Systems and methods are provided for fabricating a fuselage of an aircraft. The method includes: disposing arcuate sections of fuselage at a track of a factory such that concavities of the arcuate sections of the fuselage face a floor of the factory, and bearing edges of the arcuate sections of fuselage directly contact the track; advancing the arcuate sections of fuselage synchronously along the track in a process direction; and performing work within concavities of the arcuate sections of fuselage during pauses between pulses of the arcuate section of fuselage via stations that are disposed beneath the concavities and that are directly mounted to the floor of the factory.