A visual inspection yesterday showed that damage was limited to the back end of the engine and doesn't indicate a fleet-wide problem, said Rick Kennedy, a spokesman for GE. The cause is "far from being determined" because a team will have to tear the engine apart and examine it piece by piece, he said.
Debris blew out of the engine during a July 28 high-speed taxi test of an Air India Ltd. 787 at the Charleston, S.C., airport near Boeing's new factory there, igniting a fire in the grass along the runway and temporarily diverting and delaying flights.
"This is very uncomfortable for GE, for Boeing, for anyone who flies 747-8s and for all the 787 customers who have specified GE engines," said Hans Weber, chief executive of San Diego-based aviation consultant Tecop International Inc. "So they're going to be working really hard to find out what happened."
The debris came from the low-pressure turbine area at the rear of the engine, where the blades were damaged, Kennedy said. It was a so-called contained failure, meaning parts didn't pierce the engine casing and instead blew out the back and away from the plane as they're designed to do, he said, "so that's good."
A Rolls-Royce Holdings Plc Trent 900 engine exploded midflight in an uncontained failure on an Airbus SAS A380 superjumbo jet operated by Australia's Qantas Airways Ltd. in November 2010. After a safe emergency landing, Qantas grounded all six of its A380s for 23 days.
The 787 incident wasn't in the same catastrophic category and probably wouldn't have brought the plane down if it had been in the air, because the 787 was designed to be able to fly with just one engine if needed, even when fully loaded, Weber said.
"This is an unusual and significant failure, but it was reportedly contained, which is key to making it less of a safety issue," said Nick Cunningham, an aviation analyst at Agency Partners in London.
Still, the incident came a week after another involving engines from Rolls-Royce, which competes with Fairfield, Connecticut-based GE on power plants for the Dreamliner. Japan's All Nippon Airways Co. pulled five 787s with Rolls-Royce engines from service on July 21 after the manufacturer found that some components had a shorter-than-expected service life.
Jim McNerney, chief executive officer of Chicago-based Boeing, last week called the Rolls-Royce gear-box engine problems "pretty minor" and said they wouldn't hurt deliveries of the plane.
There are about 80 of the GEnx engines flying now, mostly on 747-8s, which have four engines apiece, Kennedy said. The model has about 125,000 flight hours in service so far, since both the 787 and 747-8 reached their first customers late last year, and "this is the first serious issue with the engine that we've seen," Kennedy said.
The U.S. National Transportation Safety Board, which sent an investigator to Charleston, will work side-by-side with the team while the engine is dismantled in Cincinnati, he said.
Marc Birtel, a spokesman for Boeing at its commercial airplane headquarters in Seattle, said he couldn't discuss the specifics of the accident while it's being investigated.
The plane involved in the incident hadn't yet flown and wasn't painted in Air India's livery yet, Birtel said. It was the second to be built at Boeing's South Carolina plant, which opened last year, and was highlighted in a July 19 employee newsletter after workers were able to roll it out of the factory in half the time and more complete than the first jet had been.
Boeing's North Charleston factory is one of two assembly sites for the twin-engine 787, along with the company's main wide-body plant in Everett.
United Continental Holdings Inc. has said it expects to start receiving 787s in September, which will make it the first U.S. airline to operate the jet. The airline plans to host a live webcast this morning of its first 787 rolling out of the paint hangar in Everett.
The 787 is the world's first composite-plastic airliner and entered service late last year, more than three years behind schedule, with Japan's All Nippon Airways. Boeing designed the plane to fly long-haul routes while cutting fuel consumption.
Japan Airlines Co., the only current 787 operator using GE engines, is in contact with Boeing and GE and hasn't received a directive to check the engines, Sze Hunn Yap, a spokeswoman, said yesterday in Tokyo. JAL's Dreamliners are flying as scheduled, she said.
The low-pressure turbine drives the engine's fan and is the tail end of the process, Weber said. There's an "incredible amount of heat" in that area because it comes after the combustion chamber, he said.
The blades "are marvels of engineering and metallurgy" that rely on fine air passages and heat-resistant coatings to resist temperatures higher than the melting point of the nickel alloys used, he said.
Every part is carefully inspected and tested at the engine factories before being installed, said Weber, a physicist who has worked in the aviation industry for about 30 years and helped develop better part-testing techniques in the 1990s.
"I can't imagine how some defect could have slipped through,' he said. 'Hopefully this will continue to be an extremely rare event and one that we won't see again in a very long time."