First- my apologies in advance for what will be a long post.
I have an aviation background (`4400hrs in fixed and rotary wing AC) and an engineering background. I’ve been following this story for a few days, and noodling on the evidence we’ve been presented with. With the hysteria surrounding the possibility of a bomb I thought it might be time to share whatever wisdom I have. (Or don‘t have!!)
There is a video that I am fairly sure everyone has seen already but just in case it can be seen here:
https://www.youtube.com/watch?featur...&v=Vv_kXAFa_P8 The video shows in close-up HD the failure points of the rear fuselage, from both sides and from front and back. Others have already commented on this failure, but I don’t think anyone here has really laid out what we are looking at- and why it argues pretty strongly for an empennage failure of some sort.
As can be seen clearly in that video the following statements can be made:
1. The upper half of the fuselage failed under tension. (Look at the rivet line where the skin tore- you can see the stretching and scallop line between the rivets, as well as the missing paint that could not remain adhered to the elongating metal. Additionally the stringer failures show that they too failed under tension, with the angle of the failure indicating generally that the rear section was rotating downward with a tremendous amount of force.
2. The lower half of the fuselage in the same area was torn beginning at roughly the halfway point of the fuselage- where the metal would be under compression as a result of the failure described in #1. This failure was with somewhat less force, and based on the tear line the movement of the tail was downward as it separated from the aircraft.
3. The horizontal stabilizer is completely gone. It appears (but is not certain) that the mounting bulkhead for the stabilizer jackscrew may be in an upward position, possibly indicating an upward moving departure/failure.
4. The vertical stabilizer is only present in front of the rudder and shows sign of a violent tearing failure slightly in front of the rudder attachment points.
5. The APU is gone- in fact pretty much everything aft and below the rear hinges for the horizontal stabilizer has been disappeared from the airplane.
Take those facts and it is reasonable to make a few simple conclusions.
1. There was a tremendous quasi-symmetrical downward force applied to the tail of the aircraft- of enough violence to literally tear the skin in front of the bulkhead apart.
2. The failure of the aircraft fuselage in front of the bulkhead was the result of something else happening- it was caused by clearly evident physical application of a bending force. For a variety of reasons this force could not have been applied from either inside the AC or from anywhere in front of the failure point.
3. The only possible thing that could apply such symmetrical force aft of the failure point is the horizontal stabilizer.
4. The only way the horizontal stabilizer could provide such loading and such a consequent bending force so quickly is if it failed at the front hinge-pin/mounting point, and presumably rotated leading edge downward.
5. If the HS failed upwards it would explain the missing APU and rudder as well.
This post is not intended to address the actual cause(s) of why the airplane catastrophically failed, but CNN is now reporting that they are “certain” that it was brought down by a bomb. If you are going to argue that a bomb brought it down you are going to have to account for the incredible longitudinal bending force that was applied to the tail- which as far as I can resolve could only have beencaused by a failure of the front attach point of the HS.
Could someone have placed a bomb under or around the HS jackscrew assembly?? Absolutely. Could a bottle of whiskey filled with C4 inside the pressure hull cause the HS to fail so catastrophically?? No idea, but since they are now suggesting that it definitively is a bomb that brought down the aircraft I look forward to discovering the chain of events that led to the horrible incident- and the evidence as indicated above. (mainly because for the moment I cannot connect the two scenarios.)
Just my .02 as always,
dce