connecting flight time with a change of terminals at LHR

One hour is not enough. Could you give us the flight numbers because I can't find a pair with that tight a connection..

Unfortunately American is notorious for schedule changes.

The minimum connect time for transfers between terminals is 90 minutes, so this will not work.

https://www.britishairways.com/en-us/information/airport-information/flight-connections

Call AA and tell them you need a different flight out of Heathrow, not to Luxembourg but to another airport with more frequent flights so you won't have to wait 11 hours. There should be other major airports from which you can easily reach Trier by train.. Maybe Munich? Or Stuttgart? Look up the travel times by train from these to Trier, and then look up the flight schedule to that airport on British Airways. It is best to have something in mind when you call to ask for ( or demand) a different flight.

Frank, my flight numbers are AA050 (American Airlines flight 50) DFW-LHR departing 5/17 & arriving 0655 5/18; and BA flight 416 departing at 0755 to LUX. I will investigate flights from LHR to other cities with trains to Trier.

If your original purchase was a single ticket, DFW to LUX, with a change in LHR and AA changed the arrival time, it is their problem to help you find a solution to get you there. Call them and ask for help.

As others have mentioned, call American and ask to be rebooked. Frankfurt would be my suggestion, (Stuttgart and Munich are both further away from Trier). And Frankfurt being a major hub means there should be no shortage of flights between Heathrow and Frankfurt. Even better if they can rebook you on their direct flight to Frankfurt, not having to transfer in Heathrow is always a huge advantage.

There should be other major airports from which you can easily reach Trier by train.. Maybe Munich? Or Stuttgart?

Frankfurt or Cologne would be the next nearest airports to Trier after Luxembourg. And both have train connections.
Or even Düsseldorf.

This is very simple and it will be free of cost.

First, go online to the American Airlines website and search for 2 to 3 itineraries with plenty of connection time that will work for you between DFW and your final destination airport in Luxembourg. The connecting airport may not necessarily be Heathrow. Or, it may mean finding an earlier flight from DFW to Heathrow giving you more time. Keep in mind, British Airways is also an option between DFW and Heathrow besides American as they are codeshare partners in the same alliance. So that earlier flight could be on American or British airways. Again, pick 2 or 3 itineraries that are acceptable to you.

With that information, you call American Airlines customer service and explain to the agent very politely what your original itinerary was and how American and not you made a change giving you only one hour at LHR.

You tell that person that one hour isn’t enough given your mobility. You then offer the 2 or 3 itineraries as a SUGGESTION which gives that agent less work to do and the agent may be very appreciative that you did the work for him or her. If the agent on the phone is rude or simply non-accommodating, thank the person, end the call, & call back to speak with another agent. Do this as many times until you speak with an agent who makes the change for you.

I think it would be a lot simpler to ask to change the one flight ( DFW to LUX) to a different flight and airport, than ask to re-work the whole itinerary. The current flight does not meet the "minimum connect time" for connections requiring a transfer between terminals, so it must be changed. Since the ultimate destination is Trier, Denise does not require an itinerary that gets her to Luxembourg.

While I see what you’re saying, Lola, as far as American Airlines is concerned, the destination is Luxembourg. That’s it. They may not work out an entire new destination free of cost even with their change to the transatlantic flight.

Thank you all for your help. AA does have a DFW - LUX flight leaving at 2155 arriving LHR at 1 pm. That would mean only a 5 hr layover before the flight to LUX. I could walk around the airport & get some exercise. I’ll work on that tomorrow. My brain is tired!

Problem solved. American rebooked my flight. Now flying DFW to Frankfurt, then will catch a Flexibus from the airport to Trier, ~ 3 hr trip. I should have done this in the 1st place. It helps to talk things out, though. Again, many thanks to y'all who responded.

Great result! Sounds like they were willing to be very flexible and you actually got a better flight ( direct to Frankfurt, no layover).

Now you can relax and look forward to your trip.