HAA - Height Above Airport  HAR - High Altitude Redesign  HAT - Height Above Touchdown HCH - Heliport Crossing Height HF - High Frequency  HIRL - High Intensity Runway Lights HS - Hot Spot MEA - Minimum Enroute Altitude MEF - Maximum Elevation Figure MF - Medium Frequency MIA - Minimum IFR Altitude  MIRL - Medium Intensity Runway Lights MOA - Military Operations Areas MOCA - Minimum Obstruction Clearance Altitude MON - Minimum Operational Network MORA - Minimum Off-Route Altitude MRA - Minimum Reception Altitude MSA - Minimum Safe Altitude MSL - Mean Sea Level MTA - Minimum Turning Altitude MTR - Military Training Route MVA - Minimum Vector Altitude IAC - Interagency Air Committee IACC - Interagency Air Cartographic Committee IAF - Initial Approach Fix IAP - Instrument Approach Procedure ICAO - International Civil Aviation Authority IDT - Identifier IF - Intermediate Fix IFR - Instrument Flight Rules ILS - Instrument Landing System IMC - Instrument Meteorological Conditions INS - Inertial Navigation System IR - Instrument Route (Military) IRU - Inertial Reference Unit N - North N/A - Not Applicable NA - Not Authorized NAAS - Naval Auxiliary Air Station NAS - Naval Air Station NAS - National Airspace System NAV - Naval Air Facility NAVAID - Navigational Aid (Ground based) NDB - Non-Directional Radiobeacon NextGen - Next Generation Air Transportation System NFDC - National Flight Data Center NFPO - National Flight Procedures Office NM - Nautical Mile NOAA - National Oceanic and Atmospheric Administration NO A/G - No Air-to-Ground Communication NOTAM - Notice to Airman NoPT - No Procedure Turn NPA - Non-Precision Approach NTAP - Notices to Airman Publication NWS - National Weather Service JO - Joint Order KIAS - Knots LAA - Local Airport Advisory LAAS - Local Area Augmentation System LAHSO - Land and Hold Short LDA - Landing Distance Available LDA - Localizer-type Directional Aid Ldg - Landing LF - Low Frequency LIRL - Low Intensity Runway Lights LNAV - Lateral Navigation LOC - Localizer LOM - Locator Outer Marker LPV - Localizer Performance with Vertical Guidance LRRS - Long Range Radar Station LTP - Landing Threshold Point OAT - Outside Air Temperature OBS - Omni Bearing Selector OCA - Ocean Control Area OCS - Obstacle Clearance Surface ODP - Obstacle Departure Procedure OM - Outer Marker OROCA - Off Route Obstruction Clearance Altitude MAA - Maximum Authorized Altitude MAP - Missed Approach Point MCA - Minimum Crossing Altitude MCAS - Marine Corps Air Station MDA - Minimum Descent Altitude MDH - Minimum Descent Height PA - Precision Approach PAR - Precision Approach Radar PBN - Performance-Based Navigation PRM - Precision Runway Monitor PT - Procedure Turn PTP - Point-to-Point Pvt - Private 130 P M O FAA Chart Users’ Guide - Abbreviations K J L N I H