Abstract: A high-capacity aircraft fuselage having two lobes placed side by side and assembled together along two longitudinal lines of junction is designed to facilitate passenger movement from one lobe to the other in accordance with aviation safety regulations. The fuselage includes a top longeron (28) for reinforcing the top line of junction, a floor (23) providing a separation between an upper internal space which can serve as a cabin (24) and a lower internal space (25) which can serve as a hold, a girder (32) for supporting the cabin floor and connecting it to the bottom portion of the fuselage, rows of seats extending from one side of the bilobed body to the other, a bottom longeron (29) for reinforcement along the bottom line of intersection, and posts (31) disposed in spaced relation in the rows of seats for connecting the top longeron (28) to structural members located in the lower region of the fuselage (32, 29).