WASHINGTON (Reuters) – Damage to an engine fan blade that failed on a United Airlines Boeing 777 flight is consistent with metal fatigue, based on a preliminary assessment the chairman of the US. Aircraft accident investigators said on Monday

The Pratt & Whitney PW4000 engine failed with a “loud bang,” four minutes after takeoff in Denver on Saturday, Robert Sumwalt, chairman of the National Transportation Safety Board (NTSB), told reporters after an initial analysis of the flight data recorder and the cockpit dictation machine

He said it remained unclear whether the incident was related to an engine failure on another flight to Hawaii in February 2018 due to a fatigue failure in a fan blade

“What is important is that we really really understand the facts, circumstances and conditions surrounding this particular event before we can compare it to any other event,” said Sumwalt

The engine that failed and spilled parts over a Denver suburb on the 26-year-old Boeing Co 777 was a PW4000 that was used on 128 aircraft, or less than 10% of the global fleet of more than 1600 777 wide-body jets delivered

In another incident on Japan Airlines (JAL) 777 with a PW4000 engine in December 2020, the Japanese Transport Safety Board reported that two damaged fan blades were found, one with a metal fatigue crack, an investigation is ongoing

The focus is more on engine maker Pratt, and analysts expect little financial impact on Boeing However, the PW4000 issues are causing new headaches for the aircraft manufacturer as it recovers from the far more severe 737 MAX crisis, Boeing’s flagship narrowbody jet was on the ground for nearly two years after two fatal crashes
The United engine’s fan blade will be examined Tuesday after it was flown to a Pratt lab where it will be examined under the supervision of NTSB investigators

The US. The Federal Aviation Administration (FAA) said Monday it had already considered whether to adjust fan blade inspections following the December incident in Japan, after reviewing maintenance records and performing a metallurgical examination of the fan blade fragment

Boeing advised airlines to stop using the aircraft while the FAA established an appropriate inspection protocol, and Japan imposed a temporary suspension of flights

Pratt & Whitney, owned by Raytheon Technologies Corp.Has Advised Airlines Increase Inspections in A Plan Under Review by the FAA. Pratt did not immediately respond to a request for comment

The FAA has announced that it will shortly issue an emergency airworthiness policy that will require increased inspection of fan blades for fatigue

“United Airlines has grounded all affected aircraft with these engines, and I understand the FAA is also working very quickly and Pratt & Whitney has repeated or revised a service bulletin,” Sumwalt said. “It looks like action is in progress seized ”

In March 2019, following the United engine failure in 2018 due to fan blade fatigue, the FAA ranked all 6500 cycle inspections on A bike is a take-off and a landing

The South Korean Ministry of Transportation said Tuesday that it had instructed its airlines to stop the fan blades every 1Checking 000 cycles according to Pratt’s instructions after the incident in the United States

Sumwalt said the United incident wasn’t an uncontrolled engine failure as the safety ring contained the parts when they were blown out

NTSB will investigate why the hood parted from the aircraft and why a fire broke out despite indications that the fuel for the engine was cut, Sumwalt added,

Industry claims that the hood or case is made by Boeing, although the engine is made by Pratt. Boeing referred questions to the NTSB

Nearly half of the global fleet of Boeing 777 jets with PW4000 equipment operated by airlines such as United, JAL, ANA Holdings, Korean Air and Asiana Airlines have already been in a decline in travel demand due to the coronavirus pandemic landed

Reporting by David Shepardson in Washington and Jamie Freed in Sydney; additional coverage by Tracy Rucinski in Chicago, Joyce Lee in Seoul and Tim Hepher in Paris; Editing by Kim Coghill and Gerry Doyle

All offers were delayed by at least 15 minutes. For a full list of exchanges and delays, see

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World news – FI – United Boeing 777 engine damaged due to metal fatigue: NTSB

Source: https://www.reuters.com/article/us-boeing-777-ntsb/damage-to-united-boeing-777-engine-consistent-with-metal-fatigue-ntsb-idUSKBN2AN03S