London's Heathrow Airport (LHR) is one of humankind's truly immense connecting points. The United Kingdom might be leaving the European Union, and there are larger airports, but LHR and British Airways -- its largest tenant -- converge the people of the world together at a single geographic point like few other institutions. In less lofty terms, LHR generally and Terminal 5 in particular also happen to be the closest thing to a sure bet for anyone who crisscrosses Europe and North America more than a few times in their life. Here's what you need to know when navigating through it.
I did some research after making that grand statement above, and found that (according to Wikipedia), LHR in fact is the third busiest airport in the world by international passenger traffic, the busiest in Europe by passenger traffic, and the sixth busiest airport in the world by total passenger traffic.
This place is big
Terminal 5 is the beautiful facility that most of British Airways (BA) at LHR calls home. The airline's close tie-ups with Spain's Iberia (they are effectively the same company), American Airlines (they are like the closest of cousins), and other OneWorld partner airlines only increase the likelihood that you will pass through. BA operates from other terminals, but this is the mothership.
The terminal consists of three large buildings in the form of the main facility, Pier B, and Pier C. They are connected with one another by underground train, to other terminals and to London itself via the Heathrow Express train or the London Underground subway. British Airways and Iberia (different airlines, same company) operate their flights within Europe from the main terminal, and use the piers for long haul international routes. No other airline operates from Terminal 5.
...and security screening is really big here
If you are transiting the airport in order to connect to a destination outside of the United Kingdom or Ireland, you will proceed to the connecting flights area that whose signs are clearly marked in purple. Don't try to reason your way out of this, for it is the reality that applies to a huge number of people. Be prepared to very immediately present your boarding pass and passport for inspection (premium class passengers and travelers with Ruby, Sapphire, and Emerald pass through a quicker fast track lane here). You'll then be shuffled in short order to the automated security screening lanes. The word "automated" is important here because these things work with a ruthless efficiency unheard of almost everywhere else. Here's how it works:
- Queue in line until there is an opening ahead of you, then scan your boarding pass to enter the screening area;
- Proceed on your own to an empty station where bins are waiting, do not queue at the same station as your companions;
- Place laptops and tablets in a bin; place toiletries, belts, and jackets in another bin, place your bags themselves in yet more separate bins;
- Walk through the human screening contraption once you’ve verified all pocket contents are in a bin as well.
If you've packed appropriately (i.e. you've binned everything out correctly, you have not packed an oversized bag of liquids, you are not trying to scam the system by imagining that chap stick isn't a gel, etc), you should be able to collect your belongings on the other side of the conveyor belt. If your stuff even appears to have broken any of these rules, the computer (remember, this is automated) will have the offending bin pushed off the conveyor belt and into a separate queue for manual screening. Collect your other paraphernalia and wait for your offending bin to be called for manual screening. Complaining will be frowned upon. Rule breaking does not yield rewards here, so pack sensibly.
An aside for those simply flying in to actually visit London or to connect on another flight within the United Kingdom or Ireland, you'll avoid the aforementioned-purple-signed connecting flights rigmarole and go direct to passport control. Have fun!
...so are ways to occupy yourself pre-flight
Once through security, welcome to the glistening cocktail of steel and glass, humanity, high end shopping, and (oh yeah…) flights to almost anywhere your heart desires that is Heathrow Terminal 5 proper. The main level houses the security apparatus through which you have presumably cleared, mostly small shops, and a Harrods store. The level beneath houses most of the gates for shorter range travel (i.e. elsewhere in Europe), and the third level contains the train to the other two piers on which you will find most of the gates for longer-haul travel). Like magical towers in the sky, airline lounges are up the escalators on the uppermost level above the security fray.
Don't waste time if you're under an hour to your next flight. There's a lot of ground to cover. Most flights will begin boarding about 40 minutes before departure. The smaller flights within Europe may board a bit later.
Consider shopping or lounging if you've got some time, though. Travelers outfitted with only Priority Pass lounge membership will want the Aspire lounge in Terminal 5A (the main building), while travelers with access to the British Airways Galleries lounges can find them on either far end of 5A, or in 5B. The BA lounge in 5B is the quietest. All are made of quality things, and all offer actual meals; Aspire offers massages. Remember that OneWorld Sapphire members and above can access the BA lounges (as an American Airlines Platinum member, I may bring one guest), but that groups in which only one traveler has OneWorld status will be better served by the Aspire lounge.
Further reading: How to get and use Priority Pass lounges to find peace, quiet, (free) wine, and food at the airport
As is typical when flying internationally, be prepared to show your passport in addition to your boarding pass before boarding. I've seen one too many passengers forget about this, only to cause a bottleneck as they fish through their bag at the final moment.