As a UAL pilot, let me assure you that there are NO foreign pilot bases. On occasion, we have had pilots based overseas on a TDY (Temporary Duty) basis, but since the LHR 727 days, nothing has been permanent (and in all cases, the pilots have been US citizens). Finally, there has never been a BKK pilot base (we had a cabin crew domicile at one point), and we do not qualify our pilots on both the 747 and 777 at the same time (closest is gets is the 757/767 and A319/A320). Hope that helps!