Aircraft Noise
- Environmental Impact Assessment
- Public Engagement
- Aircraft Noise Monitoring
- Aircraft Noise Mitigating Measures
- Aircraft Noise Complaint
Environmental Impact Assessment
1. During the design stage of the Three-Runway System (3RS) project, Airport Authority Hong Kong (AAHK) conducted an Environmental Impact Assessment (EIA) study in accordance with the Environmental Impact Assessment Ordinance (EIAO).
2. As part of this EIA study, AAHK conducted an assessment on aircraft noise. The assessment covered areas under and near the flight paths, with particular emphasis on neighbouring districts of the Hong Kong International Airport (HKIA). The assessment results indicated that, following the implementation of various aircraft noise mitigating measures, aircraft noise of the 3RS operation would not cause a greater impact on the surrounding areas and the relevant aircraft noise standards (including the NEF 25 criterion(1) ) would be fully complied with.
3. Upon fulfilment of all statutory requirements under EIAO, the Director of Environment Protection approved the EIA report for the 3RS project (including the aircraft noise assessment report) and issued an Environmental Permit (EP) to AAHK in November 2014. In compliance with the EP requirements, AAHK submitted the aircraft noise monitoring plan and procedures for aircraft noise mitigation to the Environmental Protection Department (EPD) and received approval prior to the commencement of the 3RS operations. AAHK will continue to undertake the necessary work in accordance with the EP requirements, and to ensure the 3RS operation fully complies with all relevant statutory requirements. Relevant details could be found in AAHK's 3RS website (https://env.threerunwaysystem.com/en/index.html).
Note (1): In accordance with the standards set under EIAO, the aircraft noise arising from the 3RS of the HKIA must meet the Noise Exposure Forecast (NEF) 25 criterion. This means that the NEF 25 contour of the 3RS operation should not extend to new areas that are particularly sensitive to noise, such as residential areas, educational institutions, hospitals and clinics. NEF is an internationally recognised noise metric for assessing aircraft noise and has all along been adopted in Hong Kong under EIAO, and also a widely adopted standard worldwide. It takes into account the duration of flyover, the peak noise level and the number of aircraft movements during both daytime and night-time periods. AAHK will ensure that the NEF 25 requirement is strictly adhered to under the 3RS operation.
Public Engagement
4. CAD and AAHK attach great importance to community engagement. CAD has been working closely with AAHK to provide relevant stakeholders (including Legislative Council members, District Councils members, and key representatives of the relevant communities etc.) with updated information on the 3RS project (including information related to aircraft noise) through various channels.
5. To strengthen ties with the community, AAHK has set up various Community Liaison Groups (CLGs) in the neighbouring districts of the HKIA. The groups consist of District Councils members and community leaders. AAHK has held multiple stakeholder engagement activities to provide information related to the 3RS project. AAHK has also set up a complaint hotline and email channel to collect public feedback on the 3RS project. Relevant details could be found in AAHK's 3RS website (https://env.threerunwaysystem.com/en/index.html).
Aircraft Noise Monitoring
6. The CAD monitors the noise caused by aircraft operations through a computerised Aircraft Noise and Flight Track Monitoring System (ANFTMS). The ANFTMS is comprised of multiple outdoor noise monitoring terminals (NMTs) which are located along or close to the flight paths operating into and out of the HKIA to collect noise data, and a computer system which correlates noise data collected with the actual aircraft flight tracks detected by the CAD's radar system. In view of the commencement of 3RS operation starting from 28 November 2024, the CAD has expanded the ANFTMS through the installation of additional NMTs at locations close to the new flight paths to ensure more comprehensive monitoring of aircraft noise under 3RS operation. At present, the NMTs are located respectively at Sha Lo Wan, Tung Chung, Sunny Bay, Ma Wan, Tsing Yi (2 terminals), Tai Lam Chung, Tsing Lung Tau, Ting Kau, Tsuen Wan, Kwai Chung, Tai Wai, Mid-Levels, North Point, Jardine's Lookout, Shau Kei Wan, Tuen Mun, Siu Lam, Tai Mo Shan, Ma Liu Shui, Clearwater Bay and Tsz Wan Shan. The distribution of noise levels at various districts is summarized in the table below:-
Table 1
Distribution of Noise Levels at Various Districts
(1 Jan 2024 - 31 Dec 2024)
| Distribution of Noise Levels | ||||
