This is interesting:
ARRIVALS & DEPARTURES
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.. OCL for the approach is 660'.
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. By the way, at Hong Kong we need about 8-9 N.M. between aircraft on final to enable us 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 we need 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 we have 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 we space aircraft 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, we monitor all departures 13 and approaches 31 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.