VASI-

(See VISUAL APPROACH SLOPE INDICATOR.)

VCOA-

(See VISUAL CLIMB OVER AIRPORT.)

VDP-

(See VISUAL DESCENT POINT.)

VECTOR- A heading issued to an aircraft to provide navigational guidance by radar.

(See ICAO term RADAR VECTORING.)

VERIFY- Request confirmation of information; e.g., “verify assigned altitude.”

VERIFY SPECIFIC DIRECTION OF TAKEOFF (OR TURNS AFTER TAKEOFF)- Used by ATC to ­ascertain an aircraft's direction of takeoff and/or direction of turn after takeoff. It is normally used for IFR ­departures from an airport not having a control tower. When direct communication with the pilot is not possible, ­the request and information may be relayed through an FSS, dispatcher, or by other means.

(See IFR TAKEOFF MINIMUMS AND DEPARTURE PROCEDURES.)

VERTICAL NAVIGATION (VNAV)– A function of area navigation (RNAV) equipment which calculates, ­displays, and provides vertical guidance to a profile or path.

VERTICAL SEPARATION- Separation between aircraft expressed in units of vertical distance.

(See SEPARATION.)

VERTICAL TAKEOFF AND LANDING AIRCRAFT (VTOL)- Aircraft capable of vertical climbs and/or ­descents and of using very short runways or small areas for takeoff and landings. These aircraft include, but are ­not limited to, helicopters.

(See SHORT TAKEOFF AND LANDING AIRCRAFT.)

VERTIPAD- A small, designated area, usually with a prepared surface, on a vertiport, airport, landing/takeoff ­area, apron/ramp, or movement area used for takeoff, landing, or parking of powered‐lift aircraft.

VERTIPORT- An area of land, water, or a structure used or intended to be used to support the landing, takeoff, ­taxiing, parking, and storage of powered‐lift aircraft or other aircraft that vertiport design and performance ­standards can accommodate.

VERY HIGH FREQUENCY (VHF)- The frequency band between 30 and 300MHz. Portions of this band, 108 ­to 118MHz, are used for certain NAVAIDs; 118 to 136MHz are used for civil air/ground voice communications. ­Other frequencies in this band are used for purposes not related to air traffic control.

VERY HIGH FREQUENCY OMNIDIRECTIONAL RANGE STATION-

(See VOR.)

VERY LOW FREQUENCY (VLF)- The frequency band between 3 and 30kHz.

VFR-

(See VISUAL FLIGHT RULES.)

VFR AIRCRAFT- An aircraft conducting flight in accordance with visual flight rules.

(See VISUAL FLIGHT RULES.)

VFR CONDITIONS- Weather conditions equal to or better than the minimum for flight under visual flight ­rules. The term may be used as an ATC clearance/instruction only when:

1. An IFR aircraft requests a climb/descent in VFR conditions.
2. The clearance will result in noise abatement benefits where part of the IFR departure route does not ­conform to an FAA approved noise abatement route or altitude.
3. A pilot has requested a practice instrument approach and is not on an IFR flight plan.

   VFR FLIGHT-

   (See VFR AIRCRAFT.)

   VFR MILITARY TRAINING ROUTES (VR)- Routes used by the Department of Defense and associated ­Reserve and Air Guard units for the purpose of conducting low‐altitude navigation and tactical training under ­VFR below 10,000 feet MSL at airspeeds in excess of 250 knots IAS.

   VFR NOT RECOMMENDED- An advisory provided by a flight service station to a pilot during a preflight ­or inflight weather briefing that flight under visual flight rules is not recommended. To be given when the current ­and/or forecast weather conditions are at or below VFR minimums. It does not abrogate the pilot's authority to ­make his/her own decision.

   VFR‐ON‐TOP- ATC authorization for an IFR aircraft to operate in VFR conditions at any appropriate VFR ­altitude (as specified in 14CFR and as restricted by ATC). A pilot receiving this authorization must comply with ­the VFR visibility, distance from cloud criteria, and the minimum IFR altitudes specified in 14CFR part91. ­The use of this term does not relieve controllers of their responsibility to separate aircraft in Class B and Class ­C airspace or TRSAs as required by FAA Order JO 7110.65.

   VFR TERMINAL AREA CHARTS-

   (See AERONAUTICAL CHART.)

   VFR WAYPOINT-

   (See WAYPOINT.)

   VHF-

   (See VERY HIGH FREQUENCY.)

   VHF OMNIDIRECTIONAL RANGE/TACTICAL AIR NAVIGATION-

   (See VORTAC.)

