V
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.
(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.)
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.)
(See ICAO term VERTICAL
SEPARATION.)
VERTICAL SEPARATION [ICAO]-
Separation between aircraft expressed in units of vertical distance.
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:
a. An IFR aircraft
requests a climb/descent in VFR conditions.
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.
c. A pilot has
requested a practice instrument approach and is not on an IFR flight plan.
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 JO 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
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, 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 14 CFR Part 91.)
(Refer to AIM.)
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.
(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.
a. Flight
Visibility-The visibility forward from the cockpit of an aircraft in flight.
b. Ground
Visibility-The visibility at an aerodrome as reported by an accredited observer.
c. 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-
(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.
(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 14 CFR Part 91.)
(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 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.)
(Refer to 14 CFR Part 91.)
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.)
(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 heavy 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 AIRPORT/FACILITY
DIRECTORY.)
(Refer to 14 CFR Part 91.)
(Refer to AIM.)
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.)
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