Aircraft Hire Rates

As with any industry, there are a multitude of terms and acronyms that are commonly used in aviation.

Included below is a selection of those terms, which will hopefully assist in the demystification process!

A	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
ab initio	Literally `from the beginning', elementary flying training.
AD	Aerodrome
ADF	Automatic direction finder/finding. Radio compass which gives a relative bearing to the non-directional radio beacon to which it is tuned.
airport elevation	Highest point of an airport's usable runway(s) expressed in feet above mean sea level (amsl)
agl	Above ground level
AH	Artificial Horizon An instrument that depicts the current attitude of the aircraft in terms of pitch and roll.
Aileron	Control surfaces on the trailing edge of the wing. Ailerons on each side of the airplane deflect in opposite directions to control the roll, or bank, of the aircraft. Movement of the ailerons is controlled by either the control yoke or side stick. A trim system minimizes the force needed to hold the ailerons in the proper position for various flight conditions.
AIP	Aeronautical Information Publication Aeronautical Information Publication (AIP) Australia consists of a package of douments which provide all the operational information necessary for the safe and efficient conduct of national (civil) and international air navigation throughout Australia and its Territories. The AIP text is issued in two hard cover binders and includes the Aeronautical Information Circular (AIC) and (AIP) supplement text, dividers and 12 month amendment service. AIP Supplements (SUPs) include operational information appropriate to the AIP. A SUP is published when the information is of a temporary nature and requires advanced notification. Aeronautical Information Circulars (AICs) contain information of a technical nature and are generally educational, giving advance notice of new facilities, services and procedures.
Alternate	Aerodrome specified on a flight plan to which an aircraft chooses to divert if a landing at its intended destination is not possible (for reasons of poor weather, for example).
Altimeter	A pressure-sensing instrument that displays the altitude of an aircraft above the mean sea level (MSL).
Altimeter Setting	Barometric pressure reading in millibars, hectopascals or (in USA) inches of mercury (Hg) used to set a pressure altimeter's sub-scale to QFE or QNH.
Altitude	The height expressed in units of distance above a reference plane, usually above mean sea level or above ground level.
Attitude	An aircraft's position in relation to the horizon (i.e., whether the aircraft is flying level, nose up, nose down, or banking left or right).
AOPA	Aircraft Owners and Pilots Association (of Australia) There are branches in Australia, US and around the world.
ATC	Air Traffic Control
ATIS	Automatic Terminal Information Service A continuous recorded broadcast of routine non-control airport information, usually at large airports. Includes important information such as the active runway(s) and weather conditions at the field.
ATPL	Air Transport Pilot's Licence, needed to act as pilot-in- command of a commercial air transport aircraft exceeding 20,000 kg all-up weight.
ATSB	Australian Transport Safety Bureau
AUW	All-Up Weight A term for the total loaded weight of an aircraft, made up of empty weight plus useful load; maximum auw is the maximum allowable weight, including fuel and payload, specified in an aircraft's Certificate of Airworthiness. Sometimes referred to (in USA especially) as gross weight and maximum gross weight respectively. Also MTWA, maximum total weight authorised; BOW Basic operating weight, the weight of an aircraft with all equipment, lubricants, fuel and operating crew, but without payload; MLW, maximum landing weight, above which fuel must be burned off or jettisoned before landing or there may be risk of structural 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. Jet A1
B	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
Base (leg)	Base leg is the crosswind segment bringing the aircraft from the downwind leg to final approach. See also Crosswind, Downwind and Final.
Basic Empty Weight	Weight of the basic aeroplane including all fixed equipment, plus unusable fuel, full oil, hydraulic and other fluids.
C	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
CAAP	Civil Aviation Advisory Publication Civil Aviation Advisory Publications (CAAPs) are advisory documents which set out in simple language the purpose of the Regulation/Order and ways to comply with the mandatory requirements. They have three sections: blue - operational; green - airworthiness; yellow - aerodrome.
CAO	Civil Aviation Order The Civil Aviation Regulations make provision for Civil Aviation Orders (CAO), which include information on technical standards and specifications. In particular, they contain detailed mandatory operational, airworthiness and safety requirements, including design requirements, standards, specifications, mandatory operational, technical and administrative procedures and safety instructions.
CAR	Civil Aviation Regulations The Civil Aviation Act provides the primary legislative base for air safety control in Australia and contains a number of important regulatory provisions. In accordance with the Civil Aviation Regulations (CAR) contain the mandatory regulatory requirements in relation to airworthiness and operational matters, licencing and requirements, enforcement powers and air traffic control.
CASA	Civil Aviation Safety Authority.
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 precipitation, thunderstorms, shallow fog or low drifting snow.
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's service ceiling is the density altitude at 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).
