BREAKING NEWS: airliner missing within Egyptian FIR
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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?
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Israel is absolutely silent on the whole matter. For those of us that have slightly deviated from military instructions (not Israeli, necessarily) when operating under their guidance, you know how accurate their equipment is. They saw and recorded the entire event.
With Israel's experience with the Sinai, they watch that airspace very closely.
Of course, the US knows as well from their various satellites monitoring in real time.
If it were a purely structural breakup, the major powers would have been clued in.
Judge the past by the actions in the present.
With Israel's experience with the Sinai, they watch that airspace very closely.
Of course, the US knows as well from their various satellites monitoring in real time.
If it were a purely structural breakup, the major powers would have been clued in.
Judge the past by the actions in the present.
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So, as the CVR recorded a 'bang' and based on the photos we have seen, it seems almost certain that there was some sort of mid-air fire.
With all the theories around structural failure expounded, can anyone give a rationale for a mid-air fire?
Surely the only potential explosive fuel would be jet fuel. But kerosene only ignites easily in atomised form and where there is plenty of oxygen available. At FL310 oxygen levels are at about 6.5% (c/f 21% at sea level). Could sparks from structural failure really be sufficient to ignite kersone given the rush of air from massive sudden decompression and the air stream of say 400kts that would suck sparks away from the aircraft almost instantaneously? And that would assume that kerosene was escaping in large enough quantities following a structural failure.
I can't think of a single example of serious structural failure and/or decompression that resulted in a mid-air fire. Loss of control, yes. Fire, no.
Speedbird 911 (Japan 1966) no mid-air fire
Braniff 250 (USA 1966) no mid-air fire
Lake Central 250 (USA 1967) no mid-air fire
BEA 706 (Belgium 1971) no mid-air fire
AA 96 (USA 1972) no mid-air fire
Turkish 981 (France 1974) no mid-air fire
AA 191 (USA 1979) no mid-air fire (despite huge fuel stream from port wing at low altitude)
JAL 123 (Japan 1985) no mid-air fire
United 811 (over Pacific 1988) no mid-air fire
El Al 1862 (Netherlands 1992) no mid-air fire
China Air 611 (Taiwan 2002) no mid-air fire
Surely, the only possible 'accidental' cause could be a catastrophic engine fire combined with simultaneous damage to the fuselage and fuel tanks, which would surely have had to include wing tanks?
But even then would the aircraft not have continued under normal flight for at least half a minute?
Am I missing something?
With all the theories around structural failure expounded, can anyone give a rationale for a mid-air fire?
Surely the only potential explosive fuel would be jet fuel. But kerosene only ignites easily in atomised form and where there is plenty of oxygen available. At FL310 oxygen levels are at about 6.5% (c/f 21% at sea level). Could sparks from structural failure really be sufficient to ignite kersone given the rush of air from massive sudden decompression and the air stream of say 400kts that would suck sparks away from the aircraft almost instantaneously? And that would assume that kerosene was escaping in large enough quantities following a structural failure.
I can't think of a single example of serious structural failure and/or decompression that resulted in a mid-air fire. Loss of control, yes. Fire, no.
Speedbird 911 (Japan 1966) no mid-air fire
Braniff 250 (USA 1966) no mid-air fire
Lake Central 250 (USA 1967) no mid-air fire
BEA 706 (Belgium 1971) no mid-air fire
AA 96 (USA 1972) no mid-air fire
Turkish 981 (France 1974) no mid-air fire
AA 191 (USA 1979) no mid-air fire (despite huge fuel stream from port wing at low altitude)
JAL 123 (Japan 1985) no mid-air fire
United 811 (over Pacific 1988) no mid-air fire
El Al 1862 (Netherlands 1992) no mid-air fire
China Air 611 (Taiwan 2002) no mid-air fire
Surely, the only possible 'accidental' cause could be a catastrophic engine fire combined with simultaneous damage to the fuselage and fuel tanks, which would surely have had to include wing tanks?
