Abstract: A supported davit arm extension assembly for a descent apparatus comprising an escape shuttle suspended from a cable defining a descent path from an initial point at a receiver of a platform to a terminal point proximate to a ground surface. The extension assembly comprises a davit arm extending above the platform and secured to the receiver, and a fall arrest trolley operatively coupled to the shuttle at a first end and terminating at a second end extending substantially away from the terminal point. The second end of the fall arrest trolley has a securement point for connection to and support of a load, such as a worker, by an overhead fall arrest. While the shuttle is docked with the receiver, the fall arrest trolley extends over the platform, supported by the davit arm, and facilitates substantially unfettered movement of the worker around the platform. As the worker enters the shuttle, it is disengaged from the receiver and follows the descent path of the cable toward the ground surface.