Article-Facts and misconceptions about the Three-Runway System (11.4.2016)

Raymond Li, Assistant Director-General of Civil Aviation (Air Traffic Management)

The Civil Aviation Department (CAD) welcomed the decision of the Town Planning Board (TPB) to submit the draft Chek Lap Kok Outline Zoning Plan to the Chief Executive-in-Council for approval to pave way for the implementation of the Three-Runway System (3RS) of Hong Kong International Airport (HKIA), which is essential to meet our long-term air traffic demand. I noticed that certain misconceptions were raised at the relevant TPB meetings, and would like to clarify as follows. 

Fact 1: To meet safety requirements, the maximum capacity of the existing two runways is 68 movements per hour

Some comments suggested that the maximum capacity of the existing two runways could reach 86 movements per hour if airspace were better managed. This appears a conjecture based on misinterpretation of the New Airport Master Plan (NAMP) commissioned by the then Provisional Airport Authority in 1992.

The NAMP report presumed that if the two runways were able to support an Independent Mixed Mode (i.e. two runways were used for both take-offs and landings at the same time as if they were two independent airports), the maximum capacity of the two runways could reach 86 movements per hour. Nonetheless, the same report clearly stated in its conclusion that, fettered by the surrounding terrain of Lantau Island, it is impractical for the two runways at HKIA to adopt this mode of operation due to incompliance with the safety requirements of the International Civil Aviation Organisation (ICAO), particularly in relation to the specific safe distance1 to be maintained between aircraft during take-off and landing (lest the aircraft might lose balance due to the air vortex generated by the aircraft in front). In other words, the capacity of the existing two runways is constrained by two major factors, namely, the HKIA’s surrounding terrain and the necessary safe distance between aircraft and, hence, it is impossible for the two runways to reach 86 movements per hour. Other subsequent international consultancy studies also reaffirmed this conclusion2

Let me draw a comparison between the HKIA and a train station. If there are only two platforms at the station and the trains have to operate at a fixed time interval at each platform, the maximum number of trains that this train station can operate is constrained. Without new platform, the number of trains to be operated by this station will never go beyond the limit even if more tracks are built to connect this station with other stations. The same applies to the two runways at the HKIA. Only by building an additional runway can greatly enhance the number of aircraft movements at the HKIA.      

Fact 2: Removing some small hilltops on Lantau will not enhance runway capacity

There were also views that the capacity of the two runways could be boosted if the apex of two small hills on Lantau Island could be removed. This misconception again probably stemmed from the aforesaid NAMP report. While the report mentioned about removing the peaks of two hills, which were 610 and 810 feet high, the suggestion was made in connection with possible options of lowering the climb out gradients for  departure aircraft in case of encountering engine failure. This has nothing to do with the runway capacity.

If we were to alter the surrounding terrain for the sake of increasing the capacity of the two runways, most of the high peaks on Lantau Island would have to be levelled to satisfy the relevant ICAO safety requirements. This would mean forgoing the Ngong Ping Cable Car, Big Buddha and Po Lin Monastery and part of the Lantau Country Parks, which do not appear acceptable to the community at large.

Fact 3: Unfounded claims that flight tracks between Hong Kong and Shenzhen will be in confliction

In as early as 2004, the Mainland, Hong Kong and Macao set up a Tripartite Working Group (TWG) to formulate measures to rationalise the airspace structure and air traffic management arrangements in the Pearl River Delta (PRD) region to optimise the use of airspace and enhance safety. The three sides jointly established a Plan in 2007 which has taken into account the operational needs of the 3RS at the HKIA as well as the development needs of Shenzhen and other major airports in the PRD region. Progressive implementation of the Plan will not lead to any conflict between the flight tracks of the 3RS and that of the Shenzhen airport (or any other airports in the PRD region). I have seen a graphic depicting the existing flight tracks of Shenzhen airport together with the flight tracks of the future 3RS, suggesting that the flight tracks are overlapping and unsafe. We treat this kind of misleading accusation very seriously as there is absolutely no question of the government compromising aviation safety in any manner. In planning the flight procedures and air routes, the CAD would strictly comply with the safety standards and regulations set out by ICAO, and would maintain close liaison with the Mainland aviation authority.

Fact 4: Shared use of airspace complies with the Basic Law

Some people alleged that the shared use of airspace between Hong Kong and Shenzhen may violate the Basic Law. This is absolutely groundless. As a matter of fact, ICAO has been advocating that air route structure and air traffic management efficiency, instead of national boundaries, should be the prime considerations in planning the airspace. This kind of airspace management methodology is a common international practice, for instance between Singapore and Malaysia, and between Germany and Switzerland. The High Court has earlier rejected an application for a judicial review in relation to 3RS. The complaint that the implementation of the principle of shared use of airspace under the Plan would breach the Basic Law is considered not reasonably arguable. The court also considered that even though the CAD would permit the Mainland authority to utilise a small portion of Hong Kong airspace to facilitate the air traffic control, and vice versa, the ownership of the concerned airspace still belongs to the original civil aviation authority.

The Central People’s Government supports the development of the 3RS at the HKIA

The State Council issued a guideline on March 15 on promoting co-operation within the pan-PRD region, which clearly stated that the Central People’s Government supports the development of the 3RS at the HKIA to reinforce Hong Kong's position as an international aviation hub and the closer co-operation between the HKIA and its neighbouring airports in the Mainland. The guideline also clearly supports the co-ordinated management and utilisation of pan-PRD airspace resources.

I sincerely hope that this article can help dispel people’s misconceptions about the 3RS.


1 Depending on aircraft types, the safe distance normally ranges from 4 to 6 nautical miles.
2 Namely the Airspace Design Consultancy report conducted by the Washington Consulting Group in 1994 and the Airspace and Runway Capacity Study by the British Aviation expert, NATS, in 2008