Jet Fighter Acrylic Canopy Failure

Failure analysis was performed on the acrylic canopy of a fighter jet that fractured in mid-flight. The analysis included fractographic examination of the failed canopy and comparison to laboratory-induced monotonic overload and environmental stress cracking (ESC) fractures. Chemical, thermal, mechanical, and exposure testing was also performed to determine if material degradation played a role in the failure. Stress analysis, including finite element analysis and a fracture mechanics assessment, was utilized to characterize the in-flight stresses and to estimate a critical flaw size.