I'm certainly not saying the whole system isn't broken, just trying to explain my little bit of it
5nm from in excess of 100nm out, HK is one example
Interesting, a few follow on questions if I may?
- is that for unrestricted descent or step descent on top of preceding traffic?
- what speed control if any?
- is that straight in or onto downwind?
- what typically is the time from latest possible landing clearance to clear of runway?
PS re profiles, speed is only half the issue, alt is the other. For example, a domestic 737 10-12 miles behind an international A330 can easily be 10,000' higher. In practice you need considerable difference in IAS to match ground speeds.