Boeing's long-awaited 787 Dreamliner became a commercial reality on Sunday when the U.S. planemaker signed a final contract to deliver the world's first lightweight composites jetliner to its Japanese customer.

Boeing says the plastics-based structure will generate 20 percent fuel savings for All Nippon Airways and other airlines, and give passengers a more comfortable ride with better cabin air and large, electronically dimmable windows.

The aircraft was handed over three years behind schedule after persistent delays that cost Boeing billions of dollars.

It took a lot of hard work to get to this day, said Scott Fancher, vice president and general manager of the 787 program.

Just about an hour ago we transferred ownership of the first 787 to All Nippon Airways, he said at the outset of two days of celebrations at the plane's Seattle production plant.

The $200 million long-range aircraft, which boasts a graceful new design with raked wingtips, will leave for Japan on Tuesday and enter service domestically on October 26.

Boeing has taken orders for 821 Dreamliners, which will compete with the future Airbus A350, due mid-decade.

The much-anticipated handover came a week after another major first delivery -- the 747-8 Freighter -- was abruptly postponed because of a contract dispute with the customer.


Boeing has never disclosed the amount of money spent to develop the Dreamliner, but experts estimate the program is billions of dollars over budget.

The Seattle Times reported on Sunday that 787 program costs had topped $32 billion. That estimate raised questions, the newspaper said, over whether the revolutionary jetliner would make money for Boeing before well into the 2020s, if ever.

After a series of glitches in bringing the airplane into service, Boeing also faces a challenge in reaching its target of lifting production to 10 aircraft a month by 2013, analysts say.

First delivery is the end of a long and painful road for Boeing, aerospace analyst Scott Hamilton said.

They have never had a commercial airplane program that has had this many problems, so yes, it is a milestone but the challenges aren't over yet. Boeing still has to achieve a smooth production ramp-up and still has to do rework on some 40 airplanes that it says will (take) years to complete.

Boeing has declined so far to say how many aircraft it needs to sell to break even. If it is 1,200, they should make money; if it is larger than that it could be challenging, Hamilton said.

The planemaker, meanwhile, is locked in a legal dispute with one of its top labor unions in Washington state, where it has traditionally built its aircraft.

The International Association of Machinists and the National Labor Relations Board have accused Boeing of building a non-union 787 assembly plant in South Carolina to punish the IAM for past strikes.

Boeing denies that claim, saying the jobs in South Carolina represent new employment, not the relocation of existing work. The issue has become a political lightning rod, with Republicans denouncing the Democratically controlled NLRB as being unfriendly to U.S. companies.

(Additional reporting by Kyle Peterson, Editing by Dale Hudson)