Influence of mass changes of flying objects on their dynamic features

The aim of this work is the experimental study of the weight loss impact on the properties of flying objects. Work is hased on the results of resonance tests of the helicopter, gliders and military aircraft. In the presented flying objeets group the possible occurrence of weight losses during the flight are up to 50%. The paper posed the following questions: How big can be, in practice, the weight loss during the flight? To which resonance the mass loss has the greatest impact? How and by what rules the map of resonances changes? Does in the process of weight loss there are other, worth-knowing events? Gliders, airplanes and a helicopter were investigated in the Resonance Test Laboratory of Institute of Aviation. The author has organized and for over 20 years led the Resonance Test Laboratory at the Institute of Aviation, in which he made or directed the investigations of dozens of aircraft, gliders, helicopters and their elements and components. Effect of weight loss on the flying objeets properties is one of several ,,unusual" research topics phenomena, which the author observed during a standard resonance tests. The resonance of the mode shape of Jantar 15 glider, comparison of the relative increase in the frequencies of the resonances with mode shape for SZD-50 Jantar 15-2 and IS-2 Revelation gliders, results of investigations of the underwing stores loss of mass impact on the „Pattem" aircraft resonances freąuencies, the resonance frequency of the 1-22 Iryda aircraft are presented in the paper. The resonance of the mode shape of Jantar 15 glider, comparison of the relative increase in the frequencies of the resonances with mode shape for SZD-50 Jantar 15-2 and IS-2 Revelation gliders, results of investigations of the underwing stores loss of mass impact on the ,,Pattern" aircraft resonances frequencies, the resonance frequency of the 1-22 Iryda aircraft are presented in the paper.