Legislative Council

LC Paper No. CB(1)163/98-99
(These minutes have been
seen by the Administration)

Ref: CB1/PL/EA

LegCo Panel on Environmental Affairs

Minutes of special meeting
held on Tuesday, 18 August 1998, at 10:45 am
in Conference Room A of the Legislative Council Building

Members present :

Hon Christine LOH (Chairman)
Hon HUI Cheung-ching (Deputy Chairman)
Dr Hon Raymond HO Chung-tai, JP
Hon CHAN Wing-chan
Hon Mrs Sophie LEUNG LAU Yau-fun, JP
Hon LAU Kong-wah

Members attending :

Hon Andrew WONG Wang-fat, JP
Hon Andrew CHENG Kar-foo

Member absent :

Prof Hon NG Ching-fai
Hon Bernard CHAN
Dr Hon LEONG Che-hung, JP
Hon WONG Yung-kan
Hon YEUNG Yiu-chung
Hon Mrs Miriam LAU Kin-yee, JP
Hon CHOY So-yuk
Hon LAW Chi-kwong, JP

Public officers attending :

Deputy Secretary for Planning, Environment and Lands (Environment)

Mr Howard LEE,
Principal Assistant Secretary for Economic Services (New Airport)

Mr Maurice YEUNG,
Acting Principal Environmental Protection Officer Environmental Protection Department

Mr Albert LAM,
Deputy Director of Civil Aviation (Operations and Standards)

Mr Alex AU,
Acting Deputy Director of Civil Aviation (Administration)

Mr Simon LI,
Chief Planning Officer, Civil Aviation Department

Attendance by invitation :

The Aircraft Noise Concern Committee

Mr Albert CHAN,
Tsuen Wan Provisional District Board member

Mr CHAN Sung-ip,
Tsuen Wan Provisional District Board member

Miss HO Suk-ping,
Shatin Provisional District Board member

Ms LI CHAN Miu-ha,
Chairman, Incorporated Owners of Greenwood Terrace (Shatin)

Clerk in attendance :

Miss Odelia LEUNG,
Chief Assistant Secretary (1)1

Staff in attendance :

Miss Becky YU,
Senior Assistant Secretary (1)3

Before commencing discussion, members agreed to discuss the following subjects at the next meeting on Friday, 11 September 1998, at 10:45 am:

    - Air quality study in Pearl River Delta Region; and

    - Phase I of Environment Impact Assessment for Stage II of the Strategic Sewage Disposal Scheme.

Members also agreed that an informal meeting would be held on Thursday, 24 September 1998, at 9:30 am to exchange views on environmental issues with Sir Crispin TICKELL.

I Aircraft noise

Meeting with the Aircraft Noise Concern Committee
(LC Paper No. CB(1) 111/98-99(01))

2. At the invitation of the Chairman, Mr CHAN Wai-yip, Tsuen Wan Provisional District Board member briefed members on the submission from the Aircraft Noise Concern Committee (ANCC). He noted that at the last meeting on 30 July 1998, the Administration advised that the use of arrival flight path for Runway 07 or 25 would depend on the wind direction and strength. It was therefore not feasible to restrict the use of Runway 25 at night time as suggested by ANCC. To ascertain the effect of wind direction and strength on the alignment of flight paths, ANCC had conducted an analysis on the information obtained from the Hong Kong Observatory and the Civil Aviation Department (CAD) for the period from 6 July to 28 July 1998. It was revealed that both Runway 07 and Runway 25 had been used under similar wind conditions, and that the arguments put forward by the Administration were not always true. Since Runway 25 would fly above Shatin, Tsuen Wan and Tsing Yi whereas Runway 07 would go above the sea, ANCC remained of the view that CAD should use only Runway 07 for landing at night time to avoid overflying residential locations.

Meeting with the Administration

Aircraft noise assessment

3. While acknowledging the public's concern on aircraft noise, the Principal Assistant Secretary for Economic Services (New Airport) (PAS/ES(NA)) emphasized that it was not possible to avoid aircraft noise completely in Hong Kong given its geographical constraint and high density of population. Assessment was made using an internationally accepted approach. The use of the Noise Exposure Forecast (NEF) 25 contour for the new airport was also in line with the standard of many developed countries. According to the Environmental Impact Assessment (EIA) completed in 1991/92 and its update completed in 1997/98, only a very small number of residents in North Lantau, predominantly in Sha Lo Wan were within the coverage of the NEF 25 contour of the airport at design capacity and regarded as subject to aircraft noise beyond acceptable level.

