In work aircraft thin-walled structures: panels, shells supported stringers are considered. Structures are made both from isotropic and of composite multilayered materials. Critical for thin-walled structures are compress loadings of buckling and also the post buckling loadings leading to structural failure In work the main emphasis is put on search of the critical loading and the corresponding forms of the deformed structures. Instruments of research are as variation-analytical methods and numerical finite element method by Nastran Code. Important dynamic characteristics of aircraft structures are the natural frequencies and forms of free and forced vibrations. The work is represented these values of the first frequencies and the corresponding mode shapes. The received results are compared with natural tests performed of Aircraft Structures Laboratory of Aerospace Engineering Faculty of Israel Institute of Technology, Haifa city