Chief Flying Instructor	Individual who is appointed by a flying school and CASA to supervise the flying training given by the school.
CIR	Command Instrument Rating
Circuit	Pattern around which aircraft fly when arriving at an airfield, usually rectangular in Australia and UK but not necessarily elsewhere. The circuit ("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.
Clearance	Authorisation from air traffic control to proceed as requested or instructed. Used for ground and air manoeuvring, thus "cleared for take-off", "cleared flight-planned route", "cleared to descend" etc.
Clouds	Commonly-used abbreviations for cloud types :- AC = altocumulus AS = altostratus CB = cumulonimbus (thunderstorm) CC = cirrocumulus CI = cirrus CS = cirrostratus CU = cumulus NS = nimbo stratus SC = stratocumulus ST = stratus
c of g	Centre of gravity The point on an aircraft through which the entire aircraft's weight 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.
CPL	Commercial Pilot's Licence
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
Crosswind (leg)	The leg before downwind is called the Crosswind leg. See also Downwind, Base and Final.
CS or CSU	Constant-speed (propeller). A variable-pitch propeller which maintains constant rpm via a manually operated lever which is able to chnage the propeller's blade angle. Also CSU, constant-speed unit.
D	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
DAME	Designated Aviation Medical Examiner
Deadstick	Descent and landing with engine(s) shut down and propeller(s) stopped.
DF	Direction-finding A DF bearing can be provided by airfields or other facilities such as D & D cells (above) having suitable direction-finding equipment to locate an aircraft.
DH	Decision height The height on a precision approach at which a pilot must have the runway approach lights in sight to continue the descent, or if not, must initiate a go-around.
DG	Directional gyro A gyro instrument which indicates the magnetic heading of an aircraft. The DG is free of the turning errors associated with magnetic compasses but is prone to precession (wander) and must be reset against the magnetic compass at intervals
DME	Distance-measuring equipment A combination of ground and airborne equipment which gives a continuous slant range distance-from-station readout 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.
Downwind	Downwind is the segment of the circuit paralleling the runway and flown on a reciprocal heading. See also Crosswind, Base and Final.
Drag	The air's resistance to moving objects.
E	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
EAT	Estimated approach time
EET	Estimated elapsed time
ELB	Emergency locator beacon. See ELT.
Elevator	A control surface on the trailing edge of the horizontal stabilizer used to control the up or down movement of the airplane's nose. In some airplanes, the entire horizontal stabilizer can move, acting as the elevator. Movement of the elevator is controlled by either the control yoke or side stick. A trim system minimizes the force needed to hold the elevator in the proper position for climb, cruise, descent, and other flight conditions.
ELT	Emergency locator transmitter A small radio transmitter fixed to an aircraft's structure which is automatically activated by impact or water immersion and transmits a code on emergency frequencies enabling SAR satellites or search units equipped with DF to locate the crash or ditching site.
Endorsement	An authorisation indicating that a pilot is qualified to fly a particular type or class of aircraft. The authorisation is in the form of a log book entry. (Some operational approvals which require a log book entry are also called endorsements)
Empty weight	Weight of the basic aeroplane including all fixed equipment, plus undrainable fuel, oil, hydraulic and other fluids.
ERC - High Chart	Enroute Chart (ERC) (H) Designed to provide selected information similar to that of the ERC (L) series and is primarily for use by aircraft operating on transcontinental and intercapital routes at FL200 and above. This chart is amended every 6 months.
ERC - Low Chart	Enroute Chart (ERC) (L) Drawn to various scales to accommodate significant air traffic route areas and shows controlled airspace, prohibited, restricted and danger areas, air routes, ATS and radio-navigation services. Aeronautical information within Terminal areas may not be complete. Pilots should use a TAC or VTC. This chart is amended every 6 months.
ERSA	Enroute Supplement Australia The ERSA is a joint military/Airservices publication which contains information vital for planning a flight and for the pilot in flight. It contains pictorial presentations of all licensed aerodromes. Other information includes aerodrome physical characteristics, hours of operation, visual ground aids, lighting and aerodrome operators’ details. The RDS provides take-off and landing distances data and supplementary data for all licensed aerodromes.
ETA	Estimated time of arrival.
ETD	Estimated time of departure.
ETE	Estimated time en route.
F	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
FAA	Federal Aviation Administration, USA, their equivalent of our CASA.
Final	Final approach 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 also Crosswind, Downwind and Base.
Fixed Wing	Related to aeroplanes as opposed to helicopters, balloons, gyroplanes or airships
FL	Flight level A level of constant atmospheric pressure shown by an altimeter set to a standard 1013.25 millibars, expressed in rounds hundreds of feet, thus FL330 is 33,000 feet.
