A Denver plane engine fire corresponds to metallic fatigue in the propeller blade, investigators say | Air transport

Metal fatigue in the fan blades may be behind the motor’s failure Boeing Plane in Denver at the weekend, the US National Transportation Safety Board said.

A Pratt & Whitney engine caught fire shortly after take-off on a United Airlines Boeing 777-200, while in flight from Denver To Honolulu, with 231 passengers and 10 crew members on board. The pilots issued a distress call and returned to Denver.

the next day, Dozens of 777 aircraft were grounded After Boeing said those with Pratt & Whitney PW4000 engines should not be used until full inspections can be made.

The president of the National Transportation Safety Board (NTSB), Robert Sumwalt, said Monday that a preliminary assessment indicates that the damage is consistent with metal fatigue and that the code will be examined Tuesday at Pratt & Whitney under the direction of NTSB investigators. .

Somwalt said it was unclear if the PW4000 engine failure on Saturday was consistent with another engine failure on another United flight to Hawaii in February 2018 that was attributed to a fatigue break in the fan blade.

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

In another engine-type accident on Japan Airlines Flight 777 in December 2020, the Japan Transportation Safety Board reported that it had found two damaged propeller blades, one of which had a crack caused by metal stress.

The Federal Aviation Administration (FAA) has planned to issue an Aircraft Airworthiness Directive soon that will require extensive inspections of propeller blades for fatigue.

After engine failure in February 2018 was attributed to propeller blade fatigue, the Federal Aviation Administration ordered inspections every 6,500 revolutions.

Sumwalt said the United incident did not consider an unseated engine failure because the containment ring contained the parts as they were flying. He said there was minor damage to the fuselage, but no structural damage.

Somwalt added that the National Transportation Safety Board will look into why the hood has split off from the aircraft and also why a fire has broken out despite indications that the fuel in the engine has been turned off.