An aircraft duct assembly comprising at least two ducts extending along a general direction of rectilinear extent, each duct being an electrical, hydraulic or aeraulic duct connected to a duct support. The duct support comprises a first slideway element configured to cooperate with a second slideway element to form a slideway in the general direction of extent of the ducts. The duct assembly can thus be inserted, after mounting, by translation along the direction of the slideway into an aircraft fuselage portion. The mounting of the duct assembly and installation thereof in a fuselage are simplified, and the duct assembly is more reliable.