L
L Left
L Locator
L Logistics
L/D Lift/Drag Ratio
L/F Load Factor
L/MF Low/Medium Frequency
LA Low Approach
LAA Local Airport Advisory
LAADR Low Altitude Arrival/Departure Routing
LAAS Local Area Augmentation System
LAAS Low Altitude Alert System
LAB Laboratory
LABRDR Labrador
LABS Leased A B Service
LABS Leased Service A/B System
LABS Los Angeles Basin Study
LABS Low Altitude Bombing System
LABSC LABS GS-200 Computer
LABSR LABS Remote Equipment
LABSW LABS Switch System
LAC Logical Access Control
LADP Local Airport Deicing Plan
LAE Limited Aircraft Examiner
LAGPS Local Area Global Positioning System
LAHSO Land and Hold Short Operation
LAM Logical Acknowledgement
LAMP Localized Aviation MOS Program
LAN Inland
LAN Local Area Network
LANTIRN Low-Altitude Navigation Targeting Infa-Red for Night
LAPADS Light-weight Acoustic Processing and Display System
LAPC Laptop Auxiliary Performance computer
LAPUT Light-Activated Programmable Unijunction Transistor
LARAM Light-Addressed Random Access Memory
LARCT Last Radio Contact
LASCAR Light-Activated Silicon Controlled Rectifier
LAT Latitude
LATA Local Access and Transport Area
LAU Linear Accelerometer Unit
LAWRS Limited Aviation Weather Reporting Service
LAWRS Limited Aviation Weather Reporting Station
LAWRS Limited Aviation Weather Reporting System
LB Left Base
LB Pounds (weight)
LBR LAN Based Random Access Plan Position Indicator
LBS Lateral Beam Sensor
LC Local Control
LCA Locally
LCC Life Cycle Cost
LCD Liquid Crystal Display
LCF Local Control Facility
LCGS Low Cost Ground Surveillance Radar
LCL Local or locally
LCLY Locally
LCN Local Communications Network
LCT Locate
LCTD Located
LCTMP Little Change in Temperature
LCTN Location
LD Load
LD Long Distance
LDA Landing Directional Aid
LDA Landing Distance Available
LDA Localizer Directional Aid
LDA Localizer type Directional Aid
LDAP Lightweight Directory Access Protocol
LDG Landing
LDI Landing Direction Indicator
LDIN Lead-In Lights
LDR Labor Distribution Reporting
LEC Local Exchange Carrier
LED Light Emitting Diode
LEMAC Leading Edge of the Mean Aerodynamic Chord
LEN Length
LERX Leading Edge Root Extensions
LETFO Letter Follows
LEX Leading Edge Extensions
LF Low Frequency
LFC Laminar Flow Control
LFC Level of Free Convection
LFDS Large Facility Demarcation System
LFM Limited Fine Mesh Model
LFME Local Flow Management Enhancements
LFNT Low Frequency Intersection
LFR Low Frequency Radio Range
LFT Lift
LFTG Lifting
LGB Laser-guided Glide Bombs
LGRNG Long Range
LGT Light
LGTD Lighted
LGTR Lighter
LGWV Long Wave
LI Lifted Index
LIC Linear Integrated Circuit
LICOF Land Lines Communications Facilities
LIFO Last In First Out
LIFR Low IFR (weather reports only)
LIH Light Intensity High
LIL Light Intensity Low
LIM Light Intensity Medium
LIN Linearity
LINCS Leased Interfacility NAS Communications System
LINS Laser Inertial Navigation System
LIRL Low Intensity Runway Edge Lights
LIRL Low Intensity Runway Lights
LIS Logistics and Inventory System
LK Lake
LKLY Likely
LKS Lakes
LKTYP Like Type
LL Landline
LL Logic Level
LL Low Level
LLJ Low Level Jet
LLTV Low-Light Television
LLWAS Low Level Wind Shear Alert System
LLWS Low Level Wind Shear
LLZ Localizer
LM Locator Middle
LM/MS Low/Medium Frequency
LMM Compass Locator at ILS Middle Marker
LMM Locator Middle Marker
LMS Logistics Management Specialist
LMS LORAN Monitor Site
LMT Limit
LMT Local Mean Time
LMTD Limited
LMTG Limiting
LMTS Limits
LN Line
LNAV Lateral Navigation
LND Land
LNDG Landing
LO Liaison Officer
LO Locator Outer Marker
LO Outer Locator
LOA Letter of Agreement
LOA Letter of Authorization
LOB Line Of Business
LOC Localizer
LOCID Location Identifier
LOCMOS Local Oxidation Complementary Metal Oxide Silicon Semiconductor
LOCOR Local Coordinator
LOD Line of Death - Line between movement and non-movement area
LODA Letter of Deviation Authority
LODISNAV Long Distance Navigation
LOE Line Operating Experience
LOE Line Operational Evaluation
LOEAT lowest temperature equaled for all time
