A way to secure operational safety for an aircraft structure according to a strength criterion

Fatigue and survivability requirements for transport aircraft structures formulated in the US Federal Aviation Regulations FAR 25.571, Advisory Circular AC 20-107B and in the Russian Aviation Regulations AR 25.571 are analyzed. Information on the lifetime of foreign and Russian aircraft, those new and those operating for a long time, is presented. Strength, fatigue and crack growth resistances of foreign and Russian improved aluminum alloys are compared. Ways for applying composite materials in the structure of foreign and Russian aircraft are illustrated. It is shown that aluminum and composite materials fail in different ways.