ACARS: Aircraft Communication
Adressing and Reporting System
APP: Approach control
APU: Auxiliary Power Unit. Device (usually a
small turbine) that provides power for engine-starting and other
systems while on the ground.
Such device is present on large aircraft and some business jets,
and replaces the GPU*.
ARTCC: Air Route Traffic Control Centre
ATA: Actual Time of Arrival
ATC: Air Traffic Control
ATCC: Air Traffic Control Centre
ATIS: Automatic Terminal Information Service.
Automatically recorded message transmitted on a particular frequency,
containing current
weather conditions, QNH* setting, active runways,
etc., provided at the major airports.
AVGAS: Aviation Gasoline. Usually followed by
the octane rating. Used by piston-engined aircraft.
AVTUR: Aviation Turbine fuel (kerosene). Used
by turboprops and jet aircraft.
Black Box: Popular name given to either the CVR* or
the FDR* used to investigate an accident.
Callsign: Phrase used in radio transmissions
to identify an aircraft
Ceiling: Height above ground or water level of
the base of the lowest layer of cloud, below 20,000 feet, covering
more than half of the sky.
Service ceiling also means an aircraft's density altitude* at
which its maximum rate of climb is lower or equal to 100 feet per
minute. The
absolute celing is the highest altitude at which the aircraft
can maintain level flight.
Clearance: Authorization given by ATC* to
proceed as requested or instructed, e.g. "Cleared for take-off", "Cleared
for visual approach",
"Cleared to land".
Crosswind: Wind perpendicular to the motion of
the aircraft. The crosswind leg is also one of the many words describing
the approach
segments. See Final* for a diagram.
out by measuring time-lapse of a signal transmitted by the aircraft
to the station and responded back. DMEs can also provide
groundspeed and time-to-station readouts by differentiation.
DME:
Distance Measuring Equipment is a transponder-based radio navigation
technology that measures distance by timing the propagation
delay of VHF or UHF radio signals.
Downwind: One of the many words describing the
approach segments.
EAT: Estimated (or expected)
Approach Time
ETA: Estimated Time of Arrival
ETD: Estimated Time of Departure
ETOPS: Extended-range Twin Operations. Certification
given to two-engine aircraft for long overwater flights. Popular
deformation of this
term is "Engines Turning Or Passengers Swimming"!
F/A: Flight Attendant. Also known
as Air Hostess in the UK, formerly known as Steward(ess) in North
America.
Final: Final Approach. One of the many words
describing the approach segments. The part of a landing sequence
or aerodrome circuit
procedure in which the aircraft has made its final turn and is
inbound to the active runway. See picture at right.
FL: Flight Level. Altitude at barometric setting
of 1013.2 millibars or 29.92 inches of mercury, expressed in rounds
hundreds of feet. This
is usual mostly above 18,000 feet. FL350 is 35,000 feet.
F/O: First Officer. Also known as Co-Pilot.
GND: Ground
Go-Around Balked approach, when the aircraft
climbs away from the runway during the approach, to either start
the approach again, or proceed
to the alternate* airport.
GPS: Global Positioning System (Navstar). Navigational
system using orbiting satellites to determine the aircraft's position
on the Earth.
GPWS: Ground Proximity Warning System. A radar-based
flight deck system to give pilots audible warning by means of horns,
hooters, taped or
synthetic voices of terrain close beneath an aircraft's flight
path. One of the GPWS' warnings might be: "TERRAIN! WHOOP
WHOOP! PULL UP!" or
"WINDSHEAR! WINDSHEAR!".
Ground speed: Actual speed of an airplane as
measured relative to the ground.
GS: Glideslope. Vertical guidance, part of an
ILS, establishing the safe glidepath to a runway. A standard ILS
glideslope is 3 degrees.
Heavy: Suffix used in radio transmission callsigns* (e.g. "United
492 Heavy") to indicate the aircraft is capable of generating
wake turbulence.
Holding pattern: Manoeuver consisting of making
the aircraft turn around the aerodrome at an assigned altitude,
while awaiting further ATC
instructions.
IATA: International Air Transport Association
ICAO: International Civil Aviation Organisation
IFR: Instrument Flight Rules prescribed for the
operation of aircraft in instrument meteorological conditions.
ILS: Instrument Landing System. Consists of the
localizer, the glideslope and marker radio beacons (Outer, Middle,
Inner). It provides horizontal and
vertical guidance for the approach.
Knot (kt): Standard unit of speed in aviation
and marine transportation, equivalent to one nautical mile per
hour. One knot equals 1.1515 mph.
