In March 2011 VZLU carried out a certification of flutter resistance of the ultra-light airplane FM 250 "Vampire II" in accordance with a LTF-UL-2003 regulation, Section 629 of the German National Bureau of Aviation Safety. In the course of certification a complete ground vibration test (GVT) and calculation of flutter were carried out.
The purpose of the ground vibration test is to determine in detail the frequencies and shapes of vibration of the airframe, which are the basic input data for calculating the flutter. The calculation of flutter then deals with the dynamic stability of the aircraft in the interaction of unsteady aerodynamic, elastic and inertial forces. Modal testing was performed using an experimental apparatus PRODERA 2008, for the calculation of the flutter ZAERO v8.4 was used.
The work was performed for Flying Machines s.r.o.