Demonstration of a Probabilistic Technique for the Determination of Aircraft Economic Viability

Over the past few years, modern aircraft design has experienced a paradigm shift from designing for performance to designing for affordability. This paper contains a probabilistic approach that will allow traditional deterministic design methods to be extended to account for disciplinary, economic, and technological uncertainty. The probabilistic approach was facilitated by the Fast Probability Integration (FPI) technique; a technique which allows the designer to gather valuable information about the vehicle's behavior in the design space. This technique is efficient for assessing multi-attribute, multi-constraint problems in a more realistic fashion. For implementation purposes, this technique is applied to illustrate how both economic and technological uncertainty associated with a Very Large Transport aircraft may be assessed. The assessment is evaluated with the FPI technique to determine the cumulative probability distributions of the design space, as bound by economic objectives and performance constraints. These distributions were compared to established targets for a comparable large capacity aircraft, similar in size to the Boeing 747-400. The conventional baseline configuration design space was determined to be marginally feasible and non-viable, motivating the infusion of advanced technologies, including laminar flow control, advanced materials, and advances in propulsion technology as to reflect 2005 entry into service. The resulting system benefits and penalties were qualitatively assessed with technology metric “k” factors. The infusion of technologies shifted the VLT design into regions of greater feasibility and viability. The study also demonstrated an method and relationship by which the impact of new technologies may be assessed in a more system focused approach. The impact of technology readiness and its associated risk was also addressed in this study and is not presented here.