Boeing has unveiled its 787 Dreamliner at an event hosted by former television news anchor Tom Brokaw before 15,000 people near Seattle and broadcast live by satellite in nine languages.

The 787, which features carbon-fiber composites that reduce weight and improve fuel efficiency, will begin test flights around early September, and delivery of the first plane to a customer is slated for May 2008.

"There are a lot of new systems on this airplane that are different," International Lease Finance chief executive Steven Udvar-Hazy said. "Some have been proven and tried on military aircraft, but not on this scale."

Udvar-Hazy has 74 Dreamliners on order, making ILFC the plane's biggest customer.

The unveiling day is symbolic: July 8, 2007 (7/8/07). Also, 60 years ago to the day, Boeing's 377 Stratocruiser, its first plane to sell successfully to non-US airlines, flew for the first time. The Stratocruiser used cutting-edge technology of the period, cabin pressure, letting it fly above the weather.

"The weeks and months ahead are sure to be filled with excitement, hard work and the challenges that come with the history-making efforts like this one," Boeing chief executive James McNerney said at the unveiling.

Since events for the 787 unveiling began on July 6 that Air Berlin and Kuwait-based lessor ALAFCO placed orders totaling 35 planes. ALAFCO ordered 10 additional 787s and Air Berlin ordered 25.

"The rollout is for show," said Richard Aboulafia, an analyst at Teal Group, a Fairfax, Virginia-based aviation consulting company. "The real money is getting it to fly right. This is a notably aggressive flight test schedule with little room for error."

Improved technology and flight simulators have reduced the need for tests once possible only after the plane was built. The test flights are scheduled to last three fewer months than the 11 months required for the 777 in the early 1990s. The 777 entered service in 1995.

The extensive use of simulators has enabled Boeing to spend three fewer years in developing the 787 versus the 777. Boeing used computer-simulated testing to run air flows on the Dreamliner's wings and fuselage. Simulation reduced the number of 787 wings tested in wind tunnels to 11 from the 77 tested for the 767 about 25 years ago.