LOEFM lowest temperature equaled for the month
LOESE lowest temperature equaled so early
LOESL lowest temperature equaled so late
LOFT Line-Oriented Flight Training
LOI Letter of Intent
LOM Compass Locator at Outer Marker
LOM Locator Outer Marker
LONG Longitude
LONGL Longitudinal
LOP Line of Position
LORAC Long Range Accuracy
LORAN Long Range Air Navigation System
LORAN Long-Range Aid to Navigation
LOS Line of Sight
LOS Line Oriented Simulation
LOTMP Lowest Temperature
LOV List of Values
LOX Liquid Oxygen
LOXAT Lowest temperature exceeded for all time
LOXFM Lowest temperature exceeded for the month
LOXSE Lowest temperature exceeded so early
LOXSL Lowest temperature exceeded so late
LOZ Low Impedance
LP Left Traffic Pattern
LP Linear Polarization
LP Liquid Propane
LP Localizer Performance without vertical guidance
LP Low Pressure
LPC Logistics Program Coordinator
LPV Lateral Precision Performance with Vertical Guidance
LPV Localizer Performance with Vertical Guidance
LR Lapse Rate
LR Last message received
LRA Landing Rights Airport
LRCO Limited Remote Communications Outlet
LRCOM Long Range VHF/UHF Communications
LRCS Long-Range Communications System
LRG Large
LRG Long Range
LRGLY Largely
LRGR Larger
LRGST Largest
LRMTS Laser Ranger and Marked Target Seeker
LRNAV Long Range Navigation
LRNS Long Range Navigation System
LRR Long Range Radar
LRRA Low-range Radar Altimeter
LRRAP Long Range Resource Allocation Plan
LRRS Long Range Radar Station
LRS Lake Reporting Service
LRU Line Replaceable Unit
LS Last message sent by me
LS Left Side
LS Loud Speaker
LSA Light Sport Aircraft
LSI Large-Scale Integration
LSIA Large-Scale Integration Array
LSMS Line Station Maintenance Section
LSQ Line Squall
LSR Loose Snow on Runway
LSSAS Longitudinal Static Stability Augmentation System
LST Local Standard Time
LSU Logic Switching Unit
LT Light
LT Turn left after takeoff
LTA Lighter-Than-Air
LTAV Light and variable
LTD Along Track Distance
LTD Limited
LTF Local Training Flight
LTFC Landing Traffic
LTG Lightning
LTGCA Lightning Cloud to Air
LTGCC Lightning Cloud to Cloud
LTGCCCG Lightning Cloud to Cloud, Cloud to Ground
LTGCG Lightning Cloud to Ground
LTGCW Lightning Cloud to Water
LTGIC Lightning in Clouds
LTL Little
LTLCG Little Change
LTNG Lightning
LTP Landing Threshold Point
LTR Later
LTR Letter
LTST Latest
LTT Landline Teletypewriter
LTTR Latter
LV Leaving
LV Light and Variable
LVDT Linear Voltage Differential Transducer
LVE Leave or leaving
LVG Leaving
LVL Level
LVLOF Level Off
LVLS Levels
LVPS Low-Voltage Power Supply
LWR Lower
LWRD Lowered
LWRG Lowering
LX Low Index
LYR Layer or Layered or Layers
LYRD Layered
LYRS Layers
M
M In RVR indicates visibility less than lowest reportable sensor value (e.g. M600)
M In temperature field means “minus” or below zero
M Mach number
M Maritime (air mass)
M Metres (preceded by figures)
M Missing (weather reports only)
M Mountain Standard Time (time groups only)
M1FC Model 1 Full Capacity
MA Map Analysis
MAA Maximum Authorized Altitude
MAC Maintenance Action Code
MAC Mean Aerodynamic Cord
MAC Military Airlift Command
MACH MACH Number (speed ratio to speed of sound)
MACKAY Mackay Radio and Telegraph Company
MACVFR Make Altitude Changes VFR
MAD Magnetic Anomaly Detector
MAD Mutually Assured Destruction
MADGE Microwave Aircraft Digital Guidance Equipment
MAFAP Minimum Altitude over Facility on Final Approach Course
MAG Magnetic
MAGSI Minimum Altitude at Glide Slope Intersection Inbound
MAHWP Missed Approach Holding Waypoint
MAINT Maintenance
MAL Maintain at Least (altitude)
MALS Medium-Intensity Approach Lighting System
MALSF Medium-Intensity Approach Light System with Sequenced Flashers
MALSR Medium-Intensity Approach Lighting System With Runway Alignment Indicator
MALU Mode Annunciation Logic Unit
MAM Maintenance Assumed Monitoring
MAMS Military Airspace Management System
MAN Manitoba
MAN Manual
MANAM Manual Amendment
MANOP Manual of Operations
MAP Maintenance Automation Program
MAP Manifold Absolute Pressure
MAP Military Airport Program
