By Matt Tomsic
mtomsic@scbiznews.com
Published Aug. 9, 2012

A fan shaft fractured on a GEnx engine during a 787 pre-flight taxi test in North Charleston, the National Transportation Safety Board announced Wednesday.

The fan mid-shaft of the GEnx engine, above, is joined to the front fan shaft with a retaining nut and connects the fan to the low-pressure turbine. At left, the general location of the fracture that caused an engine malfunction during a 787 pre-flight taxi test in North Charleston. (Photos/National Transportation Safety Board)

The fracture happened at the front of the fan’s mid-shaft near where it connects to the forward fan shaft with a connecting nut. The two components make up the fan shaft, which connects the front fan of the engine to the low-pressure turbine in the back, said Rick Kennedy, a spokesman for GE Aviation, which built the GEnx engine.

The engine was mounted to the second Lowcountry-built 787 Dreamliner.

The safety board also confirmed the malfunction as a contained failure, meaning debris exited the tail pipe instead of out the side of the engine.

The investigation is ongoing, and the safety board is processing the cockpit voice recorder and flight data recorder at its lab in Washington, D.C.

“Moving forward, investigators will continue the detailed examination of the engine and metallurgical analysis of its components,” according to an NTSB news release. “The investigators have also begun reviewing the engine manufacturing and assembly records.”

The engine malfunction happened July 28 and caused a small grass fire at the end of runway 2-1, used by Joint Base Charleston and Charleston International Airport. The incident delayed two flights, and no one was injured.

Days later, the National Transportation Safety Board announced an investigation into the incident, and since then, officials with the Boeing Co., the safety board and GE have looked into the malfunction. GE shipped the engine to Cincinnati, where investigators have disassembled it.