While most carriers say they will put 550 or so passengers in the A380, the craft is certified to carry up to 853 — about twice the capacity of the biggest version of the Boeing 747.

Even though American carriers are not buying the craft, the A380 will be flying in American skies. International carriers are planning to use the plane for flights in and out of Kennedy, O’Hare, Dulles, San Francisco and Los Angeles. Eventually, Miami, Orlando, Dallas and Denver may also see A380s.

For airports, the sheer size of the plane represents both a challenge and a solution. Its wingspan is almost as long as a football field, and it is eight stories tall, meaning airports have had to come up with special double-deck gates so that passengers can enter the plane on two levels.

Because airports are concerned about congestion both in the air and on the ground, anything that increases the number of passengers without increasing the number of flights is welcome.

“It’s not desirable to have more flights, but it is desirable to have more people,” said William DeCota, director of aviation for the Port Authority of New York and New Jersey, which operates airports in the New York region, including Kennedy.

At the moment, many have been spending millions of dollars to make the changes needed to accommodate the A380. New passenger gates must be built. In some cases, runways or taxiways must be moved or expanded. Taxiways over highways at some airports need to be strengthened to carry the additional weight.

Over the last few months, Airbus has sent the A380 to about 40 airports around the globe to generate publicity and give rides to local officials and the media. The flight in Washington this week will carry members of Congress, their staffs and other government officials.

Part of the reason for the demonstration tour is to see whether the plane can actually fit at gateway airports (and to prompt airports that are lagging to speed up their renovations). At night, airports will test how the plane maneuvers at gates and how it negotiates taxiways and clears buildings.