|---|---|---|---|---|
| <65 dB(A) | 65–69.9 dB(A) | 70–74.9 dB(A) | ≧75 dB(A) | |
| Sha Lo Wan | 76.3% | 14.6% | 7.8% | 1.3% |
| Tung Chung | 89.3% | 9.1% | 1.6% | 0.0% |
| Sunny Bay | 82.4% | 13.7% | 3.5% | 0.4% |
| Ma Wan | 85.0% | 10.9% | 3.4% | 0.7% |
| Tai Lam Chung | 85.1% | 3.0% | 9.8% | 2.1% |
| Tsing Lung Tau | 94.2% | 5.0% | 0.8% | 0.0% |
| Ting Kau | 99.3% | 0.7% | 0.0% | 0.0% |
| Tsuen Wan | 99.5% | 0.4% | 0.1% | 0.0% |
| Tsing Yi #1 | 99.7% | 0.2% | 0.1% | 0.0% |
| Tsing Yi #2 | 99.3% | 0.6% | 0.1% | 0.0% |
| Kwai Chung | 99.3% | 0.6% | 0.1% | 0.0% |
| Tai Wai | 99.4% | 0.6% | 0.0% | 0.0% |
| Mid-Levels | 97.9% | 1.9% | 0.2% | 0.0% |
| North Point | 97.7% | 1.6% | 0.6% | 0.1% |
| Jardine's Lookout | 98.1% | 1.5% | 0.4% | 0.0% |
| Shau Kei Wan | 98.4% | 1.1% | 0.4% | 0.1% |
| Tuen Mun | 99.5% | 0.5% | 0.0% | 0.0% |
| Siu Lam | 85.1% | 6.3% | 7.7% | 0.9% |
| Ma Liu Shui | 99.4% | 0.6% | 0.0% | 0.0% |
| Tsz Wan Shan | 98.7% | 1.2% | 0.1% | 0.0% |
| Tai Mo Shan | 93.9% | 5.7% | 0.4% | 0.0% |
| Clearwater Bay | 99.7% | 0.3% | 0.0% | 0.0% |
| Supplementary Information: | |
| 1. | Lmax is the peak instantaneous noise level of a noise event. |
| 2. | The noise level experienced at various district is subject to the arrival/departure routes used and therefore varies. |
| 3. | Statistics are based on data recorded by the Aircraft Noise and Flight Track Monitoring System. |
| 4. | The above percentages are with reference to the total movements of aircraft during the period concerned. |
| 5. | NMTs in Tuen Mun and Siu Lam have been put into operation since July 2022. |
| 6. | NMTs in Tai Mo Shan, Ma Liu Shui, Clearwater Bay and Tsz Wan Shan have been put into operation since 28 November 2024. |
Aircraft Noise Mitigating Measures
7. With a view to minimising the impact of aircraft noise on local communities, CAD has been implementing various aircraft noise mitigating measures on the condition that aviation safety is not compromised. Major measures are set out below:-
- In accordance with the Civil Aviation (Aircraft Noise) Ordinance (Cap. 312), aircraft that do not comply with the noise standards stipulated in Chapter 3 of Annex 16 Volume I, Part II to the Convention on International Civil Aviation ("Chapter 3 noise standards") are not allowed to land or take off in Hong Kong;
- As a step further, airlines are not allowed to schedule aircraft whose noise levels only marginally meet the Chapter 3 noise standards to land and take off in Hong Kong;
- Airlines are also forbidden from scheduling aircraft that do not comply with the more stringent noise standards stipulated in Chapter 4 of Annex 16 Volume I, Part II to the Convention on International Civil Aviation, or equivalent, to land and take off in Hong Kong between 10 p.m. and 7 a.m. on the following day;
- Subject to weather and safety considerations, arrival aircraft between 11 p.m. and 7 a.m. on the following day are normally instructed to land from the southwest over the water. This measure aims to reduce the number of aircraft overflying populated areas such as Sai Kung, Ma On Shan, Sha Tin, Kwai Chung, Tsing Yi, Tsuen Wan and Tuen Mun (Siu Lam / Tai Lam Chung) during the overnight period;
- Subject to weather and safety considerations, aircraft departing to the northeast of the airport between 11 p.m. and 7 a.m. on the following day are required to use the southbound route via the West Lamma Channel. This measure aims at reducing the number of aircraft overflying populated areas such as Tuen Mun (Siu Lam / Tai Lam Chung), Tsuen Wan North and Kowloon East;
- Subject to weather and safety considerations, all aircraft approaching the HKIA from the northeast between 11 p.m. to 7 a.m. on the following day are encouraged to adopt the Continuous Descent Approach (CDA). As aircraft on CDA fly higher altitudes, noise experienced in areas such as Sai Kung and Ma On Shan will be lower;
- Aircraft departing to the northeast of the HKIA are required to adopt the noise abatement take-off procedures laid down by ICAO so as to reduce the noise impact on areas located in the vicinity of the HKIA. Under these procedures, aircraft are required to reduce their power upon reaching an altitude of 800 feet or above to abate aircraft noise; and
- All aircraft equipped with satellite-based navigation technology departing to the northeast of the HKIA between 11 p.m. and 7 a.m. on the following day are encouraged to adopt a set of Radius-to-Fix ("RF") flight procedures. Aircraft flying RF procedures adhere closely to the nominal centre line of the flight track when making south turn to the West Lamma Channel. This keeps the aircraft at a distance away from the areas in the vicinity of the flight paths, and reduces the impact of aircraft noise on people in these areas.
