CHAPTER 3 DEFINITIONS ETC.
3.01 Definitions etc.
(1) In this instrument:
(a) approval means approval in writing by CASA, unless the contrary intention appears; and
(b) words and phrases have the same meaning as in Part 139 of CASR, unless the contrary intention appears in subsection (2).
Note Various other words and expressions used in this MOS have the same meaning as in the CASR Dictionary.
(2) In this instrument:
AAIS means automatic aerodrome information service.
accelerate-stop distance available (ASDA) is the length of the take-off run available (TORA) plus the length of any stopway (SWY).
Note 1 ASDA = TORA + SWY.
Note 2 Any available clearway (CWY) or runway end safety area (RESA) is not included.
Act means the Civil Aviation Act 1988.
ADS-B means automatic dependent surveillance – broadcast.
AEP means aerodrome emergency plan.
aerodrome has the same meaning as in the Act.
aerodrome beacon means an aeronautical beacon used to indicate the location of an aerodrome from the air.
aerodrome elevation means the elevation of the highest point of the landing area.
aerodrome facility means any of the following physical things at an aerodrome as mentioned in this MOS for an aerodrome:
(a) the physical characteristics of any movement area including runways, taxiways, taxilanes, shoulders, aprons, primary and secondary parking positions, runway strips and taxiway strips;
(b) infrastructure;
(c) structures;
(d) equipment;
(e) earthing points;
(f) cables;
(g) lighting;
(h) signage;
(i) markings;
(j) visual approach slope indicators;
(k) any other similar thing that is physical matter and is used for the operation of aircraft at the aerodrome.
Note 1 Aerodrome facilities are physical matter. For example, a safety management system is not an aerodrome facility. Management and administrative processes do not constitute an aerodrome facility.
Note 2 The expression aerodrome facilities and equipment is defined in the CASR Dictionary. The different expression aerodrome facility is defined in this MOS and has a different meaning.
aerodrome frequency confirmation system means a system which:
(a) responds automatically when a radio transmission is broadcast on an assigned aerodrome frequency; and
(b) is used to confirm that the correct aerodrome frequency has been selected on the air‑band radio.
aerodrome layout is the number of runways, taxiways and aprons at an aerodrome that are provided with lighting, in 1 of the following categories of aerodrome:
(a) basic — an aerodrome with 1 runway, with 1 taxiway to 1 apron area;
(b) simple — an aerodrome with 1 runway, having more than 1 taxiway to 1 or more apron areas;
(c) complex — an aerodrome with more than 1 runway, having more than 1 taxiway to 1 or more apron areas.
aerodrome movement, for an aircraft, means a take-off, a landing, or a touch-and-go manoeuvre at an aerodrome.
aerodrome reference code (ARC) has the meaning given to it in Chapter 4 of this MOS.
aerodrome reference point (ARP) means the designated geographical location of an aerodrome.
aerodrome technical inspection means an inspection of the facilities, equipment and operation of a certified aerodrome, conducted by, or on behalf of, the aerodrome operator to ensure detection of any deterioration that could make any of the facilities, equipment or operations unsafe for aircraft operations.
Aerodrome Terrain and Obstacle Chart — ICAO (Electronic) means an electronic chart that portrays such terrain, obstacle and aeronautical data for an aerodrome as is reasonably required to:
(a) enable an operator to:
(i) carry out operating limitations analysis for aircraft using the aerodrome; and
(ii) know whether the operator’s aircraft may land at, and take off from, the aerodrome within the operating limitations of the aircraft; and
(iii) develop procedures for use in the event of:
(A) a missed approach or take-off; or
(B) an emergency during landing or take-off; and
(b) support the following activities for the safety of air navigation:
(i) instrument procedure design (including circling procedures);
(ii) aerodrome obstacle restriction and removal;
(iii) provision of source data for the production of other aeronautical charts.
Note See sections 7.21 and 7.24.
aerodrome traffic density means the number of aircraft movements in the mean busy hour, in 1 of the following categories:
(a) light — not greater than 15 movements per runway, or typically less than 20 total aerodrome movements;
(b) medium — 16 to 25 movements per runway, or typically between 20 to 35 total aerodrome movements;
(c) heavy — 26 or more movements per runway, or typically more than 35 aerodrome movements.
aeronautical beacon means an aeronautical ground light visible at all azimuths, either continuously or intermittently, to designate a particular point on the surface of the Earth.
aeronautical ground light means any light specially provided as an aid to air navigation, other than a light displayed on an aircraft.
aeronautical study means an investigation of a problem concerned with aircraft operations, aimed at identifying:
(a) possible solutions (if any); and
(b) the solution (if any) which best preserves an acceptable level of aviation safety.
