British Airways has extended its minimum connection time between flights at Heathrow Airport.
It has been increased from one hour to 75 minutes in an effort to reduce the number of passengers who miss onward flights.
The airline is hoping it will have to deal with fewer people stranded and requiring re-booking at great commercial cost.
But customers will have to put up with longer journey times in total, which could be a commercial disadvantage for BA.
Analysis by The Independent shows that passengers travelling from Nice to Los Angeles will no longer be able to arrive by lunchtime, with the first connecting flight from Heathrow Airport now arriving in California at 4.10pm.
Meanwhile, travellers headed from Berlin to Miami on a BA afternoon flight will have to leave 70 minutes earlier than before.
Rob Burgess, who is the editor of the frequent-flyer website Head for Points, said the move is not unexpected because "British Airways has been very public about its desire to reduce aircraft delays at Heathrow".
He said: "It would make more sense to tackle the root of the problem at Heathrow, however, rather than simply enforce longer connecting times."
Mr Burgess added that "BA is simply making itself less attractive to transit passengers" when many European competitors can guarantee much shorter connections.
British Airways said: "Following customer feedback, we're increasing the minimum connection time for some of our flights through Heathrow T5.
"This will give customers more time to make their next flight and reduce the risk of missing their onward service, which we know is incredibly frustrating."
It comes as travellers may face confusion about security rules in the UK this summer, as airports are reportedly set to miss a deadline for installing new scanner technology.
Operators have until June to introduce advanced CT scanners which would enable the 100ml liquid limit for carry-on luggage to be scrapped so passengers can take up to two litres through security.
It would also eventually mean that people would not have to remove laptops and tablets from their cabin bags.
But delays to the introduction of this technology at Heathrow, Gatwick, Stansted and Manchester airports are "almost inevitable", sources told The Times.
A source said: "It’s going to be a struggle for the big airports. One of the biggest issues they face is fitting the new scanners and retraining staff without impacting the flow of passengers."
Heathrow has already told the Civil Aviation Authority the changes will be "difficult to deliver" in time, according to the source.
The major airport, which has 146 security lanes, reportedly does not expect to complete the project until 2025.
But a spokesperson said it was spending £1 billion on the upgrades and was working "as quickly as practically possible".
