Originally Posted by
SEA737
I fly LHR->LAX and LHR->DFW fairly often, and have never gotten pre-boarding interviews. Random bag checks happen but always just a handful of people.
Strange. On pretty much every US-bound flight I've flown (from LHR or elsewhere), there is usually a series of questions you have to answer before being admitted into the boarding area. At LHR, I've had questions at check-in, and they'll put a little sticker on the back of your passport (although it's been a while since I've checked in at the check-in desks at LHR, so not sure if they still do this).
Although I've experienced the "pre-boarding" screening questions at airports besides LHR, LHR is by and large the airport at which I've experienced the strictest security in general (strict scrutiny of liquid amounts, pat downs, etc.). This is probably more a LHR thing than a US-flight thing, though.