Paralympic competitors are flying into Heathrow in large numbers on the busiest day for competitor arrivals at the west London airport.
It is also the first day of the Paralympic Games lanes coming into force.
British Airways is flying in Paralympic teams from 25 countries, including ParalympicsGB, who are thought to be arriving at Heathrow next week from their training camps abroad.
Along with the athletes, BA is also transporting around 300 wheelchairs and sporting equipment such as firearms, weapon bags, physiotherapist cases, bike boxes, tandem bikes, bow and arrows, and hand cycles.
BA operations director Andy Lord said: "It has been a mammoth operation that we have been planning and preparing for since the 2008 Beijing Games, when we flew Team GB and ParalympicGB home on a gold nose aircraft. It is a privilege to fly thousands of athletes into London for the Paralympic Games and follows on from the great service we delivered for the Olympic Games."
The first Paralympic Games lane is between junctions 3 and 2 on the M4 which takes traffic from Heathrow into central London. It will be in operation each day as needed from 5am to 10pm, with "ordinary" traffic able to use it outside these times.
The M4 lane is part of a much smaller Games lane operation than for the main Olympics with just 8.7 miles of special lanes for the Paralympics which start next Wednesday (August 29) and end on September 9.
The lanes are part of the Paralympic Route Network (PRN), which, in turn, is much smaller than the 109-mile Olympic Route Network. Apart from the M4 lane, the PRN will not come into force until next Wednesday. It will be focused on the City of London where the International Paralympic Committee and the world's media will be based and on venues in east London.
On most days, the number of people travelling to the Olympic Park will match that of the Olympics, with up to 215,000 spectators expected.
London Mayor Boris Johnson said: "The Paralympic Games are shaping up to be the best ever as London continues to buzz with Olympic excitement, and Paralympic tickets are selling like hot cakes."