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Old 9th Jan 2019, 18:16
  #14 (permalink)  
old,not bold
Join Date: Apr 2006
Location: uk
Posts: 795
Originally Posted by DHC4 View Post
I remember a few months after the crash talking to one of the line techs, he said that one of the engines had high vibs and they recommend an engine change. This was overruled and the aircraft flew.
Q1. Would the vibration be a warning of possible fan blade fracture? I have no idea, but if not it's not relevant.

Q2. If the "Line Tech", presumably a certifying engineer, really thought that the engine should be changed before another flight, he or she only had to refuse to release the aircraft to service, giving full reasons. If he or she doesn't think that, then the aircraft can be released. What the "Line Tech" really should not do is release it to service, then mutter after the disaster that "I told you so". So I'm wondering who "over-ruled" whom in the story you heard from the "Line Tech", and who actually released it to service.


Re Q1; here's what Wiki says, which I missed.......

The inquiry attributed the blade fracture to metal fatigue, caused by heavy vibration in the newly upgraded engines, which had been tested only in the laboratory and not under representative flight conditions..
So that's the answer to Q1. I suppose a better answer is that any heavy vibration could have serious consequences in all sorts of ways, just one of which might be a blade fracture.
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