BREAKING NEWS: airliner missing within Egyptian FIR

[DaveReidUK]

I ask the question again would those rapid degree of heading changes cause the VS to fail or and what do the they indicate ie what could be the cause.

You might want to bear in mind firstly that those are track, not heading, values (FR24 appears not to know the difference and uses both terms interchangeably).

Secondly, and more importantly, the track values are GPS-derived and are subject to the issues described in previous posts (for example at one point the FR24 GPS coordinates show the aircraft apparently going backwards, which clearly didn't happen).

So I don't think the data supports an AAL587 scenario here.

[Ruimte Aap]

I have made a little comic below to illustrate my thoughts.
I understand that the top of the fuselage near the tail section is on a “pull” load, holding the nose up, whist the underside is on a “push” load, see arrows. (sorry, English is not my native language) What do the stress engineers here think of the following thought: We know there has been a fire in the hold, for whatever reason. This would damage/weaken the structure of the lower part of the fuselage. With the tail pushing down the floor crumples up, the stress on the rivet-joint of the top of the tail section to fuselage is too great and rivets sheer off leaving a large gap following the loss of cabin pressure etc. Depending where the data and power cables for the black boxes run, this could be the moment where these are damaged. Before or during this process outer panels are ripped off from the fuselage hitting the HS etc.

Now, the question is: how do I insert a picture.... :confused:

https://www.dropbox.com/home?preview=31-10-2015+a5.jpg

Hope this will work

[slats11]

Great post Andrasz (#1737 at 0310). Very helpful to summarise the knowns and help keep things on track. I personally found your analysis of the damage and likely sequence very interesting. Engineering background?

The one thing I take exception to is the last paragraph

MODS, could we banish all this nonsense talk about the video to a separate thread on jet-blast ? A) the aircraft was NOT downed by a missile B) those with knowledge of video making / editing have conclusively demonstrated it is fabricated. It has ZERO credibility, it was released hours after the news were already splashed over every conceivable news site, the persistent discussion adds a totally unnecessary clutter on this thread swamping meaningful posts.

Given we don't know what happened, I believe it is a mistake to dismiss something as an irrelevant and meaningless nuisance.

We have a video that increasingly seems to fit the likely circumstances of the explosion. Both our understanding of the crash. And our understanding of what the SBIRS system saw. Not all this information was out before the video was released.

No one has put forward an alternative event or explanation for this this video.

No government body has dismissed this. They obviously have the ability to determine it is a fake. Egypt and Russia in particular both have an incentive to denounce it as a fake if they knew it to be. Even Western governments with no direct involvement in this tragedy would likely chose to reassure their citizens it was a fake (and ISIS couldn't bomb at aircraft with this degree of reliability).

Some people here with significant expertise (Thadbeier) are persuasive it is a fake. Others (DIBO) have presented impressive analysis it is likely genuine. This is often the case with expert opinion.

Some people here initially said you couldn't get that clear an image of an aircraft at FL330 - until others here did just that.


This video is of central importance. If true, then it was a bomb. If it was a bomb, the precise breakup sequence is no longer particularly critical. It is very interesting. But it is not that critical. The bomb is the critical issue.

Egypt and Russia don't want this to be a bomb. People are circumspect about Egypt's expertise and agenda. People are circumspect about Russia's agenda. The bodies are all in Russia. Apparently debris samples are being tested for explosive residue in Russia. So what will we all think if Egypt and Russia say "no bomb?"

Like it or not, that video may (or may not) turn out to be the one piece of transparent evidence we have. And people call it irrelevant. :ugh::ugh::ugh::ugh:

[oldoberon]

DaveReidUK

thank you I was not aware of the situation of FR24 interchanging the terms and also the fact this was GPS derived, which I agree at that stage of events makes them dubious.

[md80fanatic]

I don't want to get involved in this, but just thought I'd point out one thing if I might. If the HS is ever free to move about it's pivot point (ie sans jackscrew) it will align itself with the oncoming air (weathervaning), not slam to one or the other stop. It's takes the path of least resisitence. :8

[dccdz]

Reuters : Investigators '90 percent sure' of bomb on crashed Russian plane
"The indications and analysis so far of the sound on the black box indicate it was a bomb," said the Egyptian investigation team member, who asked not to be named due to sensitivities. "We are 90 percent sure it was a bomb."

[andrasz]

@ slats11

Anyone with basic understanding of the dynamics and effects of an explosion at 31 thousand feet at 400 knots would and should instantly recognise that the video cannot show this accident, smoke will never propagate that way under those conditions.

Also such black smoke comes from a sustained incomplete combustion of heavy carbon compounds (heavy fuels, plastics, rubber, etc.), a bomb (especially high explosives)will give off a puff of white smoke, as the essence of a chemical explosion is instantaneous complete combustion. Obviously the makers of the video did not consider this (of course not, because the video was made when everybody was getting excited about a missile, and the video was made to fit that theory).

If above not sufficient, we know that whatever happened resulted in a near-instantaneous break-up of the airplane, which we do not see on the video. The wreckage provides ample evidence that a (likely fuel fed) fire erupted in the air AFTER the breakup.

I do not wish to dwell on this any longer, those who want to believe rather than think will never listen to reason. The video was created with a laymans understanding of what such an explosion would look like, as this forum is proof that many are falling for it.

This does not mean that it was not a bomb, or IS did not do it (though there are plenty of other loonies out there with an axe to grind, some of them carry Russian passports), it simply means that the video is a fake, full stop.

PS: not engineering, bean counting. But I have learned to recognise the people who know more about a subject than I do, and listen to them.

[Solidfuel]

Interesting as it may be to discuss, I don't see that it matters that much whether the video is real or not.

If it is fake it doesn't mean that the bombing hypothesis is wrong. It's quite plausible that the perpetrators might have a fake video ready to support their claim rather than go to the trouble of filming the actual event.

[funfly]

we will all be angry if it does turn out to be a bomb.

That might be the case but it will be of more concern if this was a structural failure.

To some extent we can take precautions against outsiders taking action even though these actions may only be to reassure passengers and to make it more difficult for the perpetrators. Structure failures would reflect on the airworthiness of a lot of aircraft currently in service with far more repercussions.

FF

[sarabande]

" If the HS is ever free to move about it's pivot point (ie sans jackscrew) it will align itself with the oncoming air (weathervaning), not slam to one or the other stop. It's takes the path of least resisitence."


If the jackscrew lower trunnion fails, the HS may initially align itself to the dominant airflow, but the remainng JS may then jam ( especially if the PF tries to correct a sudden change in pitch) on some part of the supporting structure and cause the HS to create max upthrust on the tail.


Rather like accidentally switching off your car ignition key, causing the lock to operate and jam the steering wheel unless you wiggle it to release the lock.)

Witness marks of the end of JS having flailed around might support that suggestion, however unlikely a 'cheese hole' it might be.

[henra]

Would have sheared the wing off from overload, not broken the tail.



Not necessarily. At 280kts IAS at 30kft and ~Mach 0,75 it probably won't break off, no matter the AOA. Stall speed at that Mach number in clean config at the given weight should be at least 150 - 160kts. 280kts will give you between 3 and 3,5g. That shouldn't suffice to shear the wings off.

[funfly]

Apart from political influence, is there any suggestion that the final diagnosis might well be related to the costs and placement of liability?

[glad rag]

Reuters : Investigators '90 percent sure' of bomb on crashed Russian plane


https://upload.wikimedia.org/wikipedia/commons/thumb/4/43/Punch_-_The_Dogs_of_War.png/438px-Punch_-_The_Dogs_of_War.png

[lomapaseo]

I note many folks trying to match a whole bunch of pieces together in order to complete the picture in their mind.


One thing to consider is that under wing pylon mounted engines don't break loose from pitch loads no matter how violent. They do break loose from side loads most commonly in a spin of some sort. Thus the engines have a tendency to be found relatively close together near where the wings end up.

[RTM Boy]

Exclusive - Investigators '90 percent sure' of bomb on crashed Russian plane | Reuters (http://uk.reuters.com/article/2015/11/08/uk-egypt-crash-russia-flights-tourists-idUKKCN0SX07R20151108)

When (and it's when, not if) the Russians, Egyptians, Irish, Airbus and all other parties to the investigation agree it was a bomb and say so, there will still be posters on pprune insisting it's all a conspiracy and the plane exploded in a fireball at FL310 because of a jackscrew.

[StuntPilot]

All this chatter about what various governments want, about 'agenda's', unnamed 'officials' speaking on condition af anonimity, conspiracies etc. is really affecting the signal to noise ratio in an otherwise interesting discussion.

Please post opinions that are disconnected from facts and tangible evidence, unverifyable claims, visions from a crystal ball and everything else that is out of touch with reality in the topic about the Metro Jet crash in the Jet Blast forum. Thanks. :ok:

P.S. The topic is here: http://www.pprune.org/jet-blast/570266-metrojet-flight-9268-whodunnit.html

[CONSO]

#1748 (http://www.pprune.org/9173876-post1748.html) (permalink (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-88.html#post9173876))

.."This was not a location for a join of fuselage sections.

Please take a close look in the photo- a few inches to the right of the letters A321- there is a vertical line visible from there to the bottom. Also just belwo the two blanked windows is a horizontal line.

The vertical line IS a production join- The horizontal line is a doubler " plate" around the row of windows- typically riveted-bolted internal to the skin as a tear stopper. Where the horizontal and vertical lines visible on the skin join is slightly above where the red lines showing the ' tear" turn horizontal - and are all typical of where a failure in tension would take place. This supports a tension failure in upper half of body- with the section aft of red line being pushed downward.

[A0283]

One of the things that surprised my is that the chairman did not give an overview of the official status of the number of passengers found and the number of passengers identified. Nor was there any mention of the crew.

Cause might be the fact that he expected these to be read by a Russian representative.

Does anyone know? The last number that i read was 163 bodies and 58 identifications. Perhaps Kulverstukas can pull them from the magic hat again. Preferable with a link to the site that is most directly connected to official announcements.

[gonebutnotforgotten]

I can't believe there is still discussion on whether this was a bomb, of course it was. check out the photos of the almost 'unrolled' fuselage sections posted on 5th Nov @ 19:19, or 6th Nov @17:01. (Sorry for some reason I don't seem able to attach images or files, anyone explain why not?) The second in particular shows skin deformed more away from internal stiffeners, and together they just shout 'internal overpressure'. You don't need to take it from unnamed 'intelligence' sources (the same as those who identified non existent WMD in Iraq...), just look.

[Bertie Bonkers]

On a point of order, is it 100% nailed-on certain that the HS photographed is port/left side?

[Downwind Lander]

gonebutnotforgotten says:
"I can't believe there is still discussion on whether this was a bomb, of course it was. check out the photos of the almost 'unrolled' fuselage sections posted on 5th Nov @ 19:19 ... "

To save you the grief:
http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-61.html

[AN2 Driver]

The one thing which does anger me is that the way these investigations are done in recent times, and that is not limited to this one, the tremendous pressure exercised via the press who will print just about everything regardless of quality in order to sell papers, via the internet, where people will do anything to get 5 seconds of fame or make a buck and finally via politicians, who will misuse such stuff for their own agendas, perverts the way these investigations should be done.

ICAO Annex 13 is the bible for that and it is via that excellent piece of regulation that an investigation and the communication about it has to be done.

I found the remark of the ENAC chair very much to the point yesterday, when he acidly remarked that those who have "facts" should forward them to the investigation team instead of politicians and the press.

What has happened here in this case is a total disgrace.
- It undermines the principles of civil aviation accident investigation
- It gives tremendous attention and ideological support to terrorist groups
- It undermines the authorities of the countries involved and forces them into totally unwarranted action
- It exposes the West as weak, without principles and without stamina.

If every time some guy posts a twitter that he sunk the Titanic or something else our governments react in the way they did and get people running like cockroaches from where ever things happen, we will see more and more such imagined or, worse, real attacks happen. Until there is no place left to to run.

Face it: If this turns out to be a technical structural failure caused by fatigue, engine trouble or whatever can cause a plane to come apart, the way British and US "intelligence" services have handled this case, it will have benefitted IS to no ends. It will make thousands of Joe Publics re-think their holiday plans and it will leave Egypt with mass layoffs and lots of people descending into poverty, right into the recruiting scheme for IS.

I do hope that if that were the case, that someone will take these guys to court. I would honestly wish that C.Y.A shots from the hip should be much more painful for the cowards involved than being prudent and very rarely wrong.

[Prada]

I can't believe there is still discussion on whether this was a bomb, of course it was.

I would suggest you to read TWA800 final report. The way all kind of theories were excluded.
It is not that you something "obvious" and jump to immediate conclusions and exclude all other theories. Instead it is about to exclude theories one by one after they become impossible due to revealed evidence.

So far, bomb theory is not excluded.

[ILS27LEFT]

The reaction of major governments, including significant powers like the US, UK,RU,NL and many more, proves that they are confident that this accident was caused by something sinister which could be easily repeated, the same threat is clearly still present at that airport and in the entire region, both in terms of culprit and technique used: this matches with the theory of an airport worker who successfully loaded explosive into the cargo hold of this aircraft. The terrorists, very likely belonging to ISIS in Sinai, did not know if their newly found technique would have been successful until the explosion was triggered hence the lack of further messages from ISIS, after they released their video, as they do not want to disclose any more info about the modality of loading and detonation, obviously they are fully aware now that they can do it again and very easily. Intelligence agencies were reported by the media to have listened into terrorists' conversations showing a sense of victory, similar to Osama Bin Laden when he watched the Twin Towers collapsing, no terrorist knew for sure that the explosion would have actually brought down the plane, they simply did not know if they would have been successful or not as it was something never tested before inside a real flying plane: imagine if the explosive was hidden inside a scuba tank, as a guess, this has never been tested before and maybe this is why the investigators will probably not find any unusual and unexpected material amongst debris on the ground nor signs of explosives as some types do not leave traces. A possible scenario in my opinion which would validate the unprecedented decisions recently taken by major governments against Egypt.

[flash8]

Egypt and Russia don't want this to be a bomb. People are circumspect about Egypt's expertise and agenda. People are circumspect about Russia's agenda. The bodies are all in Russia. Apparently debris samples are being tested for explosive residue in Russia. So what will we all think if Egypt and Russia say "no bomb?"

Like it or not, that video may (or may not) turn out to be the one piece of transparent evidence we have. And people call it irrelevant.

Egypt almost certainly. It will (going on previous form) never be admitted by them to be a bomb, that is the only certainty coming out of Egypt I'm afraid.

If MAK are involved (as they are) however I cannot see this situation happening, also recall BEA and IAA are there as well, amongst others.. this won't be swept under the carpet by the Egyptians no matter how hard they try.

And please, living in Moscow sixteen years (and having day to day contact with Russian officials nowadays) I can say I genuinely believe there will not be a cover up, not for this at least, although the Russian Government do themselves no favours dragging the obvious out.

[CésarVLC]

All this chatter about what various governments want, about 'agenda's', unnamed 'officials' speaking on condition af anonimity, conspiracies etc. is really affecting the signal to noise ratio in an otherwise interesting discussion.
Agreed. I've been following the thread since day one. It has got really valuable contributions, analyzing factual data, providing images as they were released, and posting news updates. But, for a couple of days now, it's become sort of a chat in the lines of "my viewpoint is right no matter what the final report will tell". Special thanks to the ones who tried to analyze the video (or videos if they're actually two) in a scientific way. Good work.

[RTM Boy]

AN2, I understand your unhappiness, the whole thing is far from ideal. But it's nothing new. With AA191 in 1979 when the port engine fell off on take off from O'Hare and the DC10 rolled to the left before crashing the NTSB initially put it down to metal fatigue in a bolt and showed it proudly to all at a press conference. It transpired to actually be due to a maintenance handling issue that damaged the engine pylon mounts through a combination of not following correct procedure and human error. This combined with in-flight emergency response procedures that turned out to guarantee a stall that led to the loss of the aircraft. The bolt was actually damaged during the crash. 36 years later we haver 24-7 rolling news. You just have to deal with it.

If the whole speculation thing is such a problem there is a solution of course; live video streams from all flights - cockpit, cabin and external. Technically easily possible, at a cost. That way at least we would know what the incident looked like almost immediately even with no living witnesses. It would not necessarily give you the exact cause, but would narrow it down considerably.

