Abbreviation/ Meaning
Acronym
SWSL . . . . . . Supplemental Weather Service Locations
RAIS . . . . . . Remote Airport Information Service
RBDT . . . . . . Ribbon Display Terminals
RCAG . . . . . Remote Center Air/Ground
RCC . . . . . . . Rescue Coordination Center
RCLS . . . . . . Runway Centerline Lighting System
RCO . . . . . . . Remote Communications Outlet
RD . . . . . . . . Rotor Diameter
REIL . . . . . . . Runway End Identifier Lights
REL . . . . . . . Runway Entrance Lights
RFM . . . . . . . Rotorcraft Flight Manual
RIL . . . . . . . . Runway Intersection Lights
RLIM . . . . . . Runway Light Intensity Monitor
RMI . . . . . . . Radio Magnetic Indicator
RNAV . . . . . . Area Navigation
RNP . . . . . . . Required Navigation Performance
ROC . . . . . . . Required Obstacle Clearance
RPAT . . . . . . RNP Parallel Approach Runway
Transitions
RVR . . . . . . . Runway Visual Range
RVSM . . . . . . Reduced Vertical Separation Minimum
RWSL . . . . . . Runway Status Light
SAFO . . . . . . Safety Alerts For Operators
SAM . . . . . . . System Area Monitor
SAR . . . . . . . Search and Rescue
SAS . . . . . . . Stability Augmentation System
SBAS . . . . . . Satellite-based Augmentation System
SCAT-1
DGPS . . . . . . Special Category I Differential GPS
SDF . . . . . . . Simplified Directional Facility
SFL . . . . . . . . Sequenced Flashing Lights
SFR . . . . . . . Special Flight Rules
SIAP . . . . . . . Standard Instrument Approach Procedure
SID . . . . . . . . Standard Instrument Departure
SIGMET . . . . Significant Meteorological Information
SM . . . . . . . . Statute Mile
SMGCS . . . . Surface Movement Guidance Control
System

SNR . . . . . . . Signal-to-noise Ratio

SOIA . . . . . . Simultaneous Offset Instrument
Approaches
SOP . . . . . . . Standard Operating Procedure
SPC . . . . . . . Storm Prediction Center
SPS . . . . . . . . Standard Positioning Service
STAR . . . . . . Standard Terminal Arrival
STARS . . . . . Standard Terminal Automation
Replacement System

Abbreviation/ Meaning
Acronym
TA . . . . . . . . . Traffic Advisory
TAA . . . . . . . Terminal Arrival Area
TAC . . . . . . . Terminal Area Chart
TACAN . . . . Tactical Air Navigation
TAF . . . . . . . Aerodrome Forecast
TAS . . . . . . . True Air Speed
TCAS . . . . . . Traffic Alert and Collision Avoidance
System
TCH . . . . . . . Threshold Crossing Height
TD . . . . . . . . Time Difference
TDLS . . . . . . Tower Data Link System
TDWR . . . . . Terminal Doppler Weather Radar
TDZ . . . . . . . Touchdown Zone
TDZE . . . . . . Touchdown Zone Elevation
TDZL . . . . . . Touchdown Zone Lights
TEC . . . . . . . Tower En Route Control
THL . . . . . . . Takeoff Hold Lights
TIBS . . . . . . . Telephone Information Briefing Service
TIS . . . . . . . . Traffic Information Service
TIS-B . . . . . . Traffic Information Service-Broadcast
TLS . . . . . . . Transponder Landing System
TPP . . . . . . . . Terminal Procedures Publications
TRSA . . . . . . Terminal Radar Service Area
TSO . . . . . . . Technical Standard Order
TWEB . . . . . Transcribed Weather Broadcast
TWIB . . . . . . Terminal Weather Information for Pilots
System
UA . . . . . . . . Unmanned Aircraft
UAS . . . . . . . Unmanned Aircraft System
UAV . . . . . . . Unmanned Aerial Vehicle
UFO . . . . . . . Unidentified Flying Object
UHF . . . . . . . Ultrahigh Frequency
U.S. . . . . . . . United States
USCG . . . . . . United States Coast Guard
UTC . . . . . . . Coordinated Universal Time
UWS . . . . . . . Urgent Weather SIGMET
VAR . . . . . . . Volcanic Activity Reporting

VASI . . . . . . . Visual Approach Slope Indicator

VCOA . . . . . Visual Climb Over the Airport

VDA . . . . . . . Vertical Descent Angle
VDP . . . . . . . Visual Descent Point
VFR . . . . . . . Visual Flight Rules
VGSI . . . . . . Visual Glide Slope Indicator
VHF . . . . . . . Very High Frequency
VIP . . . . . . . . Video Integrator Processor
VMC . . . . . . Visual Meteorological Conditions