Pilot/Controller Glossary 

6/17/21 

CHART SUPPLEMENT U.S.

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 A publication 

designed primarily as a pilot’s operational manual 
containing all airports, seaplane bases, and heliports 
open to the public including communications data, 
navigational facilities, and certain special notices and 
procedures. This publication is issued in seven 
volumes according to geographical area. 

CHARTED VFR FLYWAYS

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 Charted VFR Fly-

ways are flight paths recommended for use to bypass 
areas heavily traversed by large turbine-powered 
aircraft. Pilot compliance with recommended 
flyways and associated altitudes is strictly voluntary. 
VFR Flyway Planning charts are published on the 
back of existing VFR Terminal Area charts. 

CHARTED VISUAL FLIGHT PROCEDURE 
APPROACH

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 An approach conducted while 

operating on an instrument flight rules (IFR) flight 
plan which authorizes the pilot of an aircraft to 
proceed visually and clear of clouds to the airport via 
visual landmarks and other information depicted on 
a charted visual flight procedure. This approach must 
be authorized and under the control of the appropriate 
air traffic control facility. Weather minimums 
required are depicted on the chart. 

CHASE

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 An aircraft flown in proximity to another 

aircraft normally to observe its performance during 
training or testing. 

CHASE AIRCRAFT

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(See CHASE.) 

CHOP

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 A form of turbulence. 

a. 

Light Chop– Turbulence that causes slight, 

rapid and somewhat rhythmic bumpiness without 
appreciable changes in altitude or attitude. 

b. 

Moderate Chop– Turbulence similar to Light 

Chop but of greater intensity. It causes rapid bumps 
or jolts without appreciable changes in aircraft 
altitude or attitude. 

(See TURBULENCE.) 

CIRCLE-TO-LAND MANEUVER

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 A maneuver 

initiated by the pilot to align the aircraft with a 
runway for landing when a straight-in landing from 
an instrument approach is not possible or is not 
desirable. At tower controlled airports, this maneuver 
is made only after ATC authorization has been 

obtained and the pilot has established required visual 
reference to the airport. 

(See CIRCLE TO RUNWAY.) 
(See LANDING MINIMUMS.) 
(Refer to AIM.) 

CIRCLE TO RUNWAY (RUNWAY NUMBER)

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Used by ATC to inform the pilot that he/she must 
circle to land because the runway in use is other than 
the runway aligned with the instrument approach 
procedure. When the direction of the circling 
maneuver in relation to the airport/runway is 
required, the controller will state the direction (eight 
cardinal compass points) and specify a left or right 
downwind or base leg as appropriate; e.g., “Cleared 
VOR Runway Three Six Approach circle to Runway 
Two Two,” or “Circle northwest of the airport for a 
right downwind to Runway Two Two.” 

(See CIRCLE-TO-LAND MANEUVER.) 
(See LANDING MINIMUMS.) 
(Refer to AIM.) 

CIRCLING APPROACH

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(See CIRCLE-TO-LAND MANEUVER.) 

CIRCLING MANEUVER

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(See CIRCLE-TO-LAND MANEUVER.) 

CIRCLING MINIMA

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(See LANDING MINIMUMS.) 

CLASS A AIRSPACE

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(See CONTROLLED AIRSPACE.) 

CLASS B AIRSPACE

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(See CONTROLLED AIRSPACE.) 

CLASS C AIRSPACE

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(See CONTROLLED AIRSPACE.) 

CLASS D AIRSPACE

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(See CONTROLLED AIRSPACE.) 

CLASS E AIRSPACE

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(See CONTROLLED AIRSPACE.) 

CLASS G AIRSPACE

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 Airspace that is not 

designated in 14 CFR Part 71 as Class A, Class B, 
Class C, Class D, or Class E controlled airspace is 
Class G (uncontrolled) airspace. 

(See UNCONTROLLED AIRSPACE.) 

CLEAR AIR TURBULENCE (CAT)

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 Turbulence 

encountered in air where no clouds are present. This 
term is commonly applied to high-level turbulence 
associated with wind shear. CAT is often encountered 
in the vicinity of the jet stream. 

(See WIND SHEAR.) 
(See JET STREAM.) 

PCG C

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