Note CASA guidance on aeronautical studies is contained in CASA Advisory Circular (AC) 139.A-04: Applying for aerodrome authorisations, exemptions and approvals, as existing from time to time and freely available on the CASA website.
aeroplane reference field length means the minimum field length required for an aeroplane to take off at maximum certificated take-off mass, at sea level, in standard atmospheric conditions, in still air and with zero runway slope, as shown in:
(a) the aeroplane’s aircraft flight manual approved by the national aviation authority which issued the initial type certificate for the aeroplane; or
(b) equivalent data from the aeroplane manufacturer.
AFRU means aerodrome frequency response unit and is the abbreviation used for an aerodrome frequency confirmation system.
AIP means Aeronautical Information Publication.
AIP-ERSA means Aeronautical Information Publication - En Route Supplement of Australia.
aircraft classification number (ACN), until the end of 26 November 2025, means a number expressing the relative effect of an aircraft on a pavement for a specified standard subgrade category.
aircraft classification rating (ACR) means the number that expresses the relative effect of an aircraft on a pavement for the specified standard subgrade strength of the pavement.
aircraft movement means 1 of the following:
(a) the landing of an aircraft at an aerodrome;
(b) the take-off of an aircraft from an aerodrome;
(c) a touch-and-go manoeuvre of an aircraft at an aerodrome.
aircraft movements, when referred to numerically for an aerodrome, for a financial year, means the numbers of aircraft movements at the aerodrome during the financial year, as compiled by the aerodrome operator or the ATS provider.
Note CASA may require an aerodrome operator or an ATS provider to provide it with aircraft movement data: see regulations 139.140 and 139.145 of CASR.
aircraft parking position means an open-air designated area on an apron for parking an aircraft.
Note 1 An aircraft parking position is also known as an aircraft stand.
Note 2 An aircraft parking position does not include any area that is within a fully or partially‑enclosed aircraft hangar.
Note 3 An area designated on an apron as being available for the parking of aircraft is considered to be an aircraft parking position.
airline means an aircraft operator operating aircraft in regular public transport operations.
airside means the following areas, access to which is restricted by the aerodrome operator, or by a Federal or State authority, to authorised persons only:
(a) the movement area of the aerodrome;
(b) where their purpose and use is to directly support aircraft operations — the terrain and buildings adjacent to the movement area, or particular portions of such adjacent terrain and buildings.
Note The word “landside” is used colloquially to denote areas of an aerodrome that are not airside, for example, passenger terminals.
airside driver means a person who drives or operates an airside vehicle.
airside vehicle means a vehicle, including equipment that is mobile under its own power, that is operated airside under the authorisation of the aerodrome operator.
air transport operation has the same meaning as in clause 3 of Part 2 of the CASR Dictionary.
Note An aerial work operation is not an air transport operation.
air transport passenger means a passenger in an air transport operation.
air transport passenger movement numbers, for an aerodrome, for a financial year, means the numbers, published by the Department, of air transport passenger movements at the aerodrome during the financial year, and any reference to air transport passenger movements is a reference to the movements compiled in these numbers.
AIS provider means a person who holds a certificate under regulation 175.055 of CASR.
APEI means the official publication known as Airport Engineering Instructions issued:
(a) by CASA or its predecessors, before the Rules and Practices for Aerodromes (RPA) was first issued; or
API means the official publication known as Airport Instructions issued:
(a) by CASA or its predecessors, before the Rules and Practices for Aerodromes (RPA) was first issued; or
approved means approved by CASA, whether with or without conditions, unless the contrary intention appears.
apron means a defined area on a land aerodrome to accommodate aircraft for the purposes of loading or unloading passengers, mail or cargo, fuelling, parking, or maintenance.
apron taxiway means a portion of a taxiway system located on an apron to provide a through taxi route for aircraft across the apron to another part of the taxiway system.
ARC means aerodrome reference code.
ARFF unit, for an aerodrome, means the aviation rescue and firefighting unit at the aerodrome.
ARFFS means aviation rescue and firefighting service.
artificial, in relation to an obstacle, object or structure, means an obstacle, object or structure made by human skill and labour.
ATC means air traffic control.
ATS means air traffic service.
AT-VASIS means abbreviated T visual approach slope indicator system.
Australian Height Datum means the datum that sets mean sea level as zero elevation.
A-VDGS means advanced visual docking guidance system.
barrette means 3 or more aeronautical ground lights closely spaced in a transverse line so that from a distance they appear as a short bar of light.
Note Transverse means transverse to the runway centreline.
becomes aware means:
- in relation to an aerodrome operator’s awareness of the numbers of aircraft movements at the aerodrome within a period — the operator is taken to know the relevant number of such movements as soon as a reasonable operator, monitoring such movements in any way, would know; and
(b) in relation to an aerodrome operator’s awareness of the numbers of aircraft passenger movements at the aerodrome within a period — the operator is taken to know the relevant number of such movements at the earlier of the following:
(i) the date of publication, if any, by the Department, of the aircraft passenger movement numbers for the aerodrome for the period;
(ii) as soon as a reasonable operator, monitoring such movements in any way, would know.
bypass pad means a pad resembling a runway turn pad except that:
- it is extended beyond the declared end of the runway; and
- it allows an aircraft to go around the runway end stripe and runway end lights before turning around 180 degrees to use the runway in a reciprocal direction.
