The analysis of safety of flights is considered. The new structure of the analysis of safety of flights is offered. The economic estimation of efficiency of analyses of safety of flights is made. The principle of gathering of primary data which are used at the analysis is resulted. Aviation enterprises have the fulfilled system of analyses of safety of flights which are base of system of prevention of aviation incidents and incidents. The system of prevention of aviation incidents and incidents demands essential resources for its functioning. As in itself it does not provide a sure gain, always there is a question on an estimation of its efficiency. In work one of methods of such estimation is offered.