At the end of 2009, we were supervised by Ing. Václav Chvála, Chief Inspector of the ULL technique of the Czech Amateur Aviation Association, successfully carrying out tests of the strength of the aircraft structure at various loads. The test consisted of strength tests of the hull, wings, wings, buoyancy flaps, tail surfaces, chassis, engine mounting and steering system according to the Czech UL-2 regulation and the German LTF UL regulation. The strength of the wing was tested up to its fracture, which occurred at a design load of 5.3 g x 1.5 at a maximum take-off mass of 472.5 kg. The strength tests of the horizontal and vertical tail surfaces were carried out at various prescribed load combinations. The chassis test also included the so-called drop test.
Part of the certification process – EASA Viper SD4 type certification, is also the execution of ground vibration tests. The result of vibration tests is that there is no dangerous phenomenon during operation at design speeds on the Viper SD4 aircraft – the vibration of the aircraft control surfaces (Flutter). As part of conducting vibration tests, we also implemented a process of comparing injected and expelled wavelengths on aircraft control surfaces. Thanks to the oscillating frequency devices, the vibrations oscillate the aircraft, then the wavelength is read. The resulting vibrations generate the sound of the aircraft on the control surfaces.