8. In addition to the aircraft noise mitigating measures that are in force, according to the EP requirements, AAHK is required to implement a series of aircraft noise mitigating measures. CAD would collaborate with AAHK to actively implement the relevant measures. For details, please refer to AAHK's 3RS website (https://env.threerunwaysystem.com/en/index.html).
9. With the advancement of aviation technology, aircraft engines are quieter than before and the improved design of airframe has also helped reduce noise significantly. It is noted that more airlines have introduced quieter aircraft, and the ratios of newer-model aircraft in their fleets are on the rise. This will alleviate the aircraft noise impact in the long run.
10. As regards the measures mentioned in paragraph 7(d) and (e) above, Tables 2 and 3 below show the achievement figures. The results indicate that high percentages of achievement have been attained during the periods with the implementation of the measures. These measures could not be applied only on a small number of occasions due to various operational reasons including prevailing wind conditions, maintenance of navigation aids prior to flight calibration, or air traffic conflicts.
Table 2
Achievement record for aircraft arriving
between midnight and 7 a.m. on the following day to land from the southwest
when wind conditions and traffic situation permit (1)
| Year | Total number of aircraft arriving between 00:00 and 07:00 hours(1) | Total number of aircraft landed from the southwest during the same period | Achievement Rate (%) |
|---|---|---|---|
| 1998 (Oct-Dec) | 1,066 |
1,037 |
97.3% |
| 1999 | 4,720 |
4,293 |
91.0% |
| 2000 | 5,695 |
5,248 |
92.2% |
| 2001 | 5,526 |
5,201 |
94.1% |
| 2002 | 7,065 |
6,660 |
94.3% |
| 2003 | 6,838 |
6,409 |
93.7% |
| 2004 | 8,641 |
7,958 |
92.1% |
| 2005 | 10,865 |
9,437 |
86.9% |
| 2006 | 12,622 |
11,126 |
88.1% |
| 2007 | 14,002 |
11,950 |
85.3% |
| 2008 | 14,869 |
13,263 |
89.2% |
| 2009 | 13,266 |
12,201 |
92.0% |
| 2010 | 17,126 |
14,704 |
85.9% |
| 2011 | 19,713 |
17,174 |
87.1% |
| 2012 | 21,099 |
18,006 |
85.3% |
| 2013 | 24,111 |
21,434 |
88.9% |
| 2014 | 27,655 |
23,601 |
85.3% |
| 2015 | 30,039 |
23,548 |
78.4% |
| 2016 | 29,333 |
24,538 |
83.7% |
| 2017 | 29,509 |
25,670 |
87.0% |
| 2018 | 29,364 |
24,904 |
84.8% |
| 2019 | 32,018 |
25,874 |
80.8% |
| 2020 | 19,867 |
16,422 |
82.7% |
| 2021 | 20,524 |
16,859 |
82.1% |
| 2022 | 18,197 |
15,980 |
87.8% |
| 2023 | 28,464 |
24,772 |
87.0% |
| 2024 | 39,155 |
34,482 |
88.1% |
Year 2024
| Month | Total number of aircraft arriving between 23:00 and 07:00 hours(1) | Total number of aircraft landed from the southwest during the same period | Achievement Rate (%) |
|---|---|---|---|
| January | 3,128 | 3,128 | 100% |
| February | 2,854 | 2,854 | 100% |
| March | 3,204 | 3,009 | 93.9% |
| April | 3,148 | 2,388 | 75.9% |
| May | 3,239 | 3,068 | 94.7% |
| June | 3,185 | 2,176 | 68.3% |
| July | 3,323 | 2,631 | 79.2% |
