Research on Evolution Process and Control Method of External Shapes in the Life-cycle of Modern Civil Jets

External shape is a key property of aircraft. With the wide application of digital technology, various external shapes are produced in different states and different uses in the life-cycle of modern civil jets. If these external shapes are not clearly distinguished, they might be used improperly. Therefore, in this paper, various shapes in the full life-cycle of modern civil jets are defined, and the evolution process of these external shapes is researched. Based on the control of these external shapes, some advanced management methods are put forward, which have been successfully applied in civil jet development in China, and effectively improve the efficiency of civil jet product development.