Heathrow bosses are warning passengers of ‘initial teething problems’ as the new Terminal 2 opens its doors today.
The first passengers will pass through the £2.5 billion terminal which is opening in phases, with only 10 per cent of its full capacity being reached today, to avoid repeats of the calamitous Terminal 5 opening six years ago.
A spokesman said: “Heathrow is confident but not complacent about the opening. We recognise that there will inevitably be some teething problems in the first few days.
"We will be focused on identifying and resolving issues as quickly as possible to deliver a smooth journey for passengers.”
American carrier United Airlines is operating the first flight - a service from Chicago that is scheduled to reach Heathrow around 5.55am.
There will be just 34 flights to and from T2 today, involving only 6,000 passengers.
By autumn more than 20 airlines will have moved in and traffic will be flowing at the rate of 330 flights a day to 50 destinations.
It is all in stark contrast to the T5 first day, when there was travel chaos, with flights badly delayed, huge queues and thousands of bags going missing.The debacle led to two British Airways' chiefs - operations director Gareth Kirkwood and customer services director David Noyes - leaving the airline.
Eventually providing a home to 26 airlines, including Virgin's domestic operation Little Red, T2 boasts 60 check-in gates and 66 self-check-in kiosks, 29 security lanes, 33 shops, 17 restaurants, more than 7,000 seats, 634 toilets and 42 water fountains.
Facilities also include a John Lewis store and a Heston Blumenthal restaurant.
It replaces the old Terminal 2 at Heathrow which closed in 2009 after 54 years of service.
More than 180 trials for T2 have taken place over the last six months involving 14,000 volunteers. As many as 100,000 bags have already passed through the T2 baggage system, with peak loads tested at 4,000 bags per hour compared with an expected peak of 2,500 bags.
Every person working at the terminal has been required to participate in familiarisation and training sessions with more than 1,700 sessions taking place.
T2 is officially named Terminal 2 The Queen's Terminal. After today's operational opening, the Queen and the Duke of Edinburgh will officially open T2 on June 23.