It is well known now that the compressive residual stresses produced using surface treatment like Laser Shock Peening (LSP) are beneficial in improvement of the fatigue life of structural materials. The residual stress field obtained after surface treatment is used in the design process to improve factor of safety and fatigue life of the materials. However, this entire process works on the assumption of stable residual stress field in the service life of the treated component, which is inaccurate. In this experiment, we are investigating the stability of LSP residual stresses in aircraft components under fatigue loading. We will measure the relaxation of residual stress in textured aluminium alloy before and after fatigue loading. The measurement will allow us to develop a meso-scale model of residual stress relaxation in engineering components.