The loss of three De Havilland Comet aircraft in about a year during 1952-53 showed a lack of understanding of metal fatigue at a time when NDT was in its infancy. The need for research into these fields propelled a number of initiatives that still took years to bring effective solutions.
Early instrumentation was only suitable for laboratory use but the real demand was for portable equipment that could be taken out to the airplanes. Companies both in the US and Europe started development that has over the years become what we are more familiar now. Most cracks started at fastener holes and this became the focus of the majority of inspections and this remains the case even today.
After the overview we will look at specific applications that influenced the development of both probes and instrumentation that is still going on today, including possible future designs.