Aluminum alloys are used in various critical aerospace applications that require properties that are obtained from very specific heat treatments. The fracture surface of an aluminum alloy can indicate details of the thermal history of the component, and may provide the necessary information to the failure analyst to determine if the proper heat treatment was conducted. This study evaluated the effect of varying the cooling rate and aging time on the fracture surface of 7050 and 7075 aluminum alloys. Samples were heat treated at various cooling rates and aging times and tested to failure in uniaxial tension. Fractography was conducting using a scanning electron microscope. The ductile dimple size was correlated with the measured tensile strength. The results of this study can be used by the failure analyst to determine the heat treatment and tensile strength of a 7050 or 7075 aluminum alloy component that failed in tension.