Damage to a spinning shaft inside a General Electric Co. jet engine was uncovered by U.S. investigators probing a malfunction that spewed hot shards of metal during a test run of a Boeing Co. 787 Dreamliner.
The National Transportation Safety Board said it’s looking for the cause of the fracture in an engine component called the fan mid-shaft. Tokyo-based IHI Corp., the supplier, is assisting in the inquiry along with specialists from GE and Boeing, Rick Kennedy, a GE spokesman, said yesterday in an e-mail.
First-flight preparations were under way on a 787 due for delivery to Air India when the incident occurred July 28 near Boeing’s Charleston, South Carolina, factory. The debris ignited a brush fire and shut Charleston International Airport for an hour, and the NTSB began an investigation three days later.
“That’s an extremely rare problem,” said Hans Weber, a physicist and aviation-industry veteran who helped develop better part-testing techniques in the 1990s.
“There will be a lot of pressure on GE to come up with a solid explanation very quickly of what the problem is, what they have to do to make sure it doesn’t happen again, and why this is a unique event and the other engines wouldn’t be affected,” said Weber, who now runs San Diego-based aviation consultant Tecop International Inc.
GE has about 80 GEnx engines in service on 787s and Boeing’s 747-8 jumbo jets, and those planes have remained in operation, Kennedy said.
Japan Airlines Co., the only operator of GE-powered 787s, is flying its four aircraft as normal, Sze Hunn Yap, a spokeswoman, said by phone. The carrier hasn’t received any directives from Boeing to check the engines and it isn’t performing any special maintenance, she said.
The engine in the Charleston case was taken off the plane, partially dismantled and sent to GE’s facilities in Ohio to be examined by an engine specialist and a metallurgist. Crash-proof recorders monitoring engine performance and pilot communications were taken to an NTSB lab in Washington.
Air India is still making plans to pick up its first Dreamliner after winning government approval for the delivery late last week, Boeing India President Dinesh Keskar said yesterday. The three 787s waiting for the carrier at the Charleston airport will be handed over in intervals of seven to 10 days so the senior pilots in charge get the required rest time between flights, he said. The fourth plane was the one involved in the incident.
“We are in continuous discussion with Air India to deal with the schedule for the delivery,” Keskar said in a telephone interview from Seattle.
Doug Alder, a Boeing spokesman, said the company is working with the NTSB and declined to comment further about the inquiry. IHI has sent engineers to assist, Genki Yamamoto, a spokesman, said by phone from Tokyo.
“If it was a manufacturing error, it can be remedied, but if it’s a design problem, that’s a little more integral to the engine,” said William Storey, president of consultant Teal Group in Fairfax, Virginia. “That’s the crux of what the issues are moving forward. These engines are complex and to get to an actual cause will probably take a while.”
Ethiopian Airlines Enterprise plans to pick up its first Dreamliner, which will have GEnx engines, from Boeing’s delivery center north of Seattle on Aug. 14. Only JAL and All Nippon Airways Co. have received 787s so far.
ANA fitted its 787s with Rolls-Royce Holdings Plc engines, the only alternative to the GE ones. The twin-engine aircraft entered service in late 2011. It is the first airliner built with composites, helping it cut fuel use and fly farther than other jets its size.
The GEnx engine is more efficient and releases less carbon than earlier models. It reduces weight by replacing metal with carbon composite materials, according to Fairfield, Connecticut-based GE’s website.