Calculate the maximum internal crack length allowable for a 7075-T651 aluminum alloy (Table 9.1) component that is loaded to a stress one-half its yield strength. Assume that the value of Y is 1.35. (Note: internal crack = 2a) internal crack - 0.1304 inch internal crack - 0.4528 inch internal crack - 0.065 inch internal crack - 1.30 inch internal crack - 1.35 inch iinternal crack