the NTSB report mentions" the stress cracks originated from the "concave" side, and here's a pic:
Posted on 03/06/2021 7:31:38 AM PST by G Larry
A fan blade that snapped off a United Airlines engine mid-flight, causing it to rain debris over Colorado last month, had microscopic cracks, federal investigators with the National Transportation Safety Board said Friday.
The engine part was last inspected more than four years ago.
The Boeing 777 made an emergency landing back at Denver International Airport on Feb. 20 after the engine caught on fire soon after takeoff. No one onboard or on the ground was injured.
The broken blade on the Pratt & Whitney engine had been used on 2,979 flights since its last inspection in 2016, the NTSB said. It wasn’t due for another inspection until it reached 6,500 flights – more than twice the number it had flown when it broke.
(Excerpt) Read more at foxnews.com ...
How else to explain failure in less than half the time between inspections, let alone lifecycle expectancy?
Don’t hold me to this, but I read those blades had unique design wherein they were hollow. Saved weight I guess if this is so but that design was changed for later engines, I wonder why!
stress corrosion cracking?
why no examination of new systems?
I think you’re probably right. But would the routes the aircraft flew have any effect on blade life? Cars in northern states would rust out their bottoms faster due to all the salts that the states would lay down on the roads during winter months. (Not sure how true that is these days.)
Might aircraft flying routes that carry them low over big cities acquire corrosive salts or other particulates?
Some turbine blades are hollow.
Would not have guessed some fan blades are hollow!
Some turbine blades are hollow.
I did not know that except I did read those on the engines used on the next series were not.
The engineers predicted the wing would break when put to the normal tests, it did. But they just kept going. At least 25 years ago.
Ahh yes, the NTSB. They’re as trustworthy as the FBI.
TWA flight 800 exploded because of a spark from a fuel pump. Riiiiiiight.
Say, speaking of the NTSB, did you see where they “dismantled and destroyed” the flight 800 display they used to train agents about crash reconstruction “science”?
They claim modern animation is so advanced that physical reconstruction is outdated. In reality, I suspect far too many future agents with a brain were questioning the absolute lies they were being told at this fraudulent training class “display”.
They also claim they are destroying the wreckage out of respect for families of the deceased, citing a promise made to them that the wreckage never be displayed to the public. Ok, whatever.
More like they don’t want the public to see their lies.
the NTSB report mentions" the stress cracks originated from the "concave" side, and here's a pic:
Maybe they spin the blades too fast?
An early year for Boeing 777 ops, and I was in Denver at the airport.
A United 777 was not going anywhere, because the front-most right hatch would not shut and seal properly in the frigid cold weather.
Inspections should have been done based upon flight hours. Inspection costs suffered with cost cuts because of the impact of the pandemic.
Now how about the 747 and the other 777 that had the same mishap in the same three day period?
the 777 is universally acknowledged as one of the safest planes in the sky. terrific safety record.
this was an ENGINE problem. boeing doesn’t manufacture engines.
your brother’s scary story doesn’t apply. does someone have a relative that works for pratt and whitney to tell us a scary fairy tale?
jesus. what a mess.
“Chinese steel?”
I don’t think their steel.
Not exclusively an engine problem.
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