The POD Working Group under the Engine Titanium Consortium [1] is currently conducting a series of ultrasonic experimental and theoretical investigations using aircraft engine titanium alloy specimens. These efforts, in conjunction with corresponding statistical model developments, represent a new attempt to construct an integrated physical/statistical methodology for estimating the probability of detection (POD) of flaws in (titanium) materials. An important aspect of this new methodology is the use of physical models, to the extent possible, to predict the flaw and noise signals under the influence of various inspection parameters, thereby reducing the experimental effort and providing a basis for extrapolating to cases not covered by experiment. The ultrasonic investigations described in this paper are required to validate the accuracy and range of applicability of the models before they can be utilized with confidence.