Originally Posted by
atflyer
That is what I wrote (LON-AMS-SFO is non schengen - non schenge) but I would say even IF you would clear immigration (sorry for using customs) and you had an EU-AMS-SFO even that is doable.....
It might be what you meant, but it's not what is written.
You need to pass customs but there usually are short connection lanes if busy.
I understand what you mean now. Agree an hour is fine, even if was coming from a Schengen country.