Definitions — Page 57, Lesson 41

I want to walk you through a set of definitions from the Communications manual. These are the standard ICAO abbreviations and acronyms you will use in flight planning, weather reports, NOTAMs, and radio communications. Let's go through them in order, starting with the V section. First, VA stands for Volcanic Ash. That's a critical hazard in aviation — volcanic ash can damage engines and airframes, so you'll see this in SIGMETs and NOTAMs. VAC is Visual Approach Chart. This is the chart you use when you're conducting a visual approach into an aerodrome, showing terrain, obstacles, and visual reference points. VAL means In Valleys — used in weather reports or NOTAMs to describe a location. VAN is Runway Control Van. That's the mobile unit at an aerodrome that controls runway operations. Now, VAR appears twice. First, VAR is Magnetic Variation — the angular difference between true north and magnetic north at a given location. Second, VAR also stands for Visual-Aural Radio Range, an older type of radio navigation aid that provides both visual and aural signals. VASIS is the Visual Approach Slope Indicator System — a set of lights on the ground that gives you a visual indication of whether you're on the correct glide path during approach. VC means Vicinity of aerodrome. This is followed by a code for the phenomenon, for example VC FG means Vicinity Fog. Other combinations include VC FC for Funnel Cloud, VC SH for Showers, VC PO for Dust/sand whirls, VC BLDU for Blowing Dust, VC BLSA for Blowing Sand, or VC BLSN for Blowing Snow. So when you see VC in a METAR, it means the condition is near but not at the aerodrome itself. VCY is simply Vicinity. VDF is Very High Frequency Direction Finding Station — a ground station that can determine the bearing of your aircraft's VHF transmission. VER means Vertical. VFR is Visual Flight Rules — the set of regulations under which you fly by visual reference to the ground and sky, with specific weather minima. VHF is Very High Frequency, specifically the band from 30 to 300 MHz. This is the primary frequency band for voice communications in aviation. VIP is Very Important Person — used in flight planning for special passenger handling. VIS is Visibility — the horizontal distance you can see and identify prominent objects, reported in metres or kilometres. VLF is Very Low Frequency, the band from 3 to 30 kHz. This is used for long-range navigation systems like Omega and some military communications. VLR is Very Long Range — describing aircraft or equipment capable of operating over great distances. VMC is Visual Meteorological Conditions — the weather conditions that meet the minima for VFR flight. VM(C) is Visual Manoeuvring (Circling) — a circling approach procedure flown visually after an instrument approach. VOLMET is Meteorological information for aircraft in flight — a continuous broadcast of weather reports for specific aerodromes, usually on HF or VHF. VOR is Very High Frequency Omnidirectional Radio Range — the primary short-to-medium range navigation aid that gives you a radial bearing from the station. VORTAC is a VOR and TACAN combination — a single facility that provides both VOR azimuth guidance and TACAN distance and bearing for military aircraft. VOT is VOR airborne equipment test facility — a ground-based test transmitter that lets you check the accuracy of your aircraft's VOR receiver. VRB means Variable — used in wind reports when the direction is changing. VRP is Visual Reference Point — a prominent landmark used for visual navigation or as a holding point. VSA means By visual reference to the ground — used in approach procedures. VSP is Vertical Speed — the rate of climb or descent, usually in feet per minute. VSTOL is Very Short Take-Off and Landing — aircraft capable of operating from very short runways. VTOL is Vertical Take-Off and Landing — aircraft like helicopters that can take off and land vertically. Now moving to the W section. W stands for West or Western longitude when used in coordinates. It also stands for White when describing lights or markings. WAC is World Aeronautical Chart - ICAO 1:1,000,000 (1 mil) — a standard chart series used for visual navigation at a scale of one to one million. WAFC is World Area Forecast Centre — the centres in London and Washington that produce global aviation weather forecasts. WB is Westbound — used in flight planning and ATC. WBAR is Wing Bar lights — lights on the wingtips or along the wing for visibility. WDI is Wing Direction Indicator — a wind direction indicator mounted on a wing. WDSPR means Widespread — used in weather reports. WED is Wednesday. WEF is With Effect From OR Effective From — used in NOTAMs and regulatory documents to indicate the start date and time. WI means Within — used in position reports and NOTAMs. WID is Width. WIE is With Immediate Effect OR Effective Immediately — used when a change takes effect right now. WILCO is Will Comply — a standard radiotelephony phrase meaning you have received the instruction and will carry it out. WINTEM is Forecast upper wind and temperature for aviation — a specific type of forecast for flight planning. WIP is Work in Progress — used in NOTAMs to indicate construction or maintenance on an aerodrome. WKN means Weaken or Weakening — used in weather forecasts. WNW is Wet North West — a compass point. WO means Without. WPT is Waypoint — a defined geographical position used for navigation. WRDA is Weapon Range Danger Area — an airspace area where weapons testing occurs. WRNG is Warning. WS is Windshear — a sudden change in wind speed or direction that can be hazardous, especially during takeoff and landing. WSW is West South West — another compass point. And finally, WT — that's the start of another entry, but the excerpt ends there. Let me show you the diagrams that accompany these definitions. These are the standard abbreviations you'll encounter in every phase of flight. Take your time with them — you'll need to recognise them instantly in real operations.