[_Phoenix]

check out the photos of the almost 'unrolled' fuselage sections posted on 5th Nov @ 19:19 ...

"Unrolled" fuselage is not relevant, since the aircraft at cruise altitude(inflated state) behaves as a punctured balloon.
At 90% level of confidence, the investigators might heard the explosion blast only which was not preceded by any decompression sound (structural failure). The rapid decompression sound is very distinctive, in video below at 0:33
https://youtu.be/m24Gr67i_7o?t=32
The explosion was not after PSB either, since the back box looks pretty good.
With, rupture before PSB, the tail should come down in one piece (including HS and rudder), since free fall doesn't exceed 120 kts < cruise speed < VNE.
We are still missing serious forensics expertise.

[RTM Boy]

Prada TWA800 is still plagued by all sorts of highly creative conspiracy theories asserting all manner of causes - even to this day! However, two things are indisputable; there was an explosion and the in-flight breakup was not initiated by a pre-existing condition resulting in a structural failure and decompression.

So, even with TWA800, structural failure was not the cause, which brings me back to the point I've been making all along; an in-flight explosion at FL310 resulting in a fireball cannot be due to structural failure. It must either be a bomb, or involve an engine explosion puncturing fuel tanks.

[Pontius Navigator]

Phoenix, that mirrored my experience. Rapidly reduced pressure leads to a much slower speed of sound and no explosive noise. However the key word is RAPID.

Whilst that is known colloquially as a Bang Chamber it is actually a RAPID decompression simulator and not an EXPLOSIVE decompression experience.

I think you are generally correct, any explosion noise does not come from the decompression.

[wilyflier]

I don't want to get involved in this, but just thought I'd point out one thing if I might. If the HS is ever free to move about it's pivot point (ie sans jackscrew) it will align itself with the oncoming air (weathervaning), not slam to one or the other stop. It's takes the path of least resisitence. :8


Sorry.
Depends whether aeroD CofP is ahead of or behind remaining pivot point.
Been there, seen that. Thats why Im Wilyflier.

Edges of fuselage clearance holes unlikely to act as movement stops .
The only proper stops I can see on construction photos is that blobby thing on the end of the jackscrew.....Plus the mounting for the screw motor and Jesus! nut at the top.

[Mr Optimistic]

High explosive gives a very sharp 'crack': unmistakeable, just as you can tell the difference between a shotgun and a high velocity round.

[Mesoman]

n in-flight explosion at FL310 resulting in a fireball cannot be due to structural failure. It must either be a bomb, or involve an engine explosion puncturing fuel tanks.

How about a central fuel tank explosion similar to TWA800? Has that been completely prevented by actions taken since TWA800, or is it still a possibility? Such an explosion would explain all the evidence that I've seen.

[Ian W]

That might be the case but it will be of more concern if this was a structural failure.

To some extent we can take precautions against outsiders taking action even though these actions may only be to reassure passengers and to make it more difficult for the perpetrators. Structure failures would reflect on the airworthiness of a lot of aircraft currently in service with far more repercussions.

FF

Strangely, considering this forum, this point seems to have been grossly underestimated. Rather than join those running around trying to prove it was a bomb it might be best to work painstakingly to show that it could not have been a structural failure.

The Horizontal Stabilizer and rudder broke off. It would appear that only one half of the HS has been found and it shows extreme structural failure breaking upward without apparent impact damage from aircraft structures. This is a failure most aircraft engineers would say was close to impossible to envisage even if there had been a bomb in the rear of the aircraft. I think I am right in saying that there is not a case of a 321 crash where the horizontal stabilizer has broken away cleanly at its attachment point.
We will be living with terrorist bombs on aircraft for decades to come and there are ways of ensuring security. But we also need to ensure that there is no problem with maintenance or airframe design that might cause this type of breakup. So the investigators really need to find the other HS and show how and why they broke off the aircraft.

[Mauersegler]

I'm also puzzled as the damage to the HS/VS, a possible explanation would be:

-explosive event (decompression due to skin failure and/or bomb) detach fuselage skin directly in front of VS, that goes up to the VS increasing the load instantly over the design limits, VS crumbles it basis, deforming the attachment of the jackscrew assembly, this would go forward, pulling the HS upwards (or jackscrew break free with similar consequences).
-This put the AC in a nose down attitude instantly, bending the engine pylons upwards and probably detaching the APU/tail cone.
-The HS exceeds the design limits also, breaking in the left side and departing.
-The remaining HS departs with the underside of fuselage probably still attached and also maybe the jackscrew assembly.
-The remaining tail fuselage becomes detached later maybe under aerodynamic and or rotational forces.

[DaveReidUK]

How about a central fuel tank explosion similar to TWA800? Has that been completely prevented by actions taken since TWA800, or is it still a possibility? Such an explosion would explain all the evidence that I've seen.

If a fuel/air explosion in the CWT or ACT was found to be the cause, the fallout wouldn't bear thinking about - both from the airworthiness point of view (all Airbus narrow-bodies grounded?) and politically (large quantities of international humble pie being eaten).

[b1lanc]

“The indications and analysis so far of the sound on the black box indicate it was a bomb,” said the Egyptian investigation team member, who asked not to be named due to sensitivities. “We are 90 percent sure it was a bomb.”

Interesting quote from Tim Clark:

“What happened in Sharm al-Sheikh last week, and to a lesser extent with the … (Germanwings) aircraft, are game changers for our industry,” Emirates Airlines President Tim Clark said, referring to the crash of a Germanwings airliner in the French Alps in March, believed crashed deliberately by its co-pilot.
“They have to be addressed at industry level because no doubt the countries — U.S., Europe — I would think will make some fairly stringent, draconian demands on the way aviation works with security,” he said at the Dubai Airshow.

[Leightman 957]

After 1800 posts is a lot of certainty by posters had emerged, yet the current set of posted conclusions are significantly divided in direct opposition. A lot of certainty is going to eventually be proven wrong. What we do know so far as possibilities, though less so as probabilities:

The ‘event’ may have been of long (20+ seconds) or short (3 seconds) duration.

Primary cause may or may not have been an onboard explosion, missile strike, mechanical failure, or fatigue failure.

Explosion may or may not have been a bomb, missile, battery+, or other, and may not have, by itself, been sufficient to cause the results, meaning more than one item combined to produce an explosive effect, intentionally or by happenstance.

An intentional 'bomb'-- pyro or non pyro—may have been loaded by happenstance, or placed very intentionally at a very specific location for a very specific reason.

A fire in the aft hold so far cannot be ruled out as primary or located with certainty in the event sequence.

HS failure, tail section parting, aft fuselage parting, and any of the three HS support points may each have been primary in sequence.

HS shearing off may have been up, or down, or multiple ups and downs of high or low frequency….and the HS or support structure may have been previously compromised by chemical or mechanical action.

Loss of any of the three HS support points dooms the airframe and frees the HS to large movements in response to both positive and negative loads. The range of possible sequences of resulting actions of the loss of one of the HS pivots in an AC departing normal flight attitudes have not yet been argued and there is as yet no consensus.

It is generally deemed to be in the best interests of the public and of the investigation that the public including Pprune should not know all that is known.


Of note:
Engine pylons are weaker against abrupt yaw than abrupt pitch loads.
Maximum accelerations in pitch or yaw by an intact airframe will be lower than accelerations by an incomplete airframe.
A missile strike does not always result in a warhead explosion. Especially if the warhead explosive has been removed.
“Smoke” in the video may have been added not to enhance an effect but to obscure something, like the absence of smoke, or to misdirect from something else. If you can refrain from laughing, ask why that might be done. One reason might an absence of explosive fingerprint.

The list or people, organizations, political entities, government agencies, and governments who/which for a wide variety of perhaps extremely bizarre reasons known only to themselves might want to “down” a very specific or just some random airliner to leverage some very large political rock is very very long, with most of them probably thinking in terms of a false flag operation rather than advertising their name.

[Kulverstukas]

I can make some summarizing again if you don't mind.

1) I'm sure investigators, contrary to pprune detectives, has all photos of all parts of plane and some of them have plenty of time to look at them at site and even touch them with their own hands. So there is no "mystery" of lost part of HS and VS (for them, or we will know).
2) We cant beat them in game "look we found some suspicious holes, it's a bomb!" so if there was clear evidence of explosion it will be found and nailed already.
3) There is no clear evidence of the way relaxed security at SSH make bomb planting possible or we already will read about suspects arrested.
4) All other "clues", such as sat surveillance, phone intercepts etc. are too weak to make case strong enough to pinpoint it. They can however add flavors after it will be solved through other means.

Major mess organized in Egypt by other countries in my opinion can be not directly driven by any proof but by the fear that in current conditions - even if this was not terrorist case - bombing can be easily made. For example, if you found that your jewelry was stolen, you will check locks and latches and repair them immediately, asking somebody to guard your house till you will go to hardware store, even if most probable case was that your housemaid stole them.

[Leightman 957]

Kulver, Thanks so much for your continuing supply of photos. Your last HS pic at 1790 shows a LOT of leading edge damage not previously visible. The damage is generalized along the visible length (as it would be by a large flying skin section), and not an impact at a single point.

Would posters who have suggested a failure of the left HS tip upward agree that the LE damage in this pic would have probably decreased the strength of the left of HS and increased the probability of the line of failure at the HS center sections as observed? Absent any pic so far of the right HS, how would LE damage to it impact a proposed sequence of events?

[Kulverstukas]

Your last HS pic at 1790 shows a LOT of leading edge damage not previously visible.

Are you sure it is leading edge? As pprune conclusion was it's left wing of HS, for me it looks more like elevator was torn off.

[susier]

Leightman, I hesitate to question a pro but is it not the trailing edge/elevator that is damaged or missing, rather than the leading edge?


ETA, crossed posts with Kulverstukas

[FDMII]

. . . .

Would posters who have suggested a failure of the left HS tip upward agree that the LE damage in this pic . . .
Leightman 957, I believe we're seeing the top of the LH HS, and the damage is along the trailing edge.

[andrasz]

@ Leightman 957

That is the LEFT HS and we are seeing the top surface. The damage is to the trailing edge, probably caused by elevator flutter. But yes, it could have contributed to the weakening of the structure.

Kulver, thanks for the contribution, once again the first new information after so many pages of circular arguments.

Edit: wow, a few of us jumped on this quiet fast, 3 comments to the same extent before I finished typing :)

[Kulverstukas]

And if it is trailing edge, we now face strange picture about any control surfaces (rudder, elevators, slats etc.) are torn off or missing (not shown to us).

[Mauersegler]

Thanks for the new picture Kulverstukas,
As pprune conclusion was it's left wing of HS, for me it looks more like elevator was torn off. (edit: yes, we see the upper side of HS -left side- and the elevator is torn off, the leading edge is ok, see the other picture here http://cdn.aviaforum.ru/images/2015/11/720623_becd8fc01ea0285487052822868c7e21.jpg)
looks like it was suddenly put in the wrong angle... that and a smashed VS...

[Bertie Bonkers]

Absolutely 100% certain that is the top of the LH HS and not the underside of the RH? Because if it was, it would clarify a lot of previous suggestions in very short order.

[Kulverstukas]

It doesn't look as impact damage, rather as something with vector left to right (I mean last pic).

[wilyflier]

And if it is trailing edge, we now face strange picture about any control surfaces (rudder, elevators, slats etc.) are torn off or missing (not shown to us).

Sorry, Please, are we sure this last H S picture is the Left? not a djfferent one (>starboard?)

[Propduffer]

This is an outstanding thread, a credit to PPrune but there are two kinds of posts I've mostly skipped over. The first kind are the "picture analysis" posts which seem to be a separate subject to me. The second type of posts I discount are the ones that propose that if the front joint of the HS were to disengage the HS would flop to 90° to the flight path. I don't have a picture of a ready to install 321 HS but if someone can find such a picture I'm sure it will show that about 2/3rds of the surface area is behind the pivot point. Thus MD80 fanatic is correct in his statement that the HS would align itself with the wind direction in case of loss of the front connection.

It is possible that when the tail section separated from the rest of the plane the VS caught the 280kt (IAS) wind blast and overpowered the HS effects and caused the HS to snap from leading edge down to leading edge up (or even back and forth) and imposed destructive loads. But that can only be a theory for now.


A second point that has been bothering me a bit is all the finger pointing at ISIS. The Russians have been very busy for the last few weeks bombing Al Nustra front positions (read: Al Quida), so they are more likely to be the group with a grudge against Russia.

Again: great thread!

[susier]

The triangular shaped protrusion at the top left of this image:


http://cdn.aviaforum.ru/images/2015/11/720623_becd8fc01ea0285487052822868c7e21.jpg


appears not to be present in the second photograph just provided.

[Kulverstukas]

A second point that has been bothering me a bit is all the finger pointing at ISIS. The Russians have been very busy for the last few weeks bombing Al Nustra front positions (read: Al Quida), so they are more likely to be the group with a grudge against Russia.


Is there huge difference between dealing with different terrorist organizations?

"Even before the military operation in Syria, the General staff of the Defense Ministry made a responsible decision. The essence of this solution lies in our traditional Russian desire to adhere strictly to the principles of legality and justice. So now, all of our munitions are divided into two categories: regular and moderate. Against ordinary terrorists, we use only conventional munitions. Against moderate terrorists, we use solely moderate ammunition. So don't worry, we take into account the moderation of some of the terrorists and treat them with justice."

To clarify, I asked: "Tell me, how your conventional munitions differ from the moderate?"

"Our conventional munitions differ from moderate exactly the same as regular terrorists in Syria are different from the moderate terrorists: they are painted with different paint, in a lighter and more moderate tones," - said the officer and hung up.

[andrasz]

are we sure this last H S picture is the Left?
Yes, it is the same one we have already seen, just a new angle.

[Kulverstukas]

The triangular shaped protrusion at the top left of this image:
appears not to be present in the second photograph just provided.


Because it's under cameramen feets

[wilyflier]

This is an outstanding thread, a credit to PPrune but there are two kinds of posts I've mostly skipped over. The first kind are the "picture analysis" posts which seem to be a separate subject to me. The second type of posts I discount are the ones that propose that if the front joint of the HS were to disengage the HS would flop to 90° to the flight path. I don't have a picture of a ready to install 321 HS but if someone can find such a picture I'm sure it will show that about 2/3rds of the surface area is behind the pivot point. Thus MD80 fanatic is correct in his statement that the HS would align itself with the wind direction in case of loss of the front connection.

It is possible that when the tail section separated from the rest of the plane the VS caught the 280kt (IAS) wind blast and overpowered the HS effects and caused the HS to snap from leading edge down to leading edge up (or even back and forth) and imposed destructive loads. But that can only be a theory for now.


A second point that has been bothering me a bit is all the finger pointing at ISIS. The Russians have been very busy for the last few weeks bombing Al Nustra front positions (read: Al Quida), so they are more likely to be the group with a grudge against Russia.

Again: great thread!

Good points Propduffer.......
(a)My poor memory of early construction picture showed two rear pivots well aft.
(b)even so, loss of control stiffness would likely lead to flutter to destruction
very rapidly indeed, coupled with shredding and shedding of trailing edge components., rapid up downbending loads
Sorry to repeat. I've been there seen that.

[susier]

Kulvers, I think we are talking about a different thing.


The part I am talking about is on the top left of the piece in the photo I linked to; it is a triangular shaped protrusion to the side.


It ought therefore to be present on the top right of the piece in the second photograph as the angle is reversed, if indeed it is the same piece.


I cannot see it. (I don't think this is the same piece of the plane)

[wilyflier]

And if it is trailing edge, we now face strange picture about any control surfaces (rudder, elevators, slats etc.) are torn off or missing (not shown to us).

Sorry, Please, are we sure this last H S picture is the Left? not a djfferent one (>starboard?)

