In our view the impact of software engineering technology on aircraft design methodology is often not recognized by the aircraft design community. Therefore new software engineering technology is often not used and therefore a new aircraft design methodology cannot emerge.We analyze the conventional aircraft design methodology, the design systems used to realize this methodology and the software engineering technology used to realize the aircraft design systems. We present the limitations of the conventional aircraft design methodology and explain how this is effected by the conventional software engineering technology. We then present a new aircraft design methodology and explain the impact of new software engineering technology on its realization.This analysis explains how new engineering information needs differ from the capabilities provided by the conventional information systems as applied to conceptual aircraft design. We conclude that the conventional design methodology will also profit from the incorporation of new software engineering technology.