ON THE QUESTION OF SAFETY OPERATION OF A HELICOPTER AFTER CARGO DISCHARGE FROM EXTERNAL SLING

Abstract

When helicopters fly with suspended load, there may be a need for a load drop. This can be associated with both the abnormal situations in flight and with a regular load drop to a predetermined area. However, under certain conditions, after the external load drop, there may be significant changes in the parameters of the helicopter movement. In this regard, when planning the helicopter flight with suspended load, it is necessary to make sure of safety in case of a load drop. In carrying out this work, theoretical and experimental research methods have been used. The theoretical methods of research include analytical calculations and computational experiments conducted with the help of special software. Experimental methods include flight test methods. Flight experiments allowed to confirm the adequacy of theoretical methods for researching the helicopter dynamics after external load drop. The proposed methodology for ensuring the safety of helicopter operation involves a staged research of the helicopter dynamics after external load drop. At the first stage, an analytical determination of the normal vertical load factor after the load drop according to the formula derived earlier was carried out. At the second stage of the research, computational experiments were performed using the HeliCargo software package, which allowed not only to clarify the values of normal vertical load factor obtained by the analytical calculations, but also to consider the movements of the helicopter mass center and its angular movements after load drop. The conducted research shows that the helicopter dynamics after load drop can be satisfactorily investigated by the previously developed theoretical methods, which is confirmed by comparing the obtained data with the results of the flight experiments. In addition, this paper presents concrete results, stating the safety of external load drop, which can be used in planning the production of work on the delivery of suspended load to a predetermined area.