Originally Posted by
mapletree
You'd think they would only want to do pre-clearance at airports where there are very few flights to the US. Otherwise the system would be over-run. An AMS or FRA or other hub would never survive the mad rush. Unless...they play it like the Canadian airports and dedicate a whole terminal.
The beauty of DOH is that there are a finite number of flights to the US so it's much easier to control.
It's not really a totally separate terminal in Canada though per se; it's just a "sterile area" separated from the rest of the terminal. There's also a very different risk profile (IMO anyway, from a US perspective; debating whether there's an ACTUAL risk profile difference is an entirely other matter) for flights from Canada than flights from Europe, the Middle East etc. That may also influence the number of pre-clearance facilities the CBP wishes to maintain, or the size of them. So this may be part of the reason why LHR, AMS, aren't really pushing for it.
Further, you have to talk the front line agents into living where they pre-clear for a few years at a time and sort out a visa class / immigration policy which lets them work in the country that wants it.
So there's a lot that goes into it - airport design, immigration / legal exemptions, staffing, technology, risk profile, etc. It'll be interesting to see if this flies - if so then maybe AUH and SNN are a couple small tests before offering a "if you pay for it we will come" kind of service?