U.S. The National Transportation Safety Board said there could be metal fatigue in the fan blades behind Boeing jet engine failures in Denver over the weekend.
Pratt & Whitney’s engine caught fire shortly after a United Airlines Boeing 777-200 with 231 passengers and 10 crew on board took off from Denver to Honolulu. The pilots made a midday call and returned to Denver.
The next day, Boeing said dozens of 777 planes landed until full inspections were carried out using Pratt and Whitney’s PW 000,000 engines.
Robert Sumwal, chairman of the National Transportation Safety Board (NTSB), said Monday that preliminary assessments indicated the damage was consistent with metal fatigue and that the blades would be tested Tuesday at Pratt & Whitney’s laboratory under the supervision of NTSB investigators. .
Sumwal said it was not clear if Saturday’s PW4000 engine failure was consistent with the failure of another engine in an air-bound United flight in February 2018 due to fatigue fractures in the fan blades.
“It’s important that we really understand the facts, circumstances and circumstances surrounding this important event,” Sumwalt said.
In another incident on the same engine type on Japan Airlines 777 in December 2020, the Transport Safety Board of Japan reported that it had found two damaged fan blades, with a metal fatigue crack.
The Federal Aviation Administration (FAA) plans to issue an emergency airworthiness directive soon, which will require an investigation into the filling of the fan blades for fatigue.
After February 2018 United engine failure was attributed to fan-blade fatigue, the FAA ordered an investigation every 6,500 cycles.
Sumwalt said the United incident was not considered an engine failure, as there were parts in the content ring as it was going out. The body of the plane suffered minor damage but no structural damage, he said.
Sunwalt added that the NTSB would investigate why the engine camming detached from the plane and why the fire started, even though the engine was running out of fuel.