EVERETT, Washington (AP) -- More than a decade after its last all-new airliner took to the skies, Boeing Co. is poised to unveil the first of its prized 787s on Sunday.

Airlines, leasing companies and other plane buyers have ordered more than 600 Dreamliners over the last few years, eager to hold Boeing to its promise that the midsize, long-haul jet will burn less fuel, be cheaper to maintain and offer more passenger comforts than comparable planes flying today.

It will be the world's first large commercial airplane made mostly of carbon-fiber composites, which are lighter and more durable than aluminum.

Final assembly of first 787 started in late May, after a gigantic, specially outfitted superfreighter started flying wings, fuselage sections and other major parts to Boeing's widebody plant, where they essentially get snapped together piece by huge piece.

Once production hits full speed, the company each plane to spend just three days in final assembly, but this time Boeing workers spent several weeks installing electrical wiring and other innards that suppliers will eventually stuff into their sections of the plane before they're delivered to the assembly plant.

Boeing decided to handle that work in-house for the first few planes rather than risk any production delays.

Despite a few snags the company says it anticipated, including an industrywide shortage of airplane fasteners, Boeing officials say nothing so far has threatened to bump the 787 behind schedule.

The first test flight is expected to take place between late August and late September. The plane is set to enter commercial service next May after Japan's All Nippon Airways Co. receives the first of its 50 Dreamliners.

The 787 debuting on Sunday will serve as the first of six flight test airplanes, while two other planes will be used for static and fatigue tests. The ninth plane off the assembly line will be the first one delivered to All Nippon Airways.

Boeing hired former NBC Nightly News anchor Tom Brokaw to emcee the Sunday afternoon 787 premiere, which the company is broadcasting live on the Internet and on satellite television in nine languages to more than 45 countries.

Boeing has estimated roughly 15,000 will attend the premiere at the plant where the 787 and its other widebody planes are assembled.

The company invited thousands of its employees and retirees to watch the premiere via satellite at the NFL stadium where the Seattle Seahawks play, and is hosting viewing parties for 787 customers and suppliers in dozens of other locations around the globe.

The 787 is Boeing's first all-new jet since the 777, a larger long-range plane which airlines began flying in 1995.

To date, Boeing has won 642 orders for the 787, selling out delivery positions through 2013, the year rival Airbus SAS expects to roll out its competing A350 XWB.

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