The double-fuselage layout: a preliminary case study of a possible way of reducing the development costs for new high-capacity aircraft

The double-fuselage layout, sometimes proposed in the past, is considered t o be an alternative (by utilizing a great number of components of an existi ng aircraft) to a new aircraft (with the traditional layout) of about twice the size of the existing aircraft. The development cost reduction is attra ctive if the technical performance of the double-fuselage is comparable wit h that of the hypothetical new aircraft. The first aim of the present work is to sketch a double-fuselage layout wit h similar values of wing loading, thrust-weight ratio and aspect ratio to t he reference new aircraft of increased size. On the basis of this sketch, s ome other topics are discussed, such as the landing gear and tail surface c onfigurations, ground operations, etc. Particular attention has to be paid to structural problems related to the double-fuselage layout, especially th e different modes of stress in structural elements of the original aircraft .