AIP GEN 3.3
Pilots are responsible for requesting information necessary to make operational decisions (AIP GEN 3.3).
Information about the operational aspects of the following subjects is normally available from ATS:
- meteorological conditions
- air routes and aerodromes, other than ALAs
- navigational aids
- communications facilities
- ATS procedures
- airspace status
- hazard alerts
- search and rescue services
- maps and charts and
- regulations concerning entry, transit and departure for international flights.
The in-flight information services are structured to support the responsibility of pilots to obtain information in-flight on which to base operational decisions relating to the continuation or diversion of a flight. The service consists of three elements:
- ATC-initiated FIS;
- automatic broadcast services; and
- on-request service.
ATC-initiated FIS will include the provision of pertinent operational information such as:
- Meteorological conditions and the existence of non-routine MET products;
- Changes to air routes
- Changes to serviceability of navigation facilities, for example RAIM
- Change to serviceability of communications facilities
- Changes in conditions of aerodromes and associated facilities
- Changes to airspace status and
- Information on medium and heavy unmanned free balloons.
Automatic broadcast services
The automatic broadcast services consist of:
- Automatic Terminal Information Service (ATIS)
- Automatic En Route Information Service (AERIS)
- Aerodrome Weather Information Service (AWIS) and
- Meteorological Information for Aircraft in Flight (VOLMET).
At aerodromes specified in ERSA the normal operational information required by aircraft before take-off or landing is broadcast automatically and continuously either on a discrete frequency, or on the voice channel of one or more radio navigation aids. The broadcast may be pre-recorded or computerised.
When control zones are deactivated the ATIS may be used to broadcast operational information of an unchanging nature. This information may include the CTAF PAL frequency, preferred runways and noise abatement procedures. It may also include the expected reopening time of the tower. Pilots are encouraged to monitor the ATIS outside the normal hours of the tower.
The following information is transmitted on the ATIS:
Terminal information (aerodrome)
‘(Code letter)’, for example: ‘alpha’, ‘bravo’, etc; as assigned to each separately prepared transmission (zulu is not used).
‘(Time (hh mm)) UTC’, [‘(Time of observations (hh mm))’] (if appropriate).
‘(Type of approach expectation)’; For example: ‘expect ils approach’.
One runway in use
‘Runway (number)’, [‘damp’] [‘wet’] [‘water patches’] [‘flooded’] (if applicable).
More than one runway in use
‘Runway/s (number/s) and (number/s) for arrivals’.
‘Runway/s (number/s) and (number/s) for departures’, [‘damp’] [‘wet’] [‘water patches’] [‘flooded’] (if applicable).
‘Land and hold short operations in progress’ (when being used).
Holding delay (if appropriate), for example: ‘…minutes holding may be expected’.
Curfew runway nomination
When runway is nominated due to noise abatement legislation and the crosswind and/or downwind component is in excess of that specified in ENR 1.1
Crosswind and downwind components for the purposes of the above are:
- Crosswind component, including gusts = 20 kt;
- Downwind component, including gusts = 5 kt; and
- If the runway is not completely dry – downwind component > 0 kt.
Wind direction is quoted in degrees magnetic as either:
- Single mean direction or
- Two values representing variation in wind direction will be given whenever:
- the extremes in wind direction vary by 60° or more or
- the variation is considered to be operationally significant (for example the variation is less than 60°, but the variation from the mean results is either a downwind and/or significant crosswind component on a nominated runway).
- ‘variable’ will be used when the reporting of a mean wind direction is not possible, such as:
- in light wind conditions (3 kt or less) or
- the wind is veering or backing by 180° or more, for example passage of thunderstorms, or localised wind effect.
Wind speed is quoted as either:
- calm when less than 1 kt. For example, ‘wind calm’
- single maximum value whenever the extremes between minimum and maximum are 10 kt or less. For example, ‘wind 250 degrees maximum 25 knots’;
- two values representing minimum and maximum values whenever the extremes in wind vary by more than 10 kt. For example, ‘wind 250 degrees minimum 15 knots, maximum 28 knots’.
When quoting a wind with variations in speed and direction, the above criteria may be varied in order to indicate the true crosswind and/or downwind.
