A preliminary National Transportation Safety Board investigation of engine fragments found that a fan blade broke loose on the Pratt & Whitney 4000-112 engine, likely due to a crack that grew, and eventually snapped.
The engine on the Boeing 777-200 bound for Hawaii failed shortly after takeoff from Denver. The jet was a widebody that has been in use for 25 years.
None of the 229 passengers or 10 crew members were injured. There were no reports of injuries on the ground, even as the engine lost its cowling midair.
Boeing has already backed suspending 69 in-service 777s and 59 in-storage 777s with the Pratt & Whitney engines. Raytheon Technologies’ (RTX) Pratt & Whitney said Monday it dispatched a team to work with investigators.
Carriers can configure their Boeing 777 jets with engines from General Electric (GE,) Rolls-Royce or Pratt & Whitney.
P&W Engines On Boeing 777 Have History
Boeing stock fell dipped 0.4% to close at 212.12 on the stock market today and is forming a cup base with a 244.18 buy point, according to MarketSmith analysis. But fundamentals remain weak. Raytheon rose 1.4%, and GE added 0.7%.
The Pratt engines were already under extra scrutiny for fatigue following an engine failure on a United Boeing 777 flying from San Francisco to Hawaii in 2018. A Federal Aviation Administration directive calls for the engines to be inspected before 7,000 flights and then another inspection within the next 1,000 flights.
Also in December, a similar engine suffered a broken blade during a Japan Airlines Boeing 777 flight after takeoff from Okinawa en route to Tokyo.
United and carriers in Japan have grounded all their Boeing 777s with the Pratt engine configuration. South Korean regulators are allowing Boeing 777 flights to continue following engine checks.
The Denver incident comes as a Boeing 747 cargo jet operated by Longtail Aviation also scattered engine parts Saturday on the town of Meerssen, Netherlands, after its engine exploded and caught fire.
The Pratt & Whitney PW4000, a smaller version of the kind on the United flight, powered the cargo plane. The Boeing 747 landed safely in Belgium, but a Dutch woman was injured by falling engine debris.
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