Hong Kong-Equally Challenging for Pilots and Air Traffic Controllers

Ask most pilots in the world if they have heard of Kai Tak and the answer will be "yes". Its' famous curved approach to Runway 13, close to the buildings and surrounding hills of the Kowloon Peninsula, is in aircraft simulators, both military and civil with every major operator in the world. Most airlines have very strict criteria before they will allow their crews to operate at Kai Tak. The Hong Kong Kai Tak International Airport was a unique airport in the world. Its most famous IGS approach and its closeness to the town make this little airport a well-known one. All pilots flying into Hong Kong need to have a special rating to land there.However, the Kai Tak has been officially closed(Sim Pilots can still fly in :)) on the midnight of 5th July 1998 due to the increasing air traffic demands, Hong Kong Chek Lap Kok International Airport took-over Kai Tak's roles already and started its operations on 6th July, 1998.

Responsibility

The Hong Kong Air Traffic Management Division is responsible for the provision of air traffic control, flight information service and alerting service within the Hong Kong Flight Information Region (FIR) and Area of Responsibility (AOR) as assigned by the International Civil Aviation Organization. The airspace covers a total area of 573, 000 square kilometres extending over the South China Sea to some 370 kilometres to the east and south-east and 1200 km to the south-west of Hong Kong.

The first flight into Hong Kong was by balloon at the site of the Happy Valley RaceCourse on January 3rd 1890. The first powered flight was made by a Belgian by the name of Charles Van den Born on March 18th 1911 in a Farman biplane at Shatin (about 3 N.M. North of where Kai Tak now is).

To keep up with the traffic demand there has been a continuing program of equipment upgrades here for both ATC and in the form of navigation aids. Current equipment includes Toshiba TW1253A Route Surveillance Radar with a range of 200 N.M., and Alenia ATCR-4T Approach Surveillance Radar with a 60 N.M. range. A Cardion Approach SSR and a Cossor long range monopulse SSR with a range of over 250 N.M. All radars are housed in domes for protection in Typhoons. In addition, at the airport there is a Thomson CSF digital Airport Surface Detection Equipment. This is very useful not only in bad weather but also on a day to day basis. The Control Tower at Kai Tak is adjacent to the beginning of runway 13 and quite close to the runway. This means that the tower controllers have no depth perception when looking at activity at the SE end of the runway. The ASDE allows them to determine whether for instance, an aircraft can make a particular taxiway after landing. All of the radars are fed through a radar display data processing system to amber monochrome Alenia DDS 80 displays. Viewing is in a darkened environment. This is because the Approach Radar is right next to the PAR, which because of the nature of the beast, must be viewed in a darkened environment. All positions in the ACC and Tower have access to displays of weather, current and forecast, a wind analyser and clearance and departure data. The Tower has a DFTI, ASDE, Wind Analyser with in-built wind-shear warning, RVR displays, touch screen lighting panel, Ceilographs for cloud base readings at the middle marker for each end of the runway and a voice synthesised ATIS.

The primary tracking aid here is the Cheng Chau VOR which is situated on the island of Cheng Chau 11 N.M. SW of the airport. Runway 13 is used about 90% of the time because of local winds as well as other factors eg. It has a longer operational length for departures ,which are over water, while the 31 departure is over the built up areas of Kowloon and requires a left turn as soon as the aircraft is airborne. The main approach flown by aircraft is the IGS (Instrument Guidance System) approach to RWY 13. To quote the AIP " The system uses ILS components but is offset from the landing direction by 47 degrees. Pilots on final approach on the IGS must therefore make a visual right turn to line up with the runway after reaching decision height. During this visual portion it is imperative that the correct visual cue with the surface is carefully maintained, making reference to aeronautical ground lights where appropriate.

In view of the local terrain and the IGS being offset from the runway, operators intending to use the system must ensure, for flight safety reasons, that their pilots are fully conversant with, and have adequate practice in, published procedures. The system is designed for the instrument flight segment of the approach to be completed not later than the Middle Marker when visual flight must be established or an immediate missed approach procedure initiated. After passing the Middle Marker the indications are not relative to the required aircraft visual and missed approach flight paths and must be ignored. WARNING- Continued flight on the IGS flight path after passing the Middle Marker will result in loss of terrain clearance."

In other words, you will crash into a hill. The hill where the IGS is situated is painted with huge orange and white checks and is lit at night. The site is known as the Checkerboard. The approach itself is very long (around 28 N.M.) if done in its totality and commences at Cheng Chau VOR. The aircraft flies west for 7 N.M. on descent to 6000', turns right on a track of 040, descends to 4500' and after another 7 N.M. intercepts the localiser at 4500', descends on the localiser until reaching the MM, at the MM turns right 47 degrees to line up with the runway. This final leg of the approach on the localiser to touchdown is around 14 N.M. Because of air traffic numbers these days, very few aircraft carry out the full procedure. Normally the Approach Controller will vector aircraft on to the localiser to have more control on spacing. At Hong Kong about 8-9 N.M. are needed between aircraft on final to enable to get a departure away in between. Because we have so many long-haul aircraft for departure and because of taxiway and holding point configuration, it takes up to 1 minute for a 747 to line up and up to 1 minute to get airborne when cleared for take-off. During that time an aircraft on final has gone 6 N.M. Now all that is needed is 1 runway length between the departure and the landing to be legal but the problem here is the missed approach. If an aircraft makes a missed approach, he must go out on the centreline and due to the surrounding terrain he cannot turn off the centreline until he is about 6 N.M. out. The lowest altitude you can hold an aircraft on missed approach is 2500'. One runway length is 2 N.M. Therefore if there is one aircraft which has just rotated and another goes around, you have two aircraft locked on the centreline with no radar, longitudinal, lateral or vertical separation and you can't turn either of them. If conditions are visual in this context it would be bad enough but Hong Kong is not known for its good weather so aircraft are spacd even further apart when weather deteriorates.

Departure off runway 13 is straightforward with the pilot simply departing straight out on the front beam of the 31 localiser joining a standard departure route. When the weather deteriorates to a cloud ceiling of 1000' or less and/or visibility of 5000 metres or less, all departures 13 and approaches 31 are monitered with PAR. This is to ensure that all pilots stay on the centreline as they pass through a gap 2nm off the end of the runway. Departure 31 is not so straightforward. For a start, the pilot has available a much reduced operational length. Just off the end of the runway is Kowloon City with buildings of up to 6 floors. Also, if the pilot flew straight ahead, he would go straight into the 2000' range of hills North of the airport. Therefore he turns left as soon as he crosses the end of the runway and tracks towards Stonecutters Island to the West. The pilot then turns further left and tracks towards Cheng Chau VOR and thereafter on to his planned route.