British Airways cancelled 54 scheduled flights in and out of London Heathrow's expensive new terminal on Saturday, signalling a third day of travel misery for travellers.

"British Airways plans to operate 293 out of 347 scheduled flights to and from Heathrow Terminal 5 tomorrow," the airline said in a statement. "All long-haul flights from Terminal 5 will operated as planned."

Sixty-eight flights, 20 percent of the total to and from the 8.7 billion dollar (5.6 billion euro) terminal were cut Friday, the same as on its opening day Thursday.

The problems have been blamed on the supposedly state-of-the-art baggage handling system, which had to be shut down because of computer glitches, as well as problems getting staff on site.

BA chief executive Willie Walsh, who admitted earlier amid growing anger that Thursday "was definitely not British Airways' finest hour", tried to put a more positive spin on events.

"We've had a better start today," he said in a statement. "While there are still some problems to overcome we are planning to operate a larger proportion of our flying programme tomorrow (Saturday)."

The terminal is the first new addition for 20 years to Heathrow, one of the world's busiest airports, west of London.

Opened by Queen Elizabeth II this month amid great fanfare, it descended into chaos Thursday.

Long queues built up and some passengers flying into the terminal had to wait so long to be reunited with their luggage that they gave up, and asked for their bags to be sent on.

Staff reportedly complained they had not been trained to use the check-in machines and luggage systems in the new terminal, which is only used by British Airways.

Some passengers had to spend the night on the floor of the terminal.

A 15-year-old schoolgirl, Katharine Crane, said she risked missing an important school entrance exam because of the delays.

She said: "I need to get to Brunei where my father lives to take this exam so we were flying via Hong Kong today. We still don't know if we can get on a flight tomorrow so it looks like I'm going to miss it.

"If I don't take the exam, I can't go to the school."

Her mother, Teresa Crane, said: "They haven't practised before they took the public in, that's the problem to my mind. Hong Kong airport has always run so successfully, why can't the British do the same?"

Other passengers said they saw little sign that the problems were being solved.

Tony Pascoe, 35, from Oxfordshire in southern England, said he was unable to check-in to take a flight to the Austrian capital Vienna with his mother, despite arriving at the terminal at 4:00 am (0400 GMT).

"None of the desks were open and we were told to stand in a queue. After standing there for God knows how long they opened one and people who had just walked into the terminal began jumping in," he said. "It was chaotic."

Thousands of volunteers had been used to test the terminal over the past weeks.

Terminal Five, the size of 50 football pitches, has been 15 years in planning and construction and is designed to handle 30 million passengers a year.

Heathrow, used by a total 68 million passengers a year, has for years been plagued by overcrowding in its collection of ageing buildings due to soaring demand for air travel.