Glossary

A-RNP - Advanced Required Navigation Performance

ATC – Air Traffic Control

ATIS – Automatic Terminal Information Service. Broadcast service at airports which provides non-control airport/terminal area and meteorological information to pilots.

CONVENTIONAL PROCEDURE – An instrument flight procedure that requires ground based navigational aids (NAVAID) to provide course guidance for an instrument approach to an airport or a departure procedure from an airport.

CWG - Community Working Group

DCA – The three-letter identifier for either the Ronald Reagan Washington National Airport or the ground based navigational aid associated with the airport – the DCA VOR/DME.

DME – Distance Measuring Equipment – A NAVAID used to determine distance in NM from the station.

GPS – Global Positioning System – A satellite-based navigational aid.

I-ASO – The identifier for a localizer used for course guidance to the airport.

IMC – Instrument Meteorological Conditions – Instrument meteorological conditions means weather conditions below the minimums prescribed for flight under Visual Flight Rules (VFR).

LDA – Localizer type Directional Aid – A localizer normally located off-airport or on airport that is not directly aligned with the runway. Localizer – A ground based directional aid that provides precision lateral guidance to an airport or runway.

IFP – Instrument Flight Procedure

MARS – Multiple Airport Route Separation – A new separation standard currently under development by the FAA to enable reduced lateral separation between aircraft flying RNAV routes within terminal airspace.

MLS – Microwave Landing System – A largely experimental instrument landing system that was deployed to a few airports for testing in the 1980’s. Page 2 of 3

MSL – Mean Sea Level – Commonly used when referencing aircraft altitudes above the level of the oceans.

MWAA – Metropolitan Washington Airports Authority

NADP-1/2 – Noise Abatement Departure Procedure – Two specific standard climb profiles involving power settings and climb rates for departing aircraft to use resulting in reduced noise impact along the departure route.

NOA – North of Airport Committee of the Community Working Group (CWG)

NAVAID – A ground based navigational aid used to provide aircraft course guidance to/from the station and/or distance measuring equipment used to determine the slant range distance from a station.

NM – Nautical Mile

P-56 – Prohibited Area 56 – The airspace that surrounds the White House, Capitol Building, and other government office buildings in which flight by aircraft is prohibited.

PBN – Performance Based Navigation – A very precise navigational criteria or standard by which instrument flight procedures are designed allowing the use of RNAV and/or GPS to fly very accurate arrival and departure routes.

PCT – Potomac Terminal Radar Approach Control, also known as the Potomac Consolidated TRACON, is the Air Traffic Control facility that handles flights in the Washington Metroplex.

RADIAL – A specific electronic course defined in one of 360-degrees from a NAVAID such as a VOR or TACAN that aircraft may use to navigate to/from a station expressed as a number followed by the letter “R” – i.e., 328R

RF – Radius-To-Fix – A type of RNAV leg or approach segment of an IFP that is made up of two waypoints connected by an arc or uniform curved flight path.

RNAV – Area Navigation – RNAV can be one of several kinds of systems (including GPS) used by aircraft to navigate point to point without having to fly directly to/from a NAVAID.

RNP – Required Navigation Performance – RNP is a very precise version of RNAV that is normally used for instrument approach procedures but that may also be used in other instrument flight procedures.

RWY – Runway Page 3 of 3

SIAP – Standard Instrument Approach Procedure

SID – Standard Instrument Departure

SM – Statute Mile

SOA – South of Airport Committee of the Community Working Group (CWG)

SOP – Standard Operating Procedure

STAR – Standard Terminal Arrival Route

TAA – Terminal Arrival Area – Criteria used within TERPS to allow aircraft to conduct approaches from a wide area surrounding an IAF or IF that protects aircraft from terrain and obstructions without having to be established on the final approach course.

TAA Concept Test – An evaluation of a proposed SOP that will allow air traffic controllers to sequence aircraft to the IF (DARIC) rather than the IAF (FERGI) in a more randomized manner resulting in track variability over residential areas.

TACAN – Tactical Air Navigation – A NAVAID used by military aircraft.

TERPS – Terminal Procedures – The criteria by which the FAA designs instrument flight procedures.

TF – Track-To-Fix - A type of RNAV leg or approach segment of an IFP that is made up of two waypoints connected by a straight-line flight path.

VFR – Visual Flight Rules - Weather conditions reported as less than 3 statute miles visibility, or the ceiling is less than 1000 feet above the ground.

VOR – Very High Frequency Omni Range – A NAVAID that produces 360-degrees of electronic radials for aircraft to navigate to/from a station.

WP – Waypoint – A point in space that aircraft can navigate to using RNAV.