CA/GRO means a certified air/ground radio operator.
CA/GRS means a certified air/ground radio service.
CAR means the Civil Aviation Regulations 1988.
CASR means the Civil Aviation Safety Regulations 1998.
CAT, when referring to an instrument approach, means category.
CAVOK means that cloud, visibility and present weather are better than the prescribed values or conditions.
Note CAVOK is sometimes referred to as “ceiling and visibility OK”.
Chicago Convention means the Convention on International Civil Aviation.
civil aviation safety legislation means the Civil Aviation Act 1988, the regulations made under the Act, and instruments, including Civil Aviation Orders and Manuals of Standards, made under the Act or the regulations, and other instruments made under any of the foregoing.
clearway (CWY) means a defined area at the end of the TORA, on the ground or water under the control of the aerodrome operator, that is selected or prepared as a suitable area over which an aeroplane may make a portion of its initial climb to a specified height.
CNS means communications, navigation, surveillance.
Configuration A, for runway guard lights, has the meaning given in subsection 9.99 (1).
Configuration B, for runway guard lights, has the meaning given in subsection 9.99 (1).
critical obstacle means the obstacle within the take-off climb area, or within the approach area, or within both areas, which subtends the greatest vertical angle when measured from the inner edge of the take-off climb surface and/or the approach surface.
CTAF means common traffic advisory frequency.
CVOR means conventional VOR.
daylight means the period between the beginning of morning civil twilight and the end of evening civil twilight.
declared distances means the following:
(a) take-off run available (TORA), being the length of runway declared available and suitable for the ground run of an aeroplane taking off;
Note TORA may include additional length available from a starter extension if provided.
(b) take-off distance available (TODA), being the length of the take-off run available plus the length of the clearway, if provided;
(c) accelerate-stop distance available (ASDA), being the length of the take-off run available plus the length of the stopway, if provided;
(d) landing distance available (LDA), being the length of runway which is declared available and suitable for the ground run of an aeroplane landing.
Department has the meaning given in item 1 in subsection 19A (1) of the Acts Interpretation Act 1901.
Note “Department” means the Department of State of the Commonwealth that is administered by the Minister who, from time to time, administers CASR. At the date of making, this is the Department of Infrastructure, Regional Development and Cities but may change from time to time in accordance with Administrative Arrangements Orders made by the Governor-General.
dependent parallel approaches means simultaneous approaches to parallel or near‑parallel instrument runways where radar separation minima between aircraft on adjacent extended runway centrelines are prescribed.
design slope, for any aerodrome facility, means that, at the design stage of construction, the design of the slope must fall within the range of values expressed in the relevant Table or provision of this MOS for the design slope.
displaced threshold means a threshold not located at the extremity of a runway.
DME means distance measuring equipment.
D value, for a rotorcraft, is the rotorcraft’s maximum dimension when rotors are turning, and is the distance in metres measured from:
(a) the most forward position of the main rotor tip path plane of the rotorcraft;
to:
(b) the most rearward position of the tail rotor tip path plane or of the rotorcraft’s fuselage.
Note “D value” is a common design term used in ICAO Annex 14, Aerodromes, Volume II, Heliports. For ICAO documents, see section 1.07.
DVOR means the Doppler VOR.
earth mat area means the area of virgin ground that is directly underneath, and in immediate proximity to, a communications, navigation, surveillance site.
effective intensity, for a flashing light, is equal to the intensity of a fixed light of the same colour, which will produce the same visual range under identical conditions of observation.
elevation means the vertical distance of a point or a level, on or affixed to the surface of the Earth, measured from mean sea level.
exit taxiway means a taxiway connected to a runway to enable landing aeroplanes to turn off the runway.
facility has the same meaning as aerodrome facility.
FATO area means a final approach and take-off area of an aerodrome used for helicopter operations.
fixed light means a light having constant luminous intensity when observed from a fixed point.
FOD means foreign object debris, which may result in foreign object damage to an aircraft.
frangible object means an object of low mass designed to break, distort or yield on impact so as to present the minimum hazard to aircraft.
GBAS means a ground-based augmentation system comprised of a VHF data broadcast (VDB) antenna and (typically) 4 remote satellite measurement unit (RSMU) antennas, with each of these components:
(a) separately located; and
(b) performing specific functions; and
(c) with different siting requirements and restrictions.
GLS means GBAS landing system, and is a GNSS alternative to an ILS for approach and landing operations using a GBAS as the primary navigational reference.
GNSS means Global Navigation Satellite System.
gravel, for a surface, means that the surface is comprised of gravel and any binding additives but is not sealed.
hazard beacon means an aeronautical beacon used to designate a danger to air navigation.
