C-17 Landing Gear Durability and Parts Support

This report addresses C-17 landing-gear durability and tire and brake support. This report is the second in a series on tile life-cycle management program for military aircraft landing-gear parts. The first report addressed the serialization of fracture-critical and landing-gear parts for the C-17. The overall audit objective was to determine whether the Military Departments were making provisions for landing-gear life-cycle management programs on aircraft acquisition and modification programs. The objective of this segment of the audit was to determine whether tile C-17 System Program Office was providing life-cycle management of landing-gear durability and support. We also reviewed the management controls applicable to that objective. Design of the C-17 landing-gear posts and trunnions had not been sufficiently stabilized to enable the C-17 System Program Office to filly project life-cycle management cost of landing-gear support. If the contractor is unable to extend the life of those parts, through redesign, past the 1.5 lifetimes of durability testing warranted in the contract, and those parts are declared life-limited, the Government costs for C-17 landing-gear support over the life of the C-17 fleet could increase 133.2 million for landing-gear posts and 5.2 million for trunnion collars. In addition, because of a much higher usage rate than anticipated in the original specifications, support costs could increase as much as 8 13.5 million for brakes and about 29 million for tires over the life of the C-17 fleet. The development of an improved main landing-gear tire could result in potential monetary benefits of approximately 1.8 million for FYs 1999 through 2005. See the Finding section for details and Appendix E for a summary of potential monetary benefits. Management controls were adequate as they applied to the overall objective.