This document spans a decade of work by two RTCA Special Committees (151/171). During this period@ alternative technologies to the Microwave Landing System (e.g.@ satellite navigation) have evolved. Yet the need for precision@ near-airport area navigation continues. Whatever the navigation source for an operational capability@ much of the material in this document is germane to any precision@ terminal-area navigation system. The philosophy used in preparing the document was to provide guidance for any terminal area navigation system@ although the specific performance requirements and test procedures assume the MLS Random (Area) Navigation (RNAV) sensor inputs.