This chapter explains how the authors assessed the potential risks of creep-fatigue in several aerospace applications using the tools and techniques presented in earlier chapters. It begins by identifying the fatigue regimes encountered in the main engines of the Space Shuttle. It then describes the types of damage observed in engine components and the methods used to mitigate problems. It also discusses the results of analyses that led to changes in design or approach and examines fatigue-related issues in turbine engines used in commercial aircraft.

Failure investigation is an integral part of any design and manufacturing operation, providing critical information to solve manufacturing problems and assist in redesigns. This chapter addresses several aspects of failure investigation, beginning with the challenges of organizing such efforts and the need to define a clear and concise goal, direction, and plan prior to the investigation. It covers the causes of failure and the training and education organizations require to understand and prevent them. The chapter emphasizes the importance of discovering the root cause of failures, and uses examples to explain the factors involved and how to recognize them when the first appear.