One of the ways to increase durability, vitality and interference immunity of antenna technique (AT) is utilization of protective antenna complexes (PAC), that consist of radiotransperent covers (RTC) and radomes (RTR) of various purposes. Some kinds of protective devices combined with antenna and providing protection of the antennas from external influence are used as well.

Methods of estimation both durability and vitality of PAC under influence of different factors such as mechanic, temperature, climatic, radiation are the most worked out ones. The main shortcomings of the known methods of estimation are the following ones: they do not take into account the influence of all operational conditions in a complete set. In this paper a new method allowing to determine σ_eq more exactly and to get a relatively non-stopped information about intensity of design degradation is offered.