   VIDEO MAP- An electronically displayed map on the radar display that may depict data such as airports, ­heliports, runway centerline extensions, hospital emergency landing areas, NAVAIDs and fixes, reporting ­points, airway/route centerlines, boundaries, handoff points, special use tracks, obstructions, prominent ­geographic features, map alignment indicators, range accuracy marks, and/or minimum vectoring altitudes.

   VISIBILITY- The ability, as determined by atmospheric conditions and expressed in units of distance, to see ­and identify prominent unlighted objects by day and prominent lighted objects by night. Visibility is reported ­as statute miles, hundreds of feet or meters.

   (Refer to 14CFR part91.)

   (Refer to AIM.)

4. Flight Visibility- The average forward horizontal distance, from the cockpit of an aircraft in flight, at which ­prominent unlighted objects may be seen and identified by day and prominent lighted objects may be seen and ­identified by night.
5. Ground Visibility- Prevailing horizontal visibility near the earth's surface as reported by the United States ­National Weather Service or an accredited observer.
6. Prevailing Visibility- The greatest horizontal visibility equaled or exceeded throughout at least half the ­horizon circle which need not necessarily be continuous.
7. Runway Visual Range (RVR)- An instrumentally derived value, based on standard calibrations, that ­represents the horizontal distance a pilot will see down the runway from the approach end. It is based on the ­sighting of either high intensity runway lights or on the visual contrast of other targets whichever yields the ­greater visual range. RVR, in contrast to prevailing or runway visibility, is based on what a pilot in a moving ­aircraft should see looking down the runway. RVR is horizontal visual range, not slant visual range. It is based ­on the measurement of a transmissometer made near the touchdown point of the instrument runway and is ­reported in hundreds of feet. RVR, where available, is used in lieu of prevailing visibility in determining ­minimums for a particular runway.
   1. Touchdown RVR- The RVR visibility readout values obtained from RVR equipment serving the runway ­touchdown zone.
   2. Mid‐RVR- The RVR readout values obtained from RVR equipment located midfield of the runway.
   3. Rollout RVR- The RVR readout values obtained from RVR equipment located nearest the rollout end ­of the runway.

      (See ICAO term FLIGHT VISIBILITY.)

      (See ICAO term GROUND VISIBILITY.)

      (See ICAO term RUNWAY VISUAL RANGE.)

      (See ICAO term VISIBILITY.)

      VISIBILITY [ICAO]- The ability, as determined by atmospheric conditions and expressed in units of distance, ­to see and identify prominent unlighted objects by day and prominent lighted objects by night.

8. Flight Visibility- The visibility forward from the cockpit of an aircraft in flight.
9. Ground Visibility- The visibility at an aerodrome as reported by an accredited observer.
10. Runway Visual Range [RVR]- The range over which the pilot of an aircraft on the centerline of a runway ­can see the runway surface markings or the lights delineating the runway or identifying its centerline.

    VISUAL APPROACH- An approach conducted on an instrument flight rules (IFR) flight plan which authorizes ­the pilot to proceed visually and clear of clouds to the airport. The pilot must, at all times, have either the airport ­or the preceding aircraft in sight. This approach must be authorized and under the control of the appropriate air ­traffic control facility. Reported weather at the airport must be: ceiling at or above 1,000 feet, and visibility of ­3 miles or greater.

    (See ICAO term VISUAL APPROACH.)

    VISUAL APPROACH [ICAO]- An approach by an IFR flight when either part or all of an instrument approach ­procedure is not completed and the approach is executed in visual reference to terrain.

    VISUAL APPROACH SLOPE INDICATOR (VASI)-

    (See AIRPORT LIGHTING.)

    VISUAL CLIMB OVER AIRPORT (VCOA)- A departure option for an IFR aircraft, operating in visual ­meteorological conditions equal to or greater than the specified visibility and ceiling, to visually conduct ­climbing turns over the airport to the published “climb-to” altitude from which to proceed with the instrument ­portion of the departure. VCOA procedures are developed to avoid obstacles greater than 3 statute miles from ­the departure end of the runway as an alternative to complying with climb gradients greater than 200 feet per ­nautical mile. Pilots are responsible to advise ATC as early as possible of the intent to fly the VCOA option prior ­to departure. These textual procedures are published in the `Take-Off Minimums and (Obstacle) Departure ­Procedures' section of the Terminal Procedures Publications and/or appear as an option on a Graphic ODP.

    (See AIM.)

    VISUAL DESCENT POINT- A defined point on the final approach course of a nonprecision straight‐in ­approach procedure from which normal descent from the MDA to the runway touchdown point may be ­commenced, provided the approach threshold of that runway, or approach lights, or other markings identifiable ­with the approach end of that runway are clearly visible to the pilot.

