Boeing Co completed the first test flight of its new lightweight carbon and titanium Dreamliner, but the flight was cut short because of bad weather.

The flight was more than two years behind schedule because of manufacturing and design problems.

The 787 Dreamliner's highly anticipated takeoff and landing were witnessed by several thousand Boeing employees, industry VIPs, airplane enthusiasts and reporters. But excitement and relief spread throughout the aerospace industry.

The plane, which Boeing has said will save airlines million of dollars in fuel and maintenance costs, has been hampered by a shortage of bolts, faulty design and a two-month strike at its factory.

Airlines like the concept of the mid-sized plane that can carry about 250 people very long distances. They have ordered 840 of the aircraft, worth about $140 billion, since work began on the plane in 2004.

But production has been delayed five times in the past three years, and the first flight has been postponed six times.

Rival Airbus, a unit of Europe's EADS, has been attracting buyers for its competing A350 plane, which will also be made primarily from carbon-composite materials.

Exactly how much profit Boeing can expect to make from the plane is uncertain. Analysts have said the company has invested more than $10 billion in the project, and will have to give some sort of compensation to customers for late planes. How late the planes will be and how they will perform will not be known until flight tests have been completed.

It's a major step-off point to the ultimate goal which is certification and customer delivery. It's an important milestone but it's not the end goal, Clay Jones, chief executive of Rockwell Collins said at the Reuters Aerospace & Defense Summit in Washington.

Rockwell makes display systems, communications and surveillance systems and pilot controls systems for the 787.

Boeing's shares closed down 0.68 percent, or 38 cents, at $55.67 on the New York Stock Exchange. The company's shares have risen about 90 percent since March, outstripping the rebound in the Standard & Poor's 500 index.

ROUND-THE-CLOCK TESTS

The Dreamliner, painted with Boeing's blue and white logo, took off from Paine Field adjacent to its factory in Everett, Washington, 30 miles north of Seattle for a foray around the Puget Sound and inland Washington state. The aircraft landed at Boeing Field in Seattle.

The flight starts at least nine months of airborne tests on a fleet of six 787s running around the clock, which Boeing executives say will be like running a small airline.

The test flight was meant to push the plane well beyond limits expected in ordinary commercial flights, practicing mid-air stalls, dives and steep banks, as well as seeking out extremes of heat and cold.

It certainly takes one more element of uncertainty out of the mix, Scott Kuechle, chief financial officer at Goodrich Corp, said at the Reuters Summit. Goodrich makes systems such as thrust reversers and brakes for the Dreamliner.

Kuechle said Goodrich investors have been obsessed with the 787 in recent years and that two years of delays have been frustrating. But he said he never doubted the 787 would fly.

Boeing has said the first 787 should delivered to Japan's All Nippon Airways in the fourth quarter of next year, more than two years after the original target of May 2008.

NEW ISSUES

The plane has been beset by problems partly because of the new materials being used and extensive outsourcing. Early delays were due to shortages of parts and the difficulties of bringing together fuselage and wing structures from Japan, Italy and elsewhere in the United States, aggravated by a two-month strike last year.

The most recent delay occurred when Boeing needed to reinforce the side of the plane where the wing meets the fuselage.

The revolutionary use of carbon fiber and the problems of joining it to other materials mean there could still be snags.

Just as they (Boeing) found hurdles on the way to first flight, they are going to find hurdles on the way to certification, said Richard Aboulafia, aerospace analyst at research firm Teal Group.

(Reporting by Kyle Peterson and Bill Rigby; Additional reporting by John Crawley and Deepa Seetharaman)

Manufacturing Down