Residual stresses introduced into large aerospace aluminium components after the queching procedure carried out to form the desired microstructure can result in large, costly distortions upon further processing. A major variable is the delay between quenching and application of cold-compression - a process used to relieve residual stresses by plastic deformation and an optimum period after quenching when the material responds best to cold-compression should exist. It is the aim of this experiment to determine whether this is the case and to ascertain what the optimum delay may for AA7449. The study of samples with different time delays is vital in assessing the residual stress differences and validating models of the cold-compression process. ENGIN-X will allow the large samples to be studied easily whilst avoiding issues related to the microstructural variations within the part.