Pilot/Controller Glossary 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- 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. yutsrponm (See AIR TRAFFIC CONTROL SPECIALIST.) COPTER- (See HELICOPTER.) CONTROLLER [ICAO]- A person authorized to provide air traffic control services. CORRECTION- An error has been made in the transmission and the correct version follows. 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 satellitebased radio relay stations. 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 nonprecision 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. 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. (See AIRMET.) (See CWA.) (See SAW.) (See SIGMET.) (Refer to AIM.) CONVECTIVE SIGNIFICANT METEOROLOG ICAL INFORMATION- (See CONVECTIVE SIGMET.) COOPERATIVE SURVEILLANCE- Any surveil lance system, such as secondary surveillance radar (SSR), wide-area multilateration (WAM), or ADS- B, that is dependent upon the presence of certain 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.