Abstract: An extendable multi-stage trailer loader or unloader apparatus includes a frame assembly having first and second frame members that are interconnected. The second frame member is selectively extendable from the first frame member. A first conveying surface is supported by the first frame member and defines a first conveyor. The first conveying surface is operable to convey articles between an upstream end of the first conveyor and a downstream end of the first conveyor. A second conveying surface is supported by the second conveying member. The second conveying surface is defined by a second conveyor. The second conveying surface is operable for conveying articles between the downstream end of the first conveyor and a downstream end of the second conveyor. The second conveyor includes a flexible support supporting the second conveying surface.