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 residual useful life of advanced composite aircraft structures using nondestructive testing (NDT) data. Due to both its complexity and broadly applicable design features, the horizontal stabilizer of the Harrier AV-8B Jump Jet is selected 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 structural 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 stabilizer skins.