HF means the high frequency band, that is radio frequencies in the range 3 000 to 30 000 kHz.
holding bay is a defined area where aircraft can be held or bypassed to facilitate efficient surface movement of aircraft.
Note Generally, such an area is offset from the taxiway so that clearance for passing aircraft is maintained.
homogeneous runway surface means a runway surface that has a consistent surface finish across its full width.
Note A non-homogeneous runway surface means a runway surface that has different surface finishes across its full width. A non-homogeneous runway surface may result in differing friction, loading, and wet weather characteristics. Thus, it may limit the operations of some aircraft types depending on the requirements of the aircraft flight manual.
Note: IATA means International Air Transport Association.
ICAO means the International Civil Aviation Organization established under the Chicago Convention.
ICAO Annex, for a numbered ICAO document, means the Annex, of that number, to the Chicago Convention.
ICAO Annex 4 means Annex 4, Aeronautical Charts.
IFR means instrument flight rules, and has the same meaning as that given in CAR for I.F.R.
ILS means an instrument landing system comprised of the following components:
(a) VHF localizer equipment;
(b) UHF glide path equipment;
(c) VHF marker beacons or distance measuring equipment (DME);
(d) localizer far field monitor antennas.
Note Each component of an ILS performs specific functions, and is separately located along the longitudinal axis of, or alongside, the runway. Different siting requirements, and restrictions to access and movement, apply to each site.
ILS critical area means an area about the localizer and glide path antennas where vehicles and aircraft must be excluded during all ILS operations because the presence of vehicles or aircraft inside the area will cause unacceptable disturbance to the ILS signal-in-space.
ILS sensitive area means an area extending beyond the ILS critical area:
(a) where the parking and movement of vehicles and aircraft is controlled to prevent the possibility of unacceptable interference to the ILS signal during ILS operations; and
(b) which is protected against interference caused by large moving objects outside the ILS critical area but still normally within the airfield boundary.
independent parallel approaches means simultaneous approaches to parallel or near‑parallel instrument runways where radar separation minima between aircraft on adjacent extended runway centrelines are not prescribed.
independent parallel departures means simultaneous departures from parallel or near‑parallel instrument runways.
instrument approach procedures means a series of predetermined manoeuvres by reference to flight instruments with specified protection from obstacles from the initial approach fix or, where applicable, from the beginning of a defined arrival route to a point from which a landing can be completed and thereafter, if a landing is not completed, to a position at which holding or en route obstacle clearance criteria apply.
instrument meteorological conditions (IMC) means meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling, less than the minimum specified for visual meteorological conditions.
instrument runway means 1 of the following types of runway nominated for the operation of aircraft using instrument approach procedures:
(a) non-precision approach runway, being a runway, served by visual aids and non‑visual aids, intended for landing operations following an instrument approach operation with a minimum descent height or decision height (DH) at or above 250 ft (a type A operation) in runway visibility of not less than 1 000 m;
(b) precision approach runway, Category (CAT) I, being a runway, served by visual aids and non-visual aids, intended for landing operations following an instrument approach operation with a DH lower than 250 ft (a type B operation) but not lower than 200 ft, and either:
(i) in visibility of not less than 800 m; or
(ii) with an RVR of not less than 550 m;
(c) precision approach runway, Special Authorisation Category I (SA CAT I), being a runway, served by visual aids and non-visual aids, nominated for landing operations following an instrument approach type B operation with a DH lower than 200 ft but not lower than 150 ft, and an RVR of not less than 450 m;
(d) precision approach runway, Special Authorisation Category II (SA CAT II) being a runway, served by visual aids and non-visual aids, nominated for landing operations following an instrument approach type B operation with a DH lower than 200 ft but not lower than 100 ft, and an RVR of not less than 350 m;
(e) precision approach runway, CAT II, being a runway, served by visual aids and non‑visual aids, nominated for landing operations following an instrument approach type B operation with a DH lower than 200 ft, but not lower than 100 ft, and an RVR of not less than 300 m;
(f) precision approach runway, CAT III, being a runway, served by visual aids and non‑visual aids, for landing operations following an instrument approach type B operation to and along the surface of the runway and:
(i) for CAT IIIA — nominated for operations with a DH lower than 100 ft or with no decision height, and an RVR of not less than 175 m; and
(ii) for CAT IIIB — nominated for operations with a DH lower than 50 ft or with no decision height, and an RVR of less than 175 m but not less than 50 m; and
(iii) for CAT IIIC — nominated for operations with no DH or RVR limitations.
Note 1 Instrument approach procedures are classified as follows:
(a) Non-precision approach (NPA) procedure: an instrument approach procedure designed for 2D instrument approach type A operations.
(b) Approach procedure with vertical guidance (APV): a performance-based navigation (PBN) non-precision instrument approach procedure designed for 3D instrument approach type A operations.
(c) Precision approach (PA) procedure: an instrument approach procedure based on navigation systems (ILS, MLS, GLS and SBAS CAT I) designed for 3D instrument approach type A or B operations.
