AIM
4/20/23
Appendix 3
−
3
Abbreviations/Acronyms
Abbreviation/
Acronym
Meaning
LAWRS . . . .
Limited Aviation Weather Reporting
Station
LDA . . . . . . .
Localizer Type Directional Aid
LDA/PRM . .
Localizer Type Directional Aid/Precision
Runway Monitor
LGA . . . . . . .
LaGuardia Airport
LIRL . . . . . . .
Low Intensity Runway Lights
LLWAS . . . . .
Low Level Wind Shear Alert System
LLWAS NE .
Low Level Wind Shear Alert System
Network Expansion
LLWAS
−
RS .
Low Level Wind Shear Alert System
Relocation/Sustainment
LNAV . . . . . .
Lateral Navigation
LOC . . . . . . .
Localizer
LOP . . . . . . .
Line
−
of
−
position
LORAN . . . .
Long Range Navigation System
LP . . . . . . . . .
Localizer Performance
LPV . . . . . . .
Localizer Performance with Vertical
Guidance
LUAW . . . . .
Line Up and Wait
LZ . . . . . . . . .
Landing Zone
MAHWP . . .
Missed Approach Holding Waypoint
MAP . . . . . . .
Missed Approach Point
MAWP . . . . .
Missed Approach Waypoint
MDA . . . . . .
Minimum Descent Altitude
MEA . . . . . . .
Minimum En Route Altitude
MEARTS . . .
Micro En Route Automated Radar
Tracking System
METAR . . . .
Aviation Routine Weather Report
MGOW . . . .
Maximum Gross Operating Weight
MHz . . . . . . .
Megahertz
MIRL . . . . . .
Medium Intensity Runway Lights
MM . . . . . . .
Middle Marker
MOA . . . . . .
Military Operations Area
MOCA . . . . .
Minimum Obstruction Clearance Altitude
MRA . . . . . .
Minimum Reception Altitude
MRB . . . . . . .
Magnetic Reference Bearing
MSA . . . . . . .
Minimum Safe Altitude
MSAW . . . . .
Minimum Safe Altitude Warning
MSL . . . . . . .
Mean Sea Level
MTI . . . . . . .
Moving Target Indicator
MTOS . . . . . .
Mountain Obscuration
MTR . . . . . . .
Military Training Route
MVA . . . . . . .
Minimum Vectoring Altitude
MWA . . . . . .
Mountain Wave Activity
MWO . . . . . .
Meteorological Watch Office
NAS . . . . . . .
National Airspace System
NASA . . . . . .
National Aeronautics and Space
Administration
Abbreviation/
Acronym
Meaning
NAVAID . . . .
Navigational Aid
NAVCEN . . .
Coast Guard Navigation Center
NCWF . . . . .
National Convective Weather Forecast
NDB . . . . . . .
Nondirectional Radio Beacon
NEXRAD . . .
Next Generation Weather Radar
NGA . . . . . . .
National Geospatial
−
Intelligence Agency
NM . . . . . . . .
Nautical Mile
NMAC . . . . .
Near Midair Collision
NOAA . . . . .
National Oceanic and Atmospheric
Administration
NOPAC . . . .
North Pacific
NoPT . . . . . .
No Procedure Turn Required
NPA . . . . . . .
Nonprecision Approach
NRS . . . . . . .
Navigation Reference System
NSA . . . . . . .
National Security Area
NSW . . . . . . .
No Significant Weather
NTSB . . . . . .
National Transportation Safety Board
NTZ . . . . . . .
No Transgression Zone
NWS . . . . . . .
National Weather Service
OAT . . . . . . .
Outside Air Temperature
OBS . . . . . . .
Omni
−
bearing Selector
ODP . . . . . . .
Obstacle Departure Procedure
OIS . . . . . . . .
Operational Information System
OIS . . . . . . . .
Obstacle Identification Surface
OM . . . . . . . .
Outer Marker
OOP . . . . . . .
Operations Over People
ORD . . . . . . .
Chicago O’Hare International Airport
P/CG . . . . . . .
Pilot/Controller Glossary
PA . . . . . . . . .
Precision Approach
PAO . . . . . . .
Public Aircraft Operation
PAPI . . . . . . .
Precision Approach Path Indicator
PAR . . . . . . .
Precision Approach Radar
PAR . . . . . . .
Preferred Arrival Route
PC . . . . . . . . .
Personal Computer
PDC . . . . . . .
Pre
−
departure Clearance
PFD . . . . . . .
Personal Flotation Device
PIC . . . . . . . .
Pilot
−
in
−
Command
PinS . . . . . . .
Point
−
in
−
Space
PIREP . . . . . .
Pilot Weather Report
POB . . . . . . .
Persons on Board
POFZ . . . . . .
Precision Obstacle Free Zone
POI . . . . . . . .
Principal Operations Inspector
PPS . . . . . . . .
Precise Positioning Service
PRM . . . . . . .
Precision Runway Monitor
PT . . . . . . . . .
Procedure Turn
QICP . . . . . .
Qualified Internet Communications
Provider