Aeronautical Terms beginning with W
WA
AIRMET
WAAS
Wide Area Augmentation System.
WAC
World Aeronautical Chart Discontinued on June 25, 2015
Wake Turbulence
Wingtip vortices that are created when an airplane generates lift. When an airplane generates lift, air spills over the wingtips from the high pressure areas below the wings to the low pressure areas above them. This flow causes rapidly rotating whirlpools of air called wingtip vortices or wake turbulence.
Wall cloud
The well-defined bank of vertically developed clouds having a wall-like appearance which form the outer boundary of the eye of a well-developed tropical cyclone.
Warm front
Any non-occluded front which moves in such a way that warmer air replaces colder air.
Warm sector
The area covered by warm air at the surface and bounded by the warm front and cold front of a wave cyclone.
Warning area
An area containing hazards to any aircraft not participating in the activities being conducted in the area. Warning areas may contain intensive military training, gunnery exercises, or special weapons testing.
WARP
Weather And Radar Processing.
Waste Gate
A controllable valve in the tailpipe of an aircraft reciprocating engine equipped with a turbocharger. The valve is controlled to vary the amount of exhaust gases forced through the turbocharger turbine.
Water equivalent
The depth of water that would result from the melting of snow or ice.
Water vapor
Water in the invisible gaseous form.
Waterspout
A tornado that forms over water.
Wave cyclone
A cyclone which forms and moves along a front. The circulation about the cyclone center tends to produce a wavelike deformation of the front.
Waypoint
A designated geographical location used for route definition or progress-reporting purposes and is defined in terms of latitude/longitude coordinates.
Waypoint (WP)
A predetermined geographical position used for route/instrument approach definition, progress reports, published VFR routes, visual reporting points or points for transitioning and/or circumnavigating controlled and/or special use airspace, that is defined relative to a VORTAC station or in terms of latitude/longitude coordinates.
Waypoints
Area navigation waypoints are specified geographical locations, or fixes, used to define an area navigation route or the flight path of an aircraft employing area navigation. Waypoints may be any of the following types:predefined, published, floating, user-defined, fly-by, or fly-over.
WCA
Wind Correction Angle.
Weather
The state of the atmosphere, mainly with respect to its effects on life and human activities; refers to instantaneous conditions or short term changes as opposed to climate.
Weather Advisory
In aviation weather forecast practice, an expression of hazardous weather conditions not predicted in the area forecast, as they affect the operation of air traffic and as prepared by the NWS.
Weather and radar processor (WARP)
A device that provides real-time, accurate, predictive and strategic weather information presented in an integrated manner in the National Airspace System (NAS).
Weather depiction chart
Details surface conditions as derived from METAR and other surface observations.
Weather radar
Radar specifically designed for observing weather. Some types are cloud detection radar and storm detection radar.
Weather vane
A wind vane.
Weathervane
The tendency of the aircraft to turn into the relative wind.
Wedge
Same as ridge—an elongated area of relatively high atmospheric pressure; usually associated with and most clearly identified as an area of maximum anticyclonic curvature of the wind flow (isobars, contours, or streamlines).
Weight
A measure of the heaviness of an object. The force by which a body is attracted toward the center of the Earth (or another celestial body) by gravity. Weight is equal to the mass of the body times the local value of gravitational acceleration. One of the four main forces acting on an aircraft. Equivalent to the actual weight of the aircraft. It acts downward through the aircraft’s center of gravity toward the center of the Earth. Weight opposes lift.
Weight And Balance
The aircraft is said to be in weight and balance when the gross weight of the aircraft is under the max gross weight, and the center of gravity is within limits and will remain in limits for the duration of the flight.
Weight-shift-control aircraft
A powered aircraft with a framed pivoting wing and a fuselage controllable only in pitch and roll by the pilot’s ability to change the aircraft’s center of gravity with respect to the wing. Flight control of the aircraft depends on the wing’s ability to flexibly deform rather than the use of control surfaces.
Wet bulb
Contraction of either wet-bulb temperature or wet-bulb thermometer.
Wet-bulb temperature
The lowest temperature that can be obtained on a wet-bulb thermometer in any given sample of air, by evaporation of water (or ice) from the muslin wick; used in computing dew point and relative humidity.
Wet-bulb thermometer
A thermometer with a muslin-covered bulb used to measure wet-bulb temperature.
WFO
Weather Forecast Office
WGS-84
World Geodetic System of 1984
Wheelbarrowing
A condition caused when forward yoke or stick pressure during takeoff or landing causes the aircraft to ride on the nosewheel alone.
When Able
When used in conjunction with ATC instructions, gives the pilot the latitude to delay compliance until a condition or event has been reconciled. Unlike “pilot discretion,” when instructions are prefaced “when able,” the pilot is expected to seek the first opportunity to comply. Once a maneuver has been initiated, the pilot is expected to continue until the specifications of the instructions have been met. “When able,” should not be used when expeditious compliance is required.
Whirlwind
A small, rotating column of air; may be visible as a dust devil.
