Pilot/Controller Glossary 

4/20/23 

Class B and Class C airspace or TRSAs as required by FAA Order 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

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(See VFR AIRCRAFT.) 

VFR MILITARY TRAINING ROUTES (VR)

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 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

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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

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 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 FAA Order JO 7110.65. 
VFR TERMINAL AREA CHARTS

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(See AERONAUTICAL CHART.) 

VFR WAYPOINT

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(See WAYPOINT.) 

VHF

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(See VERY HIGH FREQUENCY.) 

VHF OMNIDIRECTIONAL RANGE/TACTICAL AIR NAVIGATION

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(See VORTAC.) 

VIDEO MAP

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 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

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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

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 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

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 Prevailing horizontal visibility near the earth’s surface as reported by the United States 

National Weather Service or an accredited observer. 

c. 

Prevailing Visibility

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 The greatest horizontal visibility equaled or exceeded throughout at least half the 

horizon circle which need not necessarily be continuous. 

d. 

Runway Visual Range (RVR)

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 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 

PCG V

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