An apparatus and a method of detecting wide spread fatigue damage (WFD) on aircraft using the absolute conductivity of the metal. A meandering winding magnetometer (MWM) having a plurality of parallel spaced linear conductor elements are placed in proximity to the aircraft. An electromagnetic field is...http://www.google.com/patents/US6420867?utm_source=gb-gplus-sharePatent US6420867 - Method of detecting widespread fatigue and cracks in a metal structure
