A variety (FIG. 4) of aero engines (30) can be rear-loaded into an aircraft cargo bay (10) with precision and safety and minimal clearance with the sides of the bay (10) by installing a roller conveyor trackway (20,22) along two seat rails (12,14) running the length of the bay (10) and its bottom-hinged rear-loading ramp (15). A ground trailer (33) carrying the engine (30) on its yoke (31) is coupled to a dolly (37) running on the trackway (20,22) and the yoke (31) transferred from rails (32) on the trailer (33) to rails (36) on the dolly (37). The dolly (37) is then winched (27) along the trackway into the bay (10) where it is made secure for flight of the aircraft. The dolly (37) can be dismantled when not in use and the trackway (when installed) is useful when pallets are to be transported.