But even then would the aircraft not have continued under normal flight for at least half a minute?
Am I missing something?
I don't own this space under my name. I should have leased it while I still could
Smott, all I am saying is that the video must be properly analysed before being discounted. I agree, soot is an important feature but there are still too many holes to discard any piece.
There have been regular summaries of physical bits that are known to be missing but there are other things too. No one has answered my query about contrails.
All we need is one pilot who flew that day, or even since, to confirm that there were no contrails, as in the video, or not. If there were persistent trails at that height then that would nail it.
There have been regular summaries of physical bits that are known to be missing but there are other things too. No one has answered my query about contrails.
All we need is one pilot who flew that day, or even since, to confirm that there were no contrails, as in the video, or not. If there were persistent trails at that height then that would nail it.
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Additional concept scenario
If you would list some observations as follows:
a. RUS and EGY experts officially stated earlier that no traces of explosives have been found on any of the examined victims (would be nice to have a link to an official statement, not an interview),
b. A loud NOISE at the end of the CVR recording, as officially stated today by the chairman of the investigation, he clearly does not use the word EXPLOSION,
c. No clear evidence (my impression– clearly not shared by quite a number of posters) of high velocity fragments or blast or flash on the outside of components and parts of the plane that are visible onpictures in the public domain, and certainly not many ‘possibles’ in this respect,
d. Amazingly ‘clean’ wreckage,
e. Break-up fracture lines include quite a few that are along what I call “production breaks”, where with an explosion you would expect multiple more ‘ragged’ edges, and with fatigue you would fractures further away from “production breaks”. This suggests structural failure ...
f. ...
What kind of scenario wouldb e able to cover this combination of ‘dots’.
An option might be a kind of very local, very high temperature event, weakening the structure or ‘flash through’,going from aft cargohold to the tail (via ducts?), leading to a growing overload situation, after some time causing a violent failure (triggers could be, pressure-differential exceeding a certain limit, or load caused by A/P1 induced step inclimb, or..), the violent nature of this causing the very loud noise, the chain of events proceeding so fast, that it leads to the loss of significant structural member(s) (for example pushing out the THS and APU and kicking out the rudder), a loss that instantly causes an irrecoverable loss of control, a combination which makes it impossible for the pilots to disengages A/P1 (high g’sand or surprise effect), aerodynamic loads then causing the subsequent fast break-up of the plane,
Some questions could then be:
i. What kind of event and/or product could lead to such an fast escalation within about 23 minutes of flight plus some additional time between pushback and takeoff, so say between 20-35 minutes, could that be Lithium-batteries or ...? And what would be the cause of cargo hold sensor (smoke/temperature) failures.
Hope someone can help me toget this scenario up to a more “probable” level.
Note: “Probable” not suggesting that this is THE only or even the most likely scenario.
+++
While i was writing this RTM Boy posted http://www.pprune.org/rumours-news/5...ml#post9173575 covering the subject of in-flight fire. Not the same as my scenario, but recommended reading his parallel to mine.
a. RUS and EGY experts officially stated earlier that no traces of explosives have been found on any of the examined victims (would be nice to have a link to an official statement, not an interview),
b. A loud NOISE at the end of the CVR recording, as officially stated today by the chairman of the investigation, he clearly does not use the word EXPLOSION,
c. No clear evidence (my impression– clearly not shared by quite a number of posters) of high velocity fragments or blast or flash on the outside of components and parts of the plane that are visible onpictures in the public domain, and certainly not many ‘possibles’ in this respect,
d. Amazingly ‘clean’ wreckage,
e. Break-up fracture lines include quite a few that are along what I call “production breaks”, where with an explosion you would expect multiple more ‘ragged’ edges, and with fatigue you would fractures further away from “production breaks”. This suggests structural failure ...
f. ...
What kind of scenario wouldb e able to cover this combination of ‘dots’.