MAP Missed Approach Point
MAP Missed Approach Procedure
MAP Mode Annunciator Panel
MAP Modified Access Pricing
MAPS Meteorological Aeronautical Presentation System
MAPT Missed Approach Point
MAR At Sea
MARPT Municipal Airport
MARSA Military Assumes Responsibility for Separation of Aircraft
MAS Manual A1 Simplex
MAS Military Alert System
MASPS Minimum Aviation System Performance Specification
MASS Maintenance Automation System Software
MAW Mission Adaptive Wing
MAWP Missed Approach Waypoint
MAWS Missile Approach Warning System
MAX Maximum
MB Magnetic Bearing
MB Marker Beacon
MB Millibars
MBA Marker Beacon Antenna
MBO Management by Objectives
MBPS Megabits Per Second
MBT Maneuvers Based Training
MCA Military Competency Airplane
MCA Minimum controllable Airspeed
MCA Minimum Crossing Altitude
MCA Multichip Array
MCAS Marine Corps Air Station
MCAS(H) Marine Corps Air Station (Helicopter)
MCC Maintenance Control Center
MCD Mesoscale Discussion
MCDP Maintenance Control and Display Panel
MCE Military Competency Examiner
MCH Military Competency Helicopter
MCI Mode C Intruder
MCK Maintenance Check
MCL Middle Compass Locater
MCP Mode Control Panel
MCS Maintenance and Control System
MCS Master Control Station
MCTMA Multi-Center Traffic Management Advisor
MCU Modular Concept Unit
MCW Modulated Continuous Wave
MCZNE Minimum When Control Zone Effective
MD McDonnell Douglas
MDA Minimum Descent Altitude
MDCRS Meteorological Data Collection and Reporting System
MDF Medium Frequency Direction Finding Station
MDFM Material Delivery Forecast Module
MDFR Make Descent From
MDFY Modify
MDFYD Modified
MDFYG Modifying
MDH Minimum Descent Height
MDL Model
MDLS Models
MDT Maintenance Data Terminal
MDT Moderate
MDTLY Moderately
MDZ Modernize
MDZN Modernization
MEA Minimum Enroute Altitude
MEADS Medium Extended Air Defense Systems
MEAL Micro-Extended Assembly Language
MEARTS Micro-Enroute Automated Radar Tracking System
MEC Main Equipment Center
MECH Mechanic
MED Medical
MED Medium
MEDEVAC Medical Emergency Evacuation
MEF Maximum Elevation Figure
MEGA Million
MEGG Merging
MEHT Minimum Eye Height Over Threshold
MEK Methyl Ethyl Ketone
MEL Minimum Equipment List
MEL Multi-Engine Land
MEML Memorial
MEP Mean Effective Pressure
MEPU Monofuel Emergency Power Unit
MESO Mesoscale
MET Meteorological aviation routine weather report
METAR (actual definition) Message d’observation meteorologieque pour l’aviation reguilere
METAR Aviation Routine Weather Report
METI Meteorological Information
METO Maximum Except Take-Off (Power)
METOF Meteorological Officer
METRO Metropolitan
MEX Mexico
MF Medium Frequency
MF Middle Frequency
MFD Multi-Function Display
MFJ Modified Final Judgment
MFL Maintain Flight Level
MFO Medical Field Office
MFOB Minimum Fuel on Board
MFPOF Master Flight Plan on File
MFS Military Flight Service
MFT Meter Fix Crossing Time/Slot Time
MFV Forward visibility more than (miles)
MFXT Meter Fix Time
MGAT Make good a track of (degrees)
MGMT Make good a magnetic track of (degrees)
MGMT Management
MGR Manager
MGW Maximum Gross Weight
MH Magnetic Heading
MHA Minimum Holding Altitude
MHDF Medium and High Frequency Direction Finding Station
MHDG Magnetic Heading
MHFR Military Height Finder Radar
MHKVLY Mohawk Valley
MHVDF Medium High and Very High Frequency Direction Finding Station
MHZ Megahertz
MI Manufacturing Inspector
MI Mile
MI Shallow
MIA Minimum IFR Altitudes
MIALS Medium Intensity Approach Light System
MIC Microphone
MIC Monolithic Integrated Circuit
MICROM Micro Instruction Control Read Only Memory
MID Middle
MID Midpoint (Related to RVR)
MID/ASIA Middle East/Asia Region
MIDIZ Mid Canada Identification Zone
MIDN Midnight
MIDO Manufacturing Inspection District Office
MIDPT Midpoint
MIFG Patches of shallow fog not deeper than two meters
MIJI Meaconing, Intrusion, Jamming, Interference
MIL Military
MILLI One thousandth
MIMNO Mimeographic notice
MIN Minute
MINIT Minutes in Trail
MIO Manufacturing Inspection Office
MIP Maintenance Information Printer