4. A member expressed doubt on the accuracy of NEF as some overseas countries had already abandoned the use of NEF contours for assessing aircraft noise. He also considered a direct comparison of NEF values between Hong Kong and overseas countries inappropriate as Hong Kong was a very small place with high density of population. The number of people to be affected within the coverage of NEF 25 contour would be much higher than that in overseas countries. In reply, the Acting Principal Environmental Protection Officer (Ag. PEPO) explained that NEF was a composite noise contour which took into consideration the duration of flyover, the peak noise level, the tonal characteristics and the number of aircraft movements in both daytime and night time in the noise assessment. This was also similar to the territory-wide approach for assessing noise impact of road traffic and train which took into account the cumulative noise over a period of time instead of the noise of a single event. Ag. PEPO quoted noise criteria adopted by some countries illustrating that the NEF 25 criterion adopted in Hong Kong was more stringent than some countries including USA and UK. He further added that countries like Canada and Australia were still adopting NEF contours. Subsequent to the last meeting on 30 July 1998, the Administration had conducted noise re-measurements in areas under the flight path, including Shatin, Kwai Chung, Tsing Yi and Ma Wan. The measured maximum noise levels ranged from 58.5 to 75.1 decibels. Preliminary assessment of the measured noise data confirmed that these areas, as forecast by EIA, were outside the NEF 25 contour and the noise levels were in compliance with international standards.

5. Some members remarked that the noise level readings referred to in the preceding paragraph were unconvincing as these failed to take into account the resonance between building blocks which would certainly aggravate the noise levels. A member was of the view that the Administration should adopt another system to evaluate aircraft noise as the existing use of decibel was more related to occupational disability than nuisance. Ag. PEPO clarified that NEF took into account the cumulative noise over a period instead of noise level of a single flyby.

6. In reply to the Chairman's question on mitigation measures for residents in Sha Lo Wan, the Deputy Secretary for Planning, Environment and Lands (Environment) (DS/PEL(E)) advised that measures which included installation of double-glazed windows and air-conditioners would be provided to owners of small houses and of licensed structures in Sha Lo Wan within the NEF 25 contour. However, in order to give villagers maximum flexibility, a lump sum cash payment in lieu of arranging the actual installation of such measures would be given. The District Office (Islands) was co-ordinating applications for compensation from villagers concerned. He assured members that the Administration would endeavour to offer as much assistance as possible to these villagers.

Flight paths

7. As to whether the Administration would consider using only arrival flight path for Runway 07 at night time to avoid overflying residential locations, the Deputy Director of Civil Aviation (Operations and Standards) (DD of CA/O&S) stressed that the time and frequency of the use of flight paths would depend on a number of factors such as actual weather conditions, wind direction and strength, aircraft operating criteria and runway conditions etc.

8. On approach procedures, DD of CA/O&S explained that aircraft would be informed of the landing flight paths when they were about 200 miles away from Hong Kong and came into contact with air traffic control units. Generally speaking, aircraft would have to use Runway 25 when the wind on the runway was from the southerly or westerly direction and Runway 07 when the wind direction was from the northeast and east. The flight path, once adopted, could not be altered on account of flight safety except under exceptional circumstances such as significant changes in wind strength. Although there might be cases where aircraft could choose to fly from a preferred approach so that they could reach the parking area faster, these would only be allowed without prejudice to air safety and when the traffic was very light in the early morning.

9. A member was not convinced that CAD should allow aircraft to choose preferred approaches for the sake of convenience on the one hand and insist on using Runway 25 without having regard to the interest of residents under the flight path on the other. He considered that there was a need to stipulate in law to prohibit the use of Runway 25 from 11:30 pm to 6:30 am except for specified circumstances with a view to alleviating the nuisance of aircraft noise to residents concerned. PAS/ES(NA) responded that both the approach and departure procedures for the airport were designed in accordance with international standards. Any choice of landing or take-off direction, whether for avoiding residential areas or operational convenience, must be subject to the prerequisite that it was safe to use the preferred direction at the time. The proposed restriction across the board would deprive CAD of the flexibility to take into account the actual circumstances in selecting flight paths and would have safety implications. It would also affect the overall operation of the new airport and its future development into a cargo hub.

10. On the suggestion of raising the aircraft vertical profile to higher altitudes to reduce the noise impact, the Acting Deputy Director of Civil Aviation (Administration) (Ag. DD of CA/A) illustrated the different alignment of flight paths using a set of transparencies. He explained that aircraft using Runway 25 for landing would come from the northeast direction and descend on a three-degree glide slope to the airport. Flight altitudes were fixed under the instrumental landing system. Aircraft would be descending through altitudes of 4,500, 4,000, 3,500 and 3,000 feet when they flew above Shatin, Kwai Chung, Tsuen Wan and Tsing Yi areas respectively to ensure adequate clearance of the hills in the surrounding areas such as Tai Mo Shan and Lion Rock. If the flight altitudes were to be raised, aircraft would have to dive steeply towards the runway which was not desirable for safety reason. Furthermore, the difference in noise levels would be insignificant for small elevated altitudes. Ag. DD of CA/A also ruled out the proposed use of the reversed departure track via Kap Shiu Mun for landing since aircraft would need to maintain a safe altitude of 1,000 feet above terrain. As there were hills on both sides of the proposed track and its buffer zone, aircraft would have to maintain a flight altitude of 3,000 feet in order to comply with the obstacle clearance criteria. Such an altitude was however 800 to 1,000 feet in excess of the normal descending altitude and therefore not acceptable from an air safety point of view.

