Abstract: A joining system includes a holding fixture assembly configured to hold a fuselage skin. The stringers are temporarily attached to the fuselage skin. The joining system includes an upper beam assembly including an upper beam and a lower beam assembly. The lower beam assembly includes a lower beam and at least one lower heating element. The holding fixture assembly is coupled to the upper beam assembly. The holding fixture assembly is coupled to the lower beam assembly. The upper beam is movable relative to the lower beam to clamp the at least one of the plurality of stringers and the fuselage skin together prior to and during welding.

Abstract: A door answering system is described for enabling the occupant of a structure (e.g., house, apartment, etc.) to provide a pre-recorded message to a visitor who has approached the entrance of the structure. The system includes a speaker/microphone and a call switch at the entrance for the visitor. Inside the structure there is a recorder/player for playing a pre-recorded message and recording a message left by the visitor.