Boeing conducts two-hour test flight of grounded Dreamliner A Boeing 787 with a redesigned battery system made a 2-hour test flight on Monday, and the company said the event 'went according to plan.' The test flight was an important step in Boeing Co.'s plan to convince safety regulators to let airlines resume using the plane, which the company calls the Dreamliner. Boeing will analyze information from the flight and prepare for another flight - using the same plane - to demonstrate the 787's performance to the Federal Aviation Administration, said company spokesman Marc Birtel. Preparing for takeoff: A LOT Polish Airlines 787 passenger jet takes off from Paine Field in Everett, Washington, on its two-hour test flight yesterday The timing of that demonstration flight has not been set, Birtel said. Boeing hopes to get 787s flying again within weeks, not months, but that decision will be made by aviation regulators in the U.S., Japan and elsewhere. Worldwide, airlines own about 50 Dreamliners. The fleet has been grounded since January after lithium-ion batteries aboard two planes overheated. The battery on a Japan Airlines 787 caught fire after it landed in Boston, and the battery on an All Nippon Airways jet began smoking during a flight in Japan, forcing an emergency landing. Boeing added insulation around battery cells and a steel casing on the outside to prevent fires. Company officials have said that they might never know the cause of the smoldering batteries. The U.S. National Transportation Safety Board and Japanese authorities are investigating the incidents. Success: The test flight was an important step in Boeing's plan to convince safety regulators to let airlines resume using the Dreamliner The NTSB plans to hold a forum next month in Washington on the use of lithium-ion batteries in transportation. The agency said Monday that the event April 11-12 will focus on design and performance of the batteries and regulation of their manufacturing and use. For Monday's test flight, Boeing used a 787 that it built for LOT Polish Airlines. The plane took off about an hour later than planned from Paine Field near Seattle, flew out over the Pacific and down the coast to Oregon before returning to the same airfield. Birtel, the Boeing spokesman, said the plane's 6-member crew tested landing gear, electrical and backup systems to show that all of them functioned as designed. The same plane had a similar test flight in January, but that was before the changes to the battery system. Flying high again: Boeing said a new battery is ready to go with safeguards to prevent overheating All clear: The FAA approved Boeing's plan to fix the 787 Dreamliner's batteries on March 12, 2013, with more testing required Takeoff: Boeing Commercial Airplanes President and CEO Ray Conner, center, speaks as Boeing Japan President George Maffeo, left, and Boeing Commercial Airplanes Vice President and Chief Project Engineer Mike Sinnett listen during a news conference in Tokyo to announce 787 jets will resume flying 'within weeks, not months' Boeing declined to provide access to the plane or its facilities before or after the flight. Shares of Chicago-based Boeing rose 3 cents to close at $84.85. The Boeing executives sought to allay flier fears about the 787 by repeatedly stressing their commitment to safety. They said it would take too long to figure out what had specifically caused the problems in Boston and southwestern Japan but the new design would ensure 787s are safe. Boeing came up with 80 possible causes for the battery problems, categorized them into four groups, and came up with design adjustments such as better insulation between each battery cell so any malfunctions won't spread. Up in the air: Conner said Friday they had not pinpointed the causes of the two battery problems that resulted in the global grounding of the technologically advanced Dreamliner planes Two weeks ago, Boeing Executive Vice President Ray Conner also offered his apologies to the Japanese people for the Dreamliner problems. 'We do apologize for this situation,' Conner said. He said he was in Japan to meet with aviation authorities and airlines, and the company had picked Japan as the place to outline the battery fix. That was to allow the 787 to be back in the air more promptly, they said. There were also changes to wiring for the battery, aimed at preventing overheating, and a new enclosure for the battery that would eliminate fire risk. While executives acknowledged that final approval would have to come from the FAA, and didn't rule out further delays to ensure safety, they said they were in close contact with the FAA and didn't foresee any long delays. 'It's a safe airplane. We have no concerns at all about that,' Sinnett said. Cloudy skies: Executives said final approval would have to come from the FAA, and didn't rule out further delays to ensure safety