This thesis investigates conventional and probabilistic methodologies for predicting the fatigue life of critical components in the P-3C aircraft. A probabilistic damage convolution model was developed with the intent of providing quantitative predictions of life-variability. Traditional methodologies, which are based nominally on median values, lack the capacity to adequately assess variability. Aluminum 7075-T6 was tested using a fatigue Material Test System. A fatigue data base was compiled from tests conducted at the Naval Postgraduate School and from literature sources.