[Mauersegler]

Sorry, Please, are we sure this last H S picture is the Left? not a djfferent one (>starboard?)
The triangular shaped protrusion at the top left of this image:
http://cdn.aviaforum.ru/images/2015/...22868c7e21.jpg
appears not to be present in the second photograph just provided.
indeed, but maybe due to the first taken with a long/tele lens (at distance), changing the perspective (the second has another photographer directly there -in the scene- too).
to 99.9 %, compare here (curvature as inverted wing, metallic attachment point to the rear, same composite failure upwards):
https://commons.wikimedia.org/wiki/File:Airbus-H%C3%B6henruder.jpg
and the other picture of the same HS (LH)
http://cdn.aviaforum.ru/images/2015/11/720623_becd8fc01ea0285487052822868c7e21.jpg

[Kulverstukas]

susier, which one?

https://img-fotki.yandex.ru/get/6607/6154164.285/0_b24d9_a8792807_orig

[susier]

Number 1, there. Sorry, I couldn't figure out how to annotate a photo and then insert it here :O


Also I think the profile of #3 (squarish protrusion to the upper surface) is slightly different in the two photographs.


It could of course be a camera/distance issue, I'm not certain.

[andrasz]

Gave me second thoughts at first, but just spent a couple of minutes comparing the two photos, they are definitely the same, just a trick is played by the camera angle.

The triangular bit (1) is the remnants of a frame on the underside of the skin much behind the fracture plane.

There are several broken layers of the composite skin. The brownish one is the middle at (3) is hiding the gray plane which is visible clearly from the other side.

[Kulverstukas]

As I told you, this video was shoot from point where #1 is located (if a bit further, then it's under lower text overlay). Triangular thingy is a rib and possibly pivot point for elevator, thus reinforced. Which can explain why it stays.

[susier]

Oh I understand now - perspective - I thought you meant the other cameraman.


Many thanks, and apologies for being a dufus..

[Pontius Navigator]

Egypt almost certainly. It will (going on previous form) never be admitted by them to be a bomb, that is the only certainty coming out of Egypt I'm afraid.


It's a bomb.

Well it is probably a bomb according to an Egyptian source quoted on the BBC.

[FDMII]

As I told you, this video was shoot from point where #1 is located (if a bit further, then it's under lower text overlay). Triangular thingy is a rib and possibly pivot point for elevator, thus reinforced. Which can explain why it stays.

https://photos.smugmug.com/photos/i-5fFN4xf/0/M/i-5fFN4xf-M.jpg

[Leightman 957]

Ok, thanks FDM, LE/TE very clear by your pic. Deleted all previously written in this post, except: So What caused the flutter? Control linkage failure? HS pivot failure?

Very difficult to imagine a force breaking the HS along the line it did break.

[Kulverstukas]

FDM, exactly! If only - I think - this trailing triangular point visible is next rib.

[ulrichw]

@ slats11

Anyone with basic understanding of the dynamics and effects of an explosion at 31 thousand feet at 400 knots would and should instantly recognise that the video cannot show this accident, smoke will never propagate that way under those conditions.

Also such black smoke comes from a sustained incomplete combustion of heavy carbon compounds (heavy fuels, plastics, rubber, etc.), a bomb (especially high explosives)will give off a puff of white smoke, as the essence of a chemical explosion is instantaneous complete combustion. [...]

Andrasz - I submit that you are speaking with excessive certainty here.

I'm generally skeptical, too, and dismissed the video when it first came out, but as details of the crash have become clearer, I'm not as certain anymore.

To refute your absolute claims, I'd like to refer you to the following video which shows practice shoot-downs of drones by US Air National Guard planes.

https://www.youtube.com/watch?v=xISpZYajveA

In particular, look at the "kill" at 3:22 - the missile hit apparently releases and ignites a plume of fuel from the target drone, which initially burns brightly, and then turns into a puff of black smoke.
If you continue watching, for a while, there's only a small flame visible on the wreckage until a few seconds later when the flame gets larger and a visible trail of black smoke develops again.

This is by no means conclusive proof that the footage is real, but it refutes your very absolute claims that the black smoke is impossible under the conditions of the flight.

I'm still very skeptical of the reality of the footage, but I think your absolute rejection is based on shaky arguments.

[CONSO]

#1781 (http://www.pprune.org/9174301-post1781.html) (permalink (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-90.html#post9174301)) "Unrolled" fuselage is not relevant, since the aircraft at cruise altitude(inflated state) behaves as a punctured balloon.

Nope - There are way too many crackstoppers-stringers, frames ( circumferentials ) involved to act like a puncture ballon.

https://www.discovery.com/tv-shows/mythbusters/videos/explosive-decompression-minimyth/ show what can happen using same differential pressures as at altitude.

Note the section of body part at 1:40 they are hiding behind showing typical inside absent interior trim. And the extra reinforcing around the windows, the long stringers, and part frame( circumferentials )

As to the photo- it **might** be the result of the plane tumbling at speed so the body ' tube" is into the airstream .

[AstraMike]

FDMII

An interesting picture of the L/H HS from Kulverstukas - it seems it is, as it logically should be, an inverted airfoil - doesn't it?

If so, it looks like the found part would be from the Right side? Don't you think?
And if so, it also looks as if the Leading Edge is missing?

Of course my eyes are not what they once were...

[Kulverstukas]

LifeNews (http://lifenews.ru/news/168720) today makes interview with tourist returned from SSH. They told that with all security enforcement and luggage restriction, they still was offered to be put through VIP route without security check for $20 :ugh:

[lyubko]

Astra Mike
I'm agree with you, just will add one more note - take a look at the broken leading edge of one part (post #1790) and another leading edge ..

[Chronus]

There seems to be a degree of expectation the CVR will yield some clues.

Here is an extract from the AAIB report on Pan Am Flight 103.



"It is not clear if the recorded sound is the result of the explosion or is from the break-up of the aircraft structure. The short period between the beginning of the event and the loss of electrical power suggests
that the latter is more likely to be the case.

Additionally some of the frequencies present on the recording were not present in the original sound, but are the result of the rise in total harmonic distortion caused by the increased amplitude of the incoming
signal. Outputs from a frequency analysis of the recorded signal for the same frequency of input to the CVR, but at two input amplitudes, are shown in Figures C-11 and C-12. These illustrate the effects on
harmonic distortion as the signal level is increased. Finally the recorded signal does not lend itself to analysis by a digital spectrum analyser as it is, in a large measure, aperiodic and most digital signal
analysis algorithms are unable to deal with a short duration signal of this type, however, it is hoped that techniques being developed in Canada will enable more information to be deduced from the end of the
recording.

In the aftermath of the Air India Boeing 747 accident (AI 182) in the North Atlantic on 23 June 1985 the Royal Armaments Research and Development Establishment (RARDE) were asked informally by
AAIB to examine means of differentiating, by recording violent cabin pressure pulses, between the detonation of an explosive device within the cabin (positive pulse) and a catastrophic structural failure
(negative pulse). Following the Lockerbie disaster it was considered that this work should be raised to a formal research project. Therefore, in February 1989, it was recommended that the Department of
Transport fund a study to devise methods of recording violent positive and negative pressure pulses, preferably utilising the aircraft's flight recorder systems.

Preliminary results from these trials indicates that if a suitable sensor can be developed its output will need to be recorded in real time and therefore it may require wiring into the CVR installation. This will
further strengthen the requirement for battery back up of the CVR electrical power supply."

Was "hope " ever realised since then.

[Kulverstukas]

lyubko, http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-90.html#post9174396
last paragraph.

Also isn't it funny that they still makes their little tips on security shortcuts when literally whole world is upside down?

[Ian W]

Andrasz - I submit that you are speaking with excessive certainty here.

I'm generally skeptical, too, and dismissed the video when it first came out, but as details of the crash have become clearer, I'm not as certain anymore.

To refute your absolute claims, I'd like to refer you to the following video which shows practice shoot-downs of drones by US Air National Guard planes.

https://www.youtube.com/watch?v=xISpZYajveA

In particular, look at the "kill" at 3:22 - the missile hit apparently releases and ignites a plume of fuel from the target drone, which initially burns brightly, and then turns into a puff of black smoke.
If you continue watching, for a while, there's only a small flame visible on the wreckage until a few seconds later when the flame gets larger and a visible trail of black smoke develops again.

This is by no means conclusive proof that the footage is real, but it refutes your very absolute claims that the black smoke is impossible under the conditions of the flight.

I'm still very skeptical of the reality of the footage, but I think your absolute rejection is based on shaky arguments.

Well drones do not fly at 450kts at 30,000ft which is why the video looks wrong .
This http://video.dailymail.co.uk/video/mol/2015/11/07/4009291763310182183/640x360_4009291763310182183.mp4 is a video supposedly of ISIS using a MANPAD to bring down an Egyptian army helo. Note that although the helicopter will only be doing about 1/3rd the speed of the A321 there is no 'billowing' of smoke close to the helicopter it is streaming back smoothly for a significant distance. The video claiming to be the 321 is fake. As you can see from the helo video the terrorists want the 'money shot' of the aircraft breaking/burning up and crashing, that is not present in the supposed A321 video despite the break up being only 45 seconds or so after the initial 'event'.

[Control Eng]

Some of you appear to be confusing the horizontal stabilizer blade seal panel with damage to the HS.

http://s14.postimg.org/f12s6qro1/HS_1.png

A close up view of the panel - it is attached after the HS is fitted.

http://s15.postimg.org/iuo8ievvv/HS_2.png

It may not be obvious, but the whole panel up to the riveted strip moves together with the HS to cover the aperture in the fuselage.

[stagger]

To refute your absolute claims, I'd like to refer you to the following video which shows practice shoot-downs of drones by US Air National Guard planes.

https://www.youtube.com/watch?v=xISpZYajveA

In particular, look at the "kill" at 3:22 - the missile hit apparently releases and ignites a plume of fuel from the target drone, which initially burns brightly, and then turns into a puff of black smoke.Well drones do not fly at 450kts at 30,000ft which is why the video looks wrong.

Well the drones in the video posted by ulrichw may do - as they are converted F-4 Phantoms.

[lyubko]

If somebody is intended to commence terror attack , he will find shortcuts in security system of any airport ( even LLBG ) !
Sadly in HESH it's seems cheaper than other one.
It's a sadly fact not a joke. In last case - tragedy.

[Kulverstukas]

lyubko, right and we had two planes bombed (https://en.wikipedia.org/wiki/2004_Russian_aircraft_bombings) purely for bribed security reasons.

Nevertheless, keep openly advertise $20 security shortcut in the airport just after major disaster, full of international security watchdogs... I envy this people's easy view of life. :cool:

[FDMII]

FDMII

An interesting picture of the L/H HS from Kulverstukas - it seems it is, as it logically should be, an inverted airfoil - doesn't it?

If so, it looks like the found part would be from the Right side? Don't you think?
And if so, it also looks as if the Leading Edge is missing?

Of course my eyes are not what they once were...

The airfoil shows "inverted" in the picture of the LH HS; the same form is exhibited in the leading edge of the HS, (on the right).

Further, I believe the rear spar to be intact and that the damage is to the surface structure (ref below, light-blue lines), behind the HS box formed by the fore & aft spars (dark-blue lines). Also, the leading edge is quite visible, in both photographs of the left HS posted earlier.

https://photos.smugmug.com/photos/i-6kn4nM9/0/XL/i-6kn4nM9-XL.jpg


https://photos.smugmug.com/photos/i-6DRb8np/0/XL/i-6DRb8np-XL.jpg

[_Phoenix]

"Unrolled" fuselage is not relevant, since the aircraft at cruise altitude(inflated state) behaves as a punctured balloon.

Nope - There are way too many crackstoppers-stringers, frames ( circumferentials ) involved to act like a puncture ballon.

The "tear line" construction of the aircraft cannot confine large structural failures due fatigue or explosion. Actually the point is that "unrolled" fuselage is not relevant", it doesn't rule in or out the decompression vs the explosion.
Compare the two pictures below:
http://static.apple.nextmedia.com/images/apple-photos/640pix/20050226/Article_int/26c1p6.jpg
https://upload.wikimedia.org/wikipedia/commons/f/f6/Pan_Am_103_wreckage_reconstruction.jpg

[Bertie Bonkers]

Some of you appear to be confusing the horizontal stabilizer blade seal panel with damage to the HS

Ah. I certainly was. So the long and short it is that the HS may not necessarily have failed "upwards"?

[tubby linton]

What other memory sources are onboard which could help the investigation? I can think of the fadecs, the cfds and the qar but there may be others.

[Kulverstukas]

HS shoots (http://lifenews.ru/news/168361)

Here we are, from 2:46

[IGh]

Various prior mentions: re' TWA800, ect --

See the Glossary, usage, simplified usage in the TWA800 AAR ...

Deflagration, Detonation, Overpressure-Event, "Explosion"


[Get the Manual (http://oai.dtic.mil/oai/oai?verb=getRecord&metadataPrefix=html&identifier=ADA405555)]

http://photos.failure-interactions.com/i.ashx?gallery=4702396&mid=98132137&mt=Photo&standardsize=640x480

TWA800 - usage (http://photos.failure-interactions.com/GalleryFilmstrip.aspx?gallery=4702396&mid=98132138&mt=Photo)

http://photos.failure-interactions.com/i.ashx?gallery=4702396&mid=98132143&mt=Photo&standardsize=640x480


CVR-ending: and the Source-event Path, vs Precursor-Path, CVR signatures (http://photos.failure-interactions.com/GalleryFilmstrip.aspx?gallery=4702396&mid=98132140&mt=Photo)

For reader in Russia, Egypt, maybe France (BEA) --
aero' INVESTIGATIONs : a historic role of RUMOR-Gossip-bias,
infusing-moral-values into science . . . then a quick widely embraced (erroneous) consensus.
See Day-5 of the Public Hearing (http://www.failure-interactions.com/public-hearing-mar-apr-39.html) for inflight breakup of B307 Strat' 18Mar39;

See the detailed rumor-driven distraction (http://www.failure-interactions.com/-4--crz-flaps-rumor.html) during NTSB's B727 / 4Apr79

[funfly]

I have asked a couple of times but are there any photographs that show the repair area from the previous tail strike. We should be able to see if there was any failure of the repair.
Yes, I know it was a bomb but I would still like to see how the repaired area stood up. I seem to recall that this repair was deemed 'satisfactory' but not fully compliance.
FF

[Control Eng]

Here is a view of the remains of the Blade seal panel from the top.

http://s17.postimg.org/6m8ojzhjz/HS_3.png

Look at the first three images in this post (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-88.html#post9173909) to see how the elements fit together.

[CONSO]

#1839 (permalink)
Considering the HS ' wing" as to failure

There are basically three directions ( vectors) of failure possible

A) fore to aft re airstream - that is leading edge detaches and wing simply folds back like a swing wing. Improbable due to airloads acting over a small area

B) Up relative to normal flight attitude as in a major dive and pullup bending wing (HS) up to breaking point

C) Down relative to normal flight as in a major pitchover

AND B) or C) if wing tries to turn 90 degrees to airstream becoming a relatively flat plate

I think A) can be dismissed

Which leaves from available evidence published B) or C)

With B) or C) we look at aft section ahead of PB- and it appears most likely it was a down load sufficient to tear top of body away.

Which does not exclude a major attitude change ( pitch ) or a disconnect of jackscrew while changing from climb to level flight for example

OR a bomb forward of PB in lower hold.

Thats about as close as we can get with available ..:hmm:

[susier]

CONSO;


Regarding your 'A' scenario; Given that there is more 'remnant' of the inner part of the HS towards the aft, it almost appears that it could have 'peeled' off, front to back, or at least retained the join to the airframe for longer at the aft/trailing edge.


Could you perhaps set me straight on this if you have a moment? I would be interested to know why you have discounted it, if you see what I mean.


Especially given this photo where the panel corresponding to the leading edge appears to have been torn away:


https://www.tagesschau.de/multimedia/bilder/metrojet-103~_v-modPremium.jpg

[Bertie Bonkers]

... it appears most likely it was a down load sufficient to tear top of body away.


Yes, with you on that. From the apparent lack of any lower HS supporting structure visible in the VS section of debris I've been minded from the off that the HS went LE down. While I originally considered that it went around close to 90° and was forced 'out the back' by aerodrag, taking the tail cone & APU with it, the lack of any evident damage to the front edge of the APU section which I expected to see as a result of impact by the HS pivots now makes me tend towards the idea that the rotation was limited somewhere within the 45-80° range, causing the HS section to go 'down and out', tearing out the support & skin below the pivots and pulling away the tail cone at the lower edge, while exerting downforce sufficient to open the cabin at the top forward of the PB.

