This is an interesting topic.
The actual runway separation standards used worldwide are pretty standard (I think!), but the application of them, it appears, is not.
In the US you can get a landing clearance when there are five (or six or seven - where does it end?) ahead of you. It appears that at certain UK airports (but not all, am I correct?) you can get a "land after" clearance.
In Australia we are not permitted to issue a landing clearance until you are next to use the runway - ie the runway is clear and the standard met. A small amount of anticipation is allowed to avoid late landing clearances when it is assured that the standard will be met. What's a small amount? It's not defined, there are no guidelines. One uses the sensible exercise of professional discretion, which is based on training, experience and circumstances.
Where I work (Sydney) most runway operations are mixed-mode (ie arrivals and departures on the same runway) or crossing runway operations. Most times traffic demands mean that the gaps between arrivals are minimal - just enough to accommodate a departure, be it on the same runway or a crossing one - meaning that on a routine basis the minimum runway separation standard is used and the arriving aircraft will not get a landing clearance until quite late.
One mile final is not unusual, in fact it's common - ie the landing a/c is just crossing the threshold as the departing gets airborne beyond the expected roll-out or, on crossing runways, crosses the runway intersection - in which case the landing clearance will be issued not far short of the threshold, when achievement of the standard is assured.
We quite often get adverse comment from aircrew, particularly internationals, usually British or United along the lines of "That's too close, tower."
In the case of landing behind a departing, eg a B737 landing behind a departing 747, we occasionally get complaints from the landing crew of "wake turbulence". It's not wake turbulence at all, of course, it's residual thrust turbulence at the threshold. The landing standard takes no account of that. Should ATC? To what degree? (Personally, I do with a lightie behind a medium or heavy jet. But not with any other combination.)
These are ICAO standards. Is the ICAO standard insufficient, or do other airports play it "not so squeezy" so aircrew don't get to experience the real minimum elsewhere? I doubt that. I hardly think that United pilots are not exposed to the minimums in their home environment, so why the apparent surprise out here? Or British for that matter - they fly to high density airports all over the world as well.
Thoughts, anyone?
AA