| August | 3,339 | 1,792 | 53.7% |
| September | 3,119 | 2,831 | 90.8% |
| October | 3,315 | 3,314 | 100.0% |
| November | 3,486 | 3,476 | 99.7% |
| December | 3,815 | 3,815 | 100.0% |
| Note (1): | Starting from 16 May 2023, the implementation time period has been changed to 11 p.m. until 7 a.m. on the following day. |
| Note (2): | Statistics are based on data recorded by the Aircraft Noise and Flight Track Monitoring System. |
Table 3
Achievement record for aircraft departing
to the northeast of the airport
between 11 p.m. and 7 a.m. on the following day(1)
to use the southbound route via the West Lamma Channel
| Year | Total number of aircraft departing on Runway 07 between 23:00 and 07:00 hours(1) | Total number of departing aircraft using the southbound route during the same period | Achievement Rate (%) |
|---|---|---|---|
| 1998 (Oct-Dec) | 802 |
794 |
99.0% |
| 1999 | 5,913 |
5,871 |
99.3% |
| 2000 | 9,737 |
9,686 |
99.5% |
| 2001 | 10,790 |
10,634 |
98.6% |
| 2002 | 11,416 |
11,365 |
99.6% |
| 2003 | 11,382 |
11,340 |
99.6% |
| 2004 | 14,104 |
13,989 |
99.2% |
| 2005 | 16,115 |
15,941 |
98.9% |
| 2006 | 18,533 |
18,340 |
99.0% |
| 2007 | 19,596 |
19,449 |
99.2% |
| 2008 | 21,492 |
21,239 |
98.8% |
| 2009 | 21,162 |
21,034 |
99.4% |
| 2010 | 23,195 |
22,860 |
98.6% |
| 2011 | 25,389 |
25,170 |
99.1% |
| 2012 | 26,705 |
26,605 |
99.6% |
| 2013 | 30,035 | 29,777 | 99.1% |
| 2014 | 28,761 | 28,385 | 98.7% |
| 2015 | 27,221 |
26,895 |
98.8% |
| 2016 | 28,688 |
28,289 |
98.6% |
| 2017 | 31,136 |
30,624 |
98.4% |
| 2018 | 30,875 |
29,921 |
96.9% |
| 2019 | 29,354 |
28,643 |
97.6% |
| 2020 | 17,410 |
17,244 |
99.0% |
| 2021 | 15,819 |
15,667 |
99.0% |
| 2022 | 15,002 |
14,863 |
99.1% |
| 2023 | 22,745 |
22,386 |
98.4% |
| 2024 | 26,653 |
26,042 |
97.7% |
Year 2024
| Month | Total number of aircraft departing on Runway 07 between 23:00 and 07:00 hours(1) | Total number of departing aircraft using the southbound route during the same period | Achievement Rate (%) |
|---|---|---|---|
| January | 2,400 | 2,391 | 99.6% |
| February | 2,231 | 2,223 | 99.6% |
| March | 2,352 | 2,339 | 99.4% |
| April | 1,884 | 1,846 | 98.0% |
| May | 2,376 | 2,298 | 96.7% |
| June | 1,742 | 1,660 | 95.3% |
| July | 2,052 | 1,949 | 95.0% |
| August | 1,380 | 1,360 | 98.6% |
| September | 2,244 | 2,083 | 92.8% |
| October | 2,502 | 2,462 | 98.4% |
| November | 2,655 | 2,625 | 98.9% |
| December | 2,835 | 2,806 | 99.0% |
| Note (1): | Prior to 7 January 1999, the implementation time period was between midnight and 7 a.m. on the following day. |
| Note (2): | Statistics are based on data recorded by the Aircraft Noise and Flight Track Monitoring System. |
Aircraft Noise Complaint
| 11. | Complaint Hotline: | 2769 6969 |
| Email: | aircraftnoise@cad.gov.hk | |
| Fax: | 2326 3654 | |
| Aircraft Noise Complaint Office | ||
| Civil Aviation Department Headquarters | ||
| 1 Tung Fai Road, Hong Kong International Airport | ||
| Lantau, Hong Kong | ||