[CONSO]

#1846 (permalink)
it almost appears that it could have 'peeled' off, front to back

RE MY A) scenario being unlikely. First I'll admit its like trying to pick flyspecks out of the pepper- but I'll try a simple explanation

While in your car at 30 to 50 mph stick your hand out the window- hold your palm down and level with the road ( horizontal )- you will note not much effort.

ADDED ; Note that structural tests of wings and HS essentially bend wings and HS 'up" until top surface fails- buckles under compression loads near or between ribs . For a fore and aft failure- possible perhaps with major overspeed as in a full bore dive - but available data does not seem to support that.

see for example https://www.youtube.com/watch?v=Ai2HmvAXcU0

I was at that test- and heard the detailed explanation of failure point- which was within a few inches of predicted and in buckling of the upper skin ...
END ADDED
Now tilt your hand palm up slightly- more effort to hold palm steady- as you rotate your hand towards palm forward 90 degrees to pavement , the effort to hold in place becomes significantly larger. [at 400 mph or so- you would probably break your wrist :) }

As of now- it is not obvious from avail photos as to how the front spar of the wing (HS) broke. If we assume it under the A) scenario, the fracture would likely be a tension failure as the front spar was bent back. almost ditto form the rear spar/or hinge.

If under B) fold up or down or somewhere in between, the tear would generally be from bottom up or top down.

That is why a close exam of the failure points to a degree we do not have available from photos is needed.

But a clue may well be in how the moveable shield seems to have broken which ** seems ** to be in an upward position as shown by the carbon fiber sgtrings being bent up ( or maybe by the way it impacted )

Thats about as close as I can come absent more detailed photos ( unlikely) or good shots of jackscrew position and breaking of pivot points.

:8

[Alain67]

in EU countries where people are paid 200 - 400 Euros a month
In which countries ?
BTW, the wage doesn't mean anything if you don't have a look at prices.

[Yiorgos]

Re: http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-91.html#post9174456

wilyflier,


(b)even so, loss of control stiffness would likely lead to flutter to destruction
very rapidly indeed, coupled with shredding and shedding of trailing edge components., rapid up downbending loads
Sorry to repeat. I've been there seen that.
I would like to add that loss of the trailing edge/elevators would move the CP for the remaining horizontal stabilizer forward, possibly in front of the pivot point. If this happened, then the HS would rotate (upwards or downwards) to the maximum angle mechanically possible ...

[andrasz]

they still was offered to be put through VIP route without security check for $20There seems to be a total confusion about security procedures at Egyptian airports. In order to GET IN TO THE TERMINAL you need to stand in a long queue, at the end of which a regular (possibly illiterate) policeman checks your passport and ticket, and if he succeeds in matching at least parts of the name in your passport with the name on a printed piece of paper apearing to be a ticket (in the age of e-tickets, no it is not good on a computer or phone :ugh:) and also manages to find a date somewhere that matches the currect date, he will let you in. There is an x-ray machine at the entrance of the check-in area where all luggage gets an initial screening. This is NOT a security screening but a customs screening, they are primarily looking not for weapons/explosives but for contraband (antiquities, in Sharm corals and other marine life, etc.). There is also a metal detector gate, but in practice if it beeps they look at you, if a foreigner they just wave you through.

The $20 VIP channel will only allow you to bypass the entrance passport check and customs screening before check in. After your luggage gets checked in, it undergoes the regular X-ray security screening just like everywhere else in the world (for all its worth), and passengers get screened twice, once after passport control, then again at the boarding gate. Screening is no worse than anywhere else in the world (but staff are much friendlier than the average screener in Europe or the US), but of course it offers zero protection against anyone with an airside pass, just like everywhere else in the world.

[andrasz]

Some of you appear to be confusing the horizontal stabilizer blade seal panel with damage to the HS.

I certainly did... :O

At least this confirms what several learned posters suggested that it would be impossible for the HS to fail the way I suggested.

[Blake777]

Worth reposting this video from Antelope - as a new contributor his post landed way back. I'm not sure this has been seen. Of interest 8:58 to 9:03.

http://youtu.be/Oa9Q8nCqB0w

[andrasz]

@ Blake777

Many thanks, that is indeed the first picture we have of the Right HS. On superficial look it seems to have failed the same way as the left one, and there is no sign of the central section.

[CONSO]

#1854 (permalink)


re http://youtu.be/Oa9Q8nCqB0w

at following times

8;53— a part but has near top of photo has been blurred- is it part of HS ??

11:55 book found


12;45 --- black square bag or part ??

15:00 o2 mask passenger ?

16:00 cell phones

17:20 aft section with PB

19:00 and on passports- credit cards, and logging of data

[Wantion]

Anyone say if this is normal soot/staining expected in this piece?

https://youtu.be/I9KphRd-OCY?t=158

[Jilted]

The uploader has not made this video available in your country.

Sorry about that.

(US)

[CONSO]

re
The uploader has not made this video available in your country.

Sorry about that.

(US)
++ Video is nothing new-

and anyone can view it using TOR browser


Look it up

[RatherBeFlying]

Antelope's video shows a fairly wide spread between ground searchers. Depending on color, shape and distance from searcher the smallest objects they can expect to find will be 4-6 inches.

Small fragments produced by a bomb going off nearby will tend to be much smaller and would likely blend in nicely with the pebbles and local soil.

To find those, you pretty much need a shoulder to shoulder search on hands and knees. Given the area, not really feasible. Perhaps such fragments may be found lodged in the airframe, baggage or bodies.

The local news made a big deal that an anonymous Egyptian expressed an opinion that likelihood of a bomb is considered 90%:bored:

The possibility of flutter is raising its head. Control surfaces parted company with the airframe. Whether that was the initial failure or came some milliseconds after something else remains open.

[Leightman 957]

Different damage type than the L HS. Appears some of center section remains...hard to tell, but the bend up at the root is probably deformed aluminum holding the bend so suggests that's the failure direction, ie down by the tip, not what posters have expected except those suggesting front pivot failure and full nose down HS, the center section prying apart the fuse structure, dropping all out the bottom. Would like to see the bottom of the aft fuse/VS remains when they finally move it. Outboard elev section must have been moved to pic location. Too unbelievable to have it so close. Yet other debris videoed except baggage has tended not to have been grouped by investigators. It does suggest the elev was not very far away from this piece. You Tube publish date of Nov 5. To speakers of Russian, does the video's audio tell a filming date and if so how does that compare with other films seen so far?

[FDMII]

Likely the RH HS as both wings/wing-tips are accounted for.

https://photos.smugmug.com/photos/i-qvqXk3p/0/X2/i-qvqXk3p-X2.jpg

[broadreach]

Blake777, thanks for the Antelope link, surely the most heartbreaking of all those posted so far and certainly most revealing of the search effort. Something I find mildly surprising is the extent to which the Egyptian government agreed, and so speedily, to large-scale Russian military participation in the sweep-up operation.

The men in the video were obviously combing for documentation and, possibly, remains, leaving behind anything not related to those two.

Given what looks like massive Russian deployment I'm wondering whether the presence of a large number of Russian military aircraft taking up space on the tarmac might have something to do with the turning away of "rescue" civil aircraft.

[Wantion]

Just to make sure..this picture..is this normal wear and tear..ref scrapes stain/soot?


https://idk1.smugmug.com/My-First-Gallery/i-hc88kLp/0/M/scrapes-M.jpg

[wonkazoo]

This post is my second technical review/ analysis, and it too is long- my apologies again. It builds on the first posted two evenings ago. I don’t know how to go back and find that one, but it would probably help you to read that one before this one if you haven’t already done so.

In that post I analyzed the failure of the fuselage in front of the frame just in front of the rear cabin doors, as well as the failures in the rear fuselage. Based on a more intensive review of the available data (Including the two horizontal stabilizers- which were not available to me earlier) I have the following additional observations to make:

1. The fuselage appears to have failed in front of the frame in two discrete sequences. A careful review of the rivetline along the entire plane of failure shows scalloping and clear failure under tension from the top of the cabin approximately halfway down the side of the fuselage- approximately to where the floor would be. (In other words: It was forcibly pulled apart.)

2. From there down the failures are a zipper type tear. The paint is no longer missing from the elongated sections, and between each rivet the failure is a straight line, from the rear (aft) of one rivet to the front (forward facing) edge of the next rivet.

From these observations I think it is safe to say that the fuselage initially failed due to unknown forces being applied in a downward direction aft of the failure point. After that (we’re talking just a few seconds or even less for this entire evolution) the fuselage basically just fell off the rear of the airplane, which was probably accentuated as the aircraft was tumbling nose down due to the loss of the tail surfaces.

So what force(s) caused the fuselage to fail?? I have no idea, nor does anyone else on this board, but there are a few suggestive things to look at.

1. The only thing aft of the failure point even potentially capable of exerting such force was the horizontal stabilizer.

2. The horizontal stabilizer appears to have failed in a similar catastrophic symmetrical fashion, and at least on the port side the rear hinge-pin remained intact on the HS and simply tore the mounting pin right through the attach point located on the airframe. This is very suggestive of an enormous application of bending force.

3. The port side HS shows more intact carbon fiber around the hinge and still present pin, which would be both expected given the reinforcement, but which is also suggestive of a tearing motion in a rearward direction, pulling the fibers apart longitudinally. Additionally the leading edge of the torque box for the HS shows more damage (significantly more) than the rear, indicating (possibly) that the failure was in a generally front to back direction.

3. The rear of the rudder was destroyed as well. This suggests that it may have been impacted by the departing HS.

4. The other indicative evidence currently available is already in my previous post.

So what caused the Horizontal Stabilizer to fail??

1. Flutter is unlikely as while flutter could have caused the structure to instantly fail it would not have applied the necessary forces to cause the fuselage failure as described above. Additionally the FDR would show the extreme deviations of the control surfaces, even if for only a few milliseconds.

2. In my previous post I suggested a failure of the HS causing it to slam to a 90 degree angle but have since revised that possibility to one more in line with a failure of the jackscrew mounting plate, or something more benign. Many photos have already shown this plate (or what appears to be this plate) bent upwards into the vertical stabilizer assembly. (Also possibly explaining the missing rudder…) But at that altitude and airspeed it would likely only take 15 or 20 degrees of instant pitch change to destroy the tail- and to separate the fuselage before separating from the airframe. (20 degrees of negative pitch would equate to an increase in negative lift more than four times greater than what was being provided before that instant in time.) I’m totally making these calcs up, but if the static amount of downward force before the failure was 1000Kg then the resultant of the failure would increase that nearly instantly to 4300Kg roughly at the chord of the HS. With a moment arm of 10m (total estimate) between the HS and the failure point that would result in a torque (twisting) force going from 10,000kg/m to 43,000Kg/m. That would, in any reasonable world, break pretty much anything. (Because I’m in the prehistoric US- here’s that same rough calc in English units: 2000Lb increasing to 8600Lb at the chord of the HS. 30 feet of lever gives the initial static force as 60,000 ft. pounds and the resultant force at the moment of failure as 258,000 ft. pounds.) The point of those really creative numbers is to show that no matter what the negative lift was being provided on the tail it wouldn’t take much to push it to astronomic levels at the point of the fuselage where it failed.

3. A failure as described above would make one hell of a big bang.


So to sum all this up:

1. The airplane lost control and crashed because the tail separated from the fuselage, leaving it completely uncontrollable and (likely) tumbling as it came apart.

2. The available evidence suggests strongly (very strongly) that the failure in the tail occurred prior to the failure of the fuselage and pressure hull.

3. The tail of the fuselage separated from the fuselage (nearly certainly) because something (unknown) happened aft of the point of failure that inflicted a significant amount of bending force (torque) on the airframe itself, causing the failure under tension of the upper fuselage, and the subsequent and consequent zipper failure on the lower half once the initial force had been dissipated- and the HS had departed the aircraft.

4. The aircraft tumbled, destroying the rear fuselage up to the rear of the wing torque box.

5. The tail section, minus the entire HS assembly and a good portion of the vertical stabilizer and rudder descended hull down (due to the remaining sliver of vertical stabilizer) until it impacted the ground.

Everything I have described here is possible, is indicated by the available evidence, and would adequately explain the immediate failure of the FDR and CVR as they were literally right next to the main point of initial failure.

As to what initiated the chain of events I literally have no idea. I’m still working through the available video- like many others, but for the moment I’m still waiting to be shown by the US and UK as to how a bomb in the lower compartment led to the chain of failures that the visible record indicates occurred.

My .02 as always,
dce

[tedd4u]

Wantion: I made a gallery on Flickr of recent photos I found of EI-ETJ (https://www.flickr.com/photos/tedd4u/galleries/72157660984632595/). There is a lot of black something covering the top of the tail cone under the rudder. It appears on both port and starboard sides.

I also noted a "worn" looking area on the starboard side at the bottom of the rudder.

Hope that helps.

[mitrosft]

More pictures of A321 one week before

? ???? ? ? ????? ?? ???? ????????... - ???????? ??????? (http://a-strunin.livejournal.com/126729.html)

Tail section is of interest I believe.

[Kulverstukas]

to large-scale Russian military participation

It's not military, its quite famous in the world EMERCOM (http://mchsgov.livejournal.com/?skip=10) of RF (https://en.wikipedia.org/wiki/Ministry_of_Emergency_Situations_(Russia)). They participated in many major rescue operation in the world.

[pax2908]

So if this was a bomb, how long before there is a fully reliable chemical proof ?

[Prada]

Anyone say if this is normal soot/staining expected in this piece?

https://youtu.be/I9KphRd-OCY?t=158

There isn't any pictures showing underside of rear fuselage. But this kind of sooting is not normal for sure.
It points to a fire after initial event and for quite some time. It means that after initial event tail remained attached for quite some time.

Edit:
Actually this sooting is on the roof. Right where vertical stabilzer used to be. It could be oil. From pictures you can see, that this kind of "sooting" has been almost constant throughout this plane life. As there is no obvious sooting on a tail part roof, this is not an indication of fire around fuselage.

[DaveReidUK]

So if this was a bomb, how long before there is a fully reliable chemical proof ?

It's inconceivable that investigators don't already know whether it was or not.

But the announcement of their conclusions, whatever they may be, is now going to have to be carefully stage-managed, given the developments of the last nine days. Don't hold your breath.

[G0ULI]

To date, only the intelligence services in the UK and US have suggested that there are strong indications that it may have been a bomb. They haven't actually ever said it was a bomb.

But that's the intel business, experts making a guess from limited and inadequate information at best, and indulging in outright fabrication at worst.

A bit like PPRuNe in many ways.

[Bertie Bonkers]

Likely the RH HS as both wings/wing-tips are accounted for.

https://photos.smugmug.com/photos/i-qvqXk3p/0/X2/i-qvqXk3p-X2.jpg

Agree - the HS sealing panel (as noted by Control Eng previously) visible at the top left. I particularly note the angle of the remaining attached piece of elevator.

[Kulverstukas]

This traces on APU cone looks like exhaust leaks for me, not like hydraulic.

[ionagh]

If for some reason the jackscrew link to the HS broke. The HS is not going to suddenly turn 90° but is surely going to suffer from intense flutter as it is no longer rigid? That could explain the elevator damage and final departure of the HS parts?

[Kulverstukas]

London confirms that it has passed intelligence data to Moscow which confirms that the likely cause of the A321 plane crash over the Sinai Peninsula was likely due to a terrorist act, the British Foreign Office told Sputnik on Monday.

[Kulverstukas]

Ionagh, sounds reasonable but doesnt explain sudden loss of FDR data.

[Blake777]

Thanks Kulver.

In English:
Kremlin Confirms London Gave Moscow 'Certain Information' on A321 Crash (http://sputniknews.com/world/20151109/1029805424/uk-russia-sinai-crash-peskov.html)

I guess more ducks in a row.

