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US NTSB cites inadequate inspections in 2021 United Airlines engine failure

The National Transportation Safety Board said on Friday the February 2021 engine failure on a United Airlines Boeing 777 in Colorado was due to a crack in a fan blade and cited inadequate inspections as a contributing cause. Soon after the failure, the Federal Aviation Administration (FAA) ordered immediate inspections of 777 aircraft with Pratt & Whitney 4000 engines before further flights, which led to the planes' grounding for more than a year. The Boeing 777-200 bound for Honolulu… ( More...

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sparkie624 1
Ouch... I smell a Big Fine Brewing... No reason for this kind of failure!
Greg S 3
It's not clear to me from the story whether United is being blamed, or Pratt & Whitney, or Boeing, or all three. If United followed the manufacturer's recommended inspection intervals I think they're off the hook.
sparkie624 3
I believe it would be to United... Once they order and get the parts in, it is up to their receiving inspectors to verify the authenticity of the parts. I have seen parts arrive that were found to not be real parts and our inspectors caught them early and rejected them.
Gary Bain 1
I don't believe there was any mention of bogus parts in this article. Not a factor. Whether United did not adequately inspect the blades or whether there was no procedure or method provided by the manufacturer to do so seems to be the issue here. Brian, below, is correct. This seems to have been a "no fault" issue since no entity was cited or fined.
Bill Overdue 0
The "bogus parts being used"... is the skawk above this one! 😆
Michael Osmers 1
According to the article and what I’ve heard elsewhere, the issue was the inspection interval and procedure which is dictated by P&W. Specifically, the procedure requires inspections and testing of the blades but until the procedure was changed it was impossible to compare previous inspections side by side. What I had heard was these cracks are very difficult to detect, but if the side by side comparison had been available would have let the evaluator conclude there was in fact a crack and it was getting worse.

Brian Chandler 1
Oh they're incredibly hard to detect, and it requires a skilled mx tech to find them. If it was easy they would be spotted by the FO on pre flight walkarounds.

We're talking about cracks smaller than human hairs, and they use tools to see this fine of a crack. See below example.

There are now coming out newer hi-tech approaches using computers and optical lenses to find the cracks but it's often still human oriented.
Brian Chandler 1
It's United. They're the ones inspecting the engine and they're expected to find things like this. And even if UA outsources their 772 mx, it's still on United.
Michael Osmers 1
Procedures are done by the manual published by the manufacturer, in this case P&W
Brian Chandler 2
No chance tbh. Would have already been handed down. Incident was coming up on 3 years ago. We've already been through an investigation, a grounding, a bunch of directives and the 772PW is back in the sky for a year now. Fine would have already come
There is this rare thing called "maintenance audits" by the NTSB. Are the civil servants too lazy or just plain incompetent in their jobs.
Brian Chandler 3
Did you read the article? Not sure why I asked that because I already know the answer is "no"

From the article:

> insufficient frequency of the manufacturer’s inspection intervals, which permitted the low-level crack indications to propagate undetected and ultimately resulted in the fatigue failure."

An audit of United's records would not have uncovered anything. They were doing everything per engine and plane manufacturer standards and what was legally required. The issue is given the design (flaws?!) of the specific PW engine, the blades require more frequent inspection than was called for in the mx prodecures.
Bill Overdue 0
Fake parts being used, inadequate inspections, near misses on tarmac, near misses in air, contact of planes while taxiing, clueless ATC, out of control TSA, racist pilots for not getting #clotshot...diversity and equity will get you killed yet!


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