This paper presents a method of an analysis of fight safety. A new structure of on analysis of fight safety is offered. An economic of efficiency of analysis of flight safety is made. It allows for the formulation of a principle of collection of primary data used in the analysis. Aviation enterprises make use of a system of analysis of flight safety which are a base of a system of prevention of aviation incidents and accidents. Functioning of a system of prevention of aviation incidents and accident demands essential resources. As in itself it does not offer a sure profit, there is always a question of an estimation of its efficiency. In this paper, one of methods of such estimation is offered.