Pilot/Controller Glossary

CONVECTIVE SIGNIFICANT METEOROLOGICAL INFORMATION-
(See CONVECTIVE SIGMET.)

COOPERATIVE SURVEILLANCE- Any surveillance system, such as secondary surveillance radar (SSR),
wide-area multilateration (WAM), or ADS-B, that is dependent upon the presence of certain equipment onboard
the aircraft or vehicle to be detected.
(See AUTOMATIC DEPENDENT SURVEILLANCE-BROADCAST.)
(See NON-COOPERATIVE SURVEILLANCE.)
(See RADAR.)
(See WIDE AREA MULTILATERATION.)

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.
COUPLED SCHEDULING (CS)/ EXTENDED METERING (XM)- Adds additional Constraint Satisfaction
Points for metered aircraft along their route. This provides the ability to merge flows upstream from the meter
fix and results in a more optimal distribution of delays over a greater distance from the airport, increased meter
list accuracy, and more accurate delivery to the meter fix.
COURSE-
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.)

CREWMEMBER (UAS)- A person assigned to perform an operational duty. A UAS crewmember includes the
remote pilot in command, the person manipulating the controls, and visual observers but may also include other
persons as appropriate or required to ensure the safe operation of the UAS (e.g., sensor operator, ground control
station operator).
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.