Brisbane Basin Aircraft Noise Information Report

Transcription

1 Brisbane Basin Aircraft Noise Information Report Quarter (October to December) 1

2 Version Control Version Number Detail Prepared by Date 1 - Environment January 2014 Airservices Australia. All rights reserved. This report contains a summary of data collected over the specified period and is intended to convey the best information available from the NFPMS at the time. The system databases are to some extent dependent upon external sources and errors may occur. All care is taken in preparation of the report but its complete accuracy can not be guaranteed. Airservices Australia does not accept any legal liability for any losses arising from reliance upon data in this report which may be found to be inaccurate. 2

3 Brisbane Basin - Aircraft Noise Information Report Contents 1 PURPOSE Brisbane Airport Archerfield Airport Aircraft noise monitoring in Brisbane Short term monitoring program 4 2 FLIGHT PATTERNS Jet aircraft Non jet aircraft Track density plots 9 3 AIRCRAFT MOVEMENTS Brisbane Airport Archerfield Airport 18 4 NOISE MONITORING 19 5 COMPLAINTS DATA NCIS Clients by suburb Issues raised by NCIS clients 30 6 AIRSERVICES UPDATE Community Aviation Consultation Groups Noise improvements 31 7 CONTACT US 32 APPENDIX 1 AIRSERVICES UPDATE 33 3

4 1 Purpose This report summarises data for Quarter 4 of 2013 (October to December), primarily from Airservices Noise and Flight Path Monitoring System (NFPMS) and Noise Complaints and Information Service (NCIS) for the Brisbane basin (including Brisbane Airport and Archerfield Airport) as well as some other sources (such as the Flight Charging System). 1.1 Brisbane Airport Brisbane Airport is located 14km north east of the central business district. It is bounded by residential areas to the west, south and north (see Figure 1). The majority of operations at Brisbane Airport are international and domestic regular passenger services, mostly medium to large jets. During Quarter 4 of 2013 there were around 57,200 operations at Brisbane Airport. More information about operations at Brisbane Airport is available from the Airservices website at Archerfield Airport Archerfield Airport is located 13km south west of the central business district and is surrounded by residential developments (see Figure 1). Corporate and charter services operate from the airport and it is also Queensland s largest centre for flight training 1. More information about operations at Archerfield Airport is available from the Airservices website at Aircraft noise monitoring in Brisbane Airservices NFPMS captures and stores radar, flight plan and noise data. The NFPMS covers eight city regions around Australia. For the Brisbane region, noise data is captured by five noise monitors - also known as Environmental Monitoring Units (EMUs) located around Brisbane Airport (see Figure 1). 1.4 Short term monitoring program Airservices carries out a rolling program of short term monitoring around the country to collect data for specific operational purposes and to investigate potential new sites for permanent monitoring units. Reports on short term monitoring are available at 1 A factsheet about circuit training is available at 4

5 Figure 1: Location of Brisbane Airport and Archerfield Airport. (Runway orientation at both airports is shown in the inserts. Noise monitoring sites are shown as red dots). The main runway at Brisbane Airport, 01/19, is 3.5 km long, orientated approximately south to north. This means that on Runway 01, aircraft arrive over suburbs to the south of the airport and take off over water to the north. On Runway 19, aircraft arrive over water from the north and take off over suburbs to the south. There is a smaller 1.7km long cross runway, 14/32, orientated north-west to south-east, which is primarily used by propeller aircraft. At Archerfield Airport there are two sets of parallel runways, 04L/22R - 04R/22L (oriented south west to north east) and 10L/28R 10R/28L (oriented east to west). Both are used for circuit training. Runway selection is determined by wind direction as aircraft normally land and take-off into the wind for safety and performance reasons. Information about runway selection and circuit training is available on the Airservices website at 5

6 2 Flight patterns 2.1 Jet aircraft Figure 2 and Figure 3 below show jet aircraft track plots for arrivals and departures at Brisbane Airport and Archerfield Airport for one month in Quarter 4 of 2013 (November), coloured according to height (in ft). Noise monitors (EMUs) are shown as grey circles. BRISBANE ARCHERFIELD Figure 2: Jet arrivals for the Brisbane region, November 2013 (one month) Key points shown are: Approaches from the north fly over water. However, the approaches from the south overfly suburbs at altitudes below 5,000ft. Although primarily a general aviation airport, a small number of jet movements can be identified at Archerfield Airport. The majority of Brisbane suburbs over-flown by jet arrivals are done so at altitudes above 5,000ft. Arrivals are generally aligned with runways from around 10km from the airport. 6