Where threshold wind analysers are installed, and the wind at the threshold of a duty runway varies from that of the central wind analyser or the threshold wind on the other duty runway by criteria specified for the revision of ATIS, threshold winds may be broadcast on the ATIS, for example: ‘threshold wind runway (number), …/…, runway (number), …/…’.
Where runway threshold wind analysers are installed, a tower controller must provide a departing aircraft with the wind at the upwind area of the runway if it varies from the ATIS broadcast by 10° or 5 kt or more, and the variation is anticipated to continue for more than 15 min. Such information shall be passed by use of the phrase ‘wind at upwind end…/…’.
Distance is reported as either:
- >10 km – ‘greater than one zero kilometres‘, or actual distance ‘(number) kilometres’.
- Greater than 5 km and 10 km (inclusive) – ‘(number) kilometres’.
- Up to and including 5000 m – ‘(number) metres’.
- <1500 m – RVR is reported when available.
Weather is reported as applicable. For example: ‘showers in area’, or:
- Cloud (below 5000 ft or below msa, whichever is greater; cumulonimbus, if applicable; if the sky is obscured, vertical visibility when available).
- [Other information]:
- any available information on significant meteorological phenomena in the approach, take-off and climb-out, including the presence of freezing fog.
- advice on hazard alert information including unauthorised laser illumination events.
On first contact with (for example [‘ground’], [‘tower’], [‘approach’]) notify receipt of (code letter of the ATIS broadcast). This contact information may not be transmitted when recording space is limiting.
When moderate, strong or severe wind shear has been reported on the approach or take-off paths, or has been forecast, the information will be included on the ATIS in the following format. For example:
‘Wind shear warning – Cessna 210 [(wake turbulence category) category aircra (if military atis)] reported moderate wind shear on approach runway 34 at time 0920’, (plus, if available, wind shear advice issued by MET, for example: ‘Forecast wind at 300 feet above ground level 360 degrees 45 knots’, or ‘Probable vertical wind shear from 0415 to 0430 – forecast wind at 200 feet above ground level 110 degrees 50 knots’).
A wind shear escape manoeuvre is considered to constitute an emergency operation.
The AERIS continuously broadcasts METAR from a network of VHF transmitters installed around Australia.
The information broadcast on the individual transmitters caters primarily for the needs of aircraft operating in control areas within VHF range of the facility.
The network frequencies, the operational information and transmitter locations are shown on pages 2.64.
Aerodrome Weather Information Service (AWIS) and Weather and Terminal Information Reciter (WATIR) AIP GEN 3.5
AWIS and WATIR provide actual weather conditions via telephone and/or radio broadcast at specified locations. AWIS provides information from the AWS only. WATIR combines the AWS information with additional terminal information from the airport operator.
Basic AWS provide wind direction and speed, temperature, humidity, pressure setting and rainfall. Advanced AWS provide automated cloud and visibility information. Information provided in AWIS will contain some of the following:
- message identifier ‘AWS aerodrome weather’
- station identifier as a plain language station name
- wind direction in degrees magnetic and wind speed in knots
- altimeter setting (QNH)
- temperature in whole degrees celsius
- cloud below 10,000 ft*
- dew point in whole degrees celsius
- relative humidity
- runway visual range at selected locations^
- rainfall over the previous ten minutes and
- present weather information*.
* Provided as guidance material only. Pilots should exercise caution when interpreting automated visibility and cloud information as data from these instruments may not be equivalent to human observations.
^See ERSA FAC for aerodrome specific details.
Information broadcast from the AWS and WATIR is considered to be ‘real time’ data. When information is not available about a particular item, either because of invalid data or an inoperative sensor, the element of the broadcast will be identified as ‘Currently not available’. For example:
‘Temperature currently not available’.
The integrity of the barometric system in BoM-accepted AWS is such that they are an approved source of QNH. Therefore, QNH from these AWS may be used in accordance with ENR 1.5 to reduce the published minima for DME arrival procedures, and the published landing, circling and alternate minima. Information derived from other sensors within the AWS (for example: wind and temperature), does not have the same degree of integrity and should be used at pilot discretion.
When AWIS information is available after (tower) hours and the aerodrome is uncontrolled, reference will be made to its availability in ATIS ZULU.