Note 2 When preparing or nominating their infrastructure to support the desired aircraft operation, the aerodrome operator determines the classification of instrument runway for which the runway is to be nominated provided that the relevant standards in this MOS are achieved. A certified designer under Part 173 of CASR may then be tasked to design the optimal terminal instrument flight procedure to the capabilities of the instrument runway.
Note 3 Special Authorisation Category operations may only be utilised by aircraft operators who meet specific requirements for flight crew competency, aircraft capability and any conditions relevant to the terminal instrument flight procedure.
Note 4 The visual aids provided need not necessarily be matched to the scale of the non-visual aids provided. CASA recommends that visual aids should be determined based on the requirements for the intended classification of operation and in consultation with the aircraft operators for whom it is intended to be utilised.
intermediate holding position means a designated holding position for traffic control, at which taxiing aircraft and vehicles:
- must stop and hold only if so instructed by the aerodrome control tower; and
- if so stopped, must not proceed until given clearance by the aerodrome control tower.
international aerodrome means an aerodrome:
(a) designated by the Department as an international airport in Australia (a designated international airport in Australia); and
(b) identified as a designated international airport in Australia on the Department’s website.
Note Generally, scheduled international air transport operations are conducted only at international aerodromes. The list of designated international airports in Australia may be accessed by navigating from the following link: https://infrastructure.gov.au/aviation/international/icao/desig\_airports.aspx.
international air transport operation means an international air transport operation whether or not it is conducted in accordance with a published schedule.
jet blast means the thrust force from an aircraft jet or turbofan engine when the aircraft is on or close to the ground.
Note: LAHSO means land and hold short operations.
landing area means that part of a movement area for the landing or take-off of aircraft.
landing distance available (LDA) means the length of runway (RWY) available for the ground run of a landing aeroplane. The LDA commences at the runway threshold.
Note 1 LDA = length of RWY (if threshold is not displaced).
Note 2 The stopway (SWY) and clearway (CWY) are not part of the LDA.
light failure means that:
(a) the light is deemed to be unserviceable (that is, in a failed state) when the main beam average intensity:
(i) is less than 50% of the value specified in the appropriate figure showing the isocandela diagram; or
(ii) ceases to illuminate; and
(b) for paragraph (a), for light units with the designed main beam average intensity higher than the value shown in the isocandela diagram — the 50% value must be related to that higher design value; and
(c) when assessing the main beam — specified angles of beam elevation, toe-in and beam spread must be taken into consideration.
lighting system outage means that a light or lighting system is experiencing a deteriorated performance level (including total failure) which requires:
(a) the fixing of the light or lighting system as soon as possible; and
(b) a report to be made to AIS provider requesting that a NOTAM be issued.
lighting system reliability means the probability that the complete installation operates within the specified tolerances and that the system is operationally usable.
low-visibility procedure (LVP) means a procedure applied at an aerodrome for protecting aircraft operations during conditions of reduced visibility or low cloud.
LVP means low-visibility procedure.
MAGS means movement area guidance sign.
manoeuvring area means that part of the aerodrome to be used for the take-off, landing and taxiing of aircraft, excluding aprons.
marked:
(a) when used in relation to a marking — refers to the marking; and
(b) when used in relation to a marker — refers to the marker.
marker means an object displayed above ground level in order to indicate an obstacle or delineate a boundary.
marking means a symbol or group of symbols displayed on the surface of the movement area of an aerodrome to convey surface movement, or aeronautical, information.
mass and weight, as used in this MOS, have the same meaning.
MAUM means maximum all-up mass.
MET means meteorological.
method of working plan (MOWP) means a plan to ensure that aerodrome works do not present a hazard to aircraft operations.
MLS means microwave landing system.
movement area means that part of an aerodrome to be used for the take-off, landing and taxiing of aircraft, consisting of the manoeuvring area and the aprons.
movements, for the definition of aerodrome traffic density, means the sum of the following:
(a) each take-off of an aircraft with passengers on board;
(b) each landing of an aircraft with passengers on board;
(c) each aerodrome movement that is a touch-and-go manoeuvre.
MTOM means maximum take-off mass.
MTOW means maximum take-off weight.
NDB means non-directional beacon.
near-parallel instrument runways means non-intersecting runways whose extended centrelines have an angle of convergence/divergence of 15 degrees or less.
nominated, for an ARC, means nominated by the aerodrome operator.
non-instrument runway means a runway for the operation of aircraft using visual approach procedures.
non-precision approach runway has the meaning given to it in paragraph (a) of the definition of instrument runway.
