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LCQ11: Reduce aircraft's air pollutant emissions

     Following is a question by the Hon Albert Chan Wai-yip and a written reply by the Secretary for the Environment, Mr Edward Yau, at the Legislative Council meeting today (October 19):


     At the meeting of this Council on October 20, 2010, I asked the authorities about the various levels of emissions from aircraft movements and aircraft parking at the Hong Kong International Airport in each year between 2007 and 2009 and whether the authorities would take measures to reduce emissions from aircraft so as to alleviate the problem of air pollution in Tung Chung and hence reduce the impact of such emissions on the health of Tung Chung residents. The authorities, however, could only provide data on emissions from aircraft from 2006 to 2008. The authorities also advised that measures had been taken to reduce emissions from aircraft. Yet, residents in Tung Chung have still relayed to me that the number of flights operating at the Hong Kong International Airport has been growing constantly in the recent three years and emissions from aircraft have also increased correspondingly, hence worsening the air quality in Tung Chung and affecting the health of the residents in the district. In this connection, will the Government inform this Council:

(a) whether it knows the various levels of emissions from aircraft movements and aircraft parking at the Hong Kong International Airport from 2009 to 2010, with a breakdown in table form by the model of aircraft, as well as which models had the highest level of emissions, and what measures the authorities have at present for reducing emissions from aircraft of such models;

(b) whether there is any relation between the worsening of air quality in Tung Chung and the increase in emissions from aircraft; if so, to what extent the increase in emissions from aircraft has led to the worsening of air quality in Tung Chung; if not, of the reasons for that; and

(c) whether it will take new measures to reduce the impact of emissions from aircraft on the health of Tung Chung residents; if it will, of the details; if not, the reasons for that?



(a) The aircraft arrival and departure data of the Hong Kong International Airport (HKIA) and the air pollutant emissions related to aircraft movements from 2009 to 2010 are set out in Table 1 in Annex. We have also set out the data for 2008 in Table 1 in Annex to give Members a clearer picture of the trend.

     In 2010, aircraft emissions accounted for about 1%, 7%, 1%, 1% and 3% of the total emissions of sulphur dioxide, nitrogen oxides, respirable suspended particulates, volatile organic compounds and carbon monoxide in Hong Kong respectively.

     The total quantities of air pollutants emitted from individual models of aircraft depend on a number of factors including the numbers of their arrivals and departures in a year, the type, size and number of their engines. Even for aircraft of the same model, they may not have engines of the same types or sizes and could have different quantities of emissions. In general, bigger aircraft with higher arrival and departure frequencies will have greater quantities of emissions. The percentage shares of emissions for different types of aircraft from 2009 to 2010, based on aircraft arrival and departure data of the HKIA released by the Civil Aviation Department (CAD), are set out in Table 2 in Annex.

     Air pollutants emissions from different types of commercial aircraft vary with the engine design, aircraft size and passenger load. The CAD has adopted the standards set out at Annex 16 to the Convention on International Civil Aviation (hereinafter referred to as "the Chicago Convention"), Volume 2, Part III, Chapter 2 (Turbojet and turbofan engines intended for propulsion only at subsonic speeds) to certify engines on commercial aircraft registered in Hong Kong. This document specifies the standards for four types of emissions that an aircraft engine has to meet, namely, smoke, unburned hydrocarbons, carbon monoxide and nitrogen oxides. Commercial aircraft registered elsewhere also meet generally the standards set out at Annex 16 to the Chicago Convention. Aircraft that meet the international standards for aircraft emissions can use the HKIA so as to ensure that all the engines installed on commercial aircraft meet those standards.

(b) Air quality in Tung Chung is affected by various factors, one of which is air pollutant emissions from aircraft. Over the past three years, the air pollutant concentration data recorded at the Tung Chung general air quality monitoring station bore evidence of air quality improvement in Tung Chung. Except for a slight increase in ozone concentration due to regional photochemical smog, there were reductions in the concentration of sulphur dioxide, nitrogen dioxide and respirable suspended particulates.  Please refer to Table 3 in Annex for details.

(c) Since October 22, 2009, the CAD has implemented new air routes which shorten the travelling distance for aircraft approaching from the west and north of Hong Kong. Hence, a flight to Hong Kong from the Mainland, South East Asia and Europe can save up to about 210 km in flight journey or 14 minutes in flight time. The shortened air routes and the reduced flight time can help reduce aircraft's air pollutant emissions. In 2010, a total of 57,000 flights adopted these shortened routes.  Besides, the CAD will continue to implement international standards in certifying aircraft engines, and to closely monitor and follow the international requirements in this respect.

     At the airport, the Airport Authority (AA) provides electricity powered fixed ground power (FGP) and pre-conditioned air (PCA) systems for aircraft at parking stands to reduce the need for aircraft to use their onboard fuel combustion auxiliary power generation units.  Aircraft using these systems can substantially reduce their emissions of air pollutants and carbon. About 80% of passenger flights have now adopted the FGP and PCA systems. In mid-2011, the AA further launched a renewal and upgrade programme for these systems, thereby making FGP system more readily available for use by aircraft. The upgraded PCA system will adopt a new refrigerant and a more efficient system to reduce the emissions of air pollutants and carbon. The works are due for completion in 2013, when more than 90% of passenger flights will use the FGP and PCA systems.

Ends/Wednesday, October 19, 2011
Issued at HKT 12:40


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