AUTOMATED EDDY-CURRENT SCANNING OF AIRCRAFT FOR CORROSION DETECTION

The FAA National Aging Aircraft Research Program (NAARP) predicated that improvements must be made to existing inspection techniques and devices for more reliable detection capabilities. Hence, this study was initiated to advance eddy current technology for improved corrosion detection in aircraft structure. Specifically, this study was directed toward improved corrosion detection through the implementation of instrument multifrequency mixing capabilities coupled with automated scanning and recording. This article describes the detection and recording of corrosion thinning on the internal side of typical aircraft fuselage skin panels. Quantitative measurements were made of thinning in a single skin; a skin covered by an external doubler; and a single skin in juxtaposition with a subsurface butt joint. In addition, plan view (C-scan) recordings were made of exfoliation corrosion extending outward from flush-head steel fasteners in an aluminum wing skin.