Hi all,

This past week or so I was looking at some old photos and travel logbook entries from a family trip to Greece in the summer of 2010. My grandparents, sister, and I flew British Airways BOS-LHR-ATH in late-June. I was hoping some of you out there could help me figure out our flight connection experience at London-Heathrow, Terminal 5. Given the fact that I was 15 years old at the time, my memory is somewhat limited (OK, maybe not) and my old logbook/photos are about all I have to go off of, more or less.

One summer evening we flew BA 212 from BOS to LHR, leaving BOS around 1800 and landing in LHR about 0530 local that next morning. Aircraft was the almighty Boeing 747-400, but that experience (my first and last time on a 744) deserves a thread of its own.   We landed in LHR and disembarked though a very LONG airbridge into a rather quiet and dark terminal. We were greeted with those friendly "Yellow and Purple" signs, directing us to International Arrivals and Flight Connections, respectively. About all I remember from that "journey" was that we walked for what felt like miles through long hallways, monstrous escalators, and more big hallways before reaching our first sign of life. This was what (if I remember correctly) appeared to be a Flight Connections area, with a departure monitor posted at its entrance. At the entrance there was also a sign that said something to the tune of "If your connecting flight is listed here, please proceed. If your connecting flight is NOT listed here, or if you are remaining in the UK, proceed down the escalator." We looked and sure enough, our connecting flight, BA 640 to Athens, was not listed. So back on the march we went, continuing to follow the purple signs.

Going down the aforementioned escalator, we arrived at a train station, also with more departure monitors. This time our connecting flight WAS listed. We boarded the train for a (rather short IIRC) ride before disembarking at the next station. Then guess what? More big escalators and hallways! Next pit stop was what appeared to be a UK Passport Control and Customs facility, as well as a Flight Connections area. We headed for Flight Connections, had our connecting boarding passes scanned, then went upstairs to a security screening checkpoint. Upon clearing security we overlooked the massive departure lounge of Terminal 5.

All told, a fairly simple process and probably not quite as confusing as we all seem to remember, likely given the fact that we had just gotten off an international redeye with little sleep the night before. Probably smoother than most international connections at other airports!

Once our connecting flight (BA 640, on an A320) was assigned gate A19, we went for a short walk down the terminal, found our gate, boarded the flight and then headed off to ATH at around 0815 local.

Now... After doing some research, here is my understanding of our process:

Our flight from BOS arrived at Terminal 5 - B...probably a ways off from the main departures area.
The "fork in the road" before riding the train was for passengers who's connecting flight is leaving out of B.
The train ride took us from Terminal 5 - B to Terminal 5 - A.
Our connecting flight was leaving out of Terminal 5 - A, hence no further "transportation" necessary.

Am I on the right track here? (pun intended)  

Now for the return trip, ATH-LHR-BOS, 2 or so weeks later. Very similar process, just much shorter this time.

We landed in LHR on BA 641 (another A320) around 1630 local and followed those familiar purple signs to Flight Connections. No train ride this time, just a walk down a hallway. Upon arriving at Flight Connections our experience was exactly the same as it was last time - documents check, security screening, etc. Our flight to BOS, BA 239 on a Boeing 777-200, was departing out of gate A10a. Following the signs to A10 we took an elevator (er, I mean, lift) down to the ground level of the terminal.

The was no aircraft parked there, rather just a shuttle stop. I was a bit surprised that they bused us out to a 772. I found the long bus ride itself to be quite unpleasant and crowded, but of course as soon as we got the aircraft, boarding that monster via stairs was pretty cool! We were on our way back over the Atlantic about 1930, local.

Now, my understanding on this one:

Our flight arrived in Terminal 5 - A, hence the lack of a train ride.
Our connecting flight was boarding out of Terminal 5 - A, however the aircraft itself was parked somewhere rather far from there.

In doing some further research on here:
RE: LHR Terminal 5 (by LHRjc Oct 21 2008 in Civil Aviation)
How Does Heathrow T5 Gate Assignments Work? (by LAX888 Jan 11 2012 in Tech Ops)

I found that smaller aircraft and intra-Europe flights operate out of Terminal 5 - A, and larger aircraft (international 744s, 772s, etc) operate out of Terminal 5 - B. (In 2010 when I was there, Terminal 5 - C was still under construction.) Therefore...

