Traditional Chinese Simplified Chinese Email this article
LCQ18: Air pollutant emissions from aircraft

     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 20):


     At the meeting of this Council on October 20, 2004, I enquired if there were measures to reduce emissions from aircraft so as to alleviate the problem of air pollution in Tung Chung, but the authorities said that they could not confirm that there was a direct relation between air pollution in Tung Chung and emissions from aircraft.  Yet, some Tung Chung residents have relayed to me that with the growing number of flights operating at the Hong Kong International Airport in recent years, emissions from aircraft have increased correspondingly, affecting the health of 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 in each of the past three years, and list in table format a breakdown by the model of aircraft, as well as which models had the highest level of emissions, and what measures the authorities have at present to reduce emissions from aircraft of such models; and

(b) 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) Air quality in Tung Chung is affected by various factors, one of which is air pollutant emissions from aircraft.  Based on the aircraft arrival and departure data of the Hong Kong International Airport (HKIA) provided by the Civil Aviation Department (CAD), the Environmental Protection Department (EPD) estimates the annual emissions of civil aviation.  At present, we have estimated the emissions up to 2008.  Please refer to table 1 in the annex for the aircraft arrival and departure data of the HKIA and the annual quantities of air pollutants emitted from aircraft from 2006 to 2008.

     In 2008, aircraft emissions accounted for about 1%, 6%, 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 arrival and departure of such aircraft in a year, the type, size and number of engines used in the aircraft.  Even for aircraft of the same model, they may not have the same types and sizes of engines and therefore their levels of emissions could vary.  In general, bigger aircraft with higher arrival and departure frequencies will have higher level of emissions.  Please refer to table 2 in the annex for the percentage shares of emissions for different types of aircraft from 2006 to 2008 based on CAD's aircraft arrival and departure data of the HKIA.

     Whilst the actual air pollutants emissions from each commercial aircraft type may vary (depending on the aircraft size and passenger load), aircraft engines are required to follow the standards set out at Annex 16 to the Convention on International Civil Aviation (the Chicago Convention), Volume 2, Part III, Chapter 2 (Turbojet and turbofan engines intended for propulsion only at subsonic speeds).  This document specifies the standards for four types of emissions that an aircraft engine has to meet: smoke, unburned hydrocarbons, carbon monoxide and nitrogen oxides.

     The Chicago Convention and its annexes apply to Hong Kong.  CAD has been adopting their standards when certifying engines on commercial aircraft registered in Hong Kong.  It also allows commercial aircraft registered elsewhere to use the HKIA provided that they meet the standards at Annex 16 to the Chicago Convention.  All the engines installed on commercial aircraft have met the relevant standards.

(b) Whilst continuing to implement international standards in certifying aircraft engines, CAD has also implemented new air routes with effect from October 22, 2009, which have shorter travelling distances for arrival aircraft from the west and the north of Hong Kong.  Each flight coming to Hong Kong from the Mainland, South East Asia and Europe has been able to save up to about 210 kilometres in flight journey or 14 minutes in flight time.  The shortened air routes can reduce air pollutants emissions from aircraft.

     At the airport, the Airport Authority (AA) provides electricity powered fixed ground power (FGP) and pre-conditioned air (PCA) systems for aircraft at the parking stands to reduce the need for aircraft to use their onboard fuel combustion auxiliary power generation units.  About 70% of passenger flights now adopt the FGP and PCA systems.  In early 2011, AA will start a renewal and upgrade programme to improve the efficiency of these systems.  Upon completion in 2013, more than 95% of passenger flights will use the FGP and PCA systems.

Ends/Wednesday, October 20, 2010
Issued at HKT 15:05


Print this page