Originally Posted by aussieinsf
No - you can connect between any two intl. flights in BKK without clearing immigration - it may be a 15-20 minute walk between terminals though - but it is all airside.
Dedicated security for each "pier" of gates makes security lines more managable also.
I would suggest BKK for the transit - rather than SIN - for this reason. I've done DEL//BKK-NRT-SFO before with similar timing - it was fine.
If I don't have a UA boarding pass (due to illegal connection), where would I get one in BKK? To get to regular check-in counter means long-lines at passport control. And I'm not sure that they will let me through security to get to the gate. Besides there is a 500 bhat airport tax that I'd have to pay somewhere. Any clue on where I would pay this?