.
spoken expression: zulu or universal 
Note: The expression “zulu” is pronounced “ZOO loo.”

Fr: temps universel coordonné
co-ordinates The intersection of lines of reference, usually expressed in degrees, minutes and seconds of latitude and longitude, used to determine position or location. Fr: coordonnées
co-ordinating controller
A duty controller assigned to co-ordinate flight data between two or more control positions.
Fr: contr.leur de coordination
COP Abbreviation for: change-over point Fr: COP
co-pilot
A licensed pilot assigned to duty as a pilot in an aircraft during flight time, other than as
(a)
a pilot-in-command; or

(b)
a pilot receiving flying instruction.

. also called: first officer (F/O)
Fr: copilote
“Correction” An expression used in radiocommunication meaning “An error has been made in this transmission (or in the message indicated). The correct version is . . .” Fr: . Correction .
CPDLC Abbreviation for: controller-pilot data link communications Fr: CPDLC
crash locator beacon NATO: Expression for: emergency locator transmitter (ELT)
CRDA Abbreviation for: converging runway display aid Fr: CRDA
crew member
A person assigned to duty on an aircraft during flight time.
Fr: membre d’équipage
CRFI Abbreviation for: Canadian Runway Friction Index Fr: CRFI
CRFI reading Other expression for: Canadian Runway Friction Index
critical engine The engine the failure of which would most adversely affect the performance or handling qualities of an aircraft. Fr: moteur le plus défavorable
crossing tracks An expression used in the application of separation indicating tracks that converge or diverge at an angle of 45° to 135° inclusive. Fr: routes sécantes
crosswind
When referring to wind conditions, a wind not parallel to the runway or the path of an aircraft.