In-Service Inspection of Advanced Composite Aircraft Structure.

Abstract : This report describes the work accomplished under a 12-month program conducted for the purpose of developing a reliable and practical inspection and data recording capability for service induced, or propagated flaws in composite aircraft structure. The basis of the developmental work was a portable C-scan recording system developed by General Dynamics to be used in hand-scan ultrasonic inspection on F-16 production line. In that system, a unique sonic microphone digitizing system was used to receive low-frequency ultrasound generated by a cursor attached to the ultrasonic transducer for position indication. In this program, a laboratory mock-up system was assembled to detect and record implanted flaws and impact damages in fabricated specimens, using modified and improved ultrasonic techniques. Preliminary design of a prototype system incorporating improvements from the laboratory mock-up system was completed. A cost analysis was conducted to allow an evaluation of the performance of the prototype system in the preliminary design against its cost. (Author)