Flutter computational analysis of experimental (concept demonstrator) semi-canard aircraft named EM-12 “Małgosia II” is presented. Differently from other canards, the aircraft designed by Edward Margański is equipped with a forward surface that can swing freely on transverse axis. This surface is controlled only by tabs located behind its trailing edge. The tabs are mechanically connected with sticks and spring trim in the cockpit. This solution - according to designer's idea - should have advantages of canard system and should not have canard's defects.
The swept wing of the “Małgosia II” is equipped with ailerons and split flaps. The fin with split rudder is located at each wing tip. The aeroplane is powered by piston engine with pushing propeller. The design dive speed of this aircraft is VD = 290 km/h.
The flutter analysis has been performed with the MSC/Nastran system using beam-like FEM model of structure and DLM aerodynamic model. The FEM model of the structure contains the control systems' model and it was verified by comparison with results of both static tests and GVT. Among static properties verification, the test of wing torsional rigidity has been made as described in the NACA Report 45. All ground tests were provided by Silesian Science and Technology Center of Aerospace Ltd. in Czechowice-Dziedzice.
As a result of flutter computation the wing torsional-bending flutter modes were determined which are typical for a swept wing aircraft. Three tabs configuration were examined. In the both cases of “heavy” tabs the anti-symmetric flutter mode with canard rolling and torsion appears below maximal dive speed of aircraft.