamic inputs is determined (calculated) the lowest speed at which aeroelastic phenomena can occur. This speed must be greater than 1,2 VD. For Sparker, at least approx. 450 km/h can be achieved. These analyzes are performed for several weight configurations, for variants with fixed and free control system and several flight altitudes.