NOTAM means Notice to Airmen, and is a notice issued by the NOTAM Office containing information or instructions concerning the establishment, condition or change in any aeronautical facility, service, procedure or hazard, the timely knowledge of which is essential to persons concerned with flight operations.
obstacle-free zone (OFZ) means the airspace above the inner approach surface, inner transitional surface, baulked landing surface, and that portion of the runway strip bounded by these surfaces, which is not infringed by any fixed obstacle other than a low mass and frangibly mounted one required for air navigation purposes.
obstacle limitation surfaces (OLS) means a series of planes, associated with each runway at an aerodrome, that defines the desirable limits to which objects or structures may project into the airspace around the aerodrome so that aircraft operations at the aerodrome may be conducted safely. The obstacle limitation surfaces are as follows:
(a) the outer horizontal surface;
(b) the conical surface;
(c) the inner horizontal surface;
(d) the approach surface;
(e) the inner approach surface;
(f) the transitional surface;
(g) the inner transitional surface;
(h) the baulked landing surface;
(i) the take-off climb surface.
obstacle restriction area consists of the runway strips, runway end safety areas, clearways and taxiway strips.
obstacles means fixed (whether temporarily or permanently) and mobile objects, structures, and parts of such objects and structures, that:
(a) are located on an area provided for the surface movement of aircraft; or
(b) extend above a defined surface designated to protect aircraft in flight; or
(c) stand outside the defined surfaces mentioned in paragraphs (a) and (b) and that have been assessed as being a hazard to air navigation.
OMGWS means outer main gear wheel span.
PAL means pilot-activated lighting system.
PANS-OPS means Doc.8168-OPS/611 Volume II (Procedures for Air Navigation Services – Construction of Visual and Instrument Flight Procedures) approved and published by decision of the Council of the International Civil Aviation Organization, as in force or existing from time to time.
PAPI means precision approach path indicator.
passenger movement numbers, in relation to an aerodrome for a period, means the sum of the total numbers of passengers who arrive at, or depart from, the aerodrome for the period:
- as published by the Department; or
- if paragraph (a) does not apply — as calculated in accordance with a method approved in writing by CASA.
paved, for a surface, means that the surface is prepared as a pavement.
pavement means a surface that is constructed from a combination of a sub-base, a base course, and a surface course, placed on a subgrade to support the traffic load and distribute it to the subgrade.
Note A subgrade is a prepared foundation or the natural surface on which the pavement is constructed.
pavement classification number (PCN), until the end of 26 November 2025, means a number expressing the bearing strength of a pavement for unrestricted operations by aircraft with aircraft classification number (ACN) less than or equal to the PCN.
Note For guidance, see CASA Advisory Circular (AC) 139.C-07: Strength rating of aerodrome pavements, as existing from time to time and freely available on the CASA website.
pavement classification rating (PCR) means the number that expresses the bearing strength of a pavement for unrestricted operations.
Note For guidance, see CASA Advisory Circular (AC) 139.C-07: Strength rating of aerodrome pavements, as existing from time to time and freely available on the CASA website.
pilot, when used in relation to the location of a thing relative to the pilot of an aircraft, means the pilot in command of the aircraft, unless the contrary intention appears.
PPE means personal protective equipment.
precision approach runway means a runway described in paragraph (b), (c), (d), (e) or (f) of the definition of instrument runway.
precision approach terrain chart — ICAO is a chart providing detailed terrain profile information for a defined portion of the final approach to a runway to enable an aircraft operator to assess the effects of the terrain when determining decision height using radio altimeters.
primary runway means a runway used in preference to other runways whenever conditions permit.
pushback vehicle includes a pushback unit.
QNH means altimeter subscale setting to obtain elevation (on the ground) or altitude.
rapid exit taxiway means a taxiway connected to a runway at an acute angle, designed to allow landing aeroplanes to turn off the runway at higher speeds than are achieved on exit taxiways, thereby minimising runway occupancy times.
reference elevation datum has the same meaning as in section 7.04.
road holding position is a designated position at which vehicles may be required to hold.
RSM means remote satellite measurement.
RSMU means remote satellite measurement unit.
RTAO means restrictions to aircraft operations.
RTIL means runway threshold identification lights.
Rules and Practices for Aerodromes means the official publication known as Rules and Practices for Aerodromes issued:
(a) by CASA or its predecessors, before the Manual of Standards (MOS) — Part 139 Aerodromes was first published by CASA on 1 May 2003; or
runway (RWY) means a defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft.
runway end safety area (RESA) means an area symmetrical about the extended runway centreline and adjacent to the end of the runway strip, primarily to reduce the risk of damage to an aeroplane which undershoots or overruns the runway.
runway guard light means a light system provided to caution pilots or vehicle drivers that they are about to enter an active runway.
runway holding position means a designated position at a controlled aerodrome that is provided to protect a runway, an obstacle limitation surface, or an ILS or MLS critical or sensitive area, at which taxiing aircraft and vehicles must stop and hold, unless otherwise authorised by the aerodrome control tower.
