British Airways cancelled one-fifth of its flights from Heathrow Airport's new terminal Friday as confusion surrounding the building's grand opening stretched into a second day.

Many passengers spent the night camped out in the London airport's new Terminal 5 after dozens of flights were cancelled on Thursday, the first day it was open to passengers.

Young passengers rest as they wait in the departures area at Terminal 5 of Heathrow Airport Friday.
(Matt Dunham/Associated Press)

British Airways, which has exclusive rights to use the $9-billion terminal, said passengers would be able to check baggage on Friday after restricting them to hand luggage on Thursday.

The airline also apologized for the chaos that marked the opening day.

"I am very sorry that the problems have meant that some of our customers did not experience the true potential of this amazing new building," British Airways chief executive Willie Walsh said in a statement issued late Thursday.

"This is not our finest hour."

The airline has offered to refund tickets or allow passengers to rebook if their flights were affected by the delays.

Chaos marks opening

Reports from the terminal Thursday pointed to a scene of mass confusion.

Seven flights left the terminal without any checked baggage on board. Customers were given vouchers to stay at hotels, but the coupons didn't cover the full cost of many hotels.

Some staff were unable to find parking lots or work stations, others didn't know how to operate check-in computers and baggage carousels became clogged with suitcases.

At one point in the day, all check-ins stopped throughout the entire terminal.

"The terminal looks nice but it would be better if it worked," said Vincent Groccia as he killed time waiting to see if his flight for Paris would depart late or be cancelled. "I tried to check my bags but they told me the conveyor system is not working. I'm hoping to get out of here tonight."

Passenger Sarah Lowdon, whose flight to Newcastle was cancelled, said she's "not a happy bunny."

"They said they'd refund my money, but the time I've lost is mine. They said it was because of baggage problems, but all I have is a carry-on. I'm being penalized for their mistakes."

With one of the worst records for flight delays in the world, Heathrow officials had vowed the new terminal would help cut baggage loss by 50 per cent within a year.

The delays marred what had been promoted as a milestone day in British aviation.

Officially opened by Queen Elizabeth on March 14, the new terminal took six years to build. It is home to dozens of luxury shopping boutiques and high-end restaurants.

Roughly 35 million people are expected to pass through the terminal each year.

With files from the Associated Press