Pilot/Controller Glossary

4/3/14

PCG C−7

lower than 1,200 feet up to 4,000 feet above the

airport elevation and an outer area that is not charted.

Each person must establish two-way radio commu-

nications with the ATC facility providing air traffic

services prior to entering the airspace and thereafter

maintain those communications while within the

airspace. VFR aircraft are only separated from IFR

aircraft within the airspace.

(See OUTER AREA.)

4.

CLASS D− Generally, that airspace from the

surface to 2,500 feet above the airport elevation

(charted in MSL) surrounding those airports that

have an operational control tower. The configuration

of each Class D airspace area is individually tailored

and when instrument procedures are published, the

airspace will normally be designed to contain the

procedures. Arrival extensions for instrument

approach procedures may be Class D or Class E

airspace. Unless otherwise authorized, each person

must establish two-way radio communications with

the ATC facility providing air traffic services prior to

entering the airspace and thereafter maintain those

communications while in the airspace. No separation

services are provided to VFR aircraft.

5.

CLASS E− Generally, if the airspace is not

Class A, Class B, Class C, or Class D, and it is

controlled airspace, it is Class E airspace. Class E

airspace extends upward from either the surface or a

designated altitude to the overlying or adjacent

controlled airspace. When designated as a surface

area, the airspace will be configured to contain all

instrument procedures. Also in this class are Federal

airways, airspace beginning at either 700 or 1,200

feet AGL used to transition to/from the terminal or en

route environment, en route domestic, and offshore

airspace areas designated below 18,000 feet MSL.

Unless designated at a lower altitude, Class E

airspace begins at 14,500 MSL over the United

States, including that airspace overlying the waters

within 12 nautical miles of the coast of the 48

contiguous States and Alaska, up to, but not

including 18,000 feet MSL, and the airspace above

FL 600.

CONTROLLED AIRSPACE [ICAO]− An airspace

of defined dimensions within which air traffic control

service is provided to IFR flights and to VFR flights

in accordance with the airspace classification.

Note: Controlled airspace is a generic term which

covers ATS airspace Classes A, B, C, D, and E.

CONTROLLED TIME OF ARRIVAL− Arrival time

assigned during a Traffic Management Program. This

time may be modified due to adjustments or user

options.
CONTROLLER−

(See AIR TRAFFIC CONTROL SPECIALIST.)

CONTROLLER [ICAO]− A person authorized to

provide air traffic control services.
CONTROLLER PILOT DATA LINK

COMMUNICATIONS (CPDLC)− A two−way

digital communications system that conveys textual

air traffic control messages between controllers and

pilots using ground or satellite-based radio relay

stations.

CONVECTIVE SIGMET

−  A weather advisory

concerning convective weather significant to the

safety of all aircraft. Convective SIGMETs are issued

for tornadoes, lines of thunderstorms, embedded

thunderstorms of any intensity level, areas of

thunderstorms greater than or equal to VIP level 4

with an area coverage of 

4

/

10

 (40%) or more, and hail

3

/

4

 inch or greater.

(See AIRMET.)
(See AWW.)
(See CWA.)
(See SIGMET.)
(Refer to AIM.)

CONVECTIVE SIGNIFICANT METEOROLOG-

ICAL INFORMATION−

(See CONVECTIVE SIGMET.)

COORDINATES− The intersection of lines of

reference, usually expressed in degrees/minutes/

seconds of latitude and longitude, used to determine

position or location.
COORDINATION FIX− The fix in relation to which

facilities will handoff, transfer control of an aircraft,

or coordinate flight progress data. For terminal

facilities, it may also serve as a clearance for arriving

aircraft.
COPTER−

(See HELICOPTER.)

CORRECTION− An error has been made in the

transmission and the correct version follows.
COUPLED APPROACH− A coupled approach is an

instrument approach performed by the aircraft

autopilot which is receiving position information

and/or steering commands from onboard navigation