Area navigation (RNAV) allows a cockpit-based pre-planned traversal of airspace with automatic, precise following of lateral, vertical and speed profiles. With appropriate coordination, air traffic control (ATC) and pilot voice communications are reduced because the need for altitude, heading, or speed directives is reduced. Use of RNAV in the terminal area promises benefits that include lower radio frequency congestion, greater predictability of flight path and flying time, reduced fuel burn, and increased situational awareness. The Federal Aviation Administration (FAA) has tasked The MITRE Corporation's Center for Advanced Aviation System Development (CAASD) with assessing the impact of terminal RNAV at major airports in the US. This paper presents three analyses related to terminal RNAV performance and benefits at the Las Vegas McCarran International Airport (LAS) terminal area. We analyzed route conformance, predictability given good conformance, and performed human-in-the-loop simulations.