7 Although not visible in the illustration, aircraft holding when required for arrivals into Brisbane airport from the south is done 100km south of the airport near the Gold Coast (just below the southern edge of the illustration. There are additional holding areas around 50km north of Brisbane and also to the west. In all cases aircraft are held at between 10,000 and 15,000ft and have no noise impacts on residential areas. BRISBANE ARCHERFIELD Figure 3: Jet departures for the Brisbane region, November 2013 (one month) The key points shown are: Departures to the north fly over water. However, departures to the south overfly suburbs at altitudes below 5,000ft, although the majority of suburbs only experience departing jets at altitudes above 5,000ft. Most suburbs within 20km of the airport are over-flown either by arrivals or departures from Brisbane Airport. 7

8 2.2 Non jet aircraft Figure 4 below shows non jet tracks (arrivals and departures) at Brisbane Airport and Archerfield Airport in one month of Quarter 4 of 2013 (November). Noise monitors (EMUs) are shown as grey circles. CABOOLTURE REDCLIFFE BRISBANE ARCHERFIELD RAAF AMBERLEY Figure 4: Non jet arrivals and departures for the Brisbane region, November 2013 (one month) The key points shown are: Although jet aircraft tend to operate along defined paths, when smaller aircraft movements are included on the map there are no areas of Brisbane that are not over-flown by aircraft at some time. Flights below 3,000ft tend to be operations to and from Archerfield Airport rather than Brisbane Airport. This is expected, as the majority of these operations are required to stay below controlled air space. The circuit pattern (flight training) at Archerfield Airport is visible as the red oval to the south of the map. 8

9 2.3 Track density plots The track plots in the previous section show that residents living up to 15km from the airports and in line with Brisbane Airport s runway are regularly over-flown by jet aircraft below 5,000ft. However, beyond this the regularity of flight path use is not discernible from the track plot display. A track density plot, which includes all aircraft types, can be useful in showing the underlying track patterns. A track density plot is a map which displays the pattern of aircraft flight tracks passing over the region around the airport. The region is divided into a set of small grid elements and the number of flights passing over each grid element is summed. Each grid element is coloured according to the number of over-flights. The following illustration shows a track density plot for all movements over the Brisbane Basin for Quarter 4 of The grid size adopted is 200m x 200m. The colour coding from green to red represents the range 2 flight tracks per day to 20 (184 to 1,840 flight tracks for the quarter). If any grid element is not colour coded, the number of aircraft flight tracks passing over that element during the quarter was less than 2 per day on average. Note the absence of a colour for a grid element does not mean the grid element is free of aircraft over-flights. The grey circles show the location of each noise monitor (EMU). 9

10 CABOOLTURE REDCLIFFE BRISBANE ARCHERFIELD RAAF AMBERLEY Figure 5: Track density plot for the Brisbane region, Quarter 4 of 2013 The key points shown are: There are distinct flight patterns that are regularly used to and from Archerfield, Brisbane, Redcliffe and Caboolture airports. Lanes into and out of the circuit pattern at Archerfield Airport are visible. Circuit patterns can be identified at both Caboolture Airport and Redcliffe Airport, to the north of the map. These are both small airports operating single engine aircraft, largely for training purposes. The majority of traffic to the north of Brisbane is associated with Brisbane Airport. 10

11 3 Aircraft movements 3.1 Brisbane Airport Figure 6 below shows aircraft movements at Brisbane Airport for the 15-month period to the end of Quarter 4 of Figure 6: Aircraft movements at Brisbane Airport to Quarter 4 of 2013 The key points shown are: The number of movements at Brisbane Airport has been steady over the last 15 months at around 20,000 per month (600 per day). There are more than twice as many jet movements as propeller movements. There are very few helicopters operating out of Brisbane Airport Runway Usage Figures 7-11 below show aspects of runway usage for arrivals and departures at Brisbane Airport for the 15-month period up to the end of Quarter 4 of 2013 and usage over a four-year period for the two busiest runways at the airport. Runway selection is based on wind direction and weather conditions, traffic volume and Noise Abatement Procedures. Aircraft primarily take off and land into the wind for safety and performance reasons. Therefore, as the wind direction changes the runway in operation may also change depending on the strength of the wind. 11

