梁繼昌是會計界功能組別議員。梁議員在2014年10月15日在信報引用中大幾年前有關香港機場空中交通控制的研究報告，引申攻擊港府不敢向中方爭取開放內地低空空域。中大研究全文見下面連結
http://www.bschool.cuhk.edu.hk/research/aprc/activities/files/AirSpace.pdf
要注意梁議員曾捲入立法會議員攜同親友接受國泰航空公司免費超豪歐遊醜聞。
梁議員全文如下
又到我在信報專欄〈專業為公〉的時間了！今個星期與大家談「空牆」。
「空牆」是指，內地軍方對本港進出航班所實施的航空管制。我在文章指出，當局要向公眾交代「空牆」對本地航空交通流量的影響，否則難以說服市民支持發展「三跑」。
全文如下：
//現時有關香港國際機場興建第三條跑道（下稱「三跑」）的爭議中，在環保和生態因素之外，另一個爭議重點是現時進出中國空域的高度限制（俗稱「空牆」），對香港的航班升降量和進出航道的影響。如果當局未能全面向公眾交代「空牆」對本地航空交通流量的影響，實未能說服香港市民「三跑」對香港的長遠發展有何益處，並將在往後的社會討論中引起更大爭議。
「空牆」是指中國內地軍方對本港進出航班所實施的航空管制。在「空牆」的影響下，現時香港航班須要爬升至15700呎才可以進出香港空域，由於民航客機不能於短時間內加速爬升至上述高度，因而在進出內地空域前需採取一條較迂迴的向南航道繞圈，以確保飛機有足夠時間爬升。
值得留意的是，1992年公布的新機場規劃總綱中原先規劃香港以北的空域作飛機進場和離場之用，但機場落成至今，相關的航道仍未啟用。有意見指出，增加向北的航道，能令離港航機更快地進入內地空域，從而減少在香港上空盤旋和繞圈的時間。故此，當局有必要向社會交代現時向北空域未能使用的原因，而向北航道未能如計劃般運作，又是否與現時「空牆」的限制有關？
「空牆」除了有機會對香港可使用的空域造成限制外，亦會對現時以高度分隔航機飛行的航空交通管理造成影響。一般民航客機的進場和離場高度層大約在25000呎以下，但由於「空牆」因素把香港進入內地的空域限制至15700 呎，明顯局限了香港航班進場和離場時可使用的空域，導致飛機不能使用較低的高度進入內地空域，因而限制了香港機場的實際航班處理量。
其實，「空牆」問題並非一件新鮮事，亦非只有民間才提出質疑。2007 年11 月8 日《明報》的一篇報道中，已曾引述當時國泰航空行政總裁陳南祿的說法，指香港機場航運擠塞嚴重，而進入內地空域的高度限制影響空運效率，應盡快解除，否則興建「三跑」亦屬徒然。同時，陳南祿亦估計每班航機在解除「空牆」限制後，可節省25分鐘的繞圈時間，並同時節省燃油和減少污染。如果有航空公司高層多年前已提出相同關注，是否進一步引證社會對「空牆」問題的質疑，值得當局重視和回應呢？
現時政府和機管局就興建第三條跑道所提出的論點，仍有很多不確定因素。尤其在空域管理的問題上，社會掌握的資料和討論仍然不足。筆者同意空運業對香港經濟發展的重要，但對一個耗資千億的工程，我們應該對項目的實質限制和環境影響，進行充分討論，以確保公帑運用能符合社會整體利益。//
香港空域概要圖 (取自上述中大報告)
下面是梁議員向港府質詢有關機場的文件：
LCQ14: Air traffic movements at the Hong Kong International Airport
************************************************************
Following is a question by the
Hon Kenneth Leung and a written
reply by the Secretary for Transport and Housing, Professor Anthony
Cheung Bing-leung, in the Legislative Council today (October 15):
Question:
It
has been reported recently that quite a number of flights have been
delayed in taking off from or landing at the Hong Kong International
Airport (HKIA) due to the implementation of air traffic flow control by
the mainland authorities. There have also been press comments pointing
out that the People's Liberation Army Air Force requires that an
aircraft departing from Hong Kong must reach an altitude of over 15 700
feet before it enters the mainland airspace (such altitude restriction
is commonly known as the "sky wall"). The sky wall has lengthened flight
times and prevented the existing two-runway system of HKIA from
optimising its operation efficiency, thus affecting air traffic
movements. Besides, some concern groups have recently pointed out that
the northbound routes recommended in the 1992 New Airport Master Plan
have still not been opened. In this connection, will the Government
inform this Council:
(1) of the number of times the Airport
Authority or the Civil Aviation Department was notified by the mainland
authorities of the implementation of air traffic flow control (broken
down by mainland airspace over which air traffic flow control is
implemented) and the total number of hours of delay in aircraft arrivals
and departures caused by such control since 2010;
(2) of the
number of flights which were delayed in taking off from or landing in
Hong Kong due to the implementation of air traffic flow control by the
mainland authorities, with a breakdown of the number by flight
destinations and its percentage in the total number of aircraft
movements, in each year since 2010, set out in Table 1;
(3)
whether it conducted any study in the past three years on the effects of
the "sky wall" on the number of aircraft movements; if so, of the
details; if not, whether the authorities can undertake to conduct the
study and publish the results; and
(4) of the reasons why the northbound air routes have still not been opened?
