Conceptual design of a medium-sized joined-wing aircraft

The joined-wing aircraft is a very promising concept to reduce the ever-increasing fuel costs and CO(2) emissions. Joined-wing aircraft employ tandem wings having positive and negative sweep and dihedral, arranged to form diamond shapes in both plan and front views. This article evaluates its capabilities by establishing a comparison with respect to a reference conventional wing-plus-horizontal tail aircraft. Both airplanes are designed for the same medium-/long-range transport mission. The topics considered include structural arrangement, weights and aerodynamic characteristics, as well as operational issues, such as performance and direct operating costs. The conclusions drawn at the end of this preliminary study are very positive, but further research is required in order to confirm some hypotheses regarding the structural arrangement.