[HundredPercentPlease]

Wanton,

Twisting it round makes it easier to compare:

http://i63.tinypic.com/29576uc.jpg

[Bertie Bonkers]

A second effort to illustrate a possible interpretation of HS separation. I understand this possibility is contentious/debatable and, as with my previous suggestion that the HS assembly went 'straight out the back' as a result of near 90 degree breaking off the APU section completely as it went, some evidence appears to fit, some doesn't. For simplicity's sake I have ignored movement of the elevator relative to the HS in the diagram.

And as ever, irrespective of the plausibility of this scenario, the initiating factor remains unclear.

https://pbs.twimg.com/media/CTXeqs8XAAAjjpO.jpg:large (https://pbs.twimg.com/media/CTXeqs8XAAAjjpO.jpg:large)

[Marodeur]

Quote
"But that's the intel business, experts making a guess from limited and inadequate information at best, and indulging in outright fabrication at worst.
A bit like PPRuNe in many ways".
Unquote

I think that statement is incorrect. The UK and USA Intelligence services are recognised as the best in the world in terms of global footprint and global reach. By sheer volume and diversity of (re)sources, the two biggest contributors to NATO is untouchable.
PPRuNe, members of PP Rumour Network, has thus far delivered some amazing analysis and knowledge on a very complex subject. This is the beauty of 21st Century communication, it is instantaneous, graphic and accessible by most almost anywhere.

Hiding and sweeping things under the carpet has become very difficult.

[andrasz]

@ Bertie


The logic is not entirely flawed, but there are two things firmly against it:


The slots in the fuselage side conform to allowed HS up (max 5 deg) and down (12 deg) movements, and as we have seen on several photos it is framed by strong support beams. That would limit the possible downward movement of the HS in your scenario.


As the HS moves down, the aircraft nose pitches up, and this would be recorded on the FDR prior to loss of sgnal. As the FDR loss of signal was abrupt without anything but normal parameters, the tail separation had to be one of the first events.

[mitrosft]

Bertie Bonkers

Why would HS drop down? Is there a drawing where you can compare HS areas front and aft of its horisontal axis along remaining joints ?

It should only do that if frontal area is bigger than that behind axis. AOA also has to be considered of course.

[wiggy]

PPRuNe, members of PP Rumour Network, has thus far delivered some amazing analysis and knowledge on a very complex subject.


:confused: Don't we need to know what really happened before deciding whether the above is true or not....

[Wantion]

Thank HundredPercentPlease
That helps...you can see that at least most the staining was previous...
Is it all skydrol or as Kulver says APU exhaust leaking from within the APU cone idk..?!

Here is another shot for ref..underside looks clean enough to me..no evidence of soot..,


https://idk1.smugmug.com/My-First-Gallery/i-2T5G9d5/0/O/image.jpg

[Marodeur]

Quote
"Don't we need to know what really happened before deciding whether the above is true or not...."
Unquote

No we don't. This is where 21st Century style communication enters. PPRuNe, and others, fill a void whereby armchair 'detectives and analysers' can individually and collectively contribute knowledge in real time. The days of solely relying on 'others' to spoon feed us is long gone. Right here and now we have dozens of members contributing some very factual information and graphics. Your and my presence on this forum is proof of that quest for information

Welcome the future.

[Tourist]

No we don't. This is where 21st Century style communication enters. PPRuNe, and others, fill a void whereby armchair 'detectives and analysers' can individually and collectively contribute knowledge in real time. The days of solely relying on 'others' to spoon feed us is long gone. Right here and now we have dozens of members contributing some very factual information and graphics. Your and my presence on this forum is proof of that quest for information

Welcome the future.


That all presupposes that the future doesn't show all Pprune crash speculation to be utterly specious twaddle spewn by fantasists, doesn't it....?

I may have missed the crash where Pprune armchair experts got there first, but I don't remember one.....

[A0283]

Based on the photos that i have seen thus far:

Missing - outside view, major components - assuming that the section before the wing was destroyed in the post crash fire,
a. rudder (and associated GFRP 'strip'),
b. box structure of the vertical tail (VS),
c. any trace of the (below cabin floor) aft cargo hold from forward of that aft pax door to probably 1 or 2 frames forward of the large cargo door,
d. part of the left hand upper panel with windows of above the aft cargo hold (ergo, above cabin floor). I have noted the right hand panel as a 'probable' (in my definition).

Note on the tail cone "soot" views ... I would certainly change that into "staining" ... for a number of reasons (clean surfaces inside and out, minimal staining inside the tail cone components - even less than visible on a number of photos of the plane from the last 2 years). Origin of stains (next those from normal operations) could come from the remaining fuel in the broken APU fuel line (which runs along left hand fuselage side), perhaps additional stains (maybe soot) if the APU oil tank cracked, but these effects have been minimal.

I am working on some 3D reconstructions. What is striking is how many photos you need to get some certainty. The photos in general are of low resolution. And when you get a shot from another angle, it can make quite a difference.

My impression is that i can reconstruct at least one section segment over the full 360.

So photos of the missing components of any kind are welcome. And even better resolution pictures of the known items. Thanks to all the posters providing them :-)

Next to this i am interested in if the flight plan and cargo manifest have been published. Till now i have only seen passenger bags which appear to be only the smaller ones (hand luggage?). No big suitcases or anything that looks like cargo. The inside parts of the cargo holds appear pristine like the rest.

[Newfie]

As to the decision to limit flights and baggage......

This is, or should be, a very clean investigation with a quick determination. As noted above they have most of the aircraft and it was recovered quickly and in a dry environment. This should be easy.

In the event that the investigators with hands on the evidence don't yet know, can't find evidence of a bomb, or mechanical failure, then that must be a scary situation for all. Worst of all would be that the investigators are having the same discussions as go on here.

With no clear determination, then how do you stop this from repeating?

If that is the case then the abundance of caution makes perfect sense.

At this point I think most everyone would benefit from a clear determination, thus I'm guessing that they, the investigators, may be as stumped as we. Or worse, they could have contradictory and unreconcilable info.

[Yiorgos]

mitrosft & Bertie Bonkers,


It should only do that if frontal area is bigger than that behind axis. AOA also has to be considered of course.
for small AOA, CP is typically @ 1/4 to 1/3 of MAC, not 1/2.

I would expect Airbus engineers to have set the pivot point just forward of CP. Keeping this distance small would minimize the loads on the jackscrew, allowing it to be a bit larger would be more fail-safe, see next:

I would expect that shedding of the elevators/trailing edge of HS would have moved the CP further forward. Whether that was enough to bring the CP ahead of pivot point is impossible to say without as a minimum the HS plans and knowing what was missing.

[Filler Dent]

The tail is dirty because its the APU compartment. It gets warm when the APU is used and any dirty water is going to evaporate and leave any residue behind far easier than the main fuselage. There's a sudden transition in dirt because of the firewall doesn't transmit the heat much further forward.

Airplanes don't get cleaned much these days, for various reasons, cost, environmental considerations, fleet size, etc. hence there are a few dirty looking aircraft around. Google images of a B747 and you will soon see evidence of a hydraulic leak from a rudder.

All I see here is just dirt. Skydrol or grease are most likely in the mix too, there are lots of grease points up there and it will get washed down. The transfer/paint scheme is deteriorating but that is not unusual especially at leading/trailing edges and areas where airflow vortex and turbulence occurs. This is not an indication of poor maintenance, a defect or the back of the plane falling off, but purely an aircraft that has obviously been used a lot.

[RYFQB]

Just that tear in the tail from a slightly different angle (to me anyway) - click for full size.
https://lh3.googleusercontent.com/F9Z2xaYrwTqBG2HWh8wV4fQyUFZgJ_duw4R0MI9h1PtbU-ACoPqfQDgZ2NsVhJ5ShIxMRe8=s102 (http://d3lp4xedbqa8a5.cloudfront.net/s3/digital-cougar-assets/AWW/2015/11/05/22956/Sinai-flight.jpg)

Edit: also noting that top of fr77 looks bent forwards in sardak's post (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-88.html#post9173909) yesterday.

[gcal]

@Filler Dent

That my take on it as well.
A lot of aircraft are stained/dirty in that place and it is normal wear and tear.

[ZeBedie]

Is it not the case that the fin and the tail plane were smashed up because they were hit by the hold door, by baggage and large pieces of fuselage after the bomb exploded and as part of the disintegration?

[Ian W]

@ Bertie


The logic is not entirely flawed, but there are two things firmly against it:


The slots in the fuselage side conform to allowed HS up (max 5 deg) and down (12 deg) movements, and as we have seen on several photos it is framed by strong support beams. That would limit the possible downward movement of the HS in your scenario.


As the HS moves down, the aircraft nose pitches up, and this would be recorded on the FDR prior to loss of sgnal. As the FDR loss of signal was abrupt without anything but normal parameters, the tail separation had to be one of the first events.

If the malfunction was with the jackscrew which shares the same compartment as the DFDR/CVR then whatever failed could also have broken the DFDR connection - this could also account for the CVR damage.

The strong support beams would have prevented the internal structure of the HS moving but not prevented the external structure breaking off due to the aerodynamic load/flutter. The effect could be a zoom climb then with loss of left and right HS a severe negative G bunt - both well outside the normal performance envelope. Strangely, this is what is seen on the FR24 recordings.

Just a thought

[Ian W]

Is it not the case that the fin and the tail plane were smashed up because they were hit by the hold door, by baggage and large pieces of fuselage after the bomb exploded and as part of the disintegration?

As was pointed out before the leading edges of the HS and VS do not show any damage - so they were not 'hit' by anything. Yet both left and right HS broke away from the empenage. Only aerodynamic loads well outside the design limits could do that.

[Nightingale14]

For baffling reasons, my earlier post today, where I agreed with other posters that experienced investigators have probably reached a conclusion over whether the crash was caused by a bomb on board, pointing out they could get quickly to a dry arid crash site, has been deleted.

I also asked the make up of the investigation team. So I'll I try asking again, can anyone tell me the make up of the investigation team?

[Barry Plumb]

I am completely new to Pprune. I am a light aircraft pilot and engineer. I have read this thread as it has developed over the last week, and followed with interest as the various parts have been found and photographed.

A028 has provided a recent update on which parts of the aircraft are missing, and I agree with his list. However, there is one other part of the aircraft that I have not been able to account for since the beginning of this thread.

Early pictures showed the two engines that had separated from the wings and fallen to earth some distance from the wings etc. Both engines APPEAR to be generally intact, except the left engine fan which rests in a sooty condition on it's own having separated from the engine.

However the picture of the left engine is misleading since everything forward of the Turbine section seems to be missing. This means that the compressor and combustion sections ie, a very large part of the engine, have not so far been shown to us.

Has anyone seen where these parts have gone ?

[A0283]

You can read my rough transcript of the press conference that i posted before. The chairman stated parties and number of investigators. So 47 in team plus 11 advisors makes a total of 58.

[HarryMann]

PN I'm seriously asking about how, given the video showing extended moments of black smoke engulfing the rear of the aircraft, how could the tail empennage, still attached in the video, wind up apparently soot-free?

Thick boundary layer at rear... ?

[areobat]

However the picture of the left engine is misleading since everything forward of the Turbine section seems to be missing. This means that the compressor and combustion sections ie, a very large part of the engine, have not so far been shown to us.

Has anyone seen where these parts have gone ?Exactly. And this made me wonder if there was an uncontained engine failure that started things off. Could bits of hot flying turbine parts could have ignited the center fuel tank and also created the outward hull punctures as they emerged from the other side? I would think that a catastrophic failure would also sound like a big bang on the CVR.

[RYFQB]

The effect could be a zoom climb then with loss of left and right HS a severe negative G bunt - both well outside the normal performance envelope. Strangely, this is what is seen on the FR24 recordings.
I don't think a zoom climb was recorded by FR24 (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-40.html#post9168426).

[susier]

In the photograph posted by RYFQB, (thank you for this) there is an abundance of marking to the lower (or higher, as it would have been originally) part of the VS which is directly in line with the missing HS.


What is the likelihood of the VS having failed first, and then being hit by a detaching HS?


Can we think of any other possible cause for the scraping and so on to this area?


Link: http://d3lp4xedbqa8a5.cloudfront.net/s3/digital-cougar-assets/AWW/2015/11/05/22956/Sinai-flight.jpg


Also why the 'double line' scrapes to this segment? I have not seen those before. (The two sets of parallel lines on the VS going horizontally)

[A0283]

Both engines found with both fans. Each of which has separated.

Remarkable issues:

a. Engines impact - not really possible to have a good look of what is behind the respective LP compressors. As i wrote earlier, you would expect a part to be buried, but the ground appears to be very rocky/hard. So we have to wait for photos... we will probably get answers when they are lifting them lateron.

b. Fan spinner with soot. At first sight no soot or burn marks on the cowlings and the rest. Again remarkably clean. Only thing that i could come up with is that residual (burning) fuel and oil, after impact, could only escape out to the front, but the distance to the engine discounts that, or there must have been a minor explosion blasting the fan away from the engine (which appears unlikely - the other fan has separated too without soot). The rest of the engines appear to show little or no damage by inflight fire or low or high speed fragment damage.

c. One thing that is visible on a number of photos, from seats to very heavy components, is that they appear to have landed, throwing back and forward rocks and sand, and then the components 'bouncing' one to one and a half meters. Something that i have not really seen before. At Lockerbie one of the engines smashed straight through an asphalt surface. And again suggesting a very rocking/hard surface and subsurface. As well as some sort of forward residual speed of these components.

d. Broken fan blades on one of the fans. You would need to have a matching set of photos of the cowling to see if there have been any blade excursions. Planes and engines are of course designed and tested to contain such failures.

As usual in this stage. Part of an answer but also new questions.

[Blake777]

For those wondering about the role of Israel - Israel provided intel on suspected bomb on Russian jet -- report | The Times of Israel (http://www.timesofisrael.com/israel-provided-intel-on-suspected-bomb-on-russian-jet-report/)

Please note however that Times of Israel is not always a totally reliable rag. Will be interesting to see if a more reliable source backs this up.

[RYFQB]

Also why the 'double line' scrapes to this segment? I have not seen those before. (The two sets of parallel lines on the VS going horizontally)
I wondered about those, too, but maybe they are some kind of imprint/reflection of some internal structure? Isn't there a (fainter) third line above, close to the breaking point?

[Prada]

Exactly. And this made me wonder if there was an uncontained engine failure that started things off. Could bits of hot flying turbine parts could have ignited the center fuel tank and also created the outward hull punctures as they emerged from the other side? I would think that a catastrophic failure would also sound like a big bang on the CVR.

If there was a large uncontained LH engine compressor failure, all the compressor parts flown out at high speeds and fan separated at the event, then it would be difficult to explain sooting and charring of fan that lies only some 20 or 30 meters away from the engine. There was also a comment by one russian expert exploring LH engine rear part about melted non aluminium metal. Then most probably - loose fan hitting fuselage at right point - fuselage would have been broken in half before wings.

It is most probable that the engine got damaged in the falling phase, still attached and working by ingesting flames from fire.
Left side of the forward fuselage have marks of inflight fire and sooting up to the nose cone.

[Ian W]

I don't think a zoom climb was recorded by FR24 (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-40.html#post9168426).

It was recorded the thin trace - then someone 'computed' a different trajectory smoothing where changes were not thought realistic.

[lomapaseo]

Prada

It is most probable that the engine got damaged in the falling phase, still attached and working by ingesting flames from fire.
Left side of the forward fuselage have marks of inflight fire and sooting up to the nose cone.

Agree

Sooting likiely associated with a free fall in flames while still attached to wing and later separated due to spin/spiral side loadings.

I believe the other engine which also shows up in the news videos is quite similar in completeness and ground impact damage.

Nothing of major interest except the suggestion of fire forward of the wing while the engine was still attached.

Incidently, I've never heard of a tail separation causing a fuselage break forward of a wing box but we'll see what turns out in this report as all will be revealed eventually.

[A0283]

Another set of pictures that i am still looking for is a better top down view of the main impact site. From the cockpit section to the wing.

When you look at the available images it COULD look like roughly three section segments that lie in a zig zag, one segment behind the other, between cockpit and wing.
You may have expected a denser debris field. But we dont know how long there was a fire and what rescuers had to do to put out the fire and recover the passengers.

When you estimate the distance between wing and cockpit, and then would add distance because of the possible zigzag ... what do you get? Has anyone measured either one of those two distances?