12 Figure 7: Runway usage (All) at Brisbane Airport to Quarter 4 of 2013 Figure 8: Runway usage (Arrivals) at Brisbane Airport to Quarter 4 of

13 Figure 9: Runway usage (Departures) at Brisbane Airport to Quarter 4 of 2013 Figure 10: Runway 01 usage at Brisbane Airport 2010 to

14 Figure 11: Runway 19 usage at Brisbane Airport 2010 to 2013 The key points shown in Figures 7-11 are: Seasonal variations in wind direction account for differences in runway use. In winter, prevailing winds at Brisbane Airport are from the south, which results in Runway 19 being used more frequently. Consequently, residential areas to the south of the airport are overflown more by departing aircraft. Arriving aircraft, however, approach over water. Generally, from November to February, prevailing winds at Brisbane Airport are from the north. Therefore Runway 01, which is oriented to the north, is used more during these months. As a result, residential areas to the south of the airport are over-flown more by arriving aircraft while departing aircraft fly over Moreton Bay. Movements on the smaller cross Runway accounted for less than 5% of total movements at Brisbane Airport during the 15-month period. For part of this time the runway was out of use due to construction works related to the New Parallel Runway (NPR) project. Generally jet aircraft do not use Runway because of weight restrictions. 14

15 3.1.2 Night Movements Figures below show aircraft movements at Brisbane Airport at night (11.00pm to 06.00am), by aircraft type or runway. There is no curfew at Brisbane Airport. Noise Abatement Procedures are used to reduce the impact of aircraft operations on residential areas, especially at night. From 10pm to 6am the following day, when wind and traffic conditions permit, aircraft arrive and depart over Moreton Bay (i.e. arrive on Runway 19 and depart from Runway 01). When conditions are not suitable for the application of noise abatement procedures (e.g. when there is a northerly wind on Runway 01), aircraft will depart over Moreton Bay and land over the southern suburbs. The opposite applies in the case of a southerly wind. Figure 12: Night movements (11.00pm to 6.00am) at Brisbane Airport October 2012 to December 2013 by aircraft type The key points shown are: Night-time movements at Brisbane Airport are seasonal, with more night movements in summer and fewer during the non-daylight saving period (April to September). Due to the scheduling of flights between non-daylight saving time zones (including Brisbane) and daylight savings time zones (such as Sydney and Melbourne), there is an increase in the number of flights arriving and departing Brisbane Airport before 6am between October and March. Propeller aircraft schedules are not affected by daylight saving time to the same extent and do not reflect the same trend of fewer movements during the non-daylight saving period (April to September). In general, twice as many jets as propeller aircraft operate at night. 15

16 Figure 13: Runway usage for night (11.00pm to 06.00am) arrivals at Brisbane Airport October 2012 to December 2013 Figure 14: Runway usage for night (11.00pm to 06.00am) departures at Brisbane Airport October 2012 to December 2013 As shown in the graphs above the majority of night movements (11pm to 6am) used the Noise Abatement Procedure (NAP) for departures and arrivals over water (i.e. Reciprocal Runway Operations, with departures from Runway 01 and arrivals to 16

17 Runway 19. However, due to wind conditions, it is not always possible to apply the NAPs. In the winter, in particular, when prevailing winds are from the south, it is often not possible for aircraft to take off over the coast Review of Noise Abatement Procedures (NAP) Airservices undertook a review of the Noise Abatement Procedures (NAP) at Brisbane Airport over a 12-month period in This was a technical review that considered compliance with procedures and the effectiveness of those procedures. Its purpose was to review ways to minimise the impact of aircraft noise on residential areas around Brisbane Airport, especially at night, and to explore options to focus aircraft noise away from residential areas. The review found that compliance with the NAP procedures was high around 95% in most cases. An area of low compliance, relating to daytime processing of turboprop arrivals, has been addressed with an update to the pilot instructions to ensure the published procedures can be used effectively. Other recommendations implemented include a proposal to begin Reciprocal Runway Operations at weekends as early as possible when traffic and meteorological conditions allow, and to better inform the community through the CACG as to how decisions on runway use are made to ensure the preferred runways remain available to maintain the very high compliance rate. This is particularly the case with night-time over the Bay operations when both arriving and departing aircraft come and go over Moreton Bay instead of residential areas (weather permitting). Some issues noted in the review were not considered feasible, however Airservices is committed to exploring all suggestions put forward by communities under its recently introduced Strategic Noise Improvement Program. This approach allows for early identification of the feasibility of proposals prior to full safety and environmental assessments Review of Brisbane Region Environmental Monitoring Units A review of the Brisbane region s Environmental Monitoring Units (EMUs) was also carried out over a 12-month period from 1 July 2011 to 30 June More commonly known as noise monitors, these units are part of the Noise and Flight Path Monitoring System in use at Australia s major airports. The purpose of the review was to assess the performance of the EMUs in the Brisbane area against Airservices environmental and business requirements for the management of aircraft noise in the vicinity of airports. A report is available on the Airservices website. 17

