The concept of gathering information about the current material state awareness to determine the remaining life of a component is gaining acceptance among the Department of Defense. Several efforts based on this idea are under way to support the Prognostics and Health Management (PHM) of turbine engines, with varying degrees of success. These include the determination of distribution of residual stresses in the component and the use of nondestructive testing methods to detect damage in the part as a function of life cycles. However, as the fleet ages, the increasing frequency of required inspections to determine the current material state could lead to prohibitive costs, and aircraft downtime. Developing new materials or modifying component designs to improve damage tolerance is generally extremely costly.  Introduction of compressive residual stresses at critical regions of the part can completely mitigate corrosion, fretting, or other damage induced failures. This technology enables the conversion of Life Limited Components (LLC) to Safe Life Components (SLC) without changing either the material or the design.

Examples of successful applications of LPB to control the material state of aircraft structure, landing gear and engine components will be discussed. The quality assurance (QA) program associated with LPB by way of closed-loop monitoring and control at every moment of the treatment process will be discussed. The QA exceeds six sigma and leads to repeatable safe and stable material state in the component. The importance of rigorous quality assurance program and the need for closed loop process monitoring and control of the compressive residual stress technologies to achieve the designed residual stresses with specific examples from LPB treatment of aircraft structural and engine components will be highlighted.