Time is tight on my US connection. What happens if it all goes wrong?

Q&A: Travel unravelled

Q. You recently wrote that British travellers could face long waits at US immigration this summer, because of American government cutbacks. I believe Dallas was one of the worst airports for waits. In November we're flying non-stop with BA to Phoenix, but coming back on a combination of American Airlines and BA via Dallas-Fort Worth. We have only 85 minutes between arriving from Phoenix and leaving for London. What happens if we miss the connection? Name withheld

A. Relax: you are pretty certain to make the connection, because when you leave the US there is no Customs and Border Protection check. As The Independent has reported, lines for US immigration are certainly getting longer this year (see bit.ly/USQ2013 for the full story).

But that is only when you arrive in America from abroad. Coming home, you should be issued with boarding passes for both flights at the American Airlines check-in desk at Phoenix when you arrive for your noon flight to Dallas-Fort Worth.

While "DFW" is a huge airport, transfers between American arrivals and BA departures are usually smooth. When you touch down at Dallas, you will not need to clear passport control – nor even undergo another security search.

The Transportation Security Administration regards anyone who has just arrived on a US domestic flight as being "clean" from a security perspective. (Britain does the same, eg, if you arrive at Heathrow from Edinburgh, you don't need to go through security before an international flight.)

The chance of a delay from Phoenix is low; weather problems are rare. But should airline staff know your plane is going to be late, they may route you to Heathrow via another city, such as Chicago, Los Angeles or San Francisco. Or you may be switched to the last American Airlines flight from DFW to London, giving you several more hours' leeway. But in the event of a long delay, you should energetically try to persuade them to book you on the non-stop BA flight nine hours later. Any non-stop hop is less tiring and stressful than a connecting flight.