The aerospace sector offers a wide range of applications in the field of fatigue and fracture mechanics of materials and structures. It pertains to the missions of the products. Quite innovative various research results covering this range have been obtained meeting industrial needs in this sector. One purpose of the book is to highlight these results. In order to fully understand them, it is important to detail typical structural failure cases and to address the industrial needs, to insist on some basic knowledge, to present the theories and their limitations, to point out the challenging aspects dealt with in the presented research results. This is another purpose of the book to present in a more unified manner a range of complementary knowledge, to be aware of, that is needed in order to get a better vision and grasp of the field when dealing with simple direct applications or more complex ones.