An option might be a kind of very local, very high temperature event, weakening the structure or ‘flash through’,going from aft cargohold to the tail (via ducts?), leading to a growing overload situation, after some time causing a violent failure (triggers could be, pressure-differential exceeding a certain limit, or load caused by A/P1 induced step inclimb, or..), the violent nature of this causing the very loud noise, the chain of events proceeding so fast, that it leads to the loss of significant structural member(s) (for example pushing out the THS and APU and kicking out the rudder), a loss that instantly causes an irrecoverable loss of control, a combination which makes it impossible for the pilots to disengages A/P1 (high g’sand or surprise effect), aerodynamic loads then causing the subsequent fast break-up of the plane,
Some questions could then be:
i. What kind of event and/or product could lead to such an fast escalation within about 23 minutes of flight plus some additional time between pushback and takeoff, so say between 20-35 minutes, could that be Lithium-batteries or ...? And what would be the cause of cargo hold sensor (smoke/temperature) failures.
Hope someone can help me toget this scenario up to a more “probable” level.
Note: “Probable” not suggesting that this is THE only or even the most likely scenario.
+++
While i was writing this RTM Boy posted http://www.pprune.org/rumours-news/5...ml#post9173575 covering the subject of in-flight fire. Not the same as my scenario, but recommended reading his parallel to mine.
Last edited by A0283; 7th Nov 2015 at 21:34. Reason: +++ catching up
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According to the New York Times, Vladimir Puchkof, Minister for Emergency Situations reported samples from the wreckage have been taken to Moscow.
Said he, "Russian specialists have collected swabs and scrapes from all fragments of the aircraft, luggage, and soil. The necessary samples have been taken from all items which might contain traces of explosive. All these samples have been delivered to Moscow and are being thoroughly examined now."
Said he, "Russian specialists have collected swabs and scrapes from all fragments of the aircraft, luggage, and soil. The necessary samples have been taken from all items which might contain traces of explosive. All these samples have been delivered to Moscow and are being thoroughly examined now."
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@Mary
As far as i have read, there are two testing sequences. The first that of the passengers starting a few days ago. The second the one you mention now. It would not surprise me if we get a third one when the missing components are found.
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VFX analysis of video
I'm a visual effects artist, as well as a pilot. For analyzing this video, I'll put my VFX hat on. I've made a huge number of films, you can look it up.
1) Given the orientation of the plane in the video, it has to be at least seven or eight miles away (altitude of 30,000 ft or so, and at a significant horizontal distance as well). If you look through seven miles of atmosphere, you cannot see anything black -- blacks become blue due to Rayleigh scattering.
https://en.wikipedia.org/wiki/Rayleigh_scattering
Note that the sky is actually black, but the scattered light from the sun makes the sky appear blue.
Now, ok, say that they processed the footage to bring down the bluish-blacks to look more black? I don't know why they would do that, as it makes it look less real, but if they did it would be very noisy and low-contrast.
2) Tracking the relative speed of the smoke plume to the plane isn't that hard. The span of the plane in one of the frames is 74 pixels. As the span of a A321 is 117 ft, that means each pixel is about 1.6 ft. During a half-second the smoke drifts back 37 pixels, or 116 ft/sec (80mph) if the plane was directly above the camera, or 232 ft/sec (160 mph) if the plane was only 30 degrees above the horizon. We know that the plane was going far faster than that.
3) It appears that the footage was filmed on a smartphone that was pointing at another LCD screen, perhaps even two generations of re-filming. Several instances show quick pans where the plane doubles-up, as if the camera was out-of-sync with the screen it was filming. The very strong contrast between the middle of the screen (pretty bright) and the edges (quite dark) leads me to believe that the smartphone camera was quite close to a cheap LCD screen, which has big variations in brightness with viewing angle.
The blackness of the smoke at a distance of many miles, and the slow speed of the smoke relative to the airplane lead me to believe that this is shoddy visual effects work. It could easily have been done by anybody during the 24 hours between the crash and the release of the video.
