SEATTLE — After two years of delays, Boeing Co. says the long-anticipated first flight of its new 787 jetliner could come as early as tomorrow.

Boeing announced Thursday that its window for a first flight would open tomorrow, with the actual flight timing dependent on final internal reviews, taxi testing, Federal Aviation Administration documentation and the weather.

The company said it has completed "final gauntlet" testing on the 787 and verified that fixes it made to address a structural problem worked.

Scott Fancher, vice president and general manager of the 787 program, said in two days of testing the company checked out all the airplane systems, such as avionics, hydraulics and electrical.

Boeing, based in Chicago, earlier reinforced weak points near the area where the wings attach to the fuselage, then conducted a so-called static test — essentially bending the wings — on the repairs.

Fancher said Boeing successfully completed its analysis of that test.

Boeing says the 787, made mostly of lightweight composite materials, will be more efficient, quieter and have lower emissions than other airplanes. The midsize plane also will have wider seats and aisles, and larger windows.

Depending on its configuration, the plane will hold as many as 330 passengers. Deliveries are now estimated to begin in the fourth quarter of 2010.