Damage to an engine blade that failed on a United Airlines Boeing 777 flight is related to metal fatigue, according to a preliminary assessment, the chairman of the U.S. air accident investigator said Monday.
The Pratt & Whitney PW4000 engine failed Saturday with a “loud bang” four minutes after takeoff from Denver, National Transportation Safety Board (NTSB) Chairman Robert Sumwalt told reporters after an initial analysis of the flight data recorder and cockpit voice recorder, Reuters reviewed.
According to Sumwalt, the plane’s fuselage sustained minor damage, but there was no structural damage.
He indicated that it remained unclear whether this incident is related to an engine failure on another Hawaii-bound United flight in February 2018 that was attributed to a fatigue fracture in a fan blade.
“What’s important is that we really understand the facts, the circumstances and the conditions around this particular event before we can compare it to any other event,” Sumwalt said.
The engine that failed on the 26-year-old 777 was a PW4000 used on 128 aircraft, or less than 10% of the worldwide fleet of more than 1,600 777s delivered.
The focus is more on engine maker Pratt & Whitney and analysts expect it to have little financial impact on Boeing, but the PW4000 problems are a new headache for the aircraft maker as it recovers from the 737 MAX crisis.
United’s engine blade will be examined Tuesday after being moved to a PW lab, where it will be examined under the supervision of NTSB investigators.