## N 

N —north NA —not authorized NAAQS —national ambient air quality standards NADA —ADIN concentrator NADIN —National Airspace Data Interchange Network NADSW —NADIN switches NAILS —National Airspace Integrated Logistics Support NAMS —NADIN IA NAPRS —National Airspace Performance Reporting System NAS —National Airspace System or Naval Air Station NASDC —National Aviation Safety Data NASP —National Airspace System Plan NASPAC —National Airspace System Performance Analysis Capability NATCO —National Communications Switching Center NAV —navigation NAVAID —navigation aid NAVMN —navigation monitor and control NAWAU —National Aviation Weather Advisory Unit NAWPF —National Aviation Weather Processing Facility NB —northbound NCAR —National Center for Atmospheric Research, Boulder, CO NCF —National Control Facility NCIU —NEXRAD Communications Interface Unit NCP —noise compatibility program NCS —national communications system NDB —non-directional radio beacon NDNB —NADIN II NE —northeast NEM —noise exposure map NEPA —National Environmental Policy Act NEXRAD —next generation weather radar NFAX —National Facsimile Service NFDC —National Flight Data Center NFIS —NAS Facilities Information System NGT —night NI —network interface NICS —national interfacility communications system NM —nautical mile(s) NMAC —near mid-air collision NMC —National Meteorological Center NMCE —network monitoring and control equipment NMCS —network monitoring and control system NMR —nautical mile radius NOAA —National Oceanic and Atmospheric Administration NOC —notice of completion NONSTD —nonstandard NOPT —no procedure turn required NOTAM —notice to airmen NPDES —National pollutant discharge elimination system NPE —non-primary airport entitlement 

NPIAS —national plan of integrated airport systems NR —number NRC —non-recurring charge NRCS —national radio communications systems NSAP —National Service Assurance Plan NSRCATN —National Strategy to Reduce Congestion on America’s Transportation Network NSSFC —National Severe Storms Forecast Center NSSL —National Severe Storms Laboratory, Norman, OK NSWRH —NWS Regional Headquarters NTAP —Notices To Airmen Publication NTP —National Transportation Policy NTSB —National Transportation Safety Board NTZ —no transgression zone NW —northwest NWS —National Weather Service NWSR —NWS weather excluding NXRD NXRD —advanced weather radar system 

## O 

OAG —official airline guide OALT —operational acceptable level of traffic OAW —off-airway weather station OBSC —obscured OBST —obstruction ODAL —omnidirectional approach lighting system ODAPS —oceanic display and processing station OEP —operational evolution plan/partnership OFA —object free area OFDPS —offshore flight data processing system OFT —outer fix time OFZ —obstacle free zone OM —outer marker OMB —Office Of Management and Budget ONER —Oceanic Navigational Error Report OPLT —operational acceptable level of traffic OPR —operate OPS —operation OPSW —operational switch OPX —off premises exchange ORD —operational readiness demonstration ORIG —original OTR —oceanic transition route OTS —out of service; organized track system OVR —over 

## P 

PABX —private automated branch exchange PAD —packet assembler/disassembler PAEW —personnel and equipment working PAM —peripheral adapter module PAPI —precision approach path indicator PAR —precision approach radar; preferential arrival route 

