Under the Turbine Engine Sustainment Initiative (TESI), phased array inspection technology is being implemented into an automated inspection system for detection of embedded defects in turbine engine disks. Full implementation of phased array technology requires that current inspection requirements and procedures developed for conventional single element probes be redefined for phased array probes. Studies conducted to characterize the beam profile for the array transducer showed that subsurface focusing with the array transducer can provide equivalent sensitivity and resolution to that obtained with a comparable single element conventional transducer. For some array probe configurations, the sensitivity and resolution were shown to be improved over that of the conventional transducer. However, measurements of reflected peak amplitude from side drilled hole targets showed that the amplitude of the subsurface focused beam generated by the linear array does not decrease continuously with depth in the inspected part. This non-uniformly decreasing beam amplitude would require a nonlinear depth amplitude correction to insure constant sensitivity throughout the inspection volume. Measurements of beam width for the array transducer showed that the beam width in the non-focusing direction of the linear array is comparable to that of the single element transducer. In the active focusing direction, the beam width varied with depth, approaching the theoretical limit near the focal point, and spreading away from the focal depth. Depending on the particular inspection requirements, optimization of the array focusing conditions to obtain the required resolution and sensitivity over the inspection volume may require use of multiple focal laws. Further studies are required to determine the focusing behavior of transducers with other geometries, under normal incident and angle beam configurations within a specimen, and how that behavior compares to conventional transducers.