A method of thermal inspection of a part having at least one internal cavity is provided. The method includes flowing a fluid through the at least one internal cavity. The method also includes measuring a temperature at one or more locations on the part over time. The method further includes calculating at least one of a first and a second derivative of the temperature with respect to time. The method also includes comparing at least one of the first or the second derivative to one or more baseline values to determine if the part meets a desired specification.