Staff at the UK's biggest airport face one of their busiest days yet as thousands of Olympic athletes jet home.
The competitors will be among 116,000 people who will depart from Heathrow, 21,000 more than a typical day.
The total number of people due to exit the country through the airport is close to the record of 123,000 departing passengers set on July 29 last year.
Around 6,000 athletes were able to check their bags through at the Olympic Village in east London last night. They will leave Heathrow with around 9,000 other people who played a role in the Games.
The athletes have their own specially-constructed Games terminal, which is the size of three Olympic swimming pools. It has 31 check-in desks and security lanes.
Athletes are expected to depart with more than three bags per person, including outsize sporting equipment.
They will arrive by coach and be treated to a special London-themed send-off, the details of which Heathrow operator BAA is keeping a closely-guarded secret.
No aircraft will depart from the Games terminal. Instead, athletes will take a coach to their final departure point where they will mingle with regular passengers as they wait for their flight.
Athletes will be clapped into each terminal by a guard of honour made up of Heathrow volunteers. After three days of operation, the terminal will be decommissioned and the site returned to its original use as a staff car park.
BAA chief executive Colin Matthews said: "Heathrow is proud of the part we have played in making London 2012 a success. We hope that Olympic athletes, spectators and officials enjoyed a great welcome to London.
"Olympic departures present a fresh challenge with new facilities like the Games terminal being used for the first time. We have been preparing for seven years to deliver a farewell of which the whole country can be proud."
A spokeswoman for Gatwick Airport said extra staff would be on duty, adding the airport had been preparing for the Olympics for two years.
"There are some particular challenges, such as the large number and size of the athletes' bags," she said.
"But we are used to dealing with a similar number of passengers during the busy summer period."