Affordability Assessment for a Subsonic Transport

Military budget cuts and increased competition in the commercial market have shifted the focus of aircraft design to include affordability concerns. This has resulted in the need for increased knowledge in the early stages of design when a high percentage of the available resources are committed. The Technology Identification, Evaluation and Selection methodology outlined herein provides the designer with a structured decision making method within which technological alternatives can be compared. Furthermore, this methodology is probabilistic in nature to account for the uncertainty and risk inherent in design, as well as for the variability of the aerospace market. Thus, this seven-step process leads the designer from a societal need, through a series of alternatives, to a robust solution capable of meeting customer goals within a variable environment. As a proof of concept the methodology was applied to a very large commercial transport. Evaluation criteria and potential concepts were identified through systematic techniques such as Quality Function Deployment and Morphological Matrices. The baseline concept studied could not meet all customer requirements with an acceptable degree of confidence, and therefore, three potential technologies were considered. The technologies investigated were hybrid laminar flow control, composite wing and composite fuselage, and their possible combinations. Probabilistic techniques such as Response Surface Methodology and Monte Carlo Simulation were employed to identify technically feasible and economically viable alternatives. Finally, Multi-Attribute Decision Making methods were employed to select a best alternative according to the established evaluation criteria.