A kit of parts for an aircraft structure, comprising: a fuselage having a centerline, a center section cutout, and a width at the center section cutout, the center section cutout configured to accept a center section component; a pair of wings, each wing having a wing root, a span, and an airfoil over substantially its entire span, the wings being substantially mirror images of each other; the fuselage and the wings being configured to be combined in a selected one of either a first configuration or a second configuration; wherein, in the first configuration, further comprising a center section component inserted into the center section cutout and joined to the fuselage, the wing roots being connected to opposing sides of the center section component by a side-of-body join; and wherein, in the second configuration, the wings being connected to the fuselage and also connected to each other in a centerline join in the center section cutout, a portion of the airfoil of each wing being inside the fuselage, characterized in that a said wing has a first airfoil size at its root and a second airfoil size at an end of the portion distal from its root, the kit of parts further comprising a first pair of fuselage-to-wing fairings configured to accommodate the first airfoil size for use with the first configuration; and a second pair of fuselage-to-wing fairings configured to accommodate the second airfoil size for use with the second configuration; wherein, in both of the first and second configuration, each fairing of the pair of fairings (302 or 306) is connected to both the fuselage and a wing of said pair of wings. a fuselage having a centerline, a center section cutout, and a width at the center section cutout, the center section cutout configured to accept a center section component; a pair of wings, each wing having a wing root, a span, and an airfoil over substantially its entire span, the wings being substantially mirror images of each other; the fuselage and the wings being configured to be combined in a selected one of either a first configuration or a second configuration; wherein, in the first configuration, further comprising a center section component inserted into the center section cutout and joined to the fuselage, the wing roots being connected to opposing sides of the center section component by a side-of-body join; and wherein, in the second configuration, the wings being connected to the fuselage and also connected to each other in a centerline join in the center section cutout, a portion of the airfoil of each wing being inside the fuselage, characterized in that a said wing has a first airfoil size at its root and a second airfoil size at an end of the portion distal from its root, the kit of parts further comprising a first pair of fuselage-to-wing fairings configured to accommodate the first airfoil size for use with the first configuration; and a second pair of fuselage-to-wing fairings configured to accommodate the second airfoil size for use with the second configuration; wherein, in both of the first and second configuration, each fairing of the pair of fairings (302 or 306) is connected to both the fuselage and a wing of said pair of wings.