During the aircraft design process, engineers are often called upon to make difficult decisions. An incorrect or ill-advised choice on some matters could have dire consequences. During the initial stages of design, for example, choosing an inferior configuration could lead to poor performance, inadequate mission performance capability, and ultimately, the loss of a multi-million dollar contract. Unless the optimum materials are then chosen to build the configuration, the aircraft may suffer weight, performance, cost, manufacturing, and/or maintainability difficulties. Finally, incorrect decisions during the structural design phase may lead to excess weight (i.e., lower performance) or even catastrophic in-flight failures. Unfortunately for the engineer faced with resolving these issues, only a finite amount of money, time, and personnel are available even for solving important problems such as these. Obviously, one solution to this dilemma is to make more efficient use of the available resources. This would allow the engineer to obtain the best possible answers to these important problems within the limits of manpower, schedule, and cost. One tool which will aid in doing this is ""Design of Experiments"" (DOE). ""Design of Experiments"" is defined as a body of knowledge, based on statistical theories, which allows the user to learn more efficiently from experimentation. The value of DOE has already been recognized by the Department of Defense. DOD document 5000.5 1 -G identifies DOE as an integral part of their Total Quality Management initiative for continuous improvement. DOE techniques can be used in a wide range of applications including analytical/computational trade studies, as well as empirical testing. This paper will introduce the topic of DOE methodology and explore its use at three points in the aircraft design process - configuration development, material selection, and structural design. Emphasis will be placed on the advantages offered by these techniques over more traditional approaches.