Contactor (electrical component).  A remotely actuated, heavy-duty electrical switch. Contactors are used in an aircraft electrical system to connect the battery to the main bus. 

Continuity tester.  A troubleshooting tool that consists of a battery, a light bulb, and test leads. The test leads are connected to each end of the conductor under test, and if the bulb lights up, there is continuity. If it does not light up, the conductor is open. 

Continuous Airworthiness Inspection Program.  An inspection program that is part of a continuous airworthiness maintenance program approved for certain large airplanes (to which 14 CFR Part 125 is not applicable), turbojet multi-engine airplanes, turbopropeller-powered multi-engine airplanes, and turbine-powered rotorcraft. 

Continuous-duty solenoid. A solenoid-type switch designed to be kept energized by current flowing through its coil for an indefinite period of time. The battery contactor in an aircraft electrical system is a continuous-duty solenoid. Current flows through its coil all the time the battery is connected to the electrical system. 

Continuous-flow oxygen system.  A type of oxygen system that allows a metered amount of oxygen to continuously flow into the mask. A rebreather-type mask is used with a continuous-flow system. The simplest form of continuous- flow oxygen system regulates the flow by a calibrated orifice in the outlet to the mask, but most systems use either a manual or automatic regulator to vary the pressure across the orifice proportional to the altitude being flown. 

Continuous-loop fire-detection system.  A fire-detection system that uses a continuous loop of two conductors separated with a thermistor-type insulation. Under normal temperature conditions, the thermistor material is an insulator; but if it is exposed to a fire, the thermistor changes into a conductor and completes the circuit between the two conductors, initiating a fire warning. 

Control horn.  The arm on a control surface to which the control cable or push-pull rod attaches to move the surface. 

Control stick.  The type of control device used in some airplanes. A vertical stick in the flight deck controls the ailerons by side-to-side movement and the elevators by fore- and-aft movement. 

Control yoke.  The movable column on which an airplane control wheel is mounted. The yoke may be moved in or out to actuate the elevators, and the control wheel may be rotated to actuate the ailerons. 

Controllability.  The characteristic of an aircraft that allows it to change its flight attitude in response to the pilot’s movement of the flight deck controls. 

Conventional current.  An imaginary flow of electricity that is said to flow from the positive terminal of a power source, through the external circuit to its negative terminal. The arrowheads in semiconductor symbols point in the direction of conventional current flow. 

Converging duct.  A duct, or passage, whose cross-sectional area decreases in the direction of fluid flow. 

Conversion coating.  A chemical solution used to form an airtight oxide or phosphate film on the surface of aluminum or magnesium parts. The conversion coating prevents air from reaching the metal and keeps it from corroding. 

Convex surface.  A surface that is curved outward. The outer edges are lower than the center. 

Coriolis effect.  The change in rotor blade velocity to compensate for a change in the distance between the center of mass of the rotor blade and the axis rotation of the blade as the blades flap in flight. 

Cornice brake.  A large shop tool used to make straight bends across a sheet of metal. Cornice brakes are often called leaf brakes. 

Corrugated metal.  Sheets of metal that have been made more rigid by forming a series of parallel ridges or waves in its surface. 

Cotter pin.  A split metal pin used to safety a castellated or slotted nut on a bolt. The pin is passed through the hole in the shank of the bolt and the slots in the nut, and the ends of the pin are spread to prevent it backing out of the hole. 

Countersinking.  Preparation of a rivet hole for a flush rivet by beveling the edges of the holes with a cutter of the correct angle. 

Coverite surface thermometer.  A small surface-type bimetallic thermometer that calibrates the temperature of an iron used to heat-shrink polyester fabrics. 

Crabbing.  Pointing the nose of an aircraft into the wind to compensate for wind drift. 

Crazing.  A form of stress-caused damage that occurs in a transparent thermoplastic material. Crazing appears as a series of tiny, hair-like cracks just below the surface of the plastic. 

