Abstract: An aircraft frame stringer is checked against designed specifications using a set of templates with stringer-engaging, upwardly-facing surfaces that match the designed contours of sections of the stringer at different locations along the length of the stringer. The templates are removably supported in mutually aligned and spaced relationship on a base assembly. The stringer is placed on the templates and measurements are made to determine if the stringer contours at the different locations match, within acceptable tolerance limits, the template contours at those locations. A computer model is used to determine the contours of the sections of the stringer at the desired locations thereon and to control the operation of a CNC machine for machining the templates.