Flaps	Control surfaces on the trailing edge of the wing which are used to increase the amount of lift generated by the wings at slower speeds. Allow aircraft to takeoff and land at slower speeds.
Flight Time	In the case of heavier-than-air aircraft, the total time from when the aircraft first moves under its own power for the purpose of a flight until the moment at which it comes to rest on completion of the flight.
Forced Landing	A landing necessitated by failure of engines, systems, components, or incapacitation of a crewmember, which makes continued flight impossible, and which may or may not result in damage.
G	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
g	The acceleration force of gravity, normally 1g on earth. Zero g (0g) is weightlessness, as experienced by orbiting astronauts. g is expressed as positive (+) and negative (-) values. During a normal loop a pilot experiences positive g, tending to force him down in his seat. In an outside loop, with the pilot's head on the outside of the vertical circle, negative g forces him up out of his/her starps against the harness straps. Aircraft structural load limits are expressed in positive and negative values, the positive limit usually greater than negative, except in specialist aerobatic types.
GA	General aviation.
General Aviation	Defined as all non-scheduled flying activity in aircraft allocated a VH registration by CASA, but excluding VH-registered sailplanes (powered and unpowered). Ultralight aircraft, hang gliders and autogyros are also excluded.
GFPT	General Flying Progress Test Taken by student pilots as a pre-requisite to qualify for the PPL.
gnd	Ground
GPS	Global Positioning System (Navstar). A U.S. developed satellite-based high-precision navigation system, intended primarily for military use but now in widespread use by commercial and private operators, though with reduced accuracy compared with military versions.
G/S	Groundspeed The speed an aircraft makes over the ground, a product of its airspeed and wind speed.
H	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
Hdg	Heading The direction in which an aircraft's nose points in flight in the horizontal plane, expressed in compass degrees.
Heavy	Suffix used in RT callsigns to indicate that the aircraft is a large transport, alerting controllers and following aircraft to the possibility of wake turbulence.
Hg	Inches of mercury, a unit of pressure measurement
Holding pattern	Racetrack-shaped manoeuvre which keeps aircraft within a specified airspace while awaiting further clearance from air traffic control.
Horizontal Stabilser	The airfoil or small wing at the rear of the aircraft that balances lift forces generated by the wings and increases stability. In some airplanes, the stabilizer is fixed and the elevator attached to its trailing edge. In other airplanes, the entire stabilizer can move, acting as the elevator, which controls the up or down movement of the airplane's nose. A trim system minimizes the force needed to hold the elevator in the proper position for climb, cruise, descent, and other flight conditions.
I	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
IAS	Indicated airspeed An aircraft's speed through the air as indicated by the ASI, without correction for position error, altitude or outside air temperature.
IF	Instrument flying.
IFR	Instrument Flight Rules Required for flight in 'non-visual meteorological conditions'. Rough translation: The weather is so bad you can't see out the windows.
ILS	Instrument Landing System The approach aid employing two radio beams to provide pilots with vertical and horizontal guidance during the landing approach. The localiser provides azimuth guidance, while the glide-slope defines the correct vertical descent profile. Marker beacons and high intensity runways lights are also part of the ILS.
Instrument Rating	A flight crew rating that indicates that a pilot is qualified to fly an aircraft by sole reference to the aircraft's instruments.
Instructor Rating	A flight crew rating that indicates that a pilot is qualified to train other pilots
IR	Instrument rating. See Instrument Rating.
J	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
Jeppesen	U.S.developed navigational/approach chart system with worldwide coverage.
K	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
Knot (kt)	One nautical mile per hour (never one knot per hour), the standard unit of aviation speed measurement. In terms of distance, a knot is 15 percent longer than a statute mile. Therefore, a knot is equal to 1.1515 statute miles or 1.852 kilometres. One nautical mile equals 6,080 feet.
L	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
lat	Latitude Measurement north or south of the equator in degrees, minutes and seconds.
Lift	The force generated by the movement of air across the wings of an aircraft. When enough lift is generated to overcome the weight of an aircraft.
lon(g)	Longitude Measurement east or west of the prime meridian in degrees, minutes and seconds.
M	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
M or mag	Magnetic
MAP	Missed approach point The point on a published ILS approach expressed in time or distance from the final approach fix, or as an altitude on the glideslope, at which the missed approach procedure must be initiated if the runway or approach lights are not clearly in sight.
Mayday	International radio distress call (from the French, m'aidez -- help me). It signifies imminent danger to life requiring immediate assistance.
Met	Meteorology, weather.
MH	Magnetic heading
minimums	Weather condition requirements for a particular mode of flight (e.g. for VFR operation, IFR take-offs and landings).
