The reporter has raised a safety concern in relation to the failure to notify flight crew of windshear information for the safe conduct of their flight.
The reporter states windshear information is not being included on the automatic terminal information service (ATIS).
The reporter advises the Manual of Air Traffic Services (MATS) version 66.3 (Effective 30 November 2023 to 20 March 2024) paragraph 3.1.3.1 indicates that there is a requirement to include moderate, strong or severe windshear on the ATIS when: a) reported on the approach or take-off paths, or b) forecasted.
The reporter provided the below example of a windshear forecast issued by the Bureau of Meteorology (BoM) which was not included information on the next two ATIS updates at a capital city aerodrome. A windshear warning for 'severe windshear overshoot at 100 ft on final' as provided by flight crew was included on the third ATIS update post the windshear warning issued by the BoM.
Windshear warning issued by Bureau of Meteorology at 1009
[Location] WS WRNG [date]1009 VALID [date]1050/[date]1200
WS FCST WITH SOUTHERLY CHANGE
FCST SFC WIND: 03010G15KT TURNING 18030G40KT
FCST 1000FT WIND: 18040KT
The reporter states Southerly busters are a difficult weather event associated with a runway change, with rapidly changing conditions including wind, temperature and most likely, QNH. The timely dissemination of critical safety information is vital for the safety of flights arriving and departing an aerodrome. This includes the provision of forecast wind information so that pilots can develop a mental model of the changing wind profiles during a critical phase of flight.
Finally, the reporter states, 'The windshear example in MATS should be the same as the example provided in the BoM Aeronautical Services handbook (ASH)'.
Airservices appreciates the opportunity to respond to the concerns raised in the REPCON. We understand the concern relates to notification of windshear information to pilots.
We agree with the reporter that timely dissemination of critical safety information is vital, not only for aerodrome traffic, but for all flights at all times. The Manual of Air Traffic Services (MATS) outlines the requirements for management of forecasted windshear. The relevant clauses in MATS v66.2 are as follows:
3.1.3.1 ATIS requirement
Include moderate, strong or severe windshear on the ATIS when:
a) reported on the approach or take-off paths; or
b) forecasted.
Type - Forecast
Example ATC phraseology - PROBABLE VERTICAL WINDSHEAR FROM 0510 TO 0530, FORECAST WIND AT 400 FEET ABOVE GROUND LEVEL 120 DEGREES 50 KNOTS
3.1.3.3 Low level windshear - dissemination to pilots
Upon receipt of a pilot report and/or a forecast of moderate, strong or severe windshear, alert all arriving and departing aircraft by ATIS broadcast, and directed transmission where the aircraft is not in receipt of the ATIS information.
The Aeronautical Information Publication (AIP) GEN 3.5, paragraph 4.10 also requires forecast windshear to be included on the ATIS at selected aerodromes:
4.10 Windshear warnings
Aircraft reports of windshear encountered during climb and descent are the primary means of detecting windshear. The Meteorological Office (MO) provides advice, when possible, on the likely duration of the event and forecast low level winds.
Windshear warnings for an event will specify a validity period, and sequence numbers will be assigned to each warning associated with an event. A windshear warning will be cancelled when windshear is no longer expected. This service is provided at Cairns, Brisbane, Sydney, Melbourne, Adelaide, Darwin, Perth, Hobart and some defence locations.
When windshear is forecast or reported by pilots at an intensity greater than 'light', this information, together with a forecast low-level wind, will be included on the ATIS at any of the above aerodromes.
As highlighted in the requirements, under normal circumstances, the forecast windshear is broadcast on the ATIS ‘upon receipt’. There is no time limit provided, however given the nature of windshear, controllers would be expected to afford it suitable priority. If a controller were aware of the forecast before there was an opportunity to record it on the ATIS, it would be reasonable to expect the forecast to be given to affected pilots by directed transmission.
It should be noted though that controllers have a duty to give first priority to separating aircraft, issuing safety alerts and directing traffic information (MATS 2.2.1.5) and otherwise are given latitude to use their ‘best judgement’ when, for example, the safety of an aircraft may be considered to be in doubt (MATS 2.2.1.6).
2.2.1.5 Duty priority
Give first priority to separating aircraft, issuing safety alerts and providing directed traffic information as required by this manual. Perform first that action which is most critical from a safety standpoint.
2.2.1.6 Best judgement
Do not allow anything in these instructions to preclude you from exercising your best judgement and initiative when:
a) the safety of an aircraft may be considered to be in doubt; or
b) a situation is not covered specifically by these instructions.
It is expected that all controllers would follow the procedures outlined above. Notably, multiple checks are conducted daily by Airservices Check and Standardisation Supervisors to ensure appropriate application of the ruleset by controllers.
Additionally, if a person were to notice the above procedures were not followed, the appropriate safety report should be submitted so that the necessary rectification process could be taken. Without further knowledge of the location and circumstances of the event, it is not possible to:
a) determine if the delay between the receipt of the forecast and when it was recorded on the ATIS was reasonable; or
b) assess the controller workload and/or any competing priorities that may have reasonably prevented:
i) the forecast from being recorded on the ATIS sooner than it was; or
ii) the controller issuing the forecast to affected aircraft via directed transmission.
If such information was forthcoming Airservices could undertake a review into those events and provide a more robust response as to the causes that resulted in the reported occurrence.
With regards to the ATC example phraseology in MATS aligning with the Bureau of Meteorology’s Aeronautical Services Handbook (ASH), Airservices will undertake an assessment of the operational and technical feasibility of such a proposal and progress if appropriate.
Thank you for the opportunity to review this REPCON. CASA has nothing further to add to Airservices' response.