Our BOS-LHR aircraft parked at B.
LHR-ATH out of A.
ATH-LHR into A.
LHR-BOS out of a remote stand.

...Right?

One last question I had was regarding the train that connects A, B, and (at the time) what-would-be-C. It would seem as though Heathrow uses a system along the lines of something called the "Spanish Solution" for loading and unloading. For some reason riding airport trains is almost as fun as the actual flying for me, so I wanted to check out the train at LHR on our way back to BOS. However, at the station there was a sign that said something along the lines of "Do not ride this train unless your flight is departing from the B/C gates." I guess that was good enough reason for me, so I didn't ride it. In doing further investigation on this, apparently there is no "easy" way to get back to A without going through Flight Connections again? Anyone know about this? I was looking for a map of how the train at LHR works, but no luck.

I'd greatly appreciate hearing from any "LHR experts" out there on any of the above. Or in general, any further information on passenger flow within this castle of an airport would be great!

What I can add to this:
- your interpretation of your movements between B & A gates is correct.
- gates are assigned at relatively short notice, particularly during disruption. So unlike US airports, so you are never given advance warning that "your connecting flight will leave from B42" for example when you arrive at the B or C gates. As a result there's only relatively few flights, in the next 90 minutes or so that have a gate, or even "will depart B/C gates" advertised. I was once lucky enough to do that, arriving from LCA into the B gates and guessing that my connecting flight to GRU would also go from B (as there is only one B747/777 gate in A, and C hadn't opened at the time, but still, ground staff had to confirm). And yes, the "fork" in B takes you back into B. I can't remember if I had to go through security - it's 5 years ago now - I would imagine I did.
- so therefore the vast majority of pax go back to A and either enter the UK or go through connections, which puts you back in the A gates departure area, where you are expected to spend your money in the plethora of mediocre shops.
- most short haul flights arrive at A gates, but I've seen A320 family aircraft at B and C in the past. UK Domestic arrive at low numbered A gates (although they can depart from anywhere) and pax obviously exit without going through passport control. A4 is the remote departure gate for UK domestic. I've been on at least one internal flight that has arrived at an international gate, and one international flight that has arrived at a domestic gate - the solution to both of these being a bus.
- Until the C gates were completed, there were an awful lot of long haul flights that were boarded remotely. And they always seemed to be mine. Mostly 777s (I remember remote boarding for EWR, MIA, GIG, DFW, ORD amongst others) but also one time on a High J B747 to HKG - needless to say there were a number of passengers in F who were fuming about this. It clearly still goes on both for long and short haul, and is in some respects a less than desirable process, but I think is a function of the extreme duration of the construction planning process and the growth of the airline during that period. On the upside, you generally board earlier and, I think, quicker - and if you know where to stand on the arrivals bus, then you can be first off and in passport control in seconds, very little walking at all. Since C opened, I've not boarded/arrived on many long haul flights remotely. I think arriving from ALA two years ago was the last time.
- And I think you're pretty much right on the train as well. I've never tried to get back to A having gone to B or C for a departing flight, but in any case the "return train" does not let passengers out into the departure area without going back through security for connections. I would imagine if you were in the departure area and asked someone, they would let you into the arrival area so you could get back. But clearly, the desired process is for passengers to stay at A until a gate is announced. A cynic would say this is because the shops in B and C are very limited, but also so is space and there is only one lounge in B (which isn't up to much) and none at C compared to the 4 at A gates.

In my experience of Heathrow T5 it's always best to avoid the escalators and take the lifts. You wait a bit longer initially but then go directly down to the trains or up to the gates. Less hassle and much quicker than the multiple escalator trip.

In the early days of T5 I quickly learned to dread hearing my outbound flight had been assigned to gate A10. That is in fact the bus stop for a remote stand. Most of my flights seemed to be from there.

Two words: bloody awful!