MIR Memory Information Register
MIREQ Minimum Requirements Specified
MIRL Medium Intensity Runway Edge Lights
MIS Management Information System
MIS Meteorological Impact Statement
MIS Missing
MISC Miscellaneous
MISG Missing
MISL Missile
MISO Manufacturing Inspection Satellite Office
MIT Miles In Trail
MITO Minimum Interval Takeoff
MKCT Make Check Turn
MKD Marked
MKR Marker
MKRBCN Marker Radio Beacon
MLDI Meter List Display Interval
MLS Microwave Landing System
MLTLVL Melting Level
MLW Maximum Landing Weight
MM Middle Marker
MM Millimeter
MMAC Mike Monroney Aeronautical Center
MMACH Maintain Mach
MMC Maintenance Monitoring Console
MMEL Master Minimum Equipment List
MMO Main Meteorological Office
MMPI Minnesota Multiphase Personality Inventory
MMR Multi-Mode Receiver
MMS Maintenance Monitoring System
MN Magnetic North
MNLD Mainland
MNLND Mainland
MNLY Mainly
MNM Minimum
MNPS Minimum Navigation Performance Specification
MNPSA Minimum Navigation Performance Specifications Airspace
MNS Mission Needs Statement
MNT Monitor
MNTN Maintain
MNVR Maneuver
MOA Memorandum of Agreement
MOA Military Operations Area
MOC Memorandum of Cooperation
MOC Minimum Obstacle Clearance
MOCA Minimum Obstruction Clearance Altitude
MOCC Mid-States Operations Control Center
MOD Memorandum of Decision
MOD Moderate
MOD Modulate or modulation or modulator
MODE C Altitude Reporting Mode of Secondary Radar
MODE S Mode Select; Discrete Addressable Secondary Radar System With Data Link
MODEM Modulator-Demodulator
MOGR Moderate or Greater
MON Above Mountains
MON Minimum Operational Network
MONOK Monitor resumed normal operation
MONOS Monitor out of service
MONTR Monitor
MOPS Minimum Operational Performance Standards
MOPTAR Multi Object Phase Tracking and Ranging
MOR Mandatory Occurrence Reporting
MORA Minimum Off Route Altitude
MOREPS Monitor Station Reports
MOS Military Operations Specialist
MOSFET Metal Oxide Silicon Field Effect Transistor
MOSIC Metal Oxide Silicon Integrated Circuit
MOST Metal Oxide Silicon Transistor
MOT Ministry of Transport (Canada)
MOTNE Meteorological Operational Telecommunications Network Europe
MOU Memorandum of Understanding
MOV Move
MOVD Moved
MOVG Moving
MOVMT Movement
MOVS Moves
MP Manifold Pressure
MP Maritime Polar Air
MPAR Multi-function Phased Array Radar
MPH Miles Per Hour
MPO Metropolitan Planning Organization
MPP Merit Promotion Program
MPS Maintenance Processor Subsystem (OR) Master Plan Supplement
MPS Meters Per Second
MPU Microprocessor Unit
MPVA Maintain a Position VFR and Advise
MRA Minimum Reception Altitude
MRC Monthly Recurring Charge
MRCA Multi-Role Combat Aircraft
MRG Medium Range
MRGL Marginal
MRGLLY Marginally
MRM Maintenance Resource Management
MRM Maintenance Returned Monitoring
MRNG Morning
MRP ATS/MET Reporting Point
MRR Mechanical Reliability Report
MRTM Maritime
MRU Military Radar Unit
MRV Maximum Reverse Voltage
MS Military Standard
MS Minus
MSA Minimum Safe Altitude
MSA Minimum Sector Altitude
MSAW Minimum Safe Altitude Warning
MSD Multi-Site Damage
MSDA Material Safety Data Sheet
MSDS Microsoft Data Engine
MSEC Millisecond
MSG Message
MSGCTR Message Center
MSI Medium Scale Integration
MSL Mean Sea Level
MSN Message Switching Network
MSR Message (transmission identification) has been misrouted
MSR Monthly Status Report
MSSR Monopulse Secondary Surveillance Radar
MST Monolithic System Technology
MST Mountain Standard Time
MSTLY Mostly
MSTR Moisture
MSU Mode Selector Unit
MT Maritime Tropical Air
MT Mountain
MTA Minimum Turning Altitude
MTBF Mean Time Between Failures
MTCA Minimum Terrain Clearance Altitude
MTCS Modular Terminal Communications System
MTD Moving Target Detection
MTEL Minimum Tools and Equipment List
MTFE Mid-Thrust Family Engine
MTI Moving Target Indicator
MTL Merger Transistor Logic
MTN Mountain
MTNS Mountains
MTOW Maximum Take Off Weight
MTP Maintenance Test Panel
MTR Military Training Route
MTRL Material
MTRY Momentary
MTSAT Multifunctional Transport Satellite
MTU Metric Units
MTW Mountain Wave
