V
From Pilots Almanac
From the FAA Pilot/Controller Glossary. Reference it for the original text. ICAO terms not included here.
Back to the Pilot/Controller Glossary Index.
VASI
(See VISUAL APPROACH SLOPE INDICATOR.)
VCOA
(See VISUAL CLIMB OVER AIRPORT.)
VDF
(See DIRECTION FINDER.)
VDP
(See VISUAL DESCENT POINT.)
VECTOR
A heading issued to an aircraft to provide navigational guidance by radar.
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.)
VERTEX
The last fix adapted on the arrival speed segments. Normally, it will be the outer marker of the runway in use. However, it may be the actual threshold or other suitable common point on the approach path for the particular runway configuration.
VERTEX TIME OF ARRIVAL
A calculated time of aircraft arrival over the adapted vertex for the runway configuration in use. The time is calculated via the optimum flight path using adapted speed segments.
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 established by assignment of different altitudes or flight levels. (See SEPARATION.)
VERTICAL TAKEOFF AND LANDING AIRCRAFT
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.)
VERY HIGH FREQUENCY
The frequency band between 30 and 300 MHz. Portions of this band, 108 to 118 MHz, are used for certain NAVAIDs; 118 to 136 MHz 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
The frequency band between 3 and 30 kHz.
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:
- b. 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.
Note: All pilots receiving this authorization must comply with the VFR visibility and distance from cloud criteria in 14 CFR Part 91. Use of the term does not relieve controllers of their responsibility to separate aircraft in Class B and Class C airspace or TRSAs as required by FAAO 7110.65. When used as an ATC clearance/instruction, the term may be abbreviated "VFR;" e.g., "MAINTAIN VFR," "CLIMB/DESCEND VFR," etc.
VFR FLIGHT
(See VFR AIRCRAFT.)
VFR MILITARY TRAINING ROUTES
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 14 CFR 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 14 CFR Part 91. 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 FAAO 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, 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.
- a. 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.
- b. Ground Visibility- Prevailing horizontal visibility near the earth's surface as reported by the United States National Weather Service or an accredited observer.
- c. Prevailing Visibility- The greatest horizontal visibility equaled or exceeded throughout at least half the horizon circle which need not necessarily be continuous.
- d. Runway Visibility Value (RVV)- The visibility determined for a particular runway by a transmissometer. A meter provides a continuous indication of the visibility (reported in miles or fractions of miles) for the runway. RVV is used in lieu of prevailing visibility in determining minimums for a particular runway.
- e. 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 is used in lieu of RVV and/or 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.
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.
VISUAL APPROACH SLOPE INDICATOR
(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. These procedures are published in the `Take-Off Minimums and (Obstacle) Departure Procedures' section of the Terminal Procedures Publications.
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.)
VISUAL HOLDING
The holding of aircraft at selected, prominent geographical fixes which can be easily recognized from the air. (See HOLDING FIX.)
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 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:
- a. The tower controller sees the aircraft involved and issues instructions, as necessary, to ensure that the aircraft avoid each other.
- b. 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.)
VLF
(See VERY LOW FREQUENCY.)
VMC
(See VISUAL METEOROLOGICAL CONDITIONS.)
VOICE SWITCHING AND CONTROL SYSTEM
The VSCS is 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. (See VOICE SWITCHING AND CONTROL SYSTEM.)
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.)
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.)
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 heavy aircraft can be of extremely high velocity and hazardous to smaller aircraft. (See AIRCRAFT CLASSES.) (See WAKE TURBULENCE.)
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 AIRPORT/FACILITY DIRECTORY.)
VR
(See VFR MILITARY TRAINING ROUTES.)
VSCS
(See VOICE SWITCHING AND CONTROL SYSTEM.)
VTA
(See VERTEX TIME OF ARRIVAL.)
VTOL AIRCRAFT
(See VERTICAL TAKEOFF AND LANDING AIRCRAFT.)
