philidor
in service - 6 years
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Post by philidor on Apr 4, 2019 11:55:24 GMT 1
Welcome to the forum, petterik !
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Apr 4, 2019 11:21:44 GMT 1
I posted the following in the 'ET crash' thread. I'm trying to keep this thread current. Leeham's latest piece (the link was initially posted by Kevin) means that Boeing's procedure doesn't work because it relies on manual trim, which seems to be impossible at high speed. That's a terrible conclusion for Boeing ! leehamnews.com/2019/04/03/et302-used-the-cut-out-switches-to-stop-mcas/Now comes one major question : the modest and reasonable changes they proposed in their latest presentation are they sufficiently changing the big picture ? I now doubt it. If it's not enough, what else can they do ? I have no idea, but I hope they have !
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Apr 4, 2019 10:51:06 GMT 1
Baroque, we are discussing this piece of information in the 'Lion Air crash' thread. That the repair was made in the USA is unconclusive : we don't know whether or not Lion's maintenance made any mistake, or whether or not faulty sensors were the cause of erroneous indications in the first place. Perhaps you are still the only person believes maintenance from JT still comes into play. Aircraft crashes almost always have more than one cause, they result from a chain of events. This is what you seem to forget. I wasn't accusing maintenance, and rejecting any other factor, I was claiming that we couldn't at that stage leave Lion Air's maintenance entirely off the hook - as you did in your post - since the root cause of the crash might have been the failure of a poorly installed sensor. For the sake of clarity, the root cause is the initial factor in the chain of events, not necessarily the most important one. ABC news claims that there actually was a sensor failure in the ET crash (this is the first time sensor failure is stated as a fact, not a supposition), caused by either a bird strike or foreign object dammage. Mjoelnir's post above, however, provides different information: "investigators have not identified any damage to aircraft sensors in relation to crash". This is a different event from the Lion Air crash - shouldn't we keep an open mind in both cases ? EDIT : I clarified my post since discussing two crashes in the same post can be a bit confusing
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Apr 4, 2019 10:17:29 GMT 1
Thank you, Kevin, that Leeham story was aired after I posted the Guardian article, which indeed seems ill-founded. So, what this means is that Boeing's procedure doesn't work because it relies on manual trim, which seems to be impossible at high speed. That's a terrible conclusion for Boeing ! Now comes one major question : the modest and reasonable changes they proposed in their latest presentation are they sufficiently changing the big picture ? I now doubt it. If it's not enough, what else can they do ? I have no idea, but I hope they have !
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Apr 4, 2019 9:37:01 GMT 1
Do not forget that in each plane are thousands and thousands off various parts we have no idea about and each of those must be there tested and retested. Simply just a single one might be missing or returned to the supplier or ...... And we do have a stored plane on the tarmac. Yes, but there is nothing new there. Any FAL must deal with some late supplies, as well as the need for some rework. What seems to be new is that more aircraft than usual are sitting, and we don't know the reason. It makes for interesting discussion !
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Apr 4, 2019 9:28:35 GMT 1
that was 2007 and 787 didn't get grounded until 2013 Then it was an ordinary case of government intervention, whereas I never heard before of any intervention of a government in favour of a grounded aircraft.
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Apr 4, 2019 9:19:12 GMT 1
FDR data was released. AOA was showing pitch up (no polarity flipped) and FDR is recording it (system sees it). PLEASE, tell me what else can be wrong ...... A faulty sensor is a likely cause for a wrong indication, but not the only possible one. There is an electronic connexion (through the so-called ADIRU - I don't know much about it) between the sensor, the computers and the display. If the sensor was changed (as reported), but the system was not working, whatever the reason, then wrong installation and/or insufficient testing may have been a factor - OR NOT.
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Apr 3, 2019 14:05:13 GMT 1
It gets even more worse... Baroque, we are discussing this piece of information in the 'Lion Air crash' thread. That the repair was made in the USA is unconclusive : we don't know whether or not Lion's maintenance made any mistake, or whether or not faulty sensors were the cause of erroneous indications in the first place.
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Apr 3, 2019 13:19:46 GMT 1
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philidor
in service - 6 years
Posts: 8,950
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Post by philidor on Apr 3, 2019 13:18:15 GMT 1
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