Boeing Co. brought two of its six 787 Dreamliner test jets back to Seattle today, where the fleet will remain grounded as the investigation continues into a fire during a test flight a week ago.
The company is still evaluating the potential effect of the incident on the 787’s certification and delivery schedule and can’t comment until it completes the probe and assesses whether any design changes are necessary, Boeing said in a statement. The Dreamliner is already almost three years behind schedule.
Flights have been suspended for a week, after a Nov. 9 electrical fire in a power panel under the cabin floor knocked out some controls, forcing an emergency landing in Laredo, Texas. Workers have finished inspecting the jet and have “a detailed understanding” of the incident, Boeing said.
“The fire was caused because of the heat that occurred when there was a failure in the panel,” said Lori Gunter, a spokeswoman. “What we’re investigating is the cause of that failure.”
Crews have flown to Laredo to replace the panel and insulation blanket that burned and are repairing composite- plastic support bars on the inside of the fuselage, Gunter said.
The Dreamliner is the first composite-plastic airliner and uses an all-electric system to save on fuel. The commercial debut has been delayed six times as Chicago-based Boeing struggles with the new materials, parts shortages, redesign work and a greater reliance on suppliers. United Technologies Corp.’s Hamilton Sundstrand unit makes the power panel that failed.
The 787 has been flying since December 2009 in tests toward certification for passenger service, which is targeted for the first quarter of 2011. The fleet is based in Seattle, and the six planes fly around the world in search of various weather conditions for tests required by the U.S. Federal Aviation Administration.
One of the jets was flown back today from South Dakota, where it had been refueling the day the incident happened, and another from California. Both landed at Seattle’s Boeing Field without incident, Gunter said. The FAA approved the moves after the planes’ aft electronics bays were inspected, Boeing said, adding that no tests would be performed during the return flights.
Two other Dreamliners were already at Boeing Field. A third is at Boeing’s wide-body aircraft factory in Everett, Washington, just north of Seattle, where it’s undergoing scheduled maintenance, Gunter said.
Less Than 30 Seconds
The fire, which broke out as the second plane in the fleet was preparing to land in Laredo after a test flight, lasted less than 30 seconds, Boeing said today. The total duration of the incident was less than 90 seconds, and the backup system that kicked in would have been good enough to return the plane to an airport from any point in a typical 787 mission profile, Boeing said.
The “minor structural damage” will be fixed using standard techniques from the plane’s repair manual, Boeing said, adding that crews are still evaluating the timeline for the repairs to be completed.
The 787’s fuselage is made from carbon-fiber strands woven around composite support “stringers” laid along a cylindrical form and baked in an autoclave oven. It requires different repair methods than traditional aluminum aircraft. Maintenance workers can either bolt on new material or add and cure new layers of composites. Gunter declined to give details about how the damaged fuselage would be fixed.
Boeing has advance orders for 847 Dreamliners, which have an average list price of $178 million and are intended to carry about 250 passengers.
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