Currently, engineering method is usually used to compute the load-carrying capacity of the panels in a design process. In this paper, three major engineering methods are briefly described and investigated. These methods are evaluated through the comparison of caculated results and test data, for the stiffed panels of the central wing and fuselage of an aircraft. It is shown that the results from ‘ultimate load method’ are safer and more consistent with the experimental data. The reasonable allowable stress for central wing of the aircraft is specified according to the previous comparisons and analysis. It is shown that this method can meet the requirement of an engineering design.