Connecting flight at London Heathrow

First, is this one ticket or are you buying a separate ticket from Dublin to LHR? If the former, this is pretty straightforward. I'd advise against the latter. You definitely will not have to go through immigration. I also think this is a rare case where you won't go though security. Usually at LHR, connecting passengers go through a security check. However, since you are coming from DUB, I think this might be skipped due to the agreements between the UK and Ireland. The Heathrow website shows step by step instructions for flight connections (based on destination, terminals involved, etc.), so you can check there and see. The Heathrow website will also show the minimum connection time. If you are buying separate tickets, you need to allow more time. Personally, I wouldn't take the risk. I've missed connections twice at LHR due to my inbound flight arriving late. In each case, I was coming from the States. In each case, I was put on the next flight to my destination and arrived just a few hours late.

Here is the Heathrow connections site
www.heathrowairport.com/heathrow-airport-guide/flight-connections/connection-guides Note that there are special instructions as you go through the steps for Aer Lingus passengers.

It is a separate ticket. Actually it's the second leg of open jaws flight #2 connecting to the second leg of round trip ticket #1. Doing it this way saves me about $600 and let's me leave Dublin at10am instead of 6am! If I schedule it as a multileg flight (through the United website), it still connects at LHR, using Aer Lingus from Dublin to LHR, then United from LHR to O'Hare. But there is only 1:10 provided to transfer from the Aer Lingus flight to United at Heathrow. I don't care what Uniteds website shows......that's too close for me! For some reason, none of the websites have a later combination at a reasonable price using a code share. I am contemplating buying my own Aer Lingus ticket and giving myself 2 hours to connect at LHR. I realize by disconnecting the two flights I may have an issue if flight 1 is delayed. Just considering options. Thanks

If you buy it as a single ticket and the leg from DUB to LHR is delayed and you miss the return flight, the airline is responsible for getting you back to ORD. If you buy a separate ticket and your DUB to LHR flight is delayed, they have no obligation to get you back to the U.S. I've bought a separate ticket to save money, but I've always buffered it by spending the last night in London to minimize the risk of missing my flight home. Have you already bought the R/T to London?

I haven't purchased it yet, just looking at the options. Still curious as to how long I should allot for an airline transfer at LHR Terminal 1.

I did this last spring at terminal 1..... United landed at the far end of one arm of the terminal and the connection was at the far end of another arm..... about a 35 minute walk that included a couple of security check points en route. I'd say a minimum of 90 minutes between flights.

Thanks......the airline has given me 65 minutes IF the flights are on time............I think that is cutting it too close. I will arrange for different flights.