Is 1h 40m enough time to change planes at Heathrow?

I’m planning a trip to visit my brother, who’s spending a year in school overseas. The best price I can find on plane tickets involves changing planes at London Heathrow while traveling from the US to another country.

Anybody who has ample experience with Heathrow Airport, please tell me: Is 1 hour 40 minutes enough time to change planes in international travel at that airport, or would I be cutting things too close?

Under current security…you’ll never make it.

No. It wouldn’t even have been enough before the latest security increases.

Why the heck not? If the OP isn’t leaving the international area of the terminal, he shouldn’t have to go through security screening again unless he’s nabbed again at the gate, right? I hope?

Eva Luna, who has a 1 hr. 50 min. layover at Heathrow coming up in a month-ish

(On the other hand, I suppose there are worse places to be stuck than London.)

In my experience you can easily spend 90 minutes in the queue at the processing desk (what’s it called? FCC or something). The OP didn’t make it clear whether a change of terminal is also required. If so, you can throw in at least another half hour for that. I’ve had times when I’ve had three hours to get to my next flight and basically only made it because the next flight itself was running so late.

Well, the only time I’ve had to change planes at Heathrow, I had a 9-hour layover, so I went into London and then had to go back through security anyway. My flight is already booked, so I guess I’m going to find out the hard way.

(On the other hand, it’s my flight home, and there are a bunch of alternative routings from London to Chicago, so I guess if I miss that one it won’t be the end of the world.)

As I recall, all arriving passengers at Heathrow must exit the secure area immediately upon deplaning; those connecting to other flights must then be re-screened. The setup is quite different from any American airport I’ve been in.

In April 2006 my wife and I returned to Los Angeles out of Terminal 3 at Heathrow; for reasons not important here, we were on separate flights, four hours apart. We cleared security together and I walked her to her departure gate to see her off. Once you leave the monstrous duty free mall that is the waiting area there, you’re in featureless corridors that resemble the inside of the Death Star, and the only way out is to leave the security perimeter. I found this out after she headed into her gate’s dedicated waiting/boarding room. :smack:

I had to exit security and get re-screened to get back into the shopping/waiting area.

OK, it sounds like this could be a lot less fun than I’d hoped.

As bags are checked all the way through, and I understand that all bags must now be on the same plane as their corresponding passengers, what happens if a transferring passenger is delayed at security and doesn’t arrive at the gate in time to make the secind flight? Do they have to unload the whole plane then, or how does that work?

Maybe I should just call the airline, now that I think of it. But it’s too late now, unless I want to pay an outrageous sum of money to change the ticket (which I don’t). If I get stuck in London for a few hours, or even for the night, c’est la vie.

Good question - I don’t know, I’m afraid. As recently as this past July, I’ve travelled on a different flight from my bag after having a connecting flight cancelled, so I do sometimes wonder how much they really adhere to the rule. Of course, that situation was different in that (a) it was US domestic travel, and (b) it’s not like I checked a bag and simply vanished; American Airlines knew where I was and what I was doing.

Somebody who has been to Heathrow more than once is probably a better source here, but one thing I did notice was that when I got re-screened last April it was at a different location from the initial screening - one that appeared to be dedicated to connecting passengers. (?) It felt like a shorter wait for the re-screen, but my memory is pretty hazy. This was, of course, before the recent Ban On Damn Near Everything, so the relevance of my experiences may be … low.

I have managed to change terminals at Heathrow, and make my connection, in 1 hr 15 min. This was before the recent terror scare, though.

I have changed terminals in Heathrow six times in my life, and each time it took a little over an hour. Again–before this recent scare.

We traveled through Heathrow about a month ago - just a few days before the latest brouhaha - and IIRC, we had slightly under 2 hours for our plane change, including a bus ride from one terminal to the other. It is/was a close run thing, but not undoable if you don’t have to stop for paperwork.

We did not leave the plane-side area, but we still had to go through additional security - however, being in transit, we did not have to clear customs/immigrations.

Most of the transfer time was spent queuing up waiting for security checks, and people - including airport employees - were quite good about putting those under time constraints in front of the line.

If you’re reasonably quick on your feet and you don’t get handicapped by a delay on the incoming flight, I’d say go for it. Put the game face on, though - there’s little room left for mistakes.

The reason for rescreening every passenger, under the current security measures, is because incoming passengers may not have been subject to the same checks as those required of all departures from UK airports.

If you don’t make the connecting flight, your checked baggage will probably be unloaded. UK airports and airlines have been stricter about passenger-bag matching for longer than American ones, since the Lockerbie bomb.

I was there last year, changing from international to domestic. Flew in from Australia and changed to a domestic carrier to go to Edinburgh. We allowed 2 hours 45 minutes and that was sufficient. It will depend of course, if you have to change terminals- we had to do so by bus. Also if your luggage is booked through to your final destination. You don’t want to have to collect it and rebook it.

I would say- probably enough time. I’d play it safe though and get another flight an hour later.

Don’t you have to go through cutoms first and then on to your next flight? I thought the first thing I did two years ago was get my bags and go through cutoms, which took an hour or so. I know in the states you have to come through customs before the next flight.

Keep in mind that Heathrow is actually bigger than England. It actually sticks out over both sides.

True. And that Terminal 3 is actually closer to Ireland than England.

And the new tube route to Terminal 5 includes a stop at JFK, to make those international trips more convenient.

I’ve always left it up to the airlines to schedule, and figure they know how much time is needed. I’ve had hellish experiences at Heathrow (British: 'Eaffrow) where it’s taken two hours to change terminals, and I’ve had it go very fast, depends on which terminal from/to and the whim of the bus drivers if you need to take the bus.

Thanks for the opinions, all.

I didn’t say whether a change of terminal is required because the various travel web sites aren’t supplying that information this far in advance (I’m planning to travel about 5 months or so from now). So, standard planning is to allow for reasonable worst case scenarios. On that basis, a connection as tight as I described isn’t a good idea.

I think I’ll take the second cheapest ticket, which involves a 3 1/2 hour layover at Charles de Gaulle outside Paris.