Analysis of requirements on fatigue and damage tolerance for civil transport airplanes

Abstract

The basic step to ensure safe operation of aircraft structure is to comply with regulatory requirements to structural fatigue and damage tolerance. This paper gives the analysis of the requirements stated in the FAA Regulations and Advisory Circulars (USA), in the former USSR Aircraft Airworthiness Regulations and Russian Aviation Rules. Principal requirements are given on fail safety, damage tolerance and prevention of widespread fatigue damages in operated aircrafts. Some results on multiple site fatigue damages of full-scale aircraft structure study are shown. The concept of step-by-step prolongation of Russian aircraft service lives is considered. Emphasized is the harmonization of Russian rules with USA and European regulations. The values are given of design goals, fatigue test results of full-scale structures and in-service number of flights for different airplane types. The required values of static and cyclic crack resistance of structural materials are substantiated and compared with current values of these characteristics of contemporary aluminum alloys.