The National Transportation Safety Board on Friday said the engine that caught fire and failed last month on United Flight 328 came when the plane’s pilots throttled up the engines to mitigate expected turbulence, the agency said in an update.
No blame was placed in the seven-page preliminary report. Increasing speed to escape turbulence is commonplace in aviation.
In addition, CNN is reporting that a fan blade that failed in the Boeing 777’s engine had most recently received a close inspection for wear and tear in 2016, and was less than halfway to the point of requiring another inspection.
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United Flight 328 from Denver International Airport to Honolulu on Feb. 20 dropped dozens of pieces of debris on a suburban Denver neighborhood after an engine caught fire, necessitating an emergency landing back at DIA.
Miraculously, nobody on the ground was hurt, and the plane landed safely with no injuries.
The investigation is ongoing.
According to the update, the flight crew was increasing power “to minimize time in expected turbulence” as the aircraft was climbing to its assigned altitude. The airspace around the Denver airport is known for turbulence, according to CNN affiliate KMGH.
“Immediately after the throttles were advanced a loud bang was recorded” on the cockpit voice recorder, the report said.
Travis Loock, a passenger on Flight 328, said it was about 20 minutes after takeoff that he heard a boom.
“There was a big boom and the kind of sound you don’t want to hear when you’re on the airplane,” Loock, who was flying with his wife, told CNN in a phone call after the incident. “And I instantly put my shade up, and I was pretty frightened to see that the engine on my side was missing.”
The flight data recorder indicated “the engine made an uncommanded shutdown and the engine fire warning light activated shortly after,” the report said.
CNN noted that the pilots followed proper procedure to fight the fire and determined they would not dump fuel to make the aircraft lighter before landing, the report said. They concluded that “the magnitude of the overweight landing was not significant enough to outweigh other considerations.”