下面是官方答案：
http://www.info.gov.hk/gia/general/201410/15/P201410150241.htm
Reply:
President,
Our reply to the various parts of the Hon Kenneth Leung's question is as follows:
(1)
and (2) The Civil Aviation Department (CAD) has been monitoring closely
the situation of delayed departure flights for the Mainland. The
statistics from 2010 to September 2014 are set out in Table 2.
Separately,
CAD does not have any breakdown on airspace control implemented by the
Mainland or on the destinations of the delayed flights, nor the
statistics regarding delayed arrival flights from the Mainland.
(3)
To make sure that aircraft in adjacent airspaces could operate in a
safe and efficient manner, an aircraft must reach a certain altitude
before an air traffic control (ATC) unit may hand over the control in
respect of that aircraft to another ATC unit. This is to ensure that
when aircraft in adjacent airspaces fly in opposite directions, they
could keep flying at different altitudes to prevent collisions. This air
traffic management arrangement for flights to be separated by altitudes
seeks to safeguard flight safety, and is commonly applied by busy
airports all over the world, including those in London and New
York. This arrangement has no direct relationship with the time
interval and space separation between runway movements, and hence does
not affect runway capacity.
Given the close proximity
between Hong Kong International Airport (HKIA) and its Shenzhen
counterpart and the fact that the two airports are separately managed by
two ATC units in Hong Kong and the Mainland, an aircraft departing from
HKIA must reach the designated handover altitude of 15 700 feet before
it can enter the Mainland's airspace. This designated altitude
requirement is also applicable to aircraft flying from the Mainland into
Hong Kong's airspace. After discussing with the Mainland's ATC unit,
the two sides have
since 2005 lowered the handover altitude from 15 700
feet to 12 800 feet during specified non-peak hours at night (that is,
from 11pm to 7am the following day), thereby minimising detours made by
aircraft.
(4) In accordance with the international standards and
recommendations promulgated by the International Civil Aviation
Organization, the development of flight paths should take into account
the terrain environment, runway alignment, the prescribed obstacle
clearances, airspace coordination with nearby airports, and so on.
Due
to the constraints presented by the
high mountains around HKIA, and
after giving due consideration to the relevant factors above, the two
runways of HKIA are operating under an independent segregated mode of
operations (that is,
the North Runway is used exclusively for arrivals
and the South Runway exclusively for departures), and
it is not
necessary to use flight paths north of the airport under this mode of
operations.
According to a runway capacity analysis for HKIA
in 2008 conducted by the UK aviation consultant, the National Air
Traffic Services, which is commissioned by the Airport Authority Hong
Kong, the practical maximum capacity that can be achieved by the two
runways of HKIA is 68 movements per hour. Over the years, through
continuous improvements to flight procedures and operations, and efforts
to optimise airspace structure as well as to increase the manpower of
air traffic controllers and upgrade infrastructural facilities at the
airfield, the CAD has gradually increased the capacity of the two
runways in accordance with air traffic demand, from 50 movements per
hour in 2004 to the current 65 movements per hour. The CAD will continue
to further increase the capacity of the two runways to their practical
maximum capacity of 68 movements per hour in 2015.
Ends/Wednesday, October 15, 2014
Issued at HKT 12:30
