V.P. Nesterov - Ph.D. (Eng.), Senior Research Scientist, JSC «Concern «VEGA» P.S. Kiselev - Deputy Head of Department, JSC «Vnukovo aircraft repair plant » I.I. Gorin - Ph.D. (Eng.), Senior Research Scientist, JSC «Concern «VEGA». E-mail: gorin1936@mail.ru