11. On departure procedures, some members noted that departure flight path for Runway 07 would overfly residential locations in Kwai Chung and Tsing Yi. They asked if Runway 25 or the southern track could be used more frequently to minimize the noise impact. Ag. DD of CA/A advised that CAD had to take into account the wind directions and performance of aircraft in selecting the suitable flight path since the climb gradient of Runway 07 was steeper than that of Runway 25 on account of the need to ensure adequate clearance from terrain. Although the frequency of using Runway 07 and Runway 25 had yet to be ascertained, this would be approximately the same according to the consultancy report on the new airport master plan. He assured members that the planes would be flying 5,000 to 6,000 feet above Tsing Yi and there should not be any noise problem even if Runway 07 was adopted. For the proposal of using only the southern track for taking off, Ag. DD of CA/A considered it not feasible as this would bring all the departing and arriving aircraft into a congested airspace south of Lamma Island. The proposal would thus create conflicts between arriving and departing traffic at the southeast of the airport, thereby reducing safety and efficiency of airspace utilization. A member however pointed out that the problem could be solved by extending the alignment of flight path to further south in order to expand the airspace for accommodation of more planes.

12. A member questioned the rationale for using the northeast track for departure as this was initially intended for arrival flight path for Runway 25 only. Ag. DD of CA/A advised that those aircraft departing for the Mainland would make a turn to the north after attaining sufficient terrain clearance. As these flights would enter the Mainland airspace at Lok Ma Chau, they would overfly the New Territories, including Shatin, at high altitudes. He added that at present, about one-quarter of the total number of flights departing from Hong Kong operated to the Mainland. The member was dissatisfied that the public was not informed in advance of the flight path to China. DD of CA/O&S clarified that the landmark above Lok Ma Chau was agreed between the relevant authorities in Hong Kong and China, and that this had been used long before the airport was moved to Chek Lap Kok.

Second runway

13. Members noted that new flight paths would extend to cover a vast span of areas such as Tsim Sha Tsui, Hung Hom, Wan Chai and Central. They expressed concern about the impact of noise on residents under the new flight paths and urged the Administration to consult the residents concerned in advance. DD of CA/O&S took note of members' concern but advised that as all flights would be flying at least 3,000 feet above Tsing Yi, 4,000 feet over Tsim Sha Tsui and gradually climbing higher further out east, the impact of noise would not be significant.

14. To facilitate a better understanding on the alignment of flight paths, the Administration agreed to provide a set of transparencies presented at the meeting for members' reference. In view of the significance of the issue, the Chairman requested and the Administration undertook to report back to the Panel on the progress on reduction of aircraft noise in every six months' time. A member also considered it useful for a comparison between the noise levels in Kai Tak and Chek Lap Kok to ascertain the degree of nuisance.

(Post-meeting note : The set of transparencies was circulated vide LC Paper No. CB(1)155/98-99 on 3 September 1998.)

The way forward

15. Representatives of ANCC remained unconvinced of the Administration's assertion on using Runway 25 for landing at night time. They were dissatisfied that residents under the flight paths were not informed ahead of the nuisance of aircraft noise. The situation would be further aggravated after the opening of the second runway as the number of flights would be substantially increased. They also considered that there was a need for the Administration to commission an independent consultant to re-evaluate the alignment of flight paths and to take noise measurements for affected residents.

16. In response to the Chairman, PAS/ES(NA) reiterated that CAD had to take into account stringent requirements in regard to safety and design of flight procedures in determining the use of flight paths. Although efforts would be made to use Runway 07 for landing as far as possible under permissible circumstances, it would be impracticable to exclude the use of Runway 25. DS/PEL(E) did not agree that the Administration had failed to inform the public of the impact of aircraft noise. Information on flight paths and formulation of the NEF 25 contour had been released in 1991 and 1992. However, the focus of attention at that time was on the construction aspect. He stressed that the Administration was aware of the noise impact and had installed a noise tracking system to validate noise contours and collect specific noise level readings from dedicated and mobile monitoring stations. The resulting noise and flight tracking data would be used to identify and evaluate activities which resulted in noise complaints. The noise impact on residents under the flight paths had been tremendously reduced since then. PAS/ES(NA) supplemented that the Administration acknowledged the importance of independent views and had commissioned independent consultants to undertake studies on flight paths in 1991 and 1994.

17. In the absence of a quorum, the Chairman advised that the Panel would decide on the way forward on the subject of aircraft noise at the next meeting on 11 September 1998. Meanwhile, the Administration was requested to respond to the two submissions from ANCC.

(Post-meeting note : The Administration's response to the two submissions was circulated vide LC Paper No. CB(1)155/98-99 on 3 September 1998.)

II Any other business

18. There being no other business, the meeting ended at 12:55 pm.

Legislative Council Secretariat
4 September 1998