Definitions and Acronyms  Section 9  1 2 1 9.2_SMSM_201904  Originally published April 2019  Uncontrolled copy when downloaded  SME  Subject Matter Expert  SMS  Safety Management System  SMTS  Safety Management Tracking System  SOC  Safety Oversight Circular  SRM  Safety Risk Management  SRMGSA  Safety Risk Management Guidance for System Acquisitions  STARS  Standard Terminal Automation Replacement System  T-SAP Technical Operations Safety Action Program  TCAS Traffic Alert and Collision Avoidance System  TIS Traffic Information Services  TRACON Terminal Radar Approach Control VMC  Visual Meteorological Conditions  WAM  Wide Area Multilateration 