Enhanced teardown of ex-service f/a- 18a/b/c/d centre fuselages

Abstract

The Flaw IdeNtification through the Application of Loads (FINAL) is a fatigue testing and destructive inspection program for ex-service F/A-18A-D wing attachment centre fuselage structure, known as the centre barrel (CB). It is a joint program between the Defence Materiel Organisation (DMO), Directorate General Technical Airworthiness (DGTA) and the Defence Science and Technology Organisation (DSTO). High life ex-service F/A-18 A-D CBs are cycled under a wing root bending moment spectrum until cracking from pre-existing defects can be readily found. The FINAL CB test program was originally conceived to satisfy engineering caveats associated with development of the Hornet Structural Refurbishment Program 1 (SRP1) package. SRP1 extends the fatigue life of the CB via a number of inspections and modifications to discrete CB locations. At the new CB fatigue life limit, the CB was to be replaced or the aircraft retired. At the time of SRP1 development, concerns were held that any potential combination of in-service mechanical damage, environmental degradation and widespread fatigue damage may jeopardise the useful life of SRP1 CBs. FINAL was successful in mitigating against these threats. Most recently the results from FINAL, in part, have extended the induction times for CB replacement, leading to increased aircraft availability and cost savings to the RAAF. This paper describes the FINAL program and its outcomes as well as test result interpretation. © Commonwealth of Australia 2009.