An evolved version of the Technology Identification, Evaluation, and Selection (TIES) method is presented that provides techniques for quantifying technological uncertainty associated with immature technologies. Uncertainty in this context implies forecasting. Forecasting the impact of immature technologies on a system is needed to provide increased knowledge to a decision-maker in the conceptual and preliminary phases of aircraft design. The increased knowledge allows for proper allocation of company resources and program management. The TIES method addresses the milestones encountered during a technology development program, the sources of uncertainty during that development, a potential method for bounding and forecasting the uncertainty, and a means to quantify the impact of any emerging technology. A proof of concept application was performed on a High Speed Civil Transport concept due to its technically challenging customer requirements.

No abstract

This paper outlines a comprehensive, structured, and robust methodology for decision making in the early phases of aircraft design. The proposed approach is referred to as the Technology Identification, Evaluation, and Selection (TIES) method. The seven-step process provides the decision maker/designer with an ability to easily assess and trade-off the impact of various technologies in the absence of sophisticated, time-consuming mathematical formulations. The method also provides a framework where technically feasible alternatives can be identified with accuracy and speed. This goal is achieved through the use of various probabilistic methods, such as Response Surface Methodology and Monte Carlo Simulations. Furthermore, structured and systematic techniques are utilized to identify possible concepts and evaluation criteria by which comparisons could be made. This objective is achieved by employing the use of Morphological Matrices, Pugh Evaluation Matrices, and Multi-Attribute Decision Making methods. Through the implementation of each step, the best alternative for a given evaluation metric/criterion can be identified and assessed subjectively or objectively. This method was applied to a High Speed Civil Transport as a proof of concept investigation. The TIES method identified that a conventional (present day technology) configuration could not meet imposed FAR 36 Stage III sideline noise requirements. Through the infusion of new technologies, a technically feasible design space was created. The TIES method identified a single notional concept for further investigation. This concept has a composite wing structure, Circulation Control for low speed flight, Hybrid Laminar Flow Control for cruise, and advanced engines for reduced fuel consumption and noise emissions. * Economic penalties associated with manufacturing not included, economic metrics are optimistic

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 vehicleÕs behavior in the design space. This technique is efficient for assessing multi-attribute, multiconstraint 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 ÒkÓ factors. The infusion of technologies shifted the VLT design into regions of greater feasibility and viability. The study also demonstrated a 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.

No abstract