The max total length that i expect would run from behind the front pax door to a number of frames before the third pax door.

Early on i wondered whether the whole fuselage was visible. But the clear section segment around the third pax door rejects that. Which means that my impression is that we are still missing the aft cargo hold as described in update 7.

[triumph61]

Here is a little collection of Pics. Look at Sections Door 2L and 2R

https://drive.google.com/folderview?id=0B5INjAze86wxSWVaTVBpTWZkY2M&usp=sharing

[PersonFromPorlock]

I may have missed the crash where PPRuNe armchair experts got there first, but I don't remember one..... Fair comment, but recall that the CBS/Dan Rather/Memogate scandal was uncovered by 'armchair' experts on the web who observed that the 'typewritten' 'official documents' presented in evidence were produced on a computer using software that wouldn't exist for another twenty years. So on occasion amateurs can help, and probably don't do much harm the rest of the time.

[Kulverstukas]

Taking pprune in general, I can confirm that at least RedWing overrun was solved in two Russian aviation enthusiast forums (aviaforum and forumavia ru) way earlier than any official documents was released. So was Kazan crash if not so fast and sure.

PS: way more interesting, in RW case field test was carried out with one tech guy, coordinated by forum posts ;)

[CONSO]

I note that the CVR and FDR were recovered almost immediately

Location as installed - can be shown at

http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-50.html#post9169622
4th Nov 2015, 22:38 #996 (http://www.pprune.org/9169622-post996.html) (permalink (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-50.html#post9169622))


I note that CVR shown at

http://www.pprune.org/9168948-post878.html
4th Nov 2015, 16:23 #878 (http://www.pprune.org/9168948-post878.html) (permalink (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-post9168948.html)) CVR has been removed from area attached to skin of tail cone near jackscrew


I note that other recorder is somewhat bent --- FDR - ? but removed or torn from tray ??

http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-14.html#post9165152

++++

OK- None show fire damage and all told are quite clean- rules out fire IN that compartment- sort of expected

But the generally good condition absent dirt of the CVR and the traces of dirt on the FDR - to me indicate the CVR was on or in the section including the jackscrew- maybe the HS wingbox, etc. A pair of bolt cutters could easily have been used to remove the CVR as shown by the attached framework ( either bent or cut and folded over to avoid sharp edges when handling. One was removed from tray before photo.

IF --big IF the CVR was cut from the framework or twisted off- then the part(s) missing from released photos and press etc were removed before press got to area.

Those **may** be the parts that define the problem which may not be shown until investigation is well along- IF our recent speculations are close- that it is a maintenance issue OR a well placed small explosive --- :suspect:

[andrasz]

I may have missed the crash where PPRuNe armchair experts got there first, but I don't remember one.....


I do recall that the discussion following PAF101 have settled on essentially the same conclusions within 2-3 days as were confirmed by the accident report a year later, to a large extent attributable to the accurate factual information supplied by one forum member going by the name of Kulverstukas.

[A0283]

I may have missed the crash where PPRuNe armchair experts got there first, but I don't remember one.....

It's not a game.

The main goal for accident investigation is learning lessons and thereby preventing future accidents. I would say that people on Pprune are more interested in learning these lessons than the average person.

There are many ways to look at an investigation. One for example:
a. input,
b. access,
c. processing,
d. output,
e. learning lessons,

In the input stage you usually have a number of people who know little or nothing about aircraft. Some are called witnesses. A person taking a photo of this plane just before takeoff - even if knowing nothing - is a valuable witness who provides input. Spotter's pictures are now routinely used. So even laymen can be first.
During the MH17 investigation some people offered assistance. This was rejected. Lateron the investigation asked people if they could help to provide more pictures and information. A proper investigation knows how to collect and integrate ALL information. The crowd has the advantage of numbers. This investigation has 47+11=58 persons. When you want to find a certain (input) video or photo ... and ask the investigators or pprune members ... who would find it first ... you might be surprised.

Investigators will have and should have access to all ('available') information. And they decide what is shared. So people outside the investigation have less access.

Processing is related to experience. If you compare an investigator with 1 year of experience to a person who has just retired after 40 years in the business ... who would you listen to ... I would listen to both.

Output is that of the investigation. Simple. But we all know that there can be a lot of discussion ... going on for many years ... Some extra knowledge is an advantage when you want to make up your own mind. And that brings us back to learning lessons.

A few days ago a person posted that all people visiting this site were 'idiots'. So he joined up to tell other people they were idiots visiting this forum. He gave a new meaning to the word "irony".

[Bertie Bonkers]

Is that not the cvr the chap in hi-vis is holding? Sat on the bottom tray as best I can figure from Kulverstuka's photo. Back end bent down by something large & very close behind it hitting it hard?

[Mr Optimistic]

Once the tail had departed, is it clear where the loads would come from to split the fuselage at the wing box ? The inertia of the rear fuselage may not be sufficient. If so the tail must still have been attached at that point generating a force and moment opposing the wing lift, if so the tail separation was later. Ditto the HS, is the inertia of the tail alone sufficient to allow shearing by aero forces ? If not they must also have separated when the tail was still attached to the larger body.

Hardly seems necessary to point out that this is speculation......

[RYFQB]

It was recorded the thin trace - then someone 'computed' a different trajectory smoothing where changes were not thought realistic.
Yes and no; let me explain what was done and why:

1) The thin trace is recorded pressure altitude, and yes, I didn't think it looked realistic.
2) What I did wasn't smoothing; I first took recorded vertical speeds prior to upset and used those to calculate altitudes (starting at 28000 feet). The calculated altitudes matched recorded altitudes to within a few tens of feet - prior to upset.
3) Considering that a success, I did the same from upset onwards. Now the calculated altitudes did not match recorded altitudes, and the new plot is, yes, surprisingly smooth.

The first problem with the recorded barometric altitudes post upset is that they bear no relation to the recorded vertical speeds. That "zoom climb" for instance takes place while VS is (very) negative.

Secondly, the altitude changes over time for the first "climb" works out to a VS of 95280 fpm or 488 m/s, followed by a descent at -187800 fpm or -955 m/s (M3.15). If the transition was linear, the plane pulled -42G there. And something similar happened another nine times over the next twenty seconds.

That's just not believable, is it? I'm just some random dude on the internet though, so if you don't think my calculations can be trusted either, that's fine.

[fyrefli]

Sooting likiely associated with a free fall in flames while still attached to wing and later separated due to spin/spiral side loadings.

I believe the other engine which also shows up in the news videos is quite similar in completeness and ground impact damage.

Nothing of major interest except the suggestion of fire forward of the wing while the engine was still attached.

Incidently, I've never heard of a tail separation causing a fuselage break forward of a wing box but we'll see what turns out in this report as all will be revealed eventually.

You're not the first to make this observation (although you've made it in more detail than others). I've pondered whether it's possible for the aircraft to have entered such an attitude that the flames were behind the engines (behind in the sense of the usual direction of travel) but in a state or transition such that they ended up in front of the flames in the airflow.

Please excuse the question if it's daft - the aircraft I fly are two-axis, engine-less and their stability owes itself largely to me hanging under them!

[RYFQB]

Nothing of major interest except the suggestion of fire forward of the wing while the engine was still attached.
This might be incredibly stupid, but if the aircraft was in a flat spin, could one engine be moving backwards and ingest flames from a fire behind it?
Edit: fyrefli asked basically the same thing in the previous post. And here's that iranian IL-76 (https://youtu.be/MOnsIGcZS-M?t=10) posted by rcsa earlier.

[Lonewolf_50]

This might be incredibly stupid, but if the aircraft was in a flat spin, could one engine be moving backwards and ingest flames from a fire behind it? My first instinct on that thought it "but it's also falling, so what we might think would be ingested is above it" if that makes sense. The plane falls, even in a flat spin, because a spin is a subset of a stall, and once stalled, the plane falls.

[A0283]

If you take recent accidents as an example you would expect fpm in the range of 6,000 to 13,000 fpm. With 9,000-10,000 fpm as the more likely ones.

In this case the vertical speed appears (just my first impression, no more) to have been less than in the AirAsia case. But without having any specific data you could start with a 9,500 fpm estimate.

When you look at the numbers and go over 20,000 fpm and even an order of magnitude higher ... then you know that it is highly unlikely that these numbers are correct.

Try to find a solution ... that's what random dudes do ...

[Kulverstukas]

Bertie Bonkers
@CONSO

Is that not the cvr the chap in hi-vis is holding?

CVR has square memory housing and FDR has round one (if photos in press reports are correct).

[HundredPercentPlease]

Also why the 'double line' scrapes to this segment? I have not seen those before. (The two sets of parallel lines on the VS going horizontally)

Intriguing. I have put the broken part back in position, but they still make little sense.

http://i67.tinypic.com/9lh10g.jpg

[Barry Plumb]

Thanks to Triumph61 and A0238 for further pictures and details of the engines. you are correct, the only piece missing from the front of the left engine is the fan, which is located close by.
Looking into the front of the cowling, I guess that is the front of the compressor section we can see. The by-pass duct is very sooty.

[Yankee Whisky]

QUOTE: Free Flapping HS I don't want to get involved in this, but just thought I'd point out one thing if I might. If the HS is ever free to move about it's pivot point (ie sans jackscrew) it will align itself with the oncoming air (weathervaning), not slam to one or the other stop. It's takes the path of least resisitence. :8
END QUOTE




I think the writer of the above must bear in mind that the horizontal control surfaces consist (normally) of three parts;


a) the stabilizer which leading edge is moved by a jackscrew
b) the elevator which is operated from input by cockpit controls and
c) The trim tab which is used to trim the aircraft for hands off (auto pilot) flying. (or a combination of b) and c) where the trim tab does all the work to move the elevator)


Now visualise the jack disconnecting from the stabilizer. Would the airflow then not move the stabilizer either nose up or down depending on the starting position ? Yes, the elevator, if disconnected would free float and take a position in the flow influenced by the trim tab position.

[Bertie Bonkers]

@ Bertie


As the HS moves down, the aircraft nose pitches up, and this would be recorded on the FDR prior to loss of sgnal. As the FDR loss of signal was abrupt without anything but normal parameters, the tail separation had to be one of the first events.

I'm thinking in terms of a sudden violent event - such that the inertia to be overcome in pitching the nose up would create enormous tension at the top of the cabin.

In terms of the flight recorders, I may be pushing the plausibility envelope, but I see some possibility that their connections were destroyed by the sudden movement of the HS internal structure beyond its normal operating limit.

[nonPilotContrib]

It was recorded the thin trace - then someone 'computed' a different trajectory smoothing where changes were not thought realistic.
s-mode data do not show zoom climb: vertical velocity is always negative after initial event

[Filler Dent]

No trim tabs here. It's FBW.

Just big elevators controlled by the ELACs and SECs, two actuators per elevator, one each side is from blue hydraulics and the remaining two are from green and yellow respectively.
ELAC 2 is normally in control, if it fails then ELAC 1 takes over, if it fails then one of the SECs does.

[Ka-2b Pilot]

Any GPS readings after the initial event are likely to be unreliable, as I explained in an earlier post http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-41.html#post9168602
Both GPS antennae are normally on the top of the fuselage, one over the cockpit and the other a little further back and most usable satellites are above the height of the aircraft. The antenae require direct line-of-sight with no obstruction. With the aircraft tumbling its very likely that that will not be the case for much of the time. This will cause a lot of random spikes as my earlier post explained.

[sarabande]

100% "Intriguing. I have put the broken part back in position, but they still make little sense."

Could they be scrape marks from sections of the HS flailing around as the whole assembly tumbles, prior to departure of the two main HS components ?

In previous pics of the HS on the ground, there are numerous strips of composite about the width of the scrapes.

[Kulverstukas]

andrasz I do recall that the discussion following PAF101 have settled on essentially the same conclusions within 2-3 days as were confirmed by the accident report a year later, to a large extent attributable to the accurate factual information supplied by one forum member.

It was one guy from Smolensk, not me.

[wonkazoo]

@Filler Dent

"No trim tabs here. It's FBW."

The jackscrew is the trim mechanism.

On the idea of the huge variations in vertical speed without corresponding altitude changes: This is fairly easy to explain. (At least possibly)

After the tail separated the plane almost certainly tumbled numerous times. (This also explains the disintegration of the weakened rear fuselage up to the wing box- where it was strong enough to resist the continued failure of the fuselage skin...) As it tumbled roughly around the middle of the now altered CG the nose would have gone through a series of oscillations in quick form. Down at an extreme rate until the nose passed through the vertical facing downward, then up at a fantastic rate while the nose rotated up to the vertical again, before once again beginning the down cycle as it passed through the vertical.

Because the pitot static system is located in the front of the airplane (almost as far forward as it can) the readings would have been way out of whack, and would correspond at least generally to what was seen on the traces.

Finally: A flat spin: This almost certainly did not happen as there was nothing left to induce the adverse yaw necessary to initiate the autorotation required for such a spin. Further the impact shows pretty clearly that the wings were not rotating about the yaw axis in any meaningful way. If one engine failed and the other continued generating thrust it is at least theoretically possible that the airplane could have been forced into a spin, but given the weight and balance of the failed fuselage to that point it is incredibly unlikely that this happened.

Just my .02 as always,
dce

[nonPilotContrib]

Any GPS readings after the initial event are likely to be unreliable, as I explained in an earlier post http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-41.html#post9168602
Both GPS antennae are normally on the top of the fuselage, one over the cockpit and the other a little further back and most usable satellites are above the height of the aircraft. The antenae require direct line-of-sight with no obstruction. With the aircraft tumbling its very likely that that will not be the case for much of the time. This will cause a lot of random spikes as my earlier post explained.
While this would be true in general but the gps data in s-mode also include gps accuracy and the first high g spike (~50g) is recorded while accuracy is still high, the issue here is that we do not have a timestamp at the transmitter but only at the receiver so it is hard to claim accuracy when computing accelerations

[Leodis737]

As was pointed out before the leading edges of the HS and VS do not show any damage - so they were not 'hit' by anything. Yet both left and right HS broke away from the empenage. Only aerodynamic loads well outside the design limits could do that.

Are you sure? A large part of the leading edge of this one appears to missing entirely.

http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-94.html#post9174846
(trying to link to picture of the broken HS in FDMII's post #1862)

The VS isn't exactly in good condition either... ?

[PersonFromPorlock]

The first problem with the recorded barometric altitudes post upset is that they bear no relation to the recorded vertical speeds. That "zoom climb" for instance takes place while VS is (very) negative.

Secondly, the altitude changes over time for the first "climb" works out to a VS of 95280 fpm or 488 m/s, followed by a descent at -187800 fpm or -955 m/s (M3.15). If the transition was linear, the plane pulled -42G there. And something similar happened another nine times over the next twenty seconds.

That's just not believable, is it? I'm just some random dude on the internet though, so if you don't think my calculations can be trusted either, that's fine. While the last reported instrumentation readings may not be reliable for directly showing the flight path of the plane, they may still be indirect evidence of it. Assuming (yes, big 'if') that the sensors were still functioning properly, can anyone with knowledge of the plane's systems suggest what gyrations could produce those readings?

[MrSnuggles]

Juggling the dimensions, I hope I got it right when I estimate the red arrow to be 94 cms long.

Pasteboard ? Uploaded Image (http://pasteboard.co/20SCBdFW.jpg)

Hope you can see the picture. It is from the tail fin.

[lowbank]

in answer to the questions about the engines.
the damage on the fan blades is not consistant with a blade failure. i have lots of pics to compare against, unfortunately cannot share. IP reasons
if you watch the A380 blade off test on utube around 4:50 you will see the damage being done to the tips of the blades, not very detailed but best there is out there. i was hiding when they filmed that.
damage is ground impact damage.

[Kulverstukas]

To whom it's fancy to read a lot of Russian letters - another explanation of cause of tail separation, based on forums investigation (https://yadi.sk/d/Dw0fCFR1kLSZC).

TLDR: fatigue failure of upper APU section mounts

For me it seems unreasonable that gap in the tail part can be unnoticed for a long time.

[susier]

Oh nice work boys re the VS and putting it the right way up :ok:


RYFQB I think you were right that there is one further line, partly visible on the original image at least. It appears to be the same distance apart again as the other two are from each other.