18 3.2 Archerfield Airport Figure 15 shows aircraft movements at Archerfield Airport for the 15 month period to the end of Quarter 4 of The data point for December 2013 is temporarily removed due to uncompleted data entry process at the report preparation time. Archerfield Airport Movements 5000 Circuits Arrival/Departure OCTOBER NOVEMBER DECEMBER JANUARY FEBRUARY MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER Number of Movements Figure 15: Aircraft movements at Archerfield Airport October 2012 to December 2013 The key point shown is: Fluctuations in movements at Archerfield result largely from the calendar of training schools at the airports. Students tend to be undertaking circuit flying at the same time, which causes the peaks and troughs. The increase in circuits in November 2013 was partly due to students undertaking night circuit training at this time. 18

19 4 Noise monitoring Airservices collects noise and operational data from noise monitors (EMUs) around Brisbane Airport. This data can be expressed in a number of ways, to show average noise during a period, background noise levels and number of noise events over a certain threshold. Sound is measured on a logarithmic scale with the decibel (db(a)) as the unit of measure. The sound level of typical daytime urban-based activities can vary between 40dB(A) and 80dB(A). Figure 16 through Figure 20 show data from the five Brisbane EMUs for the last 15 months (see Figure 1 for the location of EMUs). Note the term N65 refers to the average number of daily noise events caused by aircraft that are over 65dB(A). Figures for N70, N80 and N90 are also provided. 19

20 Figure 16: Average daily noise events at EMU 2 (Tingalpa) from Quarter 4 of 2012 to Quarter 4 of 2013 (captures arrivals to Runway 01 and departures from Runway 19) The key points shown are: Along with EMU 55 (Cannon Hill), EMU 2 records the highest number of aircraft noise events. These noise monitors are close to the flight paths for both Runway 01 arrivals and Runway 19 departures (aircraft arriving from and departing to the south). EMU 2 is directly over-flown by departures off runway 19 and heading south (to airports of the other eastern states). The number of aircraft noise events recorded is proportional to the number of 19 departures. The pattern for aircraft noise events recorded by EMU 2 reflects the seasonal use of Runway 19 for departures. 20

21 Figure 17: Average daily noise events at EMU 3 (Nudgee Beach) from Quarter 4 of 2012 to Quarter 4 of 2013 (captures movements on Runway 14/32 and some departures from Runway 01) The key point shown is: Less than 5% of all movements use Runway 14/32. As a result EMU 3 (Nudgee Beach) records the lowest number of aircraft noise events of all the noise monitors. Some non-jet aircraft heading north after taking off from Runway 01 will overfly EMU 3. 21

22 Figure 18: Average daily noise events at EMU 24 (Bulimba) from Quarter 4 of 2012 to Quarter 4 of 2013 (captures arrivals to Runway 01) The key point shown is: The pattern for noise events recorded by EMU 24 reflect the seasonal use of Runway 01 for arrivals. 22

23 Figure 19: Average daily noise events at EMU 54 (Kedron) from Quarter 4 of 2012 to Quarter 4 of 2013 (captures arrivals to Runway 01) The key points shown are: EMU 54 records a relatively low number of noise events as it is not aligned with any Brisbane Airport runways. The pattern for noise events recorded reflects the seasonal use of Runway 01 for arrivals.. 23