Note For the use of runway holding positions at non-controlled aerodromes, refer to CAAP 166-1.
runway inner shoulders means the portion of the runway shoulders immediately adjacent to the runway.
runway starter extension means an additional length of pavement that:
(a) is immediately before the runway threshold; and
(b) increases the distance available for take-off; but
(c) must not be used for landing.
runway slope means the slope of a runway, presented as a percentage deviation from the horizontal. It is calculated by dividing the difference between the maximum and minimum deviations from the horizontal along the runway centreline, by the runway length, multiplying the quotient by 100 and expressing the product as a percentage deviation from the horizontal.
runway strip means a defined area, including the runway and stopway, provided to:
(a) reduce the risk of damage to aircraft running off a runway; and
(b) protect aircraft flying over the runway during take-off or landing operations.
runway type FATO means the final approach and take-off area of an aerodrome having characteristics similar in shape to a runway.
runway visibility (RV) means the distance along a runway over which a person can see and recognise a visibility marker or runway lights.
runway visual range (RVR) has the same meaning as in the CASR Dictionary.
SA means special authorisation.
SALS means a simple approach lighting system.
scheduled air transport operation means an air transport operation conducted in accordance with a published schedule.
scheduled domestic air transport operation means an air transport operation conducted in Australia in accordance with a published schedule.
scheduled international air transport operation means an international air transport operation conducted in accordance with a published schedule.
sealed, for a surface, means that the surface is wholly, or preponderantly, sealed with a surface treatment which may include bitumen, asphalt, concrete or another suitable treatment.
secondary power supply, for an aerodrome’s functionality, means an electrical power supply that:
(a) is automatically connected to the relevant load when the primary power source fails; and
(b) is derived from:
(i) the normal public electrical power supply, but in a way that:
(A) supplies power for the aerodrome’s functionality from a special substation that is not the normal substation; and
(B) supplies the power through a special transmission line that follows a route different from the normal power supply route; and
(C) makes extremely remote the possibility of a simultaneous failure of the normal public electrical power supply and the power supply for the aerodrome; or
(ii) 1 or more generators, batteries, or similar devices which deliver a constant, reliable and sufficient supply of electrical power for the relevant aerodrome service.
Note See also sections 9.03 and 9.04.
segregated parallel operations means simultaneous operations on parallel or near‑parallel instrument runways in which 1 runway is used exclusively for approaches and the other runway is used exclusively for departures.
SGS means satellite ground station.
shoulders means an area adjacent to the edge of a pavement so prepared as to provide a transition between the pavement and the adjacent surface.
signal circle means an area on an aerodrome used for the display of ground signals.
SMS means safety management system, and includes the statements and documents mentioned in Chapter 25 that describe and support the system.
stopway (SWY) means a defined rectangular area on the ground at the end of the take-off run available prepared as a suitable area in which an aircraft can be stopped in the case of an abandoned take-off.
STODA means supplementary take-off distance available.
Supply Authority means the body for an area that is approved, licensed or authorised by the State or Territory government of the area (the polity), or by the legislation of that polity, to supply electrical power to the general public of the area.
switch-over time, for a light, means the time required for the actual intensity of a light measured in a given direction to fall from 50% and recover to 50% during a power supply changeover when the light is being operated at intensities of 25% or above.
tabletop exercise means a theoretical discussion in which an emergency event is simulated, usually with timescales significantly compressed, and relevant persons verbally describe how they respond to the emergency but without any physical demonstration of the actual response.
take-off distance available (TODA) is the full length of the runway plus the length of any clearway. However, if there is no designated clearway, the part of the runway strip between the end of the runway and the runway strip end must be included as part of the TODA.
Note TODA = TORA + CWY.
take-off run available (TORA) is the full length of the runway available in the relevant take-off direction.
Note 1 TORA = length of RWY.
Note 2 Neither stopway (SWY) nor clearway (CWY) are included in the TORA.
take-off runway means a runway designated for take-off only.
taxilane means a portion of an apron designated as a taxiway and for use only to provide access to, and egress from, aircraft parking positions.
Note A fully or partially enclosed aircraft hangar is not within the meaning of aircraft parking position, as defined.
taxiway (TWY) means a defined path on an aerodrome on land, established for the taxiing of aircraft from 1 part of an aerodrome to another. A taxiway includes a taxilane, an apron taxiway and a rapid exit taxiway.
Note Taxilane, apron taxiway, exit taxiway, rapid exit taxiway and taxiway system are also defined terms.
taxiway intersection means a junction of 2 or more taxiways.
taxiway strip means an area including a taxiway provided to protect an aircraft operating on the taxiway and to reduce the risk of damage to an aircraft which accidentally runs off the taxiway.
taxiway system means a number of interconnecting taxiways.
threshold means the beginning of that portion of the runway usable for landing.
time-limited works means aerodrome works that may be carried out if normal aircraft operations are not disrupted and the movement area can be restored to normal safety standards in not more than 30 minutes.
touchdown zone means the portion of a runway, beyond the threshold, where landing aeroplanes are to first contact the runway.
traffic density has the same meaning as aerodrome traffic density.
transient obstacle includes a mobile obstacle.
T-VASIS means T visual approach slope indicator system.