I cannot find an image of the internal structure of the VS that shows anything at this particular angle though.


If it was an external object which caused what appears to be paint loss along these lines, I can't for the life of me think what it can have been.

[Prada]

Intriguing. I have put the broken part back in position, but they still make little sense.

Thanks for doing reconstruction image of tail fin. I had something like that in my mind.
these vertical scratches were not present before crash. And they must have happened in flight.
They are located right over HS trailing edge. Could be marks from departing HS. Note how parallel these scratches look! Same event?
It could mean that forces that made HS to fail were from below, relative to fuselage of course.

[A0283]

Here is a little collection of Pics. Look at Sections Door 2L and 2R
https://drive.google.com/folderview?...2M&usp=sharing

When you try to make sense of these pictures, the questions with these components are:

a. are they in the place they landed on impact ?

b. or were they lifted or dragged to the side after impact to either get them out of the fire, or get better access to put out the fire, or lifted to search for and recover the victims ?

when a., this could suggest an inflight fire,

when b., this would require checking for dragging marks on the ground, and if not, for a vehicle with a crane with sufficient capacity,

I have not checked the ground or debris for dragging marks (again a better top down view picture would help). But have seen the white vehicle/truck with the 0.5-2.0 ton crane at the back. So lifting and being laid to the side is a clear option.

My impression is - low probability that both the L2 and R2 panels broke away from the fuselage at almost exactly the same time and altitude, and at low altitude (because they are so close together) ... So the burn marks could well have come from being exposed to the fire that destroyed the forward fuselage. And the panels then moved to the side, away from the center of the fuselage.

By the way, this is an example of the fact that investigators have better access to this class of input information.

[HundredPercentPlease]

What you really need to examine are all the fractures. Which is precisely what the investigators will do. Those fractures will tell you the direction of the forces that caused the fracture, and from those you can start to build a picture of which bit broke what.

None of which can be extrapolated from a bunch of photos.

In the mean time (!) here's a very approximate superimposition of the original airframe onto the previous photo:

http://i64.tinypic.com/2mmrur.jpg

[A0283]

Parallel lines ... rudder departure scratch marks ?

Elevator hinges and THS appear less probable.

This requires measurements.

There is redundant set of actuators, and hinges, and ...

++
Options:
- Rudder 7-point attachment to the fin structure.
- Three rudder actuators - unlikely, too close, for a standalone scenario,
- Structural failure exposing CFRP stiffeners or brackets - might explain the close parallel lines.
- Structural failure exposing GFRP stiffeners or brackets - might explain the close parallel lines.

or a mix of these options,

++++
If you extend these lines downward you stay within the 'envelope' of the plane and reach the tailcone behind the aft firewall of the APU space. However, these components have been found and are unlikely to cause these parallel lines.
So the options you get is either a lower piece of structure breaking out of the VS, and rotating up relative to the VS box, such a part is missing. Or the CFRP strip or rudder departure. In each case you have to put the tail section tail down to get these marks. Which would suggest this is not the immediate cause but a follow up fracture.

++++++
The lower line is at about 12 degrees, the upper at about 15 degrees with the vertical ...

[Filler Dent]

PersonFromPorlock wrote: While the last reported instrumentation readings may not be reliable for directly showing the flight path of the plane, they may still be indirect evidence of it. Assuming (yes, big 'if') that the sensors were still functioning properly, can anyone with knowledge of the plane's systems suggest what gyrations could produce those readings?

With regard to the altitude errors I'll add this.
The baro altitude is sensed either side of the aircraft and converted to a digital signal within a few inches of the static ports for the Capt and FOs systems. In normal flight, both sides sense the same static pressure, it's converted to a digital signal and sent to the ADIRUs. The ADIRUs sum this received signal to generate the Capt and FOs altitude. (ADIRU 1 for Capt, ADIRU 2 for FO)

Since the signal is summed a large discrepancy in sensed pressures (or a failed ADM) will cause a corresponding altitude error. ie. If one side sensed 20000' and the other side 10000' the ADIRU would compute 15000' and display that.

I would suggest an airplane horrifically tumbling out of control would most probably generate these errors before electrical power was lost completely.

[sardak]

Different view of the parallel lines.

http://i.imgur.com/mrERkyI.png
http://i.imgur.com/dCsqxVT.png

[LiveryMan]

Investigating a line of thought:

Can you operate the A321 with the APU running in the air to supply a generator (in the case of one generator inop?)

The line of thinking is that if the above is possible, what are the odds a catastrophic failure of the APU causing VS and HS damage to the point of them separating or controlling the steep climb?

[susier]

How far apart are the rudder attachment fixings on the VS? (anyone got a spare A321 hanging about and could grab a ladder?)


ETA: Looking at Sardak's post I think it's clear there are some more funny camera effects going on, and it isn't paint loss at all, and is related to internal structure as suggested earlier.


Sorry for wasting time.

[rogerlondon]

On the VS image near the bottom left of the blue paint looks like an entry hole, with white paint removed and primer or raw metal showing.

Horizontally above the door the left end of the scratch-like mark coincides with the concave turn in the fuselage yet strangely does not pass across it.

A challenge to discern the causes?

[Etud_lAvia]

@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.
____________________

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).

[Gavin Lundie]

Has anyone considered the following scenarios:

Explosion destroys Fly By Wire signals to elevator and rudder, causing control surface run away to extreme travels, resulting in structural failure of the empennage due to huge aero loads.

or

Hydraulic lines are severed to elevator and rudder servos, loss of pressure allows the control surfaces to flutter, as they are now not held "stiff" relative to the HS and VS. Remember that these surfaces are not mass balanced, relying on hydraulic actuators to prevent flutter.

Or a combination of the above?

Notice that both elevators and the rudder came off, suggesting flutter. Elevator flutter would also be a reason to lose the HS halves as happened.

[susier]

The lines can be seen here in this link provided earlier by Mitrosft:


? ???? ? ? ????? ?? ???? ????????... - ???????? ??????? (http://a-strunin.livejournal.com/126729.html)

[CONSO]

#1924 (http://www.pprune.org/9175495-post1924.html) (permalink (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-97.html#post9175495))

One earlier photo of the CVR was such that the label with a little magnifaction clearly spelled out solid state memory cockpit voice recorder

see

http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-44.html#post9168948

note the mangled attach points and a split in the lower orange mounting ' tray'

now look at

http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-50.html#post9169622

to determine how and where it was mounted compared to the FDR ( which mounted different but above and with a badly bent ' tray " in the hands of ?? as shown in

http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-14.html#post9165152

but no obvious ( in this view ) aluminum colored tray or attached framework.

Which is why I think that same section hit the ground with CVR still ' installed" and was taken away before press access

IMO damage to CVR and FDR was most likely from impact with ground while attached to a heavy object such as HS wing box and jackscrew brackets, etc. :hmm:

[RatherBeFlying]

Initially on seeing the tailplane missing from the tailcone and the skin below the tailplane ripped out, the most likely explanation seemed the jackscrew parting company with the tailplane leading to the tailplane pivoting down and being torn out by aerodynamic forces.

But we now have both exterior halves of the tailplane with so far no joining structure (likely containing jackscrew and hinge mounts).

Given the abrupt cessation of data to the FDR and CVR, perhaps the same event (explosive or structural) severed data buses and/or hydraulics, pneumatics etc for the flight controls, which then overloaded themselves.

[CONSO]

#1949 (http://www.pprune.org/9175671-post1949.html) (permalink (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-98.html#post9175671))
Hydraulic lines are severed to elevator and rudder servos, loss of pressure allows the control surfaces to flutter, as they are now not held "stiff" relative to the HS and VS. Remember that these surfaces are not mass balanced, relying on hydraulic actuators to prevent flutter.

problem with both electrical and or loss of hydraulic.

Your comment would be correcct IF hydraulic clyinders were directly used to position HS. BUT both systems drive motors which turn the jackscrew

Any cutting of wires or hydraulic lines would simply leave the jackscrew non moveable by rotation, and absent other issues HS would stay in place. :ugh:

[Gavin Lundie]

I was not referring to the screwjack.

The actuating servos that move the rudder and elevators are FBW and are hydraulically actuated.

[Bertie Bonkers]

#1924 (http://www.pprune.org/9175495-post1924.html) (permalink (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-97.html#post9175495))

One earlier photo of the CVR was such that the label with a little magnifaction clearly spelled out solid state memory cockpit voice recorder.

Yup, with you - my mistake. I expected the FDR to be a box+cylinder & the CVR to be box+drum - I guess it's all in the length. Looks like FDR on top from Kulverstuka's photo at 996. Thus:

http://newsimg.bbc.co.uk/media/images/45915000/jpg/_45915622_blackboxi.jpg

[CONSO]

#1954 (http://www.pprune.org/9175709-post1954.html) (permalink (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-98.html#post9175709))

RIGHT- MY GOOF re rudder servos- but does HS also use servo elevators on Airbus instead of whole HS ? :confused:

[Orestes]

The VS scrape marks aren't visible in this photo.








http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-93.html#post9174686

[Ka-2b Pilot]

CVRs/FDRs can come in different shapes/sizes. The CVRs I worked with were in standard oblong boxes, same external shape and size as many of the other avionic boxes, except they were painted Yellow/orange. The crash-fire-proof container for the tape (it was a long time ago) was inside. Only the pinger was visible, being mounted outside on the back.

[Etud_lAvia]

@Orestes:

Interesting! The long parallel marks are not visible at all in the photo to which you linked ... but very clearly visible in more than one photo, including this one (http://d3lp4xedbqa8a5.cloudfront.net/s3/digital-cougar-assets/AWW/2015/11/05/22956/Sinai-flight.jpg) from susier.

It seems to me that the crucial difference among these images, is that yours (the one showing no marks) is some combination of the perspective angle, and the position of the sun when the photo was taken.

The images showing the marks have brightly highlighted regions, in which the surface is reflecting the sun toward the camera. The image to which you linked is "flat" in terms of illumination: no strong highlights.

On this basis, my interpretation is that the marks are NOT paint scrapes, but rather contours in the VS skin (presumably furrows, but possibly ridges). This would explain why they don't show under different light angles.

If these are skin contour marks, then I suppose they might be the consequence of either:

(a) object(s) indenting the skin (but not removing the paint) as they flew past

or

(b) wrinkling of the skin, perhaps due to extraordinary deformation under the forces of the calamity

Somehow, (b) seems more probable. I've seen a number of examples of skin wrinkling on old non-pressurized planes, which didn't look anything like the patterns on the VS. But the fuselage skin on those old birds was mainly there to keep the wind out, and the construction of an A321 stabilizer is a world apart.

[Bertie Bonkers]

CVRs/FDRs can come in different shapes/sizes.

More so than I realised - this is what threw me (I won't embed the pic because it's 1300px wide):

http://www.fineksaviation.com/images/HHMPI%20with%20all%20FDR.jpg

Second from left is a CVR, third from left is FDR - it's all in the length.

[Etud_lAvia]

@CONSO:

The jackscrew (moving the entire horizontal stabilizer) makes slow / large changes of pitch moment, essentially for trim.

The hydraulically actuated elevator surfaces make fast / smaller changes of pitch moment for control of airspeed and flight path.

Jet transports have very broad CG limits. They can also experience changes of pitch moments with airspeed variation (mach number effects) and flap operation. For these reasons, they need the gigantic pitch authority provided by the movable HS.

[MountainBear]

I also asked the make up of the investigation team. So I'll I try asking again, can anyone tell me the make up of the investigation team?

Russian (MAK)--because it was their citizens and their flight.
Egyptian (ECAA)--because it landed in their territory
French (BEA)--because it was their plane.

I assume BEA will mostly be doing consulting. I suspect MAK will lead it if for no other reason than the Egyptians have no technical ability to handle the task. Of course, the last time that happened we had the Flight 990 fiasco...

[Kulverstukas]

Russian (MAK)--because it was their citizens and their flight.
Egyptian (ECAA)--because it landed in their territory
French (BEA)--because it was their plane.

Irish (2 x AAIU 1 x IAA) - because it was leased from Ireland
I heard about German team also - because of engines.

[jlangdale]

Someone asked if an explosive decompression would be heard on the CVR. I think CAL611 is relevant to Metrojet 7K9268. This is an image of it's CVR which was explosive decompression from tailstrike repair metal fatigue.

http://i.imgur.com/osIeoUt.png

SRC:
http://www.fss.aero/accident-reports/dvdfiles/TW/2002-05-25-TW.pdf

[Lonewolf_50]

Of course, the last time that happened we had the Flight 990 fiasco...Yeah, there's that which is doubtless making the Russians less than pleased, in terms of what they are looking to deal with as the investigation continues ... :(

[oldoberon]

you often see investigations into disasters etc where a small group of the investigator strongly disagree with the findings and issue a minority report, has that ever happened with aircraft crashes.?

[Mauersegler]

The new VS picture :
these lines could be from internal structures, but evidently highlighted by external factors (pressure, collision?)
But, there are more new defects on the surface, like abrasion/collision marks. (Etud lAvia was faster than I). The external skin of the VS looks very flexible, probably a glass fiber or aramid fiber composite (not carbon fiber), and specially the leading edge of the VS must be very sturdy. I can imagine an aluminum skin got there and caused overload and snapping of the VS.

Look here for an A320 cut away A320 Cutaway View (http://www.meriweather.com/flightdeck/cutaways/320.html)
http://i65.tinypic.com/2qb7hgz.jpg
(there maybe differences to the A321 or other internal structures not showing in this cut away)

For me, the yellowish structure here:
http://i68.tinypic.com/20ti1p1.jpg
(see also :http://i67.tinypic.com/acuafn.jpg and https://img-fotki.yandex.ru/get/15575/61625582.6a/0_147002_d8f86ef_XXL.jpg )

is not the jack screw support base (supposedly pushed upwards), but one of the internal structures of VS, which now is downwards inclined. That would have pushed teh screw jack plate forwards, pulling the jack screw also forwards.

Also look here:

http://i67.tinypic.com/281t25i.jpg
did you see the metall piece? What is it supposed to be?

[100LL]

One thing playing on my mind, Has Tech Log 26918 appeared yet or is it still missing? Had any Snags been reported or work carried out whilst the Aircraft was on the ground for 5 or so hours at KUF?


Going by the theories on her regarding the HS, VS & Trim Jack I can see a couple of EASA AD's published which are in the vicinity of the suspect area

1. EASA AD - 2015-0080 (http://ad.easa.europa.eu/blob/EASA_AD_2015_0080.pdf/AD_2015-0080_1) - Flight Controls – Trimmable Horizontal Stabilizer Actuator – Identification / Replacement

2. EASA AD - 2014-0217R1 (http://ad.easa.europa.eu/blob/EASA_AD_2014_0217_R1.pdf/AD_2014-0217R1_1) - Auto Flight / Instruments – Stop Rudder Input Warning – Installation / Activation

Both the above possibly resulting in loss of control of the aeroplane.

No biggie I know but looking at Metrojet's 145 approval they only hold Line approval and not Base

Just one last thing, what about Rear cargo door I have not seen any pictures of this. Could this have somehow become detached?

[Joe_K]

From Press Briefing by the Accident Investigation Committee Of Metrojet KGL-9268 (http://www.civilaviation.gov.eg/News/news%20pages%20ar/messs_7_11_2_15.html)

"The investigation team is composed of 47 investigators, as follows:
From Egypt 29
From Russia 7
From France 6
From Germany 2
From Ireland 3
And technical advisors include:
From Airbus 10
IASA 1
This will come to a total of 58 participants. "

[Kulverstukas]

where a small group of the investigator strongly disagree with the findings and issue a minority report, has that ever happened with aircraft crashes.?

Definitely, I read some of such amendments at the end of MAK reports for example. The most famous one is polish at the end of PAF 101 final report.

[Etud_lAvia]

@oldoberon:

It is not unusual for the US NTSB to have dissenting statements (usually by a single board member) in accident investigation reports.

I seem to recall that one of the high-profile airliner crashes around the 1980s had a dissent that got significant news coverage, because of the public visibility and controversy concerning the accident -- but don't remember which incident.

