US agency: Boeing 777 engine fan blade damage is due to metal fatigue
China News Service, February 23. According to a comprehensive report, a United Airlines Boeing 777 passenger plane caught fire in the air on the 20th and debris fell along the way. The National Transportation Safety Board pointed out on the 22nd that a preliminary investigation showed that the damage to the engine fan blades was related to metal fatigue.
A United Airlines Boeing 777 passenger plane flew from Denver to Hawaii on the 20th. The Pratt & Whitney PW4000 engine caught fire and some parts fell. The plane was forced to return to Denver. Boeing confirmed on the 21st that 128 777 passenger aircraft using the same engine have been grounded globally.
p > On February 20, local time, a United Airlines flight to Honolulu was forced to return to Denver International Airport due to an engine failure shortly after takeoff. The picture shows thick smoke constantly emerging from the passenger plane engine.
In February 2018, a similar accident occurred on a United Airlines Boeing 777 aircraft flying to Hawaii. The fan blade broke and the engine malfunctioned. US National Transportation Safety Board (NTSB) Chairman Suvat said at a news briefing on the 22nd that it is not clear whether the engine problem on the 20th is the same as three years ago.
In addition, a Boeing 777 aircraft using the same engine was also involved in an accident in December 2020 by Japan Airlines. At that time, the Japan Transportation Safety Board found two damaged fan blades, one of which was caused by metal fatigue. crack. The investigation is still ongoing.
It is reported that the fan blades of the Pratt & Whitney PW4000 engine in the United Airlines accident on February 20 have been sent to Pratt & Whitney’s laboratory and will be inspected on the 23rd under the supervision of NTSB investigators.
The Federal Aviation Administration (FAA) intends to issue an emergency airworthiness directive as soon as possible, requiring airlines to strengthen inspections of engine fan blades for metal fatigue problems.
NTSB will also investigate why the engine cowling fell off during the accident on the 20th, and why the engine’s fuel supply was turned off but still caught fire.