Thousands of people will act as passengers to test out a new £4.3 billion terminal which will open at the UK's biggest airport in exactly one year's time.
Around 16,000 volunteers will be used to check facilities at Heathrow's Terminal 5 (T5) which will undergo six months of proving trials before its March 27 2008 opening.
The new terminal, a new home for British Airways, will serve around 30 million passengers a year.
The first flight to be served by the new terminal will be a BA service from Hong Kong. The passengers arriving from the Far East will be the first of around 40,000 to go through the terminal on its first day of operation.
Work on the terminal began in 2002 after a lengthy, record-breaking four-year public inquiry.
It has been built on a former sewage works at the western end of the airport. It will have platforms to serve both the Heathrow Express and London Underground's Piccadilly line. There will be two platforms to serve any future new Heathrow rail link to the west.
Shops at the terminal include a Harrods, and celebrity chef Gordon Ramsay will open his first airport-based restaurant there.
Heathrow chief executive Tony Douglas said: "London is a world city, a global financial centre and needs a world-class airport.
"T5 is already a testament to the skill and hard work of the thousands of people, including architects, planners, construction workers, airport and airline staff, who have together made the building happen.
Mr Douglas said 68 million passengers would fly through Heathrow this year "in ageing terminal facilities designed to accommodate around 45 million".