24 Figure 20: Average daily noise events at EMU 55 (Cannon Hill) from Quarter 4 of 2012 to Quarter 4 of 2013 (captures arrivals to Runway 01 and departures from Runway 19) The key points shown are: Along with EMU 2 (Tingalpa), EMU 55 records the highest number of aircraft noise events as these noise monitors are close to the flight paths for 19 departures. Many arrivals onto Runway 01 conduct visual procedures which intersect the approach onto Runway 01 to the north of EMU 2. Runway 19 visual approaches do not result in noise events being detected at EMU 55. The pattern for noise events from EMU 55 reflects the seasonal use of Runway

25 5 Complaints data Airservices manages complaints and enquiries about aircraft noise and operations through its Noise Complaints and Information Service (NCIS). Complaints, enquiries and requests for information about aircraft operations received by the NCIS are collected and stored in a database for the purpose of complaint management, analysis of issues and identification of causal factors. Each complaint, enquiry or request for information is referred to as a contact and each person who makes contact with the NCIS is referred to as a client. 5.1 NCIS Clients by suburb The NCIS received contacts from 208 clients regarding Brisbane Airport and Archerfield Airport during Quarter 4 of Client density maps are used to show the number of clients from each suburb, with suburbs coloured according to how many clients had contacted the NCIS. The data does not include clients who contacted other organisations (eg. Airports). Table 1 provides a breakdown of clients from Quarter 4 of Figure 21 shows client density with flight tracks overlaid for Brisbane Airport and Archerfield Airports for Quarter 4 of Figure 22 focuses on the client density for Archerfield Airport (for all of Quarter 4 of 2013), showing circuit training tracks (the main issue of complainants) overlaid. The following data is derived from a dynamic database and is correct as at 13 th January 2014 and may change without notification. 25

26 Table 1: Recorded Clients by Suburb, Quarter 4 of 2013 Suburbs Brisbane Airport Clients Archerfield Airport Clients Total Clients Acacia Ridge 1 1 Albion 1 1 Alderley 1 1 Algester 1 1 Archerfield 1 1 Ascot 2 2 Ashgrove 1 1 Bellbowrie 1 1 Belmont 1 1 Brisbane City 2 2 Brisbane Airport 1 1 Buderim 1 1 Calamvale 1 1 Camp Hill Cannon Hill 7 7 Carina Heights 1 1 Carindale 4 4 Cashmere 1 1 Chandler 1 1 Chapel Hill Chelmer 2 2 Clayfield 3 3 Coopers Plains 2 2 Coorparoo Corinda 1 1 Deception Bay 1 1 Durack 1 1 East Brisbane 3 3 Eight Mile Plains 2 2 Fairfield 1 1 Ferny Groove 1 1 Ferny Hills 4 4 Fig Tree Pocket 1 1 Greenslopes 3 3 Hamilton 1 1 Hawthorne 3 3 Hemmant 1 1 Highgate Hill 2 2 Holland Park 6 6 Holland Park West 3 3 Jimna 1 1 Jindalee

27 Suburbs Brisbane Airport Clients Archerfield Airport Clients Total Clients Kallangur 1 1 Kenmore 1 1 Logan Central 1 1 Lota 2 2 Manly 1 1 Mansfield 1 1 Moorooka 2 2 Morningside Mount Gravatt 1 1 Mount Ommaney Murarrie 3 3 Nathan 2 2 Norman Park 8 8 Northgate 1 1 Nundah 1 1 Oxley Paddington 1 1 Pinjarra Hills 1 1 Pinkenba 1 1 Red Hill 1 1 Rochedale South 1 1 Salisbury Seven Hills Shailer Park 1 1 Shorncliffe 1 1 Sinnamon Park 1 1 Spring Hill 1 1 Springwood 1 1 Stafford Heights 1 1 Taringa 1 1 Tarragindi 6 6 The Gap 6 6 Tingalpa 5 5 Toowong 1 1 Wakerley 1 1 West End 1 1 Woolloongabba 1 1 Wooloowin 2 2 Wynnum 2 2 Wynnum West 1 1 Total

28 Table 1 shows: Four suburbs had clients for both Brisbane Airport and Archerfield Airport. The top three suburbs with the most clients for Brisbane Airport are Coorparoo, Morningside and Seven Hills. Figure 21: Client Density by Suburb with an overlay of tracks from 1 December to 3 December 2013 for the Brisbane region The key points shown in Figure 21 are: Suburbs in Brisbane with the highest number of NCIS clients are those to the south west of Brisbane Airport, which are overflown by departures from Runway 19 and arrivals to arrivals to Runway 01 (Morningside, Seven Hills, Camp Hill, Coorparoo). In particular, there has been an increase in clients living underneath the approach to Runway 01. This is partly due to the increased use of instrument approaches (ILS), due to safety and traffic management requirements. Many of the complaints are in regard to aircraft arriving early in the morning (from 4:30am to 6am) as well as in the hour from 11pm. 28

