Abbreviation/ Acronym Meaning LAWRS Limited Aviation Weather Reporting Station LDA . LDA/PRM Localizer Type Directional Aid Localizer Type Directional Aid/Precision Runway Monitor LGA . LIRL . LLWAS . LLWAS NE . LaGuardia Airport Low Intensity Runway Lights Low Level Wind Shear Alert System Low Level Wind Shear Alert System Network Expansion LLWAS-RS . Low Level Wind Shear Alert System Relocation/Sustainment LNAV LOC . LOP . LORAN LP . LPV . Lateral Navigation Localizer Line-of-position Long Range Navigation System Localizer Performance Localizer Performance with Vertical Guidance LUAW . LZ . Line Up and Wait Landing Zone MAHWP . MAP . MAWP . MDA MEA . MEARTS . Missed Approach Holding Waypoint Missed Approach Point Missed Approach Waypoint Minimum Descent Altitude Minimum En Route Altitude Micro En Route Automated Radar Tracking System Aviation Routine Weather Report Maximum Gross Operating Weight Megahertz Medium Intensity Runway Lights Middle Marker Military Operations Area Minimum Obstruction Clearance Altitude Minimum Reception Altitude Magnetic Reference Bearing Minimum Safe Altitude Minimum Safe Altitude Warning Mean Sea Level Moving Target Indicator Mountain Obscuration Military Training Route Minimum Vectoring Altitude Mountain Wave Activity Meteorological Watch Office National Airspace System National Aeronautics and Space Administration METAR MGOW MHz . MIRL MM . MOA MOCA . MRA MRB . MSA . MSAW . MSL . MTI . MTOS MTR . MVA . MWA MWO NAS . NASA Abbreviations/Acronyms Abbreviation/ Acronym Meaning NAVAID NAVCEN . NCWF . NDB . NEXRAD . NGA . NM NMAC . NOAA . Navigational Aid Coast Guard Navigation Center National Convective Weather Forecast Nondirectional Radio Beacon Next Generation Weather Radar National Geospatial-Intelligence Agency Nautical Mile Near Midair Collision National Oceanic and Atmospheric Administration NOPAC NoPT NPA . NRS . NSA . NSW . NTSB NTZ . NWS . North Pacific No Procedure Turn Required Nonprecision Approach Navigation Reference System National Security Area No Significant Weather National Transportation Safety Board No Transgression Zone National Weather Service OAT . OBS . ODP . OIS OIS OM OOP . ORD . P/CG . Outside Air Temperature Omni-bearing Selector Obstacle Departure Procedure Operational Information System Obstacle Identification Surface Outer Marker Operations Over People Chicago O"Hare International Airport Pilot/Controller Glossary PA . Precision Approach PAO . PAPI . PAR . PAR . PC . PDC . PFD . PIC PinS . PIREP POB . POFZ POI PPS PRM . PT . Public Aircraft Operation Precision Approach Path Indicator Precision Approach Radar Preferred Arrival Route Personal Computer Pre-departure Clearance Personal Flotation Device Pilot-in-Command Point-in-Space Pilot Weather Report Persons on Board Precision Obstacle Free Zone Principal Operations Inspector Precise Positioning Service Precision Runway Monitor Procedure Turn QICP Qualified Internet Communications Provider Appendix 3-3