Wide Area Augmentation System (WAAS)
A method of navigation based on GPS. Ground correction stations transmit position corrections that enhance system accuracy and add vertical navigation (VNAV) features.
Wide-Area Augmentation System (WAAS)
The WAAS is a satellite navigation system consisting of the equipment and software which augments the GPS Standard Positioning Service (SPS). The WAAS provides enhanced integrity, accuracy, availability, and continuity over and above GPS SPS. The differential correction function provides improved accuracy required for precision approach.
Wilco
I have received your message, understand it, and will comply with it.
Willy-willy
A tropical cyclone of hurricane strength near Australia.
Wind
Air in motion relative to the surface of the earth; generally used to denote horizontal movement.
Wind Correction Angle
Correction applied to the course to establish a heading so that track will coincide with course.
Wind correction angle (WCA)
The angle between the desired track and the heading of the aircraft necessary to keep the aircraft tracking over the desired track.
Wind direction
The direction from which wind is blowing.
Wind Direction Indicators
Indicators that include a wind sock, wind tee, or tetrahedron. Visual reference will determine wind direction and runway in use.
Wind Grid Display
A display that presents the latest forecasted wind data overlaid on a map of the ARTCC area. Wind data is automatically entered and updated periodically by transmissions from the National Weather Service. Winds at specific altitudes, along with temperatures and air pressure can be viewed.
Wind Shear
A sudden, drastic shift in windspeed, direction, or both that may occur in the horizontal or vertical plane.
Wind speed
Rate of wind movement in distance per unit time.
Wind vane
An instrument to indicate wind direction.
Wind velocity
A vector term to include both wind direction and wind speed.
Windmilling
When the air moving through a propeller creates the rotational energy.
Winds and temperature aloft forecast (FD)
A twice daily forecast that provides wind and temperature forecasts for specific locations in the contiguous United States.
Windsock
A truncated cloth cone open at both ends and mounted on a freewheeling pivot that indicates the direction from which the wind is blowing.
Wing
Airfoil attached to each side of the fuselage and are the main lifting surfaces that support the airplane in flight.
Wing Area
The total surface of the wing (square feet), which includes control surfaces and may include wing area covered by the fuselage (main body of the airplane), and engine nacelles.
Wing Chord
A straight-line distance across a wing from leading edge to trailing edge.
Wing Span
The maximum distance from wingtip to wingtip.
Wing Tank Liner
A liner for aircraft fuel tanks which limits the amount of fuel that can be spilled in the event of a crash.
Wing Tip Vortices
Vortices.
Wing Twist
A design feature incorporated into some wings to improve aileron control effectiveness at high angles of attack during an approach to a stall.
Winglet or tip fin
An out-of-plane surface extending from a lifting surface. The surface may or may not have control surfaces.
Wings
Airfoils attached to each side of the fuselage and are the main lifting surfaces that support the airplane in flight.
Wingtip Vortices
The rapidly rotating air that spills over an airplane’s wings during flight. The intensity of the turbulence depends on the airplane’s weight, speed, and configuration. It is also referred to as wake turbulence. Vortices from heavy aircraft may be extremely hazardous to small aircraft.
WMO
World Meteorological Organization
WMS
Wide-Area Master Station
WMSC
Weather Message Switching Center
WMSCR
Weather Message Switching Center Replacement
WND
Wind
Words Twice
A. As a request: “Communication is difficult. Please say every phrase twice.”
B. As information: “Since communications are difficult, every phrase in this message will be spoken twice.”
Work
A measurement of force used to produce movement.
Working or short-term memory
The portion of the brain that receives information from the sensory register. This portion of the brain can store information in memory for only a short period of time. If the information is determined by an individual to be important enough to remember, it must be coded in some way for transmittal to long-term memory.
World Aeronautical Charts
Aeronautical Chart.
World Aeronautical Charts (WAC)
A standard series of aeronautical charts covering land areas of the world at a size and scale convenient for navigation (1:1,000,000) by moderate speed aircraft. Topographic information includes cities and towns, principal roads, railroads, distinctive landmarks, drainage, and relief. Aeronautical information includes visual and radio aids to navigation, airports, airways, restricted areas, obstructions and other pertinent data. Discontinued on June 25, 2015
World Aeronautical Charts (WAC) (1:1,000,000)
Provide a standard series of aeronautical charts covering land areas of the world at a size and scale convenient for navigation by moderate speed aircraft. Topographic information includes cities and towns, principal roads, railroads, distinctive landmarks, drainage, and relief. Aeronautical information includes visual and radio aids to navigation, airports, airways, restricted areas, obstructions, and other pertinent data. Discontinued.
WP
Waypoint
WRS
Wide-Area Ground Reference Station
WS
SIGMET
WSO
Weather Service Office
WSP
Weather System Processor
WST
Convective Significant Meteorological Information
WW
Severe Weather Watch Bulletin
WX
Weather
WX DEV
Weather Deviation
Copyright © 2002-2026 Touring Machine Company. All Rights Reserved.