Recent advances in eddy current technology for aerospace applications

One of the aerospace inspection problems that has been growing in importance, is the testing of aircraft wheels. The improved lifetime of tyres has resulted in a much longer period between possible inspection checks and, consequently, the need to detect cracks at an early stage of propagation. Low levels of corrosion also need to be detected. The economic and reliable way to scan the wheels is by a mechanical scanning system, utilising an eddy current probe. British Airways have done much of the pioneer work in this field. A typical probe configuration is presented and the required frequency response is considered