Your information is quite out of date - remote gate arrivals are (at least sometimes) bussed to TBIT for a walk to customs and immigration at T4 (using the same walkway that used to be used to get people from T4 to TBIT baggage claim). In fact if you try to get off the bus and go into TBIT, the security folks will not let you through.

I don't know how all the different configurations work, but having arrived on LHR-LAX twice now at remote gates, I know that those flights went through T4 customs and immigration via buses to TBIT first.

LHR-LAX generally arrives at T4, or at remote gates - and I'm pretty certain you'll go through Customs and Immigration at T4 and then you would use the TSA-Pre lane in T4, rather than walking back to TBIT.

Last time I arrived at TBIT (before T4 had all the facilities - about 6 months ago) the TBIT security lanes only had pre-check-Lite, but since they also never have anyone waiting, it is still quite quick. However, I've never found the T4 pre-check line to be anything other than quick too (but maybe I'm just lucky).

Just to verify because I want to be there the second she comes out :-), picking up daughter, coming in to Gate 43 today from LHR, has GE and one gate-checked bag (darn BA at EDI). She will come out on the lower level at T4 on the side nearest TBIT?

That has been my experience arriving international at T4, yes.

Thanks, we just arrived there less than a month ago out of NRT, but we had no bags and dumped out there and my memory was hazy about them having possibly pointed us a different way with no bags.

AA109 yes... it usually will arrive during the time T4 immigration is open.
AA135 maybe... it sometimes arrive after T4 immigration is closed. The last 2 times I took 135, I ended up walking to TBIT immigration.

Currently projected to arrive at 4:39 so fingers crossed. Same parking either way I guess.

You should be OK.

For future reference AA135 did indeed come out at T4 international arrivals. Her bag did not, it seems to have decided to stay in London.

Well at least the important piece made it home!

That's terrific to hear! I last landed at T4 back in the summer, and we had to do the long walk, and further back was bussed from T4 to TBIT (wow is that annoying).

Back when the T4 facilities closed, I'd read (on FT) that AA had to pay to staff it. I wonder what made them decide it was worth it again?

In the past, after clearing immigration/customs at TBIT, I always went outside and walked to T4 to take advantage of Pre-Check.

Good to know TBIT now has Pre-Check, as walking outside is unpleasant due to people smoking.

I wonder why? Maybe has something to do with the cost?

I don't think it is cost. Sometimes there are delays so the gates the flight is assigned to is not available. It is then usually up to the crew to request alternate gate or... wait. The alternate gate could be the remote pad. And the airlines also has operational consideration... if they need the airplane to turn for another flight in a few hours, they will tell the crew to wait. If not (e.g. plane will rest overnight), they let the crew ask for alternate gate. And that's how you end up at the remote LAX parking gate.

Sorry if I wasn't clear. I was wondering why AA would bus from a hard stand (remote gate) to TBIT and then have people walk to T4 to clear customs and immigration, per @SeattleDavid's report that I quoted. I wasn't wondering why AA would use a hard stand/remote gate.

I am going to guess that the TBIT buses are not AA operated and only go from remote gate to TBIT bus gate. Those buses are not supposed to go to T4.