60 Reasons to Protest: Reason #16 – The faux Noise Improvement Trials
A recommendation stemming from the Brisbane Airport PIR Advisory Forum (BAPAF) included short-term noise improvement measures, specifically:
- A trial requiring all aircraft to use the full length of the runway (NPR) on departures over the city, and;
- Extending the time period when SODPROPS operations may be attempted to included 6am to 8am on Saturday and Sunday mornings and 8pm to 10pm on Saturday evenings, when weather conditions allow.
1. Restriction on intersection departures
From when the runway opened, aircraft were allowed to take off at different intersections on the runway resulting in aircraft remaining lower and therefore noisier over the communities than if they’d used the full length of the runway.
The trial entailed restricting intersection departures. One might wonder why it took BAPAF to identify this noise improvement option and how it wasn’t implemented as part of Noise Abatement Procedures when the runway first opened. Given that the runway was built directly pointing at some of Australia’s most densely populated areas, one would expect that all noise abatement measures should have been utilised. Airservices have now removed the requirement for aircraft to take off from the full length of the runway. BFPCA argues that under no circumstances (except in an emergency) should intersection departures be allowed for Southerly departures.
Airservices conducted a trial that wasn’t really a trial and was set to fail from the outset. When aircraft depart Brisbane they are allocated a SID (Standard Instrument Departure). These SIDs contain geographical waypoints that pilots fly to and cross at minimum specified altitudes. Prior to departure, pilots load these SIDs into the aircraft’s Flight Management Computer and ensure they reach the altitude specified in the SID by that particular waypoint (or latitude and longitude). Airservices did not modify any of the SIDs for pilots to fly to, so aircraft were still crossing the same waypoints at the same altitude as before the trial.
Furthermore, pilots use the onboard Flight Management Computer to calculate take-off thrust. With no modification to the SIDs and more runway length available, the onboard computers would suggest a reduced thrust taking off from the full length of the runway, instead of using full thrust to climb higher quicker. Airservices did not stipulate any noise abatement procedures for pilots to use. To make the trial genuine, Airservices needed to stipulate certain parameters, which would have required pilots to use full take-off thrust, a specific noise abatement procedure, aircraft to climb at the maximum climb gradient and using a modified SID. This combination would have allowed aircraft to climb higher sooner. Airservices provided the results of this trial in “fact” sheets (
) associated with the Brisbane Noise Action Plan but have not adjusted for temperature, wind velocity and other factors that affect noise and climb rates.
What does a full length take off mean for non-jet traffic departing to the South and then turning right over communities shortly after take off? Full length takeoff allows earlier manoeuvring to avoid built up areas for turboprop aircraft, which can usually climb to a safe turning height within the airfield boundaries. A full length take-off on runway 19R would result in aircraft overflying fewer suburbs; especially those to the South and South West of the runway.
If the intention is to reduce noise for as many communities as possible, there appears to be no argument against using full length take-off.
2. Extended SODPROPS
Part 68 of the Brisbane PIR Final Report states that each additional flight operating over water results in a significant reduction in noise impacts over communities. Therefore, even small changes that may only result in a slight overall difference in the total number of flights over water should be considered where viable.
On the days where conditions allow the use of SODPROPS, it’s a massive benefit to the community. Allowing people to have the occasional full night’s sleep and no noise early in the morning is a welcome relief from having their sleep cut short every day; which has associated health implications.
SODPROPS should continue on weekends and be re-instated as the number 1 priority mode at all times. Already back in November 2020, BFPCA published evidence of SODPROPS being heralded as the number one priority mode 24/7 in the 2007 MDP/EIS, only for this mode to be subsequently silently removed by Airservices without notice, community consultation or ministerial review or approval.
We acknowledge that SODPROPS is not a usable mode 24/7 due the complexities and delays that occur when expected arrival rates exceed 20/hr. Having said that, currently there is no requirement for ATCs to try to use SODPROPS outside of the time period of 10pm to 6am daily as the mode is not listed at all. SODPROPS is the preferred mode at Sydney Airport outside of curfew hours, and Sydney ATCs do use it during the day when arrival rates make it available. This is what BFPCA would like to see happen at Brisbane. The nomination of SODPROPS as the preferred mode will bring about a change of culture whereby ATCs will always aim to use this mode whenever possible, rather than only using it when they must.
BFPCA had revised Noise Abatement Procedures for Brisbane including a binding Noise Abatement Operating Plan prepared by our technical consultant. These documents were tabled as part of our PIR submission in November 2022 for Airservices’ immediate attention and implementation. – Crickets 
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