Abstract: A foldable, articulated inclined ramp or stair assembly actuation system is shown and described. The assembly comprises at least three elements connected by hinges to each other and foldable on each other under the control of a series of pulleys interconnected by a single drive cable. A method of operating the arrangement is described whereby an orderly folding sequence is automatically maintained by the actuating means. The assembly is suitable for installation within an aircraft and may be power driven to extend and retract through a loading door, thus obviating the need for any ground equipment for the purpose.