LAX-London British Airways Terminal 5

In my experience, Terminal 5 is very large, there's a lot of walking, and incoming passengers must go through another security screening before getting on another flight. It's well marked, and great that you have carryon luggage only.
Have a great trip!

Terminal 5 is by far the best terminal at LHR. Lots
of places to eat or pick up food to go. I always hope we will land and take off from there.

All the below assumes that you are travelling on one ticket and not two.

Firstly, whilst BA uses T5 for the majority of its flights some do go from T3 as well, so you need to check that.

Secondly a flight from LAX will almost certainly come into B or C concourses. If the Rome flight goes from T5 it will most likely go from concourse A, but it may go from B or C.

2.5 hours is plenty of time whatever the situation. Minimum connection time in T5 is one hour and between T5 and T3 90 minutes.

Go this website:

http://www.heathrow.com/flight-connections

Plug in your flight information and it will give you step by step instructions of what you have to do to make the connection

There’s also a train that goes from A to B to C and back, so you won’t be walking all the way.

The odd thing about transferring at Heathrow is, even though you were thoroughly screened before getting on your original flight and you've never been in an unsecured part of Heathrow, you still have to go through a TSA-style security check before being allowed to enter the terminal. And their rules are just different enough from TSA rules that you need to carefully read all posted signs and then, be prepared to be asked to do or not do stuff that contradicts the signs. Makes life interesting.

Also at Heathrow is the first time I saw directional signs posted with arrows and walking times, it's like something you would see on a trail in the Berner Oberland. But actually useful so you know if you can walk or have to run.

Terminals 5A, B and C are separate buildings. There is a fast and frequent underground train that connects them. As Johnnw52 said, your flight from LAX will likely come in to either B or C. Your gate for the next flight will likely not be posted yet when you land, but even if it is you cannot go directly there; you have to go through security, and for that you must go to 5A for the security for arriving passengers.

It is all very clearly signposted. When you get off the plane, follow the purple “Flight Connections” signs. NOT the yellow signs to “Arrivals”. You will go down escalators to the train platforms and go to T5A. Once through security, you will be in the large Departures area with lots of shops and some restaurants, including a Wagamama. Wander around and keep checking the Departures boards for your gate to be posted. Once it is, go directly to the gate—you may need to get back on the train to B or C.

Others have mentioned the trains, and they are the default pathway. But I’ll just offer that walking is also an option. (And maybe a welcome one, if your first flight arrives in time or even early, and you’d like to stretch your legs.)

The UK makes you go through security if you are arriving from a non-UK airport and connecting. But it's fairly quick.

I'm in and out of Heathrow quite often. It's really not as bad as people make it out to be.

If you use the website I listed above, you will have no surprises when you land.

Security is also not that bad. They are thorough and strict about your toiletries bag, electronices removed--anything bigger than a phone--and of course the stuff you can't take through anywhere. They also prefer you use a plain ziploc style bag for toiletries--they supply them when you first enter the security area or will hand one to you when you get to the machine--over any other fancy 3-1-1 bag. (I like Heathrow's. They have handles.)

https://www.heathrow.com/at-the-airport/security-and-baggage

If you are wearing a belt it has to come off but in most cases shoes stay on.

The USA makes everybody go through their own security too, even at preclearance airports where the passengers would have just been through one set.

The logic of the CAA at Heathrow is that passengers will have commingled on arrival & transfer so you would be taking on trust the security standards of everywhere in the world as items could have been passed from one person to another.

If you are reasonably mobile ignore the shuttle provided to get to 5A and use the lower walkway instead. This will be quicker most of the time, unless you didn't have to wait for a train.

Many, many thanks to everyone who offered great suggestions and ideas. My anxiety level has come down a few notches!

Based on what has been written, I think we're going to be ok. I'm just glad we are arriving and leaving from the same terminal, hopefully :)

Thank you all once again, have a great Thanksgiving!

Scott

As mentioned in above post about strict security, be sure that you take the items in carry-on like liquids and tech items out and put in bins. If you forget and they find those on xray, you get called aside and they go thru the items one by one and question you. I know from experience. There were people begging for them to hurry so they did not miss connections. But security personnel were unfazed by the pleas and took their time.

I am doing a short layover in London this March and am already planning on having my minimal amount liquids in totally clear plastic bag. And in a place that I will not forget about it, like a tote bag or purse rather than inside carry-on suitcase.

I arrived at Heathrow Terminal 5 on Thursday. Regardless of which building you arrive, you will have to go through security in the main terminal (A).

They were testing two lanes where you didn't have to take anything out of your bags at all.

I was originally on that line but was directed to another one where, I believe, they had a group of trainees. I got one who was so inept, so stupid, so brain dead that I actually got angry with him because I knew what the problem was--I forgot to take off my watch,--yet he wouldn't listen. He was so bad that while frisking me--the second time-- he literally pushed by pants down to my ankles. That got him more nervous and didn't understand why his wand kept beeping. I kept saying the watch and he didn' know what to do. Finally, he turned around to look at someone and then said "I could go."