The purpose was to develop and validate a new transonic wing design procedure using the numerical optimization technique. The new procedure was used to design both a transport and a fighter configuration. Because the missions and design requirements of a fighter and transport are so different, the design procedure was developed along parallel lines. Lockheed-Georgia Co. developed the transport design procedure, and Grumman Aerospace Corp. developed the fighter design procedure. This is Part 1 of a two-part volume: Part 1 details the transport development, and Part 2 describes the fighter development. The results of a transport design case study performed to evaluate the transonic aircraft design procedure developed as part of the Advanced Transonic Technology (ATT) program are presented. A derivative of the C141B aircraft was selected as the design configuration. The design procedure was applied to the baseline configuration and the performance of resulting configuration was then compared to the C141 aircraft. Extensive wind tunnel testing of the design configuration was performed to validate the design procedure. The results of the wind tunnel tests are correlated with computational results generated in the design process. In addition, the evolution of the design procedure and its application in the transport design case study is discussed.