US air safety investigators have determined that a fracture to a spinning shaft inside a Boeing 787 Dreamliner’s General Electric GEnx engine caused the contained failure that led to a brush fire at a South Carolina airport late last month.
The National Transportation Safety Board said it’s still trying to determine what caused the fan mid-shaft to break free. The incident occurred during July 28 pre-flight testing of a 787 due to be delivered to Air India. Burning debris from the engine set fire to surrounding grass, closing the Charleston International Airport for an hour.
The GEnx engines are one of two engine options available for the 787 – and are the engines chosen by Qantas for the 787-8s due to be delivered to Jetstar in the second half of the year.
In a statement, the NTSB said Boeing, GE and Tokyo-based IHI, which supplied the failed engine component, are all assisting with the enquiry.
“The fan mid-shaft is undergoing several detailed examinations including dimensional and metallurgical inspections,” the statement said, adding that the fracture had occurred “at the forward end of the shaft, rear of the threads where the retaining nut is installed.”
Japan Airlines, the only carrier operated GEnx-powered 787, told Bloomberg that it was continuing to fly its aircraft and had not received any special directives from Boeing. All Nippon Airways, the other current 787 operator, flies aircraftequipped with Rolls-Royce engines but has had to ground part of its 787 fleet over engine problems.
The latest setback for the long-delayed 787 program comes at a pivotal time for Boeing as it ramps up production of the aircraft. Nevertheless, Air India said it still planned to begin taking delivery of its four GEnx-powered 787s this month. United Airlines is scheduled to take the first US 787, also powered by GEnx engines, next month.