    VISUAL FLIGHT RULES- Rules that govern the procedures for conducting flight under visual conditions. The ­term “VFR” is also used in the United States to indicate weather conditions that are equal to or greater than ­minimum VFR requirements. In addition, it is used by pilots and controllers to indicate type of flight plan.

    (See INSTRUMENT FLIGHT RULES.)

    (See INSTRUMENT METEOROLOGICAL CONDITIONS.)

    (See VISUAL METEOROLOGICAL CONDITIONS.)

    (Refer to 14CFR part91.)

    (Refer to AIM.)

    VISUAL HOLDING- The holding of aircraft at selected, prominent geographical fixes which can be easily ­recognized from the air.

    (See HOLDING FIX.)

    VISUAL LINE OF SIGHT (VLOS)- Condition of operations wherein the operator maintains continuous, ­unaided visual contact with the unmanned aircraft.

    VISUAL METEOROLOGICAL CONDITIONS- Meteorological conditions expressed in terms of visibility, ­distance from cloud, and ceiling equal to or better than specified minima.

    (See INSTRUMENT FLIGHT RULES.)

    (See INSTRUMENT METEOROLOGICAL CONDITIONS.)

    (See VISUAL FLIGHT RULES.)

    VISUAL OBSERVER (VO)- A person who is designated by the remote pilot in command to assist the remote ­pilot in command and the person operating the flight controls of the small UAS (sUAS) to see and avoid other ­air traffic or objects aloft or on the ground.

    VISUAL SEGMENT-

    (See PUBLISHED INSTRUMENT APPROACH PROCEDURE VISUAL SEGMENT.)

    VISUAL SEPARATION- A means employed by ATC to separate aircraft in terminal areas and en route airspace ­in the NAS. There are two ways to effect this separation:

11. The tower controller sees the aircraft involved and issues instructions, as necessary, to ensure that the ­aircraft avoid each other.
12. A pilot sees the other aircraft involved and upon instructions from the controller provides his/her own ­separation by maneuvering his/her aircraft as necessary to avoid it. This may involve following another aircraft ­or keeping it in sight until it is no longer a factor.

    (See SEE AND AVOID.)

    (Refer to 14CFR part91.)

    VLF-

    (See VERY LOW FREQUENCY.)

    VMC-

    (See VISUAL METEOROLOGICAL CONDITIONS.)

    VOICE SWITCHING AND CONTROL SYSTEM (VSCS)- A computer controlled switching system that ­provides air traffic controllers with all voice circuits (air to ground and ground to ground) necessary for air traffic ­control.

    (Refer to AIM.)

    VOR- A ground‐based electronic navigation aid transmitting very high frequency navigation signals, 360 ­degrees in azimuth, oriented from magnetic north. Used as the basis for navigation in the National Airspace ­System. The VOR periodically identifies itself by Morse Code and may have an additional voice identification ­feature. Voice features may be used by ATC or FSS for transmitting instructions/information to pilots.

    (See NAVIGATIONAL AID.)

    (Refer to AIM.)

    VOR TEST SIGNAL-

    (See VOT.)

    VORTAC- A navigation aid providing VOR azimuth, TACAN azimuth, and TACAN distance measuring ­equipment (DME) at one site.

    (See DISTANCE MEASURING EQUIPMENT.)

    (See NAVIGATIONAL AID.)

    (See TACAN.)

    (See VOR.)

    (Refer to AIM.)

    VORTICES- Circular patterns of air created by the movement of an airfoil through the air when generating lift. ­As an airfoil moves through the atmosphere in sustained flight, an area of area of low pressure is created above ­it. The air flowing from the high pressure area to the low pressure area around and about the tips of the airfoil ­tends to roll up into two rapidly rotating vortices, cylindrical in shape. These vortices are the most predominant ­parts of aircraft wake turbulence and their rotational force is dependent upon the wing loading, gross weight, ­and speed of the generating aircraft. The vortices from medium to super aircraft can be of extremely high velocity ­and hazardous to smaller aircraft.

    (See AIRCRAFT CLASSES.)

    (See WAKE TURBULENCE.)

    (Refer to AIM.)

    VOT- A ground facility which emits a test signal to check VOR receiver accuracy. Some VOTs are available ­to the user while airborne, and others are limited to ground use only.

    (See Chart Supplement.)

    (Refer to 14CFR part91.)

    (Refer to AIM.)

    VR-

    (See VFR MILITARY TRAINING ROUTES.)

    VSCS-

    (See VOICE SWITCHING AND CONTROL SYSTEM.)

    VTOL AIRCRAFT-

    (See VERTICAL TAKEOFF AND LANDING AIRCRAFT.)