The availability of AWIS and WATIR is contained in ERSA FAC and MET.
On request service – Flightwatch
An on-request FIS is available to aircraft in all classes of airspace on ATC VHF or HF (domestic and international) frequencies.
Pilots must prefix any request for FIS on ATC VHF frequencies with the callsign of the appropriate ATC unit and the generic callsign ‘Flightwatch’, for example:
‘Melbourne centre flightwatch request actual weather (location)’
Due to workload considerations, ATC may redirect pilot requests for FIS to an alternative VHF frequency or FLIGHTWATCH HF.
When operating on domestic HF (callsign ‘Flightwatch’) and international HF (callsign ‘Brisbane’), pilots must include the frequency on which they are calling. For example,
’(Flightwatch or Brisbane), romeo juliet delta, six five four one, request actual weather (location)’.
Information will be provided in an abbreviated form, paraphrased into brief statements of significance. The full text of messages will be provided on request.
An alerting service will be provided (AIP GEN 3.3):
- for all aircraft provided with air traffic control services (on request and subject to ATC workload)
- in so far as practicable, to all other aircraft having filed a flight plan or otherwise known to the ATS and
- to any aircraft known or believed to be the subject of unlawful interference.
Surveillance information service (SIS)
SIS to VFR flights is available on request in Class E and Class G Airspace, subject to ATC workload. SIS is available to improve situational awareness and assist pilots in avoiding collisions with other aircraft (AIP GEN 3.3).
Pilots wanting SIS (AIP GEN 3.3):
- must be in direct VHF communications with ATC and equipped with a serviceable SSR transponder or ADS-B transmitter
- will be provided with traffic (detectable to ATC) information and upon request position or navigation information (advisory only);
- will be provided with an alerting service
- must, on initial contact, advise ATC and, if an ongoing service is requested, include the phrase ‘Request flight following’, and then, once ATC responds, advise position, level and intentions, after which (if SIS is available) SIS will commence;
- in an emergency situation, should communicate using the prefix ‘Mayday, Mayday, Mayday’ and
- must, while receiving SIS, maintain a continuous listening watch with ATC and advise before leaving the frequency, and advise ATC before any changes to track or level.
A sudden change to a component of FIS, not described in a current MET product or NOTAM, having an immediate and detrimental effect on the safety of an aircraft will be communicated by ATC using the prefix ‘Hazard alert’. Hazard alerts will (AIP GEN 3.3):
- be repeated at H+15 and H+45 in the hour following the initial transmissions
- normally cease after one hour or after an updated MET product or NOTAM is available for dissemination, whichever is earlier and
- be directed to those aircraft maintaining continuous communications with ATS at the time the hazard is assessed and that are within one hour flight time of the hazardous conditions.
Hazard alert information, or its availability, will be directed or broadcast on the appropriate ATS frequencies.
‘All stations hazard alert Melbourne. Weather observation notifies unexpected deterioration below the ifr alternate minima’.
‘All stations hazard alert Dubbo. Pilot reports unexpected deterioration below the VFR alternate minima’.
When appropriate, ATC towers may provide advice about hazard alert information on the ATIS.
Information by pilots
A pilot in command becoming aware of any irregularity of operation of any navigational or communications facility or service or other hazard to navigation must report the details as soon as practicable. Reports must be made to the appropriate ATS unit except that defects or hazards on a landing area must be reported to the person or authority granting use of the area.
When a landing is made on a water-affected runway, the pilot is requested to advise ATS of the extent of water on the runway and the braking characteristics experienced.
Terms to describe water on a runway
The surface shows a change of colour due to moisture
The surface is soaked but there is no standing water
Patches of standing water are visible
Extensive standing water is visible
Terms to describe braking characteristics experienced
Pilots should not expect to find the conditions as good as when operating on a dry runway, but should not experience any directional control or braking difficulties because of runway conditions.
Braking action may be such that the achievement of a satisfactory landing or accelerate-stop performance, taking into account the prevailing circumstances, depends on precise handling technique.
There may be a significant deterioration both in braking performance and directional control.
During the bushfire danger period, pilots in command of an aircraft should notify the nearest ATS unit promptly of any evidence of bushfires observed which they believe has not been reported previously.