Aircraft Noise


Methodology Adopted for Assessing Aircraft Noise Impact

1. Throughout the airport master planning process on the Hong Kong International Airport (HKIA), the Airport Authority in conjunction with the government have conducted assessments to determine the effects of aircraft noise impacts on off-airport areas.

2. The noise impact arising from aircraft operation can be represented by the Noise Exposure Forecast (NEF) contours, a criterion which takes into account the duration of flyover, the peak noise level, the tonal characteristics and the number of aircraft movements in both the daytime and night-time period. The noise impact assessment was conducted in accordance with the guidelines set out by the International Civil Aviation Organization (ICAO) and the Federal Aviation Administration (FAA) of the United States Department of Transport. The FAA's state-of-the-art modelling tools for assessing airport noise exposure were used to generate these noise contours. For the HKIA at Chek Lap Kok, the Hong Kong Planning Standards and Guidelines stipulate a more stringent criterion of NEF 25 contour (as against NEF 30 for Kai Tak Airport) for planning of noise sensitive land uses. This criterion is in line with the international standards adopted by many developed countries.

Results of Aircraft Noise Impact Assessment

3. According to the New Airport Master Plan – Environmental Impact Assessment (NAMP-EIA) completed by the Airport Authority in 1991, its Supplement in 1992 and its Update completed in 1998, only a very small number of residents in North Lantau, predominantly in Sha Lo Wan, are within the coverage of the NEF 25 contour of the HKIA at design capacity and regarded as subject to aircraft noise beyond acceptable level from a planning and land use point of view.

4. Since the opening of HKIA at Chek Lap Kok, several briefings on aircraft noise and flight paths have been given to the concerned District Councils including Kwai Tsing, Sha Tin, Tsuen Wan, Central & Western, Kowloon City, Southern, Yau Tsim Mong, Wan Chai, Eastern, North, Islands, Tuen Mun and Sai Kung.

Aircraft Noise Monitoring

5. The CAD monitors the noise caused by aircraft operations through a computerised Aircraft Noise and Flight Track Monitoring System (ANFTMS). The ANFTMS comprises 16 outdoor noise monitoring terminals (NMTs) which are located along or close to the flight paths operating into and out of the HKIA, and a computer to correlate the noise data with the aircraft flight tracks recorded by the CAD's radar system. At present, the 16 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 and Shau Kei Wan.

6. The measured noise levels are summarised in the table below:-

Table 1

Measured Noise Levels at Various Districts
(1 July 2020 - 30 June 2021)

  Distribution of Noise Levels Mainly affected by Operation
(Runway/Operation)
Lmax (Note 1) <65 dB(A) 65–69.9 dB(A) 70–74.9 dB(A) ≧75 dB(A)
Sha Lo Wan 69.7% 16.8% 11.1% 2.4% 07R,07L,25R,25L/Arrival (Note 2)
07R,07L,25R,25L/Departure (Note 3)
Tung Chung 89.4% 9.6% 1.0% 0.0% 07R,07L,25R,25L/Arrival (Note 2)
07R,07L,25R,25L/Departure (Note 3)
Sunny Bay 78.3% 18.0% 3.4% 0.3% 25R,25L/Arrival (Note 2)
07R,07L/Departure (Note 3)
Ma Wan 68.7% 18.8% 10.1% 2.4% 25R,25L/Arrival (Note 2)
07R,07L/Departure (Note 3)
Tai Lam Chung 94.5% 5.1% 0.4% 0.0% 25R,25L/Arrival (Note 2)
07R,07L/Departure (Note 3)
Tsing Lung Tau 78.7% 12.4% 8.2% 0.7% 25R,25L/Arrival (Note 2)
07R,07L/Departure (Note 3)
Ting Kau 88.4% 7.3% 4.2% 0.1% 25R,25L/Arrival (Note 2)
07R,07L/Departure (Note 3)
Tsuen Wan 86.7% 9.3% 3.9% 0.1% 25R,25L/Arrival (Note 2)
07R,07L/Departure (Note 3)
Tsing Yi #1 92.8% 3.6% 3.2% 0.4% 25R,25L/Arrival (Note 2)
07R,07L/Departure (Note 3)
Tsing Yi #2 94.5% 4.4% 1.1% 0.0% 25R,25L/Arrival (Note 2)
07R,07L/Departure (Note 3)
Kwai Chung 95.6% 2.8% 1.6% 0.0% 25R,25L/Arrival (Note 2)
07R,07L/Departure (Note 3)
Tai Wai 97.0% 2.9% 0.1% 0.0% 25R,25L/Arrival (Note 2)
Mid-Levels 97.0% 2.4% 0.5% 0.1% 07R,07L/Departure (Note 3)
North Point 96.2% 2.6% 1.0% 0.2% 07R,07L/Departure (Note 3)
Jardine's Lookout 97.1% 2.3% 0.6% 0.0% 07R,07L/Departure (Note 3)
Shau Kei Wan 97.3% 1.9% 0.7% 0.1% 07R,07L/Departure (Note 3)

