What does FUS/LF stand for?

Fuselage

Describes the center section of the airframe about which are oriented and attached the wing(s) and empenage. OR  The main structure, or central section, of an aircraft, which normally contains the crew, passengers, cargo, etc. OR The body structure of an aircraft. An aircraft's main body structure to which the wings, tail and, in most single-engine airplanes, engine are attached.