[oldoberon]

The new VS picture :
these lines could be from internal structures, but evidently highlighted by external factors (pressure, collision?)
But, there are more new defects on the surface, like abrasion/collision marks. (Etud lAvia was faster than I). The external skin of the VS looks very flexible, probably a glass fiber or aramid fiber composite (not carbon fiber), and specially the leading edge of the VS must be very sturdy. I can imagine an aluminum skin got there and caused overload and snapping of the VS.

Look here for an A320 cut away A320 Cutaway View (http://www.meriweather.com/flightdeck/cutaways/320.html)
http://i65.tinypic.com/2qb7hgz.jpg
(there maybe differences to the A321 or other internal structures not showing in this cut away)

For me, the yellowish structure here:
http://i68.tinypic.com/20ti1p1.jpg
(see also :http://i67.tinypic.com/acuafn.jpg and https://img-fotki.yandex.ru/get/15575/61625582.6a/0_147002_d8f86ef_XXL.jpg )

is not the jack screw support base (supposedly pushed upwards), but one of the internal structures of VS, which now is downwards inclined. That would have pushed teh screw jack plate forwards, pulling the jack screw also forwards.

Also look here:

http://i67.tinypic.com/281t25i.jpg
did you see the metall piece? What is it supposed to be?

also this image

Now for another view of the rear assemblies
if you look at this the green circle shows what I think is the top screwjack panel (the hole is there) and there is no sign of a screwjack

http://i63.tinypic.com/1zxa529.jpg

[Islay]

Someone earlier posted a photo of the aircraft a week ago. I can't find it now on the threads. But it did show a fair sized repair to the fuselage aft if door 4L covering the production joint. Does anyone else have the photo available.

[DaveReidUK]

you often see investigations into disasters etc where a small group of the investigator strongly disagree with the findings and issue a minority report, has that ever happened with aircraft crashes.?

Yes, from time to time.

For example the Arrow Air DC-8 that crashed at Gander in December 1985 - the probable cause in the Canadian investigation report (ice contamination, leading to a stall) was only endorsed by 5 of the 9 Board members and the other 4 issued a dissenting report attributing the crash to an on-board fire, possibly the result of an explosion.

[sardak]

Here is the aircraft in service with the double lines on the vertical tail visible. The full size photo is at: http://static1.businessinsider.com/image/5634a733bd86ef335d8bb2d1-4701-2644/metrojet.jpg
http://i.imgur.com/8Yf8z3x.jpg

Reference "if you look at this the green circle shows what I think is the top screwjack panel (the hole is there) and there is no sign of a screwjack". It doesn't appear to be that in the hi-res version.
http://i.imgur.com/txJHMoq.pnghttp://i.imgur.com/UrgNF97.png

Another shot of the aft end of Flight 1549 on display at the Carolinas Aviation Museum Carolinas Aviation Museum - Miracle on the Hudson (http://www.carolinasaviation.org/commercial/miracle-on-the-hudson-flight-1549). Note the similarity between the part at the base of the VS on it and the one in the views of the aft end of the Metrojet.
http://i.imgur.com/3TDIkJY.png

[A0283]

As far as i can see your tail close up photo has 3 vertical lines. If you look closely they appear to be double ones. Not as clear as on the 'groove' picture, but still.

What strikes me is that these lines cross from leading edge over to the centerbox. These are respectively GFRP and CFRP built up components.

So it is rather unlikely that the origin of these stripes had anything to do with the lay up of the various composite layers.

This could suggest that it originates in the painting scheme ... which usually includes both spray paint and very large plastic decals (read: stickers). Would be interesting to find out how they did the change of livery. Did they just stick large decals with Metrojet over the old ones or paint ... and perhaps sprayed a coating over that.

I do not know, but this may be part of an explanation.

+++
Take a look at the white leading edge ... borderline does not look very sharp ...

[mini]

IASA 1

Who are these investigators?

[RYFQB]

The external skin of the VS looks very flexible, probably a glass fiber or aramid fiber composite (not carbon fiber), and specially the leading edge of the VS must be very sturdy. I can imagine an aluminum skin got there and caused overload and snapping of the VS
http://i.imgur.com/5ugvtU6.jpg

[flash8]

where a small group of the investigator strongly disagree with the findings and issue a minority report, has that ever happened with aircraft crashes.?

Yes, in the case of the Dan Air 727 Tenerife CFIT 1980 I recall the AIB being somewhat less than pleased with the Spanish Report...

[A0283]

where a small group of the investigator strongly disagree with the findings and issue a minority report, has that ever happened with aircraft crashes.?

As far as I know aerospace was the first industry to include this industry wide as a standard option.

Happens on a regular basis. The minority report as you call it is included in the final report. You can read about it in ICAO Annex13. In many cases various parties include some comments. In NTSB cases you can find minority opinions of individual NTSB members. US military cases have a similar approach.

Some high profile dissent cases:

EgyptAir990 is a case. It crashed in international waters, which put Egypt in the lead. But Egypt delegated to the US NTSB. But in the end disagreed with the NTSB report and the Eqyptian report was included in the NTSB report.

In a similar Indonesian case, Silk Air 185, the Indonesians took the lead, the NTSB was a party. And here the NTSB disagreed with the Indonesians. The NTSB also published a 'findings' report.

[Prada]

Here is one example of a small piece of fuselage that was peeled off during a break up process. Peeling continued rearwards until structure was weak enough to break apart close to wings, not close to tail.

http://www.keri.ee/crash/piece_of_fuselage.png

I wonder if aerodynamic drag could have been large enough to yaw the plane significantly right after initial event when there was an initial hole on the left side, close to wings? I don't know how autopilot behaves if it is not able to compensate that kind of yawing? Switches off? Alternate law activates? Could pilot then break VS off by too large rudder movement?

Then I haven't seen any picture of floor. It seems that seats were shedded off the floor one by one. Could that mean that floor is also in small pieces?
It also looks like not all seats have scorching marks from fire. I remember that doctors said, scorched were passengers from very rear part.

It seems to me that after initial event on left side, that side started to shed pieces of fuselage and floor increasing aerodynamic drag and making the plane to yaw and change direction. It looks like initial event created hole between cargo hold and passenger cabin. Shedding continued until planes structure became too weak and it broke off close to wings while aerodynamic drag bent tail sharply to right, breaking it off from the remaining fuselage.

[FDMII]

Sarkak, I thought I would put your image of the Hudson A320 alongside the Metrojet image of inside the tail:

https://photos.smugmug.com/photos/i-cp9PLhv/0/XL/i-cp9PLhv-XL.jpg


https://photos.smugmug.com/photos/i-gMSQHRr/0/XL/i-gMSQHRr-XL.jpg

[A0283]

Then I haven't seen any picture of floor. It seems that seats were shedded off the floor one by one.

Quite a remarkable number of seats are found without seat-rails. Most triple seats (these seats are connected at the back with a sturdy tube ... diameter looks like about 5 cm). There is one picture of 2 rows of 3 seats that are still connected to their seat-rails. I have seen some seat-rail fragments. The pictures showing paxdoor3 left have parts of the floorgrid visible.

[oldoberon]

if people posting images edited them to fit then the page would not keep going overwidth, making it pain in the butt to read.



http://i64.tinypic.com/1z6bccg.jpg

[onetrack]

Investigators from various parties ....
and plenty of wreckage but still no definitive evidence of the catalyst

8 days later .......There is no need, and no laws, that require air crash investigators to provide public evidence immediately upon discovery, of the reasons for an aircraft crashing.
There are numerous reasons why this initial evidence is kept secure until all the evidence is assembled .. not the least of which is political .. followed by security reasons, followed by a number of other reasons.

The media have advised that there is overwhelming suspicion .. obviously backed by initial evidence .. that the aircraft was brought down by a small bomb planted in one passengers luggage.
Due to this overwhelming suspicion, numerous airlines have now been proactive in taking sensible steps to protect their aircraft, their pax and their reputations.
KLM has now advised it will carry out its own luggage security screening at SSH, to ensure proper standards of luggage security.
Egypt is now paying the price for failing to ensure that airport and luggage security levels were high .. and even higher than normally required .. in an area where terrorists have been active for an extended period of time.

It has been reported that the help of the FBI is being sought by the assembled crash investigators, with regard to explosives forensics skills, to assist the investigation.
It is not unreasonable to assume that the explosive used was in liquid form, hidden in unremarkable-looking bottles in luggage, and this process would simply confirm the standard recent MO of the terrorists, and to ensure a lack of security forces scrutiny, by the unremarkable appearance of the bottles not posing as a potential threat.

This process would also ensure that any explosive traces left were difficult to find, difficult to easily see, and would need high-level forensic examination to confirm what explosive was used, and where, and how it was detonated.

[jolihokistix]

Time to consider putting all luggage into those large explosion-proof zipped hold bags that were shown recently. I am guessing they must be expensive, but would they have helped in this case?

[oldoberon]

Time to consider putting all luggage into those large explosion-proof zipped hold bags that were shown recently. I am guessing they must be expensive, but would they have helped in this case?

hear is a video of it being tested Aircraft 'bomb bag' limits on board explosion impact - BBC News (http://www.bbc.co.uk/news/science-environment-33650713)

they need to think ahead and consider how they would defeat it because nothing 100% certain, because the terrorist will think about it that you can be certain of.

[jolihokistix]

Ah, that's the one, oldoberon. Many thanks. Some thought-provoking footage there.

[lomapaseo]

It would seem that by now the investigators have a very good idea where the first rupture occurred as well as the subsequent break-up and damages to all recovered major objects. If it was a bomb they probably have a good idea of what type and if among the luggage where and how it got stowed.

What follows is food for the press and those that are patient.

[DeRated]

From the post by FDMII #1989

From the Hudson A320 view of the Port THS pivots, the attachment point to the fuselage of the twin supports is pictured in the lower photo of the Metrojet framed by the inverted V of the cables - showing a broken support.

If this was the initial failure point, then downward pressure on the THS would rotate the THS about the remaining Starboard pivot and the jackscrew altering the relative angle of attack more of the Starboard THS creating a twisting effect on the rear fuselage.

[andrasz]

The thread seems to be going round and round in circles again.

@ everyone discussing a possible control surface failure

Please try to explain how such a failure could have brought about the breaking of the rear fuselage. While intact, the fuselage (especially if pressurized) is very strong and resilient. It will not break up due to aerodynamic forces even in unusual attitudes. It is pointless to discuss any potential failures in the tail plane without addressing this. I believe any rapid overload on the control surfaces would break them first before the fuselage itself could de damaged.

@ everyone discussing a bomb

If it was a bomb as suspected, then all the subsequent break-up sequence is just an academic engineering exercise with no bearing on the cause.

I'm not sufficiently familiar with the rear fuselage structure to be able to add anything to the conversation, but perhaps someone with more knowledge could address that barring a bomb, what structural failure (if any possible) would be required to cause an instantaneous catastrophic failure and departure of the tail. My understanding is that the fracture of any single load bearing beam would not be sufficient, the remaining beams have sufficiend design strength margin to take over the increased load (just look at the Aloha convertible, where more than 50% of the fuselage structure was missing yet it still held together).

[mitrosft]

Islay

You were asking for a week old pic with tail patch

Here it is

http://cdn1.share.slickpic.com/u/AnatolyStrunin/_20151103/org/003_Foto%20by%20Anatoly%20Strunin/web.jpg

[CONSO]

#2006 (http://www.pprune.org/9176052-post2006.html) (permalink (http://www.pprune.org/rumours-news/569907-breaking-news-airliner-missing-within-egyptian-fir-101.html#post9176052))

(just look at the Aloha convertible, where more than 50% of the fuselage structure was missing yet it still held together).

Not at all comparable - the skin unwrapped but all the load carrying stringersm and floor beams and circumferentials were intact

IN an explosion as postulated, depending on location, several major members would likely be destroyed. If carefully located a small explosive could sever for example a major structure member in the tail section and get the result. Or even poor maintenancece - as the 747 over japan demonstrated re tail .

[andrasz]

@ CONSO

Yes of course, an explosion will produce the results we are seeing. I'd be more interested if anyone is able to explain what we see in the rear fuselage with only a structural failure, that is why I brought up Aloha as a contrasting comparison.

[Prada]

Quote:
(just look at the Aloha convertible, where more than 50% of the fuselage structure was missing yet it still held together).
Not at all comparable - the skin unwrapped but all the load carrying stringersm and floor beams and circumferentials were intact

IN an explosion as postulated, depending on location, several major members would likely be destroyed. If carefully located a small explosive could sever for example a major structure member in the tail section and get the result. Or even poor maintenancece - as the 747 over japan demonstrated re tail .

I was thinking about the same. Aloha's initial event that caused shedding of all cabin skin started from roof and progressed rear and downwards until stopped by stronger fuselage-floor interconnection. Surprisingly noone seated didn't get unjured by flying parts. it means everything was peeled outward.
with metrojet a321 initial breakup should have started at the floor level, on the left side. Not far from wings. Thus peeling below and above floor level destroyed floor as well throwing out seats one by one.

[Kulverstukas]

You were asking for a week old pic with tail patch

Here it is

https://img-fotki.yandex.ru/get/9767/6154164.285/0_b2604_39302b97_XL.jpg

Unfortunately this patch is under the tail remnants so not visible. Still no explanation which forces can make this huge rupture above HS:

https://img-fotki.yandex.ru/get/4402/6154164.285/0_b2603_e855dd22_XL.jpg

[Kulverstukas]

Unnamed source in RF government said yesterday, after meeting with prime-minister at which it was mentioned that flights suspension to Egypt will not be short one (literally "possible be for years" and "for other destinations too"), that "disaster was a result of Egyptian secret services betrayal" and that "unauthorized personal was allowed to the plane".

Take it with great pinch of salt, but it was originated from Kommersant (http://www.kommersant.ru/doc/2850406), not any yellow paper...

PS: original article a bit more sober than this short squeeze but it's like they begin to cite it in the media... Go figure.

[Pontius Navigator]

If carefully located a small explosive could sever for example a major structure member in the tail section and get the result.

A small explosive in that case would need to be placed deliberately or the placement was down to chance.

[A0283]

(original article in Russian - my translation)

Russian investigators still have to find formal grounds for the re-qualification of this case as a criminal case under Art. 205 of the Criminal Code ("Terrorist Act"). Test results from the swabs and scrapings of plane fragments to detect the presence of traces of explosives will at least take a week. Only then do we know if we can talk about a terrorist attack.

++
So at this stage it is still a safety investigation and not a formal criminal investigation (with a parallel running, but subordinate safety investigation).

[Pontius Navigator]

In today's papers it is reported that the 4 UK charter airlines will resume flights not before 25th Nov and BA on 23rd Nov. Baggage for UK passengers to be flown home by Egyptair. The Sharm baggage storage is now full and tourist are to leave baggage at their hotels.

In the same report it states that hotel staff are being investigated with suspicion that a bomb could have been placed in Russian baggage at the hotel.

[triumph61]

If the VS and HS broke first and that was the Reason for downing, can someone explain what can be see here at Engine and Fan and what is the Reason for that?


http://img5.fotos-hochladen.net/uploads/fanli6u428cmk.jpg

http://img5.fotos-hochladen.net/uploads/triebwerklinkslz2ig7nsh5.jpg

[Loose rivets]

Is it conceivable there was sufficiently hot reverse gas flow while tumbling to cause that?

[funfly]

It's an engine that has been involved in a fire and dropped from 30,000 ft.
One could assume that in the case of a fire starting in the engine itself then the fan (from the front) would not show such fire evidence.
Also looks as if the engine itself was not destroyed by intense heat.

FF

[Prada]

If the VS and HS broke first and that was the Reason for downing, can someone explain what can be see here at Engine and Fan and what is the Reason for that?

It is highly unlikely that VS and HS were broken off first by aerodynamic forces. - trailing edges of VS and HS. T
Technically it is impossible while wings are still attached to the plane and fuselage is more or less intact. Planes intact body plus Fly by Wire protection does not allow such a sudden changes in tail attitude against airflow.

[Bertie Bonkers]

Picking up on previous posts by Sardak, FDMII & DeRated...

Left and right HS pivot mounts? If so, then as noted previously left side appears broken off at the top, right side appears to be sticking out at 90 degrees.

https://pbs.twimg.com/media/CTceRbqWsAA2ZP6.jpg