A & P - Airframe and Powerplant Mechanic (USA).
a/c - aircraft.
A/D - aerodrome.
A/G - air-to-ground
A/P - airport or autopilot.
aae - above aerodrome elevation. Also see aal.
AAIB - Air Accident Investigation Branch of the Department of
aal - above aerodrome level. Also see aae.
ab initio - literally 'from the beginning', elementary flying
abm abeam - an aircraft is abeam a point when that point is at
ninety degrees left or right of the aircraft's track, but term usually
used to indicate a general position rather than a specific point.
AC - alternating current.
ACARS - Aircraft Communication Adressing and Reporting System.
ACC - Area Control Centre. And ACZ Aerodrome Control Zone. See
accelerate - stop distance- calculated distance required for an
aircraft to accelerate to V1 (which see), reject take-off and brake
safely to a halt.
ACMS - aircraft condition monitoring system.
ACR - aerodrome control radar.
AD - Airworthiness Directive, issued by airworthiness
authorities to correct a defect found in an aircraft type after
certification. Compliance is mandatory and may be required immediately
and before further flight, within a specified period of time or number
of flying hours, or when next due for routine maintenance.
ADA - Advisory aispace. Advisory Area or Advisory Route.
ADC - air data computer.
ADELT - automatically deployable emergency locator transmitter.
ADF - automatic direction finder/finding. Radio compass which
gives a relative bearing to the non directional radio beacon to which
it is tuned.
ADI - attitude deviation indicator. An advanced type of
artificial horizon, part of a flight director system providing pitch
and roll information and commands.
ADIZ - Air Defence Identification Zone. An area of airspace
extending upwards from the surface, usually along a national boundary,
within which identification of all aircraft is required in the
interests of national security.
ADR - Accident Data Recorder.
ADS - Automatic Dependence Surveillance.
ADT - Approved Departure Time.
AEF - Aerodromes Environmental Federation.
Aerad - UK published flight guide and navigational chart
aerodrome/airport elevation - highest point of an aerodrome's
usable runway(s) expressed in feet above mean sea level (amsl).
AEW - Airborne early warning
AFB - air force base, usually U.S. or Canadian.
AFCS - automatic flight control system, an advanced autopilot.
Also IFCS, integrated flight control system.
AFDS - Autopilot and flight director system.
AFI - assistant flying instructor. Also AFIC, assistant flying
instructor course, FIC, flying instructor course.
AFIS - Aerodrome Flight Information Service, providing
information to, but not control of, aircraft using that aerodrome.
Also AFISO, AFIS officer, and AGO, air-to-ground operator.
AFS - Aerodrome Fire Service.
AFS - Aeronautical Fixed Service telephone/teleprinter network,
AFS - auto flight system.
AFTN - Aeronautical Fixed Telecommunications Network. A ground
based teleprinter network transmitting flight plans, weather
agl - above ground level.
AHRS - attitude-heading reference system. A sensor deriving
aircraft attitude and heading information from gyros and
AIAA - area of intense aerial activity, usually military.
AIC - Aeronautical Information Circular. Bulletins issued at
intervals by the CAA relating to matters of airworthiness,
administration, operating procedures, safety etc. AICs are
colour-coded according to subject, e.g. safety circulars are pink,
thus 'Pink 12' issued in December 1990
AIDS - Airborne integrated data system.
AIP - Aeronautical Information Publication. The UK Air Pilot,
statutory bible of aeronautical information published by the CAA.
Airep - form for reporting position and Met conditions in
Airmet - CAA's telephone aviation weather service, covering
Southern, Northern and Scottish regions of the UK. Also Metdial and
Metplan, privately-operated aviation weather services. For full
details see Pilot, February 1991.
AIS - Aeronautical Information Service. CAA unit based at
London Heathrow Airport, providing flight planning services and
information for pilots. Publishes AICs, above.
AIZ - Aerodrome Information Zone. See ATZ below.