Type A chart is a chart which contains information on all significant obstacles within the take-off area of an aerodrome up to 10 km from the end of the runway.
Type B chart is an obstacle chart which provides obstacle data from around the aerodrome.
UHF means the ultra high frequency band, that is radio frequencies in the range 300 to 3 000 MHz.
UNICOM (universal communications) means a non-air traffic control communication facility operated to provide an advisory service to enhance the value of information normally available at a non-controlled aerodrome.
unsealed, for a surface, means that the surface is not sealed.
VASI means visual approach slope indicator.
VASIS means a visual approach slope indicator system.
VDB means VHF data broadcast.
VDGS means a visual docking guidance system.
VFR means visual flight rules, and has the same meaning as that given in CAR for V.F.R.
VHF means the very high frequency band, that is radio frequencies in the range 30 to 300 MHz.
visibility (V) means visibility for aeronautical purposes and is the greater of the following:
(a) the greatest distance at which a black object of suitable dimensions, situated near the ground, can be seen and recognised when observed against a bright background;
(b) the greatest distance at which lights in the vicinity of 1 000 candelas (cd) can be seen and identified against an unlit background.
Note 1 The 2 distances have different values in air of a given extinction coefficient, and the distance mentioned in paragraph (b) varies with the background illumination. The distance mentioned in paragraph (a) is represented by the meteorological optical range (MOR).
Note 2 For international recognition and consistency, the definition of visibility is taken from ICAO Annex 3, Meteorological Service for International Air Navigation, Chapter 1, Part 1. For ICAO documents, see section 1.07.
visibility marker means a dark object of suitable dimensions for use as a reference in evaluating runway visibility.
visual aids means visual aids to navigation in the form of markers, markings, lights, signs, signals, displays or wind direction indicators, or combinations of these, which provide information to aircraft and vehicles on, or using, the movement area of an aerodrome.
visual meteorological conditions (VMC) means meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling, equal to or better than specified minima.
VOR means VHF omnidirectional radio range.
WAM means wide area multilateration.
weight and mass, as used in this MOS, have the same meaning.
wheelbase means the distance from the nose gear to the geometric centre of the main gear.
Y location code means the international code prefix used to identify Australian aerodromes.
Note: Example: YMML identifies Melbourne Airport.
(3) In addition to any relevant definitions contained in subsection (2), the following definitions apply for applicable provisions in relation to runway surface conditions:
contaminant means matter present on the surface of a runway that meets one or more of the following runway surface condition descriptors:
(a) compacted snow, being snow that has been compacted into a solid mass such that aeroplane tyres, at operating pressures and loadings, will run on the surface without significant further compaction, or rutting of the surface;
(b) dry snow, being snow from which a snowball cannot readily be made;
(c) frost, being frost that consists of ice crystals formed from airborne moisture on a surface whose temperature is below freezing;
Note 1 Frost differs from ice in that the frost crystals grow independently and, therefore, have a more granular texture.
Note 2 Below freezing refers to air temperature equal to or less than the freezing point of water (0 degrees Celsius).
Note 3 Under certain conditions, frost can cause the surface to become very slippery and it is then reported appropriately as reduced braking action.
(d) ice, being water that has frozen, or compacted snow that has transitioned into ice, in cold and dry conditions;
(e) slush, being snow that is so water-saturated that it will splatter if stepped on forcefully, or from which water will drain when a handful is picked up;
(f) standing water, being water of a depth greater than 3 mm;
Note By convention, running water of a depth greater than 3 mm is reported as standing water.
(g) wet ice, being ice with water on top of it, or ice that is melting;
Note Freezing precipitation can lead to runway conditions associated with wet ice in relation to aeroplane performance. Wet ice can cause the surface to become very slippery. It is then reported appropriately as reduced braking action in accordance with section 12.04A of this MOS. For guidance, see also Multi-Part AC 91-32 and AC 139-22 v2.0, Global reporting format – Runway surface condition.
(h) wet snow, being snow that contains enough water content to be able to make a well‑compacted, solid snowball, and from which water will not squeeze out.
Note A runway is contaminated when one or more contaminants are present on the surface of the runway.
runway condition assessment matrix or RCAM means a matrix for assessing the runway condition code from a set of observed runway surface conditions and the pilot in command’s report on braking action.
runway condition code or RWYCC is the number used in a runway condition report to describe the runway surface condition.
Note The runway condition code allows the flight crew to make an operational aeroplane performance calculation in accordance with section 12.04A of this MOS. For guidance, see also Multi-Part AC 91-32 and AC 139-22 v2.0, Global reporting format – Runway surface condition.
runway condition report or RCR means a comprehensive standardised report relating to runway surface conditions, and their effect on aeroplane landing and take-off performance.
runway surface condition descriptors: see contaminant.
slippery wet runway means a wet runway where the surface friction characteristics of a significant portion of the runway show that the runway is degraded.
Note These definitions are for use in relation to Global Reporting Format.