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V
VASI-
(See
VISUAL APPROACH SLOPE INDICATOR.)
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 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.
(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 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 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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