Residual life predictions of composite aircraft structures via nondestructive testing, part 1: Prediction methodology and nondestructive testing

We present a two part paper that contains the results of a research project whose central goal is to demonstrate the capability to predict the residua l useful life of advanced composite aircraft structures using nondestructiv e testing (NDT) data. Due to both its complexity and broadly applicable des ign features, the horizontal stabilizer of the Harrier AV-8B Jump Jet is se lected as above, the demonstration structure for the project. In part 1 we give an overview of the project, followed by a brief description of the str uctural design of the Harrier AV-8B horizontal stabilizer. We summarize the results of nondestructive tests that were conducted at the Sacramento Air Logistics Center at McClellan Air Force Base. X-ray and ultrasonic testing data are presented for an operational horizontal stabilizer. Indications of structural anomalies are discussed, and a quantitative method is proposed for characterizing the ultrasonic attenuation of the advanced composite sta bilizer skins.