Lat: Latitude
LOC: Localizer. The azimuth guidance portion
of an instrument landing system.
Mayday: The ultimate international radio distress
call, indicating imminent danger to the life of the occupants onboard
and requiring immediate
assistance.
MTOW Maximum Take-Off Weight
No-Show: Passenger with a confirmed
reservation, who failed to check baggage or to present at the gate
on time.
NOTAM: Notices To Airmen. Issued by the FAA or
its equivalent to inform pilots of new or changed aeronautical
facilities, services, procedures,
or hazards, temporary or permanent.
Pax: Passengers
Payload: Revenue passengers and/or cargo, or
more specifically their combined weight.
QNH: altitude above mean sea level based on local
station pressure.
Roger: Commonly used word in aviation communications.
Just like "10-4" in other types of communications,
it means that the instruction has been
understood. Also, to roger is to repeat the instruction as to
make sure it has been clearly understood.
RVR: Runway Visual Range. A horizontal measurement
of visibility along a runway.
rpm: Revolutions Per Minute.
RWY: Runway
SELCAL: Selective Calling. A
high-frequency system enabling air traffic control to alert a particular
aircraft, by means of flashing light or aural
signal in the cockpit, for receipt of a message without
the crew having to maintain a listening watch. Used on long-haul
over-ocean airline routes
and by intercontinental business jets.
Shanwick: ATCC located in Shannon
(Ireland) and Prestwick (Scotland, UK), hence the name. Shanwick
looks after traffic in the Northern Atlantic
coast of Europe.
Squawk (to): To transmit an assigned code via
a transponder. The squawk is also the assigned code.
STOL: Short Take-Off and Landing.
STOVL: Short Take-Off and Vertical Landing.
Tailwind: Strong wind in the
same direction as the motion of the aircraft.
TOGA: Take-off/Go Around. An autopilot setting
activating take-off or go-around* thrust.
Transponder: Airborne receiver/transmitter portion
of the SSR system which receives the interrogation
signal from the ground and automatically
replies according to mode and code selected. Modes A and B are
used for identification, using a four-digit number allocated by
air traffic control.
Mode C gives automatic altitude readout from an encoding altimeter.
TWR: Tower
TWY: Taxiway
UHF: Ultra-High Frequency. Radio
frequencies in the 300-3,000 MHz band.
UTC: Co-ordinated Universal Time, formerly Greenwich
Mean Time
V1: decision speed, up to which
it should be possible to abort a take-off and stop safely within
the remaining runway length. After reaching V1
the take-off must be continued.
VR: rotation speed, at which to raise the nose
for take-off.
VFR: Visual Flight Rules. Prescribed for the
operation of aircraft in visual meteorological conditions (VMC).
VMC is generally defined as 5 miles
visibility or more and
1,000 feet vertical and one nautical mile horizontal clearance
from cloud, but variations apply to aircraft operating below 3,000
feet AMSL.
Special VFR (SVFR) clearances
are granted at the discretion of ATC for VFR flight through some
controlled airspace where IFR* usually apply.
VHF: Very High Frequency. Radio frequencies in
the 30-300 MHz band, used for most civil air-to-ground communication.
VIS: Visibility
VNAV: Vertical Navigation
VOR: Very high frequency Omnidirectional Range.
A radio navigation aid operating in the 108-118 MHz band. A VOR
ground station
transmits a two-phase directional signal
through 360°. the aircraft's VOR receiver enables a pilot
to identify his radial or bearing from/to the ground station. VOR
is the most
commonly used radio navigation aid in
private flying. Increased accuracy is available in Doppler VORs
(DVOR) which have replaced some VORs in the UK system. Also
VORTAC, combined VOR and
TACAN, and VOT, VOR test facility.
VSI: Vertical Speed Indicator. One of the primary
flight instruments showing rate of climb or descent.
V/STOL: Vertical and Short Take-Off and Landing.
VTOL: Vertical Take-Off and Landing.
Wake turbulence: Wingtip vortices
generated behind a wing producing lift. Behind a large heavy aircraft
they can be powerful enough
to roll or even break up a smaller aircraft.
Windshear: localised change in wind speed and/or
direction over a short distance, resulting in a tearing or shearing
effect, usually at
low altitude, that can cause a sudden loss of airspeed with occasionally
disastrous results if encountered when taking-off or landing.
Zulu: Used worldwide for times of flight operations,
formerly Greenwich Mean Time, now Co-ordinated Universal Time (UTC).
(e.g. 1500Z)
