Air coupled ultrasonic C-scan (Airscan) for non destructive inspection

With the objective of Fokker Space and its subcontractors to reduce the cost of its solar arrays, the non destructive inspection (NDI) of the solar panel substrates has been identified as one of the areas of possible cost reduction. The Fokker Space solar panel substrate design consists of a sandwich construction with Aluminium honeycomb core and CFRP facesheets. Due to the optimised design of the Fokker Space solar panel substrates with regard to strength versus mass, even small defects can have an impact on the solar panel substrate performance. Therefore a specification has been established for the allowable defect sizes. The NDI test program has to be capable of detecting defects below this allowable defect size. Fokker Space has performed a market survey to find a fast and inexpensive NDI technique for the inspection of solar panel substrates, which still fulfils all NDI requirements. In this paper the outcome of the qualification test on solar panel substrate samples is presented. Furthermore the validation and implementation of the Airscan NDI equipment at Fokker Special Products (FSP) are presented. The Airscan NDI equipment has been purchased at Quality Materials Inspection, Inc. (QMI) USA. Preliminary acceptance of the Airscan equipment occurred at QMI, the final acceptance of the total equipment was at Fokker Special Products.