The box-wing configuration: a critical review of design approaches and applications

This paper provides an overview of the main applications of the box-wing configuration for transport aircraft. Its main objective is to emphasize, through a proper selection of literature references, the peculiar performance and functional characteristics of the box-wing lifting architecture from the perspective of aircraft design. Two distinct approaches can guide the introduction of innovations within the aeronautical industry. The first is an evolutionary approach, which aims to implement incremental advancements without altering the fundamental framework of the current state of the art. The second is a breakthrough approach, which introduces functional solutions that are not addressed by existing technologies, thus reaching radical changes to established paradigms. The analysis of literature regarding the design and development of box-wing aircraft presented in this paper reveals that a breakthrough approach is essential for effectively integrating this innovation into transport aviation. By examining the application of the box-wing concept across various aircraft categories, ranging from medium-range and regional transport to ultralight aircraft and urban air mobility, the paper highlights the specific performance and functional potential of this configuration. Additionally, it identifies the limitations inherent to basic research and the critical bottlenecks that currently prevent its progression toward industrial implementation.