1) Given the orientation of the plane in the video, it has to be at least seven or eight miles away (altitude of 30,000 ft or so, and at a significant horizontal distance as well). If you look through seven miles of atmosphere, you cannot see anything black -- blacks become blue due to Rayleigh scattering.
https://en.wikipedia.org/wiki/Rayleigh_scattering
Note that the sky is actually black, but the scattered light from the sun makes the sky appear blue.
Now, ok, say that they processed the footage to bring down the bluish-blacks to look more black? I don't know why they would do that, as it makes it look less real, but if they did it would be very noisy and low-contrast.
2) Tracking the relative speed of the smoke plume to the plane isn't that hard. The span of the plane in one of the frames is 74 pixels. As the span of a A321 is 117 ft, that means each pixel is about 1.6 ft. During a half-second the smoke drifts back 37 pixels, or 116 ft/sec (80mph) if the plane was directly above the camera, or 232 ft/sec (160 mph) if the plane was only 30 degrees above the horizon. We know that the plane was going far faster than that.
3) It appears that the footage was filmed on a smartphone that was pointing at another LCD screen, perhaps even two generations of re-filming. Several instances show quick pans where the plane doubles-up, as if the camera was out-of-sync with the screen it was filming. The very strong contrast between the middle of the screen (pretty bright) and the edges (quite dark) leads me to believe that the smartphone camera was quite close to a cheap LCD screen, which has big variations in brightness with viewing angle.
The blackness of the smoke at a distance of many miles, and the slow speed of the smoke relative to the airplane lead me to believe that this is shoddy visual effects work. It could easily have been done by anybody during the 24 hours between the crash and the release of the video.
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Though speaking as someone who was once a hard-core conspiracy theorist, I would suggest that beneath the veneer of competence, the governments of major powers know little more than the rest of us and are, in this case, simply erring on the side of caution. In fact it would not surprise me at all if there were currently people in Whitehall and GCHQ following this and other aviation forums in the hope of picking up any useful information and/or professional insight which might be of use in establishing a probable cause for the incident.
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@RTM Boy (on the subject of mid-air fire)
I understand that it's very difficult to ignite or sustain fuel combustion outboard the aircraft at FL 300+
But of course, the aircraft took some time to reach the ground, and soon passed into much denser air.
For example, TWA 800 fell with a "fire trail", the appearance of which was interpreted by some witnesses as an ascending missile. That flight's break-up initiated around 14,000 ft. I don't know whether the streaming fuel fire ignition source was determined -- it might have been by the explosion, but conceivably the heat of the explosion passed in a moment and the streaming fuel was subsequently ignited by another source.
If we imagine the Metrojet A321 breaking apart at altitude, and fuel streaming from a ruptured center tank, static electricity is a possible source of ignition (as the fuselage falls into sufficiently dense air).
In addition, with extreme damage to the aft of the plane, and the tail perhaps already separated, severed electrical cables might well have been persistently arcing in open air, where the arcing could come into contact with a fuel/air aerosol streaming from the center tank.
Probably, at least one engine was still turning, with its generator powering the plane's electrical systems -- arcing might have continued all the way to ground impact.
I understand that it's very difficult to ignite or sustain fuel combustion outboard the aircraft at FL 300+
But of course, the aircraft took some time to reach the ground, and soon passed into much denser air.
For example, TWA 800 fell with a "fire trail", the appearance of which was interpreted by some witnesses as an ascending missile. That flight's break-up initiated around 14,000 ft. I don't know whether the streaming fuel fire ignition source was determined -- it might have been by the explosion, but conceivably the heat of the explosion passed in a moment and the streaming fuel was subsequently ignited by another source.
If we imagine the Metrojet A321 breaking apart at altitude, and fuel streaming from a ruptured center tank, static electricity is a possible source of ignition (as the fuselage falls into sufficiently dense air).
