Architectural Decisions in Commercial Aircraft from the DC-3 to the 787

The volume of passenger air travel has increased rapidly since the first commercially viable passenger aircraft, the DC-3. Over this period, commercial aircraft increasingly appear to have consolidated around a dominant architecture. That is to say, aircraft designers have increasingly made the same architectural decisions (categorical choices such as high wing or low wing), while realizing performance gains in component technologies rather than from major architectural innovations. To quantify the assertion that a dominant architecture has emerged, in this paper, architectural decisions over time are analyzed, finding a decrease in variation of these decisions in a data set of 157 historical aircraft architectures. An architectural performance metric is defined based on passenger-carrying efficiency, technical performance, and market value, observing that, in parallel with architectural consolidation, there has been a twofold increase in average performance since the inception of the DC-3. However, the performance trend is shown to follow a trajectory similar to that of a technology S curve, implying that current improvements in performance with this dominant architecture may be reaching the stage of diminishing returns. Given current levels of activity in engine technology and potential architectural implications of large fan diameters, among other trends, this paper forms the basis for an evaluation of limits to the dominant design.