I'm looking at a connecting flight from Zurich through Heathrow onto the U.S., which would mean a transfer from T5 to T1. The layover time is 1 hour 55 minutes, but it took me well over two hours to transfer through T1 only the last time at Heathrow. The Heathrow website says that you have to transfer via the Heathrow Express or the Underground and that either take about 20 minutes. If you've connected through Heathrow recently, is 1 hr. 55 min. enough time?
" transfer via the Heathrow Express or the Underground". That is for landside transfer - which means you have to go through immigration at T5, collect your bags, if any, make the journey, check-in and then go through security at T1. I doubt you can do all this in the time you have. Instead, you want an airside connection - which is by bus between the two terminals. The recommended time for this is 90 mins, so you would be okay. Obviously you need to have the correct paperwork for your T1 departing airline (although if you need to swap this at T1, there are airline desks after "transferring passengers security" where you can).
In my opinion it is very likely not enough time and I would not be comfortable with it. I fly in and out of Heathrow about 6 times a year. Even if a flight lands on time, it will be some time before you are in the terminal, a minimum of about 20 mins. Then you have to get through one terminal before getting to the other, remembering checkin will close at T1 at least 30 mins before. I wouldn´t risk it.
Just the advice I need! Thanks to both of you. Cheers!
Check United / Lufthansa through Frankfurt if possible. Frankfurt is somewhat easier than Heathrow. My rule at Heathrow is 2.5 hours no matter what the connection. I just made a 1 hour connection from Budapest to Houston in Frankfurt last week. Yes, it was by the skin of our teeth but it would have been impossible at Heathrow.