The article has examined an issue of flow stability at last stages of low pressure cylinders. The paper reviews experimental investigations of LPC last stages. Different factors, such as low specific mass flows, negative root reaction, number of stages, supersonic Mach number and others, which influence the flow stability and energy losses, have been analyzed. The article has considered important regularities, including stability zones, flow fluctuation and dynamic stress while changing the operational mode. In order to sort out these problems the authors have proposed the re-designed large diameter last stage, which consists of two sections. This approach will allow organizing the optimal structure of the flow and improve the efficiency of the last stage.