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LCQ16: Aircraft noise
     Following is a question by the Hon Chan Chi-chuen and a written reply by the Secretary for Transport and Housing, Professor Anthony Cheung Bing-leung, in the Legislative Council today (June 14):


     The Government told this Council on June 15 last year that to reduce the impact of aircraft noise on the residents living near the flight paths, the Civil Aviation Department (CAD) had implemented a number of aircraft noise abating measures in accordance with the balanced objectives, promulgated by the International Civil Aviation Organization (ICAO), of managing aircraft noise. Such measures included requiring aircraft in the small hours to avoid, as far as possible, overflying populated areas, and to adopt ICAO's noise abatement departure procedure during take-off and the continuous descent approach for landing. Moreover, with a view to encouraging more airlines to deploy quieter types of aircraft, the Airport Authority Hong Kong (AAHK) was studying the introduction of environmental charges in relation to aircraft noise, and would consult the aviation industry and the relevant stakeholders on the findings of the study. Yet, I have learnt that aircraft noise during the period between 11pm each day and 7am of the next day still often causes nuisance to a number of residents at present, making it difficult for them to fall asleep. In recent months, I have even received complaints from Ma Wan residents pointing out that quite a number of aircraft still overfly Ma Wan at an altitude below 5 000 feet after take-off, in contravention of the authorities' undertaking made years ago that all aircraft departing Hong Kong would overfly Ma Wan at an altitude not lower than 7 000 feet. In addition, some aircraft overfly the urban areas at an altitude below 7 500 feet, causing residents in the urban areas to suffer greatly from aircraft noise nuisance. In this connection, will the Government inform this Council:

(1) of the respective numbers of aircraft departing Hong Kong last year overflew Ma Wan at altitudes (i) below 5 000 feet, (ii) between 5 000 and 7 000 feet, and (iii) above 7 000 feet (set out in a table);

(2) of the monthly data, recorded during the period between 11pm each day and 7am of the next day from April last year to May this year by various aircraft noise monitoring terminals, on aircraft noise levels which reached (i) 70 to 74 decibels (dBs), (ii) 75 to 79 dBs, and (iii) 80 dBs or above;

(3) among the aircraft departing Hong Kong last year, of the types of those with noise levels reaching 80 dBs or above, and the airlines to which such aircraft belonged;

(4) whether it knows the latest progress of the study conducted by AAHK on the introduction of the aforesaid environmental charges; and

(5) whether CAD will further strengthen the existing aircraft noise abating measures to reduce the nuisance caused to residents in the districts concerned; if so, of the details?



     In accordance with international standards and recommendations, the design of flight paths takes into account factors including terrain environment and required obstacle clearances. To ensure aviation safety, departing aircraft are required to comply with the minimum climb gradient requirements specified in the departure procedures published in the Hong Kong Aeronautical Information Publication (HKAIP). The departure procedures published in the HKAIP are designed in accordance with the safety requirements of the International Civil Aviation Organization (ICAO). According to the relevant requirements, departing aircraft are required to fly at an altitude of not less than 1 800 feet in the vicinity of Ma Wan. The actual climb gradient of departing aircraft is dependent on various factors such as the payload and performance characteristics of individual aircraft and weather conditions, etc. Generally speaking, as far as minimum climb gradient is concerned, apart from the requirements set out in the HKAIP, the Civil Aviation Department (CAD) would not specify additional requirement for departing aircraft.

     Our reply to the various parts of the Hon Chan Chi-chuen's question is as follows:

(1) The number and altitude of aircraft flying overhead of Ma Wan between 11pm and 7am the following day when departing to the northeast of the Hong Kong International Airport (HKIA) in 2016 are set out at Annex 1.

(2) The CAD has 16 noise monitoring terminals (NMT). The aircraft noise events recorded between 11pm and 7am the following day by these terminals from April 2016 to March 2017 by month are set out at Annex 2. The data for April and May 2017 are pending verification and thus not available yet.

     According to the noise data recorded at the Ma Wan NMT between 2012 and 2016, the number of noise events of 70 decibels or above and of 80 decibels or above has decreased by 27 per cent and 59 per cent respectively. This shows the effectiveness of the aircraft noise mitigating measures adopted by the CAD, the details of which are elaborated in part (5) below.

(3) In 2016, among departing aircraft, the operating airlines and aircraft types of aircraft with noise events of 80 decibels or above recorded between 11pm and 7am the following day are set out at Annex 3.

(4) The CAD understands that, on the basis of the 24-hour operation of the HKIA and by adopting the guidelines relating to aircraft noise charges issued by the ICAO, the Airport Authority Hong Kong is studying in detail the introduction of environmental charges/incentive schemes as a means of encouraging more airlines to use quieter aircraft. Subject to the findings of the study, the aviation industry and the stakeholders will be consulted accordingly.

(5) The CAD has implemented a series of aircraft noise mitigating measures in accordance with the balanced approach to aircraft noise management promulgated by the ICAO. These measures include requiring aircraft to avoid overflying populated areas, to adopt the noise abatement departure procedures prescribed by the ICAO during take-off and to adopt the quieter Continuous Descent Approach for landing, etc. in the small hours as far as possible. The CAD has also implemented a new set of flight procedures since 2012 to allow aircraft equipped with satellite-based navigation technology to adhere closely to the nominal centre line of the flight track when departing to the northeast of the HKIA and making south turn to the West Lamma Channel, thereby keeping the aircraft at a distance away from the areas in the vicinity of the flight paths, and reducing the impact of aircraft noise on these areas.

     Apart from implementing the aircraft noise abatement operational procedures mentioned above, the CAD has prohibited aircraft not meeting the relevant aircraft noise standards from landing and taking off in Hong Kong. Since 2002, aircraft not complying with the noise standards in Chapter 3 of Volume I, Part II of Annex 16 to the Convention on International Civil Aviation (Chapter 3 noise standards) are not allowed to operate in Hong Kong. To strengthen this aircraft noise mitigating measure, starting from 2014, the CAD has imposed further restrictions on aircraft which are marginally compliant with the Chapter 3 noise standards (Note) to land and take off in Hong Kong. The CAD will review this arrangement from time to time and closely monitor the latest developments of the ICAO, the international aviation industry and the operation of the HKIA in considering the need to step up the relevant requirement.

     With the advancement of aviation technology, aircraft engines are quieter than before, and the improved design of airframe has also helped reduce noise significantly. To reduce the impact of aircraft noise on the areas near the flight paths, many airlines are replacing their aircraft with quieter models progressively. The CAD will continue to monitor the progress made by airlines in aircraft fleet replacement and deployment of quieter aircraft for night time operations, as well as the effectiveness of such measures.

Note: Volume I, Part II of Annex 16 to the Convention on International Civil Aviation sets out the aircraft noise standards formulated by the ICAO at different times. The aircraft noise standards of Chapter 3, which were formulated at a later stage than those of Chapter 2, were more stringent. Generally speaking, the noise levels of Chapter 3-compliant aircraft were lower than those of Chapter 2-compliant aircraft. Aircraft marginally complying with Chapter 3 noise standards refers to an aircraft which is in compliance with Chapter 3 noise standards, but its noise level is relatively close to the upper limit prescribed in Chapter 3.
Ends/Wednesday, June 14, 2017
Issued at HKT 15:00
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