faraim.org

Aeronautical Information Manual (AIM), page 634

Pilot/Controller Glossary 5/26/16


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/ inch or greater.
4

(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- An instrument approach
performed by the aircraft autopilot, and/or visually

depicted on the flight director, which is receiving

position information and/or steering commands from

onboard navigational equipment. In general, coupled
non-precision approaches must be flown manually
(autopilot disengaged) at altitudes lower than 50 feet
AGL below the minimum descent altitude, and
coupled precision approaches must be flown
manually (autopilot disengaged) below 50 feet AGL
unless authorized to conduct autoland operations.
Coupled instrument approaches are commonly flown
to the allowable IFR weather minima established by
the operator or PIC, or flown VFR for training and
safety.

COURSE-
12/10/15

a. The intended direction of flight in the horizontal
plane measured in degrees from north.
b. The ILS localizer signal pattern usually
specified as the front course or the back course.
(See BEARING.)
(See INSTRUMENT LANDING SYSTEM.)
(See RADIAL.)

CPDLC-

(See CONTROLLER PILOT DATA LINK

COMMUNICATIONS.)

CPL [ICAO]-
(See ICAO term CURRENT FLIGHT PLAN.)

CRITICAL ENGINE- The engine which, upon
failure, would most adversely affect the performance
or handling qualities of an aircraft.

CROSS (FIX) AT (ALTITUDE)- Used by ATC
when a specific altitude restriction at a specified fix
is required.
CROSS (FIX) AT OR ABOVE (ALTITUDE)- Used
by ATC when an altitude restriction at a specified fix
is required. It does not prohibit the aircraft from
crossing the fix at a higher altitude than specified;
however, the higher altitude may not be one that will
violate a succeeding altitude restriction or altitude
assignment.

(See ALTITUDE RESTRICTION.)
(Refer to AIM.)
CROSS (FIX) AT OR BELOW (ALTITUDE)-
Used by ATC when a maximum crossing altitude at
a specific fix is required. It does not prohibit the
aircraft from crossing the fix at a lower altitude;
however, it must be at or above the minimum IFR
altitude.

(See ALTITUDE RESTRICTION.)

(See MINIMUM IFR ALTITUDES.)

(Refer to 14 CFR Part 91.)

CROSSWIND-
a. When used concerning the traffic pattern, the
word means "crosswind leg."
(See TRAFFIC PATTERN.)
b. When used concerning wind conditions, the
word means a wind not parallel to the runway or the
path of an aircraft.
(See CROSSWIND COMPONENT.)

CROSSWIND COMPONENT- The wind compo-
nent measured in knots at 90 degrees to the
longitudinal axis of the runway.

PCG C-8

Page 634 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   633 -- Page 634 -- 635