A number of fiber optic methods has been developed for the inspection of critical components of mechanical structures. For inspection from a remote location various methods have been developed for the detection of cracks and strain. Some of these monitoring methods use a fiber mesh or OTDR techniques for distributed measurement of strain or to locate cracks. Fiber optic methods for non-contact ultrasonic inspection require other techniques, e.g. a pulsed laser with fiber optic delay lines and velocity sensitive interferometers.