While the mechanics of fracture in relatively thick sections of high strength materials is reasonably well understood, thin section fracture is not. Unfortunately, aircraft structures present the designer with many thin section fracture problems. Thus specialized techniques are necessary for fracture analysis of aircraft structures.Available methods of thin section fracture analysis are surveyed and critically discussed, with particular attention to crack growth resistance curves. The limitations of assuming linear elastic behavior in many types of thin section problems are pointed out. In such cases a one-parameter fracture criterion is unlikely to be realistic and improved procedures are required.