29 Figure 22: Client density by suburb with an overlay of tracks from 1 December to 3 December 2013 at Archerfield The key point shown in Figure 22 is: The main issue for complainants living near Archerfield Airport is circuit training. Complainants refer to an increase in helicopter training and some complainants refer to an increase in training after 20:00, which is consistent with the spike in the circuit training numbers in November

30 5.2 Issues raised by NCIS clients Figure 23 shows the top five issues raised by NCIS clients regarding Brisbane Airport for the 15 month period to December A single contact can involve multiple issues (ie. a client may have raised more than one issue when they contacted the NCIS). During the 15 month period the top five issues raised relating to Brisbane Airport were Jet Aircraft, Increased Frequency of Air Traffic, Runway 01 Arrivals, Aircraft Height and Runway Selection. Figure 23: Top five issues for Brisbane Airport for the 15 month period, October 2012 to December The 5 th and 6 th ranked issues had been raised the same number of times and as such, both are included above. The key points are that: 30

31 6 Airservices update 6.1 Community Aviation Consultation Groups Airservices attends Community Aviation Consultation Group (CACG) meetings at Brisbane Airport to provide information to the community and assist in discussions on aviation matters. Appendix 1 provides a summary of issues raised by Airservices at CACG meetings since January Noise improvements Airservices has developed a process to investigate aircraft noise improvements across Australia. Working with the community and the aviation industry, Airservices will assess the benefits of noise improvement proposals and implement them if feasible. Airservices will assess the potential safety, efficiency and environmental impacts of proposals. We will seek community views throughout this process to help inform decisions. Safety remains our top priority and any change would have to meet rigorous Air Traffic Control requirements. This means that it may not be possible to implement some proposals. Airservices will only implement a new procedure or a trial after a comprehensive community engagement process, including consultation with community forums. We will also discuss potential changes with the aviation industry. Airservices will publish details of any changes to procedures or trials on its website. Appendix 1 provides details of noise improvements that have been implemented in the Brisbane Basin and others that are in progress. 31

32 7 Contact us To lodge a complaint or make an enquiry about aircraft operations, you can: go to WebTrak ( use our online form ( telephone (freecall) or (local call Sydney) fax (02) write to, Noise Complaints and Information Service, PO Box 211, Mascot NSW Airservices welcomes comments about this report. Please contact us via at community.relations@airservicesaustralia.com if you would like to provide feedback. 32

33 Appendix 1 Airservices update Noise Improvement Opportunities Runway 19 Departures Moving the MEAND Waypoint a short distance to the south-east may provide an improved noise outcome for Pinkenba residents. A year long trial will be proposed once the track design is finalised. Brisbane Airport Community Aviation Consultation Group Meetings 7 November 2013 Airservices reported on progress with the proposal to move the MEAND Waypoint (see above). Airservices also advised that a short-term noise monitoring program will be carried out in January/February to gather data on the impact of aircraft noise on residents in the Moorooka area resulting from summer weather patterns. 30 July 2013 The chairman of Airservices Board, Angus Houston, attended the meeting and noted the work being done jointly by Brisbane Airport and Airservices to bring about noise improvements for the community. A proposal to adopt a revised intersection departure procedure was discussed the meeting. The intention is to speed up throughput on the main runway and the likely noise impact will be minimal. Airservices reported that short-term noise monitoring had been carried out at Paddington, Pinkenba, Northgate, Salisbury and Tarragindi in June Reports will be published on Airservices website when available. 28 May 2013 Airservices presented the results of the Brisbane Noise Abatement Procedure Review carried out of over a 12-month period from July 2011 to June The key finding was that compliance with NAP procedures was exceptionally high and that over the Bay operations at night-time were effective in minimising the impact of aircraft noise on the community. 26 March 2013 Airservices provided a presentation on the Noise Mitigation Change Process which is intended to provide an early identification of possible improvements to noise outcomes for communities around the airport. As part of this process, Airservices had been able to implement an earlier start time for over the Bay operations at weekends an initiative put forward by residents. 33