Aerospace giant Boeing said Wednesday it was again delaying its 787 Dreamliner launch for "unanticipated rework" of the aircraft and further problems with suppliers.
The flight of Boeing's highly touted new airplane will move into the fourth quarter of this year rather than the end of the second quarter, and first delivery is now planned for the third quarter of 2009 instead of first quarter.
It was the latest in a series of delays for the Dreamliner, a fuel-efficient aircraft seen as a key to Boeing's future.
The new program "includes additional schedule margin to reduce risk of further delays on the program," Boeing said in a statement.
Boeing said "significant progress has been made" in assembling the first airplane but that the first flight "is being rescheduled due to slower than expected completion of work that traveled from supplier facilities into Boeing's final assembly line, unanticipated rework, and the addition of margin into the testing schedule."
"Over the past few months, we have taken strong actions to confront and overcome start-up issues on the program, and we have made solid progress," said Boeing Commercial Airplanes president and chief executive Scott Carson.
"Nevertheless, the traveled work situation and some unanticipated rework have prevented us from hitting the milestones we laid out in January. Our revised schedule is built upon an achievable, high-confidence plan for getting us to our power-on and first-flight milestones."
He added: "While the fundamental technologies and design of the 787 remain sound, we have inserted some additional schedule margin for dealing with other issues we may uncover in testing prior to first flight and in the flight test program."
As a result of a review launched in January of its supply chain and production procedures, Boeing said it would implement "a more gradual ramp up to full-rate production than previously planned."
Boeing shares rose four percent to 78.04 dollars despite the news.
The Dreamliner, Boeing's first new model in over a decade, takes advantage of the huge advances made in aviation technology in the past decade, and was designed using high-tech plastic composites instead of aluminum.
Up to 50 percent of the primary structure of the plane -- including the fuselage and wing -- are made of composites such as carbon-fiber, which reduce its weight.
Boeing, which aims to build some 2,000 Dreamliners over the next two decades, maintains that it will consume 20 percent less fuel then similar-sized planes already on the market.
Able to fly up to 15,750 kilometers (9,700 miles) without refueling, it could easily manage a flight between New York and Manila, or Moscow and Sao Paulo, routes so far only open to bigger planes such as Boeing's 777 or 747.
Boeing hopes the Dreamliner will be used to open up profitable flights between cities which so far have no direct links such as Seattle-Shanghai, Boston-Athens or Madrid-Manila.
The Dreamliner's other innovations include greater levels of comfort for passengers, with bigger windows, higher humidity levels within the cabin expected to reduce passenger dehydration and a new anti-turbulence system.
The news comes with Boeing and European maker Airbus in a heated battle for supremacy of the skies.
Airbus has faced delays with its key A380 superjumbo project, delivering its first aircraft in October to Singapore Airlines nearly two years behind schedule.