MSL	Mean sea level
N	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
NDB	Non-directional beacon A medium-frequency navigational aid which transmits non-directional signals, superimposed with a Morse code identifier and received by an aircraft's ADF
Night Flying	Flight time which accrues during the period between the end of the evening civil twilight and the beginning of morning civil twilight.
nm	Nautical mile
Notam	Notices to Airmen issued by the CASA (and equivalent authorities elsewhere) to inform pilots of new or changed aeronautical facilities, services, procedures or hazards, temporary or permanent.
NVFR	Night Visual Flight Rules
O	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
Okta	A measurement of cloud cover. One okta means one-eighth of the sky is covered.
P	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
Pan	International radio call signalling urgency
PAPI	Precision Approach Path Indicator A system of coloured lights installed at the approach end of a runway which provides visual guidance to the correct glidepath. A successor to VASI, below.
pax	Passengers
PIC	Pilot-in-command
Pilot In Command	Pilot responsible for the operation and safety of the aircraft during flight time.
Pitch	A description of the movement of the nose of an aircraft up or down in relation to its previous attitude.
POB	(number of) persons on board. Also SOB, souls on board.
POH	Pilot's Operating Handbook An aircraft's `owner's manual'.
PPL	Private Pilot's Licence
psi	Pounds per square inch A measurement of pressure.
Q	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
Q-code	Code system developed when air-to-ground communication was by wireless telegraphy, enabling many routine phrases and questions to be reduced to three letters. Now largely redundant, except these: QDM magnetic bearing to a direction-finding station. QDR magnetic bearing from the station. QFE atmospheric pressure at aerodrome elevation. With its sub-scale set to the aerodrome QFE an altimeter will indicate height above that airfield. QFU magnetic orientation of runway in use. QNE reading in feet on an altimeter set to 1013.25 millibars (standard pressure) when the aircraft is at aerodrome elevation. QNH altitude above mean sea level based on local station pressure. QTE true line of position from a direction-finding station. QUJ true bearing
R	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
Rabbit lights	Colloquialism for sequentially flashing lead-in runway approach lights.
Ramp weight	Maximum permissible weight of an aircraft, which exceeds maximum take-off weight by an allowance for fuel burned during engine-start and taxi.
Rating	Add-on qualification to a pilot's licence, e.g. Night Rating, Instrument Rating, etc. Individual Type Ratings are necessary to fly aircraft over 12,500 pounds MTWA.
RCL	Runway centre-line.
Roll	A description of the rolling or banking movement of an aircraft to the left or right. The wing ailerons control roll.
Rudder	A control surface on the trailing edge of the vertical stabilizer that controls the yaw motion of the aircraft - that is, the motion of the nose of the aircraft left or right. A trim system minimizes the force needed to hold the rudder in the proper position for various flight conditions.
rwy	Runway
S	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
SAR	Search-and-rescue.
SB	Service Bulletin Advisory notices issued by aircraft, engine and equipment manufacturers alerting owners and engineers to faults or problems requiring preventitive or remedial maintenance or modification. Often termed `mandatory', but do not have the legal force of Airworthiness Directives (which see).
Sectional	(U.S.) VFR navigation chart, equivalent to our 1:500,000 or `half-million'.
sl	Sea level.
SOB	Souls on board, the number of persons on board an aircraft. Also POB.
SPL	Student Pilot Licence
Squawk	To transmit an assigned code via a transponder
T	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
T	True. Also TH, true heading, and TT, true track.
TAF	Terminal Aerodrome Forecast.
TAS	True airspeed. Indicated airspeed corrected for pressure and outside air temperature.
TAC	Terminal Area Chart For use in terminal areas, these charts provide airspace, air-routes, prohibited, restricted and danger areas, navigation aids and radio frequencies. They are designed to display aeronautical information at a larger scale for easier use in congested areas. Scale varies for each chart. This chart is amended every 6 months.
TH	True heading.
THR or thld	Threshold
Track	Actual flight path of an aircraft over the ground.
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.
U	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
U.T.C	Universal Time Co-ordinate, formerly Greenwich Mean Time G.M.T
V	A \| B \| C \| D \| E \| F \| G \| H \| I \| J \| K \| L \| M \| N \| O \| P \| Q \| R \| S \| T \| U \| V \| W \| X \| Y \| Z
V-speeds	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. Va design manoeuvring speed. The speed below which abrupt and extreme control movements are possible (though not advised) without exceeding the airframe's limiting load factors. Vfe maximum flap extension speed (top of white arc on ASI). Vmca minimum control speed (air). The minimum speed at which control of a twin-engined aircraft can be maintained after failure of one engine. Vne never-exceed speed, `redline speed' denoted by a red radial on an ASI. Vmo maximum operating speed. Also Mmo, Mach limit maximum operating speed. Vno normal operating speed. The maximum