Note 1: Lmax is the peak instantaneous noise level of a noise event.
Note 2: Please refer to Appendix A PDF (PDF: 1460KB) in the Flight Path Section for the arrival flight path arrangement.
Note 3: Please refer to Appendix B PDF (PDF: 1474KB) in the Flight Path Section for the departure flight path arrangement.
Note 4: Statistics are based on data recorded by the Aircraft Noise and Flight Track Monitoring System.
Note 5: The above percentages are with reference to the total movements of aircraft during the period concerned.

Aircraft Noise Mitigating Measures

7. The government is conscious of any possible noise impact that aircraft operations may have on local communities and has implemented a number of aircraft noise mitigating measures based on the guidelines of the ICAO, aiming at mitigating noise impact caused by the aircraft without compromising aviation safety. Briefly, these are:-

a) subject to acceptable wind conditions and safety considerations, arrival aircraft between midnight and 7 a.m. are required to land from the southwest over the water. This measure aims at reducing the number of aircraft overflying populated areas such as Tseung Kwan O, Sha Tin, Kwai Chung, Tsing Yi and Tsuen Wan during the overnight period;

b) subject to acceptable operational and safety consideration, 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 the Kowloon Peninsula and Hong Kong Island;

c) 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;

d) 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), subject to weather and operational considerations. As aircraft on CDA fly higher altitudes, noise experienced in areas such as Tseung Kwan O, Sai Kung and Ma On Shan is expected to be lowered;

e) to reduce aircraft noise at source, subsonic jet 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 prohibited from landing or taking off in the HKIA;

f) to strengthen the above measure e), starting from 2014, airlines are not allowed to schedule aircraft which are only marginally compliant with the Chapter 3 noise standards to land and take off in HKIA;

g) to further alleviate the aircraft noise impact on the local communities, commencing from March 2019, airlines are not allowed to schedule 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 HKIA between 10 p.m. and 7 a.m. on the following day; and

h) 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. As regards the measures mentioned in paragraph 7(a) and (b) 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. to land from the southwest
when wind conditions and traffic situation permit

Year Total number of aircraft arriving between 00:01 and 07:00 hours 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%

Year 2021

Month Total number of aircraft arriving between 00:01 and 07:00 hours Total number of aircraft landed from the southwest during the same period Achievement Rate (%)
January 1,588 1,565 98.6%
February 1,208 1,208 100%
March 1,436 1,389 96.7%
April 1,470 1,416 96.3%
May 1,571 862 54.9%
June 1,612 655 40.6%

Note 1: 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 (Note 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* 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%

Year 2021

Month Total number of aircraft departing on Runway 07 between 23:00 and 07:00 hours* Total number of departing aircraft using the southbound route during the same period Achievement Rate (%)
January 1,626 1,626 100.0%
February 1,189 1,188 99.9%
March 1,346 1,346 100.0%
April 1,250 1,247 99.8%
May 763 751 98.4%
June 641 618 96.4%

Note 1: (*)Prior to 7 January 1999, the implementation time period was between midnight and 7 a.m..
Note 2: Statistics are based on data recorded by the Aircraft Noise and Flight Track Monitoring System.

Aircraft Noise Complaint

9. 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