In addition, with extreme damage to the aft of the plane, and the tail perhaps already separated, severed electrical cables might well have been persistently arcing in open air, where the arcing could come into contact with a fuel/air aerosol streaming from the center tank.
Probably, at least one engine was still turning, with its generator powering the plane's electrical systems -- arcing might have continued all the way to ground impact.
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With Israel's experience with the Sinai, they watch that airspace very closely.
As I said before, this is 30% aircraft investigation and 70% political intrigue.
Silver
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"e. Break-up fracture lines include quite a few that are along what I call “production breaks”, where with an explosion you would expect multiple more ‘ragged’ edges, and with fatigue you would fractures further away from “production breaks”. This suggests structural failure ..."
The damage we are seeing is entirely consistent with a small high explosive device. There is shattering and jagged damage in some areas, and very clean tensile skin failures distant from the blast.
Ample proof easily viewed by searching for such gov't tests on airframes. The breaks on this Airbus look the same.
A huge explosive device could shatter the entire airframe, but that is not what is suspected.
The damage we are seeing is entirely consistent with a small high explosive device. There is shattering and jagged damage in some areas, and very clean tensile skin failures distant from the blast.
Ample proof easily viewed by searching for such gov't tests on airframes. The breaks on this Airbus look the same.
A huge explosive device could shatter the entire airframe, but that is not what is suspected.
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Breakup sequence
I start it backwards.
Forward part fell to ground tail first upside down. That is due to aerodynamics and gravity center.
Before ground impact there was a fire underside between wings. Left underside up to the nose is sooted.
Left Engines probably ingested hot gasses from fire during falling phase. Main fan is sooted and scorched. Engine shows over heating damage.
These facts we know for sure.
Plane breakup last phases were abrupt with tail separation. There is very large piece of fuselage of right side. Almost from wings to tail. That one was last to break off. It could be that tail was last piece to break off from rear fuselage. At near cruising speed. That would explain strange hs and vs damage. Somewhat.
there was fire. First insid rear part that scorched seats and bodies.
could be it started from act tank installed on the plane. It was probably almost empty. But that is not sure.
fire started close to initial event.
Here i stop speculation.
Forward part fell to ground tail first upside down. That is due to aerodynamics and gravity center.
Before ground impact there was a fire underside between wings. Left underside up to the nose is sooted.
Left Engines probably ingested hot gasses from fire during falling phase. Main fan is sooted and scorched. Engine shows over heating damage.
These facts we know for sure.
Plane breakup last phases were abrupt with tail separation. There is very large piece of fuselage of right side. Almost from wings to tail. That one was last to break off. It could be that tail was last piece to break off from rear fuselage. At near cruising speed. That would explain strange hs and vs damage. Somewhat.
there was fire. First insid rear part that scorched seats and bodies.
could be it started from act tank installed on the plane. It was probably almost empty. But that is not sure.
fire started close to initial event.
Here i stop speculation.
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A fire in the hold would surely elicit response/record on cvr/fdr.
I understand that it's very difficult to ignite or sustain fuel combustion outboard the aircraft at FL 300+
The fundamental assumption these posts make is that the instrumentation was working properly and being monitored properly. We don't know that. All we know is the that the flight parameters were normal.
It is possible that fire happened in the hold that went undetected or unnoted and by the time it right FL 300 damage was done.
I'm not saying that this is what happened; I still think a structural failure is more likely. But none of the evidence produced so far categorically eliminates the possibility of a fire being the proximate cause of the crash, the intransigence of the mods of this board notwithstanding.
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Prada:
The interesting part is that after the tail breaks off, HS failure and APU cone breakaway become much less likely. A HS failure on the other hand can result in APU cone break away but after the HS is gone the tail breakaway is much less likely. Even a scenario where a 'pressure event' causes both the APU cone ejection and a HS damage, one expects that this causes either the tail to break after which HS failure is less likely or one expects the HS to break off fully, after which the tail is