This chapter introduces stress corrosion cracking (SCC) in aircraft alloys, highlighting its significance and possible repercussions. Due to the complexity of SCC in materials used for aviation applications, it is necessary to improve understanding of this phenomenon, which will help develop new knowledge. Discussing the workings of SCC is accomplished, highlighting how tensile stress and corrosive environments contribute to crack formation and advancement. The chapter focuses on the microstructural characteristics of aircraft alloys and how grain boundaries, precipitates, and other features affect SCC behavior.