This dataset contains experimental and forensic data obtained through microscopy, spectroscopy, and electrochemical methods, supporting the PhD thesis Bridging Laboratory Testing and In-Service Coating Performance for Structural Aerospace Applications. The data are organized by thesis chapter and correspond to peer-reviewed publications, covering a range of corrosion analysis techniques applied to aged and in-service aircraft coatings. Chapter 2 focuses on degradation mechanisms in chromate-based coatings; Chapter 3 investigates post-service performance and protective mechanisms; Chapter 4 compares coating behaviour under laboratory and real-world exposure conditions; and Chapter 5 expands on long-term degradation across various environments. The overarching goal is to link laboratory testing with in-service coating performance to enhance the prediction of coating durability for aerospace applications.