MU Friction value representing runway surface conditions
MUA Maximum Usable Altitude
MUF Maximum Usable Frequency
MULT Multiple
MULTILVL Multi-level
MUNI Municipal
MUX Multiplexor
MV Millivolt
MVA Minimum Vectoring Altitude
MVDF Medium and Very High Frequency Direction Finding Station
MVFR Maintain VFR
MVFR Marginal VFR
MVFR Marginal Visual Flight Rules
MVSP Maintain Visual Separation
MWO Meteorological Watch Office
MWP Meteorological Weather Processor
MWRC Maintain Well to Right of Course
MWS Master Warning System
MWT Mountain Wave Turbulence
MWTCS Modernized Weather Teletypewriter Communications System
MXD Mixed
MZFW Maximum Zero Fuel Weight
N
N North or Northern latitude
N/A Not Applicable
N1 RPM of Low-Pressure Compressor or Fan
N2 RPM of High-Pressure or Intermediate-Pressure Compressor
N3 RPM of High-Pressure Compressor on a Triple-Spool Engine
NA National Air Traffic Controllers Association
NA Not Authorized
NAA National Aeronautic Assosication
NAAQS National Ambient Air Quality Standards
NAAS Naval Auxiliary Air Station
NAATS National Association of Air Traffic Control Specialists
NAB Not Above
NACA National Advisory Committee for Aeronautics
NACG National Aeronautical Charting Group
NACO National Aeronautical Charting Office
NACOS National Communications Schedule
NADA NADIN Concentrator
NADIN National Airspace Data Interchange Network
NADSW NADIN Switches
NAF Naval Air Facility
NAFEC National Aviation Facilities Experimental Center
NAFI National Association of Flight Instructors
NAILS National Airspace Integrated Logistics Support
NAM North American Model
NAMS NADIN IA
NANAC National Aircraft Noise Abatement Council
NAP Needs Assessment Program
NAP Not At Present
NAPM National Associate Program Manager
NAPRS National Airspace Performance Reporting System
NAR National Airspace Review 66
NAR North American Route
NAR Not According to Routine
NARACS National Radio Communications System
NARP National Aviation Research Plan
NAS National Air Space
NAS National Aircraft Standards
NAS National Airspace System
NAS National Airspace System or Naval Air Station
NAS Naval Air Station
NAS Navigation, and Collision Avoidance System
NASA National Aeronautics and Space Administration
NASC National AIS system center
NASDC National Aviation Safety Data
NASE NAS Adaptation Services Environment
NASEO National Airways System Engineering office
NASP National Airport System Plan
NASP National Airspace System Plan
NASPAC National Airspace System Performance Analysis Capability
NASR National Airspace System Resources
NASSI National Airspace System Status Information
NASTEP National Airspace System Technical Evaluation Program
NAT North Atlantic
NAT Not ARTS Tracked
NAT/OPS North Atlantic Operation
NATA National Air Transportation Association
NATCA National Air Traffic Control Association
NATCA National Air Traffic Controllers Association
NATCO National Communications Switching Center
NATL National
NATO North Atlantic Treaty Organization
NATOPS North Atlantic Operation
NATR No Additional Traffic Reported
NATS National Air Traffic Service
NATS Noise Abatement Test System
NAV Navigation
NAV Naval Air Facility
NAVAID Navigation Aid
NAVAID Navigational Aid
NAVAIDS Navigational Aids
NAVLO Navy Liaison Officer
NAVMN Navigation Monitor and Control
NAVREP Navy Representative to the
NAVWASS Navigation and Weapon-Aiming Sub System
NAWAU National Aviation Weather Advisory Unit
NAWPF National Aviation Weather Processing Facility
NB New Brunswick
NB Northbound
NBAA National Business Aircraft Association
NBC Nuclear-Biological-Chemical
NBCAP National Beacon Code Allocation Plan
NBCFAE National Black Coalition of Federal Aviation Employees
NBFR Not Before
NBND Northbound
NBRHD Neighborhood
NC National Air Transport Coordinating Committee
NC No Change
NC No Connection
NC Normally Closed
NC Numerical Control
NCAR National Center for Atmospheric Research
NCD No Computed Data
NCDC National Climatic Data Center
NCE No Change in Estimates
NCEP National Centers for Environmental Prediction
