Wednesday, April 16, 2008


CABIN ALTITUDE—Cabin pressure in terms of equivalent altitude above sea level.

CALIBRATED AIRSPEED (CAS)—Indicated airspeed corrected for installation error and instrument error. Although manufacturers attempt to keep airspeed errors to a minimum, it is not possible to eliminate all errors throughout the airspeed operating range. At certain airspeeds and with certain flap settings, the installation and instrument errors may total several knots. This error is generally greatest at low airspeeds. In the cruising and higher airspeed ranges, indicated airspeed and calibrated airspeed are approximately the same. Refer to the airspeed calibration chart to correct for possible airspeed errors.

CAMBER—The camber of an airfoil is the characteristic curve of its upper and lower surfaces. The upper camber is more pronounced, while the lower camber is comparatively flat. This causes the velocity of the airflow immediately above the wing to be much higher than that below the wing.

CANARD—A horizontal surface mounted ahead of the main wing to provide longitudinal stability and control. It may be a fixed, movable, or variable geometry surface, with or without control surfaces.

CANARD CONFIGURATION—A configuration in which the span of the forward wings is substantially less than that of the main wing.

CANTILEVER—A wing designed to carry the loads without external struts.

CEILING—The height above the earth's surface of the lowest layer of clouds, which is reported as broken or overcast, or the vertical visibility into an obscuration.

CENTER OF GRAVITY (CG)— The point at which an airplane would balance if it were possible to suspend it at that point. It is the mass center of the airplane, or the theoretical point at which the entire weight of the airplane is assumed to be concentrated. It may be expressed in inches from the reference datum, or in percent of mean aerodynamic chord (MAC). The location depends on the distribution of weight in the airplane.

CENTER-OF-GRAVITY LIMITS—The specified forward and aft points within which the CG must be located during flight. These limits are indicated on pertinent airplane specifications.

CENTER-OF-GRAVITY RANGEThe distance between the forward and aft CG limits indicated on pertinent airplane specifications.

CENTER OF PRESSURE—A point along the wing chord line where lift is considered to be concentrated. For this reason, the center of pressure is commonly referred to as the center of lift.

CENTRIFUGAL FLOW COMPRESSOR.An impeller shaped device that receives air at its center and slings the air outward at high velocity into a diffuser for increased pressure. Also referred to as a radial outflow compressor.

CENTRIFUGAL FORCE — An outward force, that opposes centripetal force, resulting from the effect of inertia during a turn.

CENTRIPETAL FORCE—A center-seeking force directed inward toward the center of rotation created by the horizontal component of lift in turning flight.

CHORD LINE—An imaginary straight line drawn through an airfoil from the leading edge to the trailing edge.

COEFFICIENT OF LIFT—The ratio between lift pressure and dynamic pressure.

COLD FRONT—The boundary between two air masses where cold air is replacing warm air.

COMPLEX AIRCRAFT—An aircraft with retractable landing gear, flaps, and a controllablepitch propeller.

COMPRESSOR PRESSURE RATIO—The ratio of compressor discharge pressure to compressor inlet pressure.

COMPRESSOR STALL—In gas turbine engines, a condition in an axial-flow compressor in which one or more stages of rotor blades fail to pass air smoothly to the succeeding stages. A stall condition is caused by a pressure ratio that is incompatible with the engine r.p.m. Compressor stall will be indicated by a rise in exhaust temperature or r.p.m. fluctuation, and if allowed to continue, may result in flameout and physical damage to the engine.

CONDENSATION.A change of state of water from a gas (water vapor) to a liquid.

CONDENSATION NUCLEI—Small particles of solid matter in the air on which water vapor condenses.

CONFIGURATION—This is a general term, which normally refers to the position of the landing gear and flaps.

CONSTANT-SPEED PROPELLER—A controllable-pitch propeller whose pitch is automatically varied in flight by a governor to maintain a constant r.p.m. in spite of varying air loads.

CONTINUOUS FLOW OXYGEN SYSTEM—System that supplies a constant supply of pure oxygen to a rebreathes bag that dilutes the pure oxygen with exhaled gases and thus supplies a healthy mix of oxygen and ambient air to the mask. Primarily used in passenger cabins of commercial airliners.

CONTROLLABILITY—A measure of the response of an aircraft relative to the pilot's flight control inputs.

CONTROLLED AIRPORT—An airport that has an operating control tower.

CONTROLLED AIRSPACE—A generic term that covers the different classifications of airspace and defined dimensions within which air traffic control service is provided in accordance with the airspace classification. Controlled airspace consists of Class A, B, C, D, and E airspace.

CONVECTIVE SIGMET—A weather advisory concerning convective weather significant to the safety of all aircraft. Convective SIGMETs are issued for tornadoes, lines of thunderstorms, thunderstorms over a wide area, embedded thunderstorms, wind gusts to 50 knots or greater, and/or hail 3/4 inch in diameter or greater.

CONVENTIONAL LANDING GEAR—Landing gear employing a third rear-mounted wheel. These airplanes are also sometimes referred to as tailwheel airplanes.

COUPLED AILERONS AND RUDDER—Rudder and ailerons are connected with interconnect springs in order to counteract adverse yaw. Can be overridden if it becomes necessary to slip the aircraft.

COURSE—The intended direction of flight in the horizontal plane measured in degrees from north.

COWL FLAPS — Shutter-like devices arranged around certain air-cooled engine cowlings, which may be opened or closed to regulate the flow of air around the engine.

CREW RESOURCE MANAGEMENT (CRM)—The application of team management concepts in the flight deck environment. It was initially known as cockpit resource management, but as CRM programs evolved to include cabin crews, maintenance personnel, and others, the phrase "crew resource management" was adopted. This includes single pilots, as in most general aviation aircraft. Pilots of small aircraft, as well as crews of larger aircraft, must make effective use of all available resources; human resources, hardware, and information. A current definition includes all groups routinely working with the cockpit crew who are involved in decisions required to operate a flight safely. These groups include, but are not limited to: pilots, dispatchers, cabin crewmembers, maintenance personnel, and air traffic controllers. CRM is one way of addressing the challenge of optimizing the human/machine interface and accompanying interpersonal activities.

No comments:

Post a Comment