PPRuNe Forums - View Single Post - BREAKING NEWS: airliner missing within Egyptian FIR
Old 9th Nov 2015, 18:22
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Etud_lAvia
 
Join Date: Apr 2013
Location: New Jersey USA
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@Yankee Whiskey:

Practically every big jet ever made lacks pitch trim tabs. Instead, they trim by changing the angle of the horizontal stabilizers to the fuselage. That's the function of that jackscrew people keep banging on about...

@susier:

Those parallel scrape marks on the vertical stabilizer are intriguing .... indebted to you for noticing and pointing them out. I struggle to imagine how they came to be, in combination with the stabilizer being so grotesquely fractured.

A0283's notion of the departing rudder makes a lot of sense. But what does it mean, that the slipstream was (presumably) at that angle with respect to the stabilizer? Were the marks made while the vertical stabilizer was still in its normal relation to the aft-most fuselage, or after the fracture?

Whatever story the empennage is trying to tell us, its condition surely bears witness to the intense extremity of the circumstances that ensued once the airframe began its breakup. Dreadful to contemplate.
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Edited to add:

The long parallel scrape marks don't resemble any photographic artifact I am familiar with. I am confident that they accurately indicate the surface condition of the vertical stabilizer. Anyway, they are clearly visible in photographs taken from different perspectives -- the camera didn't make them.

I don't know what the inside of the A321 VS looks like, but typically the internal structural elements are nearly parallel to the long axis of the (tilted aft from vertical in the normal orientation of the VS), and more or less at right angles to that (horizontal in the normal orientation). If an aerostructure isn't built in this manner, it is likely to be needlessly heavy (for a given level of stiffness and ultimate strength). I don't see how it would be structurally efficient to have elements at the angles of the scrape marks.

I have tried and tried, but I am unable to visually correlate the photos recently posted by sardak with the photos showing the long parallel scrapes (which are farther aft in normal orientation, than the area shown in the sardak close-ups).

Last edited by Etud_lAvia; 9th Nov 2015 at 18:49.
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