NCF National Control Facility
NCIU NEXRAD Communications Interface Unit
NCO NCEP Central Operations
NCP NAS Change Proposal
NCP Noise Compatibility Program
NCS National Communications System
NCU Navigation Computer Unit
NCWF National Convective Weather Forecast
NCWX No Change in Weather
ND Navigation Display
NDAA Non-Development Airlift Aircraft
NDB Non-Directional Beacon
NDB(ADF) Non-Directional Beacon (Automatic Direction Finder)
NDB/DME Non-Directional Beacon and Distance Measuring Equipment (Collocated)
NDBLO Not to Descend Below
NDC National Data Center
NDFD National Digital Forecast Database
NDI Nondestructive Inspection
NDNB NADIN II
NDP National Airspace System Defense Programs
NDRO Non-Destructive Readout
NDT Non-Destructive Testing
NE Northeast
NEB National Examiner Board
NEB Northeast Bound
NEC National Electric Code
NEC Necessary
NED National Elevation Data
NEF No Further Clearance Required
NEG Negative
NEGLY Negatively
NELY North-Easterly (weather reports only)
NEM Noise Exposure Map
NEMC Network Enterprise Maintenance Center
NEPA National Environmental Policy Act
NERN Northeastern
NESDIS National Environmental Satellite Data and Information Service
NESS National Environmental Satellite Service
NETR No Essential Traffic Reported
NEW ENG New England
NEWD Northeastward
NEXRAD Next Generation Weather Radar
NEXTGEN Next Generation Air Transportation System
NF RPM of free turbine
NFAX National Facsimile Service
NFD National Flight Database
NFDC National Flight Data Center
NFDD National Flight Data Digest
N-FET N-Type Conduction Field Effect Transistor
NFH NATO Frigate Helicopter
NFIS NAS Facilities Information System
NFLD Newfoundland
NFP NIMS Premier Facility
NFPO National Flight Procedures Office
NFQ Night Frequency
NFT No Filing Time
NFU Not For Us
NG National Guard
NGA National Geospatial-Intelligence Agency
NGATS Next Generation Air Transportation System
NGM Nested Grid Model
NGT Night
NGV Nozzel Guide Vanes
NHC National Hurricane Center
NHCFAE National Hispanic Coalition of Federal Aviation Employees
NHD Not Heard
NI Network Interface
NICS National Airspace System Interfacility Communications System
NICS National Interfacility Communications System
NIL None
NIL SIG No Significant
NIL Unable to transmit
NIMA National Imagery and Mapping Agency
NIMS NAS Infrastructure Management System
NIPT National Infrastructure Planning Team
NIS Not In System
NISC NAS Implementation Support Contract
NISC NAS Integration Support Contractor
NIST National Institute of Standards and Technologies
NL No Layers
NLT Not Later Than
NLY Northerly
NM Nautical Mile
NM North Mark
NMAC Near Mid Air Collision
NMBR Number
NMBRS Numbers
NMC National Meteorological Center
NMCE Network Monitoring and Control Equipment
NMCS Network Monitoring and Control System
NMI No Middle Initial
NML Normal
NMN No Middle Name
N-MOS N-Channel Metal Oxide Silicon Semiconductor
NMPH Nautical Miles Per Hour
NMR Nautical Mile Radius
NMRS Numerous
NNE North North east
NNELY North-northeasterly
NNERN North North Eastern (weather reports only)
NNEWD North North Eastward (weather reports only)
NNNN End of message
NNW North North West
NNWLY North-northwesterly
NNWRN North North Western (weather reports only)
NNWWD North North Westward (weather reports only)
NO Not Available
NO A/G No Air-to-Ground Communication
NOAA National Oceanic and Atmospheric Administration
NOAC No Action Necessary
NOC NAV On Course
NOC Notice Of Completion
NOCC National Operation Control Center
NOF NOTAM Office
NOFIN No Further Information
NOG National Operations Group
NOHOL Not Holding
NOIFN No Information
NOM NAS Operations Manager
NOM National Communications Center
NOMAD Naval Oceanographic Meteorological Automatic Device
NONEG Negative replies not required
NONRVSM Non-RVSM capable flight
NOPAC North Pacific
NOPAR Do Not Pass to Air Defense Radar
NOPT No Procedure Turn Required
NORAC No Radio Contact
NORAD North American Aerospace Defense Command
NORDO No Radio
NOREC No Record
NOREP National Oceanic Review and Enhancement Program
NOREP No Report
NORIV No Arrival Report
NORPI No pilot balloon observation will be filed next collection unless weather changes significantly
NORR No Reply Received
NORST No Restrictions
NOS National Ocean Service
NOSI Now Simultaneous
NOSIG No Significant Ghange
NOSPL No special observations taken (weather reports only)
NOSUM NOTAM Summary
NOTAM D Distant Notice to Air Missions (NOTAM)
NOTAM D Distant Notice to Airmen (NOTAM)
NOTAM L Local Notice to Air Missions (NOTAM)
NOTAM L Local Notice to Airmen (NOTAM)
NOTAM Notice to Air Missions
NOTAM Notice to Airmen
NOTAR No Tail Report
NOZ Normal Operating Zone
NPA Non Precision Approach
NPB Nuclear Powered Bomber
NPDES National Pollutant Discharge Elimination System
NPE Non-Primary Airport Entitlement
NPI Nonprecision Instrument
NPIAS National Plan for Integrated Airport Systems
NPM NAS Program Manager/Management
NPR National Performance Review
NPRL No Parallel Traffic
NPRM Notice of Proposed Rulemaking
NPRM Notice of Proposed Rulemaking
NPRS Nonpersistent
NPT National (Tapered) Pipe Thread
NR Near
NR Number
NRAB Naval Reserve Air Base
NRC Non-Recurring Charge
NRCS National Radio Communications Systems
NRD No record of destination
NRH No reply heard
NRLY Nearly
NRN Northern
NRO National Reconnaissance Office
NRP National Route Program
NRP North American route program
NRV Nonrevenue
NRW Narrow
NS Nimbostratus
NS Nova Scotia
NSAP National Service Assurance Plan
NSC National Service Center
NSC No Significant Cloud
NSC Nonstandard C/A Code
NSCSWD No Small Craft or Storm Warning are Being Displayed
NSD Navigation System Database
NSEC Nanosecond
NSF National Science Foundation
NSP National Simulator Program
NSP Nonstandard holding pattern
NSRCATN National Strategy to Reduce Congestion on America's Transportation Network
NSSFC National Severe Storm Forecast Center
NSSL National Severe Storms Laboratory
NSSN National Standards Systems Network
NSTP Nonstop
NSW No Significant Weather
NSWRH NWS Regional Headquarters
NTAP National Track Analysis Program
NTAP Notices To Airmen Publication
NTE Not To Exceed
NTFND No Trouble Found
NTFY Notify
NTFYD Notified
NTL National
NTO Name to
NTP National Transportation Policy
NTP Notice to Proceed
NTRP No Traffic Reported
NTS Negative Torque Sensor
NTS NOTAM Tracking System
NTSB National Transportation Safety Board
NTSS Negative Torque Sensing System
NTZ No Transgression Zone
NUDET Nuclear Detonation
NVA Negative Vorticity Advection
NVM Nonvolatile Memory
NW Northwest
NWB North Westbound
NWD Northward
NWLY North Westerly (weather reports only)
NWP National Work Plan
NWP NextGen Weather Processor
NWRN North Western (weather reports only)
NWS National Weather Service
NWSO Naval Weather Service Office
NWSR NWS Weather Excluding NXRD
NXRD Advanced Weather Radar System
NXT Next
O
O&M Operations and Maintenance
O/C On Course
O/F On file
O/R On request
O/T Overtime
O21 Ocean21
OA Overhead Approach
OAC Oceanic Area Control
OAG Official Airline Guide
OALT Operational Acceptable Level of Traffic
OAMP Off-Line Aircraft Management Program
OANDR Operation and Regulation
OAOI On and Off Instruments
OAP Oceanic Automation Program
OARTS Oceanic Air Route Tracking System
OAS Obstacle Assessment Surface
OAS Oceanic Automation System
OASIS Operational and Supportability Implementation System
OAT Outside Air Temperature
OATS Office Automation Technology Services
OAW Off-Airway Weather Station
OB On Board
OBAT Outer Bleed Air Tube
OBL Obliterate
OBND Outbound
OBS Observation
OBS Omni Bearing Selector
OBSC Obscure, obscured, or obscuring
OBSCD Obscured
OBSCG Obscuring
OBST Obstacle
OBST Obstruct
OBSTN Obstruction
OC Obstruction Chart
OC On Course
OC4J Oracle Containers for Java Enterprise Edition
OCA Obstacle Clearance Altitude
OCA Oceanic Control Area
OCAC Oceanic
OCAS Out of Controlled Airspace
OCC Operations Control Center
OCDB Oracle Content Database
OCFNT Occluded front
OCH Obstacle Clearance Height
OCL Obstacle Clearance Limit
OCLD Occlude
OCLDD Occluded
OCLDG Occluding
OCLDS Occludes
OCLN Occlusion
OCNL Occasional
OCNLY Occasionally
OCR Occur
OCRD Occurred
OCRG Occurring
OCRS Occurs
OCS Obstacle Clearance Surface
OCTLA Out of Control Area
OCU Operational Conversion Unit
ODA Organization Designation Authorization
ODAL Omnidirectional Approach Lighting System
ODALS Omnidirectional Approach Lighting Systems
ODAPS Oceanic Display and Planning System
ODAPS Oceanic Display and Processing Station
ODL Oceanic Data Link
ODP Obstacle Departure Procedure
ODRA Office of Dispute Resolution for Acquisition
ODS Operational Data Store
OE Obstacle Evaluation
OE/AAA Obstruction Evaluation/Airport Airspace Analysis
OEI One Engine Inoperative
OEM Original Equipment Manufacturer
OEP Operational Evolution Plan
OETS Obstacle Evaluation Tracking System
OF Over Frequency
OFA Object Free Area
OFAS Overseas flight assistance service
OFC Office
OFDPS Offshore Flight Data Processing System
OFFL Official
OFM Out For Maintenance
OFP Occluded Frontal Passage
OFP Original Flight Plan
OFSHR Offshore
OFT Outer Fix Time
OFW Off Watch
OFXT Outer fix time
OFZ Obstacle Free Zone
OG On Ground
OGC Open Geospatial Consortium
OGN Originate
OHD Overhead
OHISS Objective Helicopter Icing Spray System
OI On Instruments
OI Operational Incident - Surface even attributed to ATC action
OIG Office of the Inspector General
OINT Omni Intersection
OIS Obstacle Identification Surface
OIS Operational Information System
OJT On The Job Training
OK Operating Normally
OK We agree or It is correct
OLDI On Line Data Interchange
OLS Optical Landing System
OM Outer Marker
OMB Office of Management and Budget
OMC Onboard Maintenance Computer
OMEGA Very Low Radio Navigation System
OMIC Operations Manager in Charge
OMO One-Minute Observation
OMSG Our Message
OMTNS Over Mountains
ONC Operational Navigation Charts
ONER Oceanic Navigational Error Report
ONS Omega Navigation System
ONSHR On shore
ONT Ontario
ONW On Watch
OOT Out Of Tolerance
OPA Opaque, white type of ice formation
OPAMP Operational Amplifier
OPC Operational Control
OPD Optimum Profile Descent
OPDT Opposite Direction Traffic
OPER Operate
OPI Office of Primary Interest
OPLT Operational Acceptable Level of Traffic
OPMET Operational meteorological (information)
OPN Open
OPN Operation
OPNML Operations Normal
OPR Office of Primary Responsibility
OPR Operate, operator, operational
OPS AF Operations
OPS Operations
OPSNET Operations Network
OPSSPECS Operational Specifications
OPSW Operational Switch
OPX Off Premises Exchange
ORD Operational Readiness Demonstration
ORD Operational Readiness Demonstration - Milestone
ORD Order, indication of
ORGPHC Orographic
ORIG Original
ORL Overrun Lights
OROCA Off-Route Obstruction Clearance Altitude
ORS Obstruction Repository System
ORS Over range station
OS Operating System
OS Operational Shakedown & Cutover
OSA Operational Safety Assessment
OSD Operational Suitability Demonstration
OSDS Oceanic System Development and Support
OSED Operational Services and Environmental Definition
OSHA Occupational Safety and Health Administration
OSIP Office Safety Inspection Program
OSRWG Oceanic Separation Reduction Working Group
OSS Over Station Sensor
OST Office of the Secretary of Transportation
OSV Ocean Station Vessel
OSV Operational Service Volume
OT On Time
OT Oral Notice
OT&E Operational Test and Evaluation
OTAS On Top and Smooth
OTFC Overflight Traffic
OTFO Operations Technical Field Office
OTLK Outlook
OTP On Top
OTPS Oceanic Traffic Planning System
OTR Oceanic Transition Route
OTR Other
OTRW Otherwise
OTS Organized Track System
OTS Out of Service
OUBD Outbound
OUTFLO Outflow
OV Location (PIREP only)
OV Over Voltage
OVAS Ocular Vergence and Accommodation Sensor
PAP This list is copywritten and belongs to proairpilot
OVC Overcast
OVD Overdue
OVHD Overhead
OVLA Overlay
OVNGT Overnight
OVR Over
OVRN Overrun
OVRNG Overrunning
OVSEA Overseas
OVTK Overtake
OVTKG Overtaking
OVTKS Overtakes
OW One Way
OWF Optimum Working Frequency
OXY Oxygen
