damage.
avgas - aviation gasoline, usually followed by the octane rating. Used by piston-engined aircraft. Also LL, low lead.
avtur - aviation turbine fuel (kerosene). Used by turboprops and jets.
AWR - airborne weather radar.
Awy - airway. B
BA - British Airways
BAA - British Airports Authority.
BAeA - British Aerobatic Association.
BALPA - British Airline Pilots Association.
base leg - The crosswind segment of an aerodrome circuit bringing the aircraft from the downwind leg to final approach
BAUA - Business Aircraft Users Association.
BCAR - British Civil Air Requirements. Airworthiness standards laid down by the CAA for certification of aircraft on the UK Civil Aircraft Register.
BCP - break cloud procedure.
BCPL - Basic Commercial Pilot\in the UK to receive payment for acting as a pilot. Also CPL, Commercial Pilot\Licence, and SCPL, Senior Commercial Pilot\
beta mode - manually-controlled mode for CS propellers on turboprop aircraft enabling reverse pitch to be selected for braking or to aid ground manoeuvring.
BFR - Biennial Flight Review (USA). Holders of U.S. FAA Private Pilot Licences must undergo a flight check with an FAA-approved examiner every two years. No UK equivalent.
BGA - British Gliding Association.
BHAB - British Helicopter Advisory Board.
bhp - brake horsepower.
BHPA - British Hang-Gliding and Paragliding Association.
Bleed air - Hot compressed air taken from turbine engines.
BMAA - British Microlight Aircraft Association.
Bottlang - Loose-leaf Euopean airfields manual for VFR operations.
BRG - bearing, the horizontal direction to or from any point expressed in degrees of the compass.
BWPA - British Women Pilots Association. C
C - Celsius (temperature) or compass.
CAA - Civil Aviation Authority.
CAD/CAM - computer-aided design/manufacture.
CAAFU - Civil Aviation Authority Flying Unit, based at Stansted Airport, which perＦＯＲＭs such tasks as navaid checking and calibration and also examines candidates for instrument ratings and commercial pilot\
CANP - Civil Aviation Notification Procedure. A voluntary system whereby civil operators notify their intention to fly at low level (at or below 1,000 feet agl, when crop-spraying or powerline inspecting for example), aimed at avoiding conflict with low-flying military aircraft.
CAP - Civil Air Publication. InＦＯＲＭation booklets issued by the CAA, e.g. CAP 53 The Private Pilot Licence.
CAS - calibrated airspeed -- indicated airspeed corrected for air density and compressibility.
casevac - casualty evacuation.
CAT - clear-air turbulence. Also CATegory when referring to certain instrument landing systems which require special aircraft instrumentation, certification and pilot qualification beyond those needed for standard instrument approaches (e.g. a CAT IIIC ILS permits operation down to the surface of the runway without external visual reference, true zero-zero operation).
CAVOK - pronounced CAV-okay (ceiling and visibility OK), visibility at least ten kilometres, with no cloud below 5,000 feet, with no Cbs, precipitation, thunderstorms, shallow fog or low
drifting snow.
CAVU - ceiling and visibility unlimited. Cloudless (or scattered cloud) conditions with visibility in excess of ten kilometres.
CCF - Combined Cadet Force
CDI - course deviation indicator. The vertical needle of a VOR indicator which shows the aircraft\
CDU - control display unit.
ceiling - height above ground or water of the base of the lowest layer of cloud below 20,000 feet which covers more than half of the sky. An aircraft\which its maximum rate of climb is no greater than 100 feet per minute. Its absolute ceiling is the highest altitude at which it can maintain level flight.
CFI - chief flying instructor (certified flying instructor in USA).
CFS - Central Flying School (RAF)
CG - centre of gravity
CH - compass heading.
Check \
CHIRP - Confidential Human Factors Incident Reporting system, whereby professional pilots and ATC staff may report in confidence incidents arising from human errors for analysis by the CHIRP Charitable Trust at Farnborough.
CHT - cylinder head temperature (gauge). A device which, by means of a probe(s) gives a cockpit readout of the temperature of one or more of an aircraft engine\
circuit - pattern around which aircraft fly when arriving at an airfield, usually rectangular in UK but not necessarily elsewhere. The circuit (known as the pattern in USA) is aligned with the active runway and may be either left- or right-handed. Dead side is the opposite side of the circuit pattern in operation from which arriving aircraft join for landing. See also final(s).
C/L - centre-line (of a runway, for example).
clamped - colloquialism referring to an airport closed to air traffic by bad weather
clean - flaps, slats and undercarriage retracted and on military aircraft no external missiles
etc.
clearance - authorization from air traffic control to proceed as requested or instructed. Used for ground and air manoeuvring, thus \for take-off\\flight-planned route\\
Clouds - commonly-used abbreviations for cloud types:
AC = altocumulus AS = altostratus CB = cumulonimbus CC = cirrocumulus CI = cirrus
CS = cirrostratus CU = cumulus
NS = nimbo stratus
SC = stratocumulus ST = stratus
C of A - Certificate of Airworthiness issued by the CAA indicating that an aircraft meets the Authority\aircraft types (Type Certification in the USA) when the first example of a type is registered. Cs of A on individual aircraft are granted in several categories, e.g. Private, Public Transport, Aerial Work etc. and much be renewed at intervals. Permits to Fly are authorisations granted to specialist aircraft and are accordingly restricted in the kinds of operation for which they may be used.
C of E - Certificate of Experience, valid for private pilot licence holders for thirteen months, and renewed by flight test or evidence of completing the minimum required flying experience in the preceding thirteen-month period. Also C of T, certificate of test.
C of G - centre of gravity. The point on an aircraft through which the entire aircraft\may be assumed to act (i.e. around which the aircraft, if suspended, would balance). C of G limits are the most forward and rearward positions of the C of G permitted for safe operation. An aircraft loaded outside its C of G limits can be difficult or impossible to control.
C of P - centre of pressure, the point through which the total effect of lift may be said to act on an aeroplane.
Com(m)(s) - communication(s)
CPL - Commercial Pilot\
CR or C/R - counter-rotating. Usually in general aviation referring to twin-engined aircraft with \effect.
CRM - cockpit resources management
crosswind (leg) - portion of an aerodrome circuit flown before downwind
CRP - compulsory reporting point.
CRT - cathode ray tube (like a television). Used in flight deck displays of new-generation airliners, business aircraft and military jets instead of conventional instruments. See also EFIS,.
critical altitude - the highest density altitude at which it is possible to maintain the maximum continuous rated power or manifold pressure of an aero engine.
critical engine - the engine on a multi-engined aircraft whose failure would most seriously effect perＦＯＲＭance or handling of the aircraft, through asymmetric effects or loss of power to systems such as hydraulics.
CRS course - the intended direction of flight in the horizontal plane expressed in degrees of the compass.
c/s - call sign.
CS - constant-speed (propeller). A variable-pitch propeller which maintains constant rpm by automatically changing blade angle. Also CSU, constant-speed unit.
CTA - Control Area. An area of controlled airspace extending upwards from specified limit agl.
CTR - Control Zone. An area of controlled airspace extending upwards from ground level to a specified upper limit.
CVR - cockpit voice recorder. A tape recorder installed on the flight decks of commercial transport aircraft and helicopters and some business aeroplanes to record crew conversation, RT transmissions and cockpit background noises (e.g. trim-wheel operation, flap motor running) in case required for incident or accident investigation.
CW - carrier wave or continuous wave.
CWR - colour weather radar.
CZ - Control Zone (USA).
CZI - compressor zone inspection. D
