A successful short-haul transport must satisfy customer and marketplace requirements and be attractive economically. This paper examines the marketplace in the late 1970 time period to determine the payload-range and other performance requirements for a wide-bodied twin-jet transport. Environmental and operating cost targets are established, and the size of the market is estimated. An “optimal” design is then described which essentially represents the best possible airplane using the technology available in the time period best suited to the customer and marketplace requirements.Design data are presented that show the sensitivities of the design to some of the primary configuration variables. Certain design compromises are considered that have to do with airframe commonality with the manufacturer's other transports. The optimal design is then biased to increase the commonality with a parent airplane, thereby realizing manufacturing cost economies for reduced airline ownership costs but increasing engine and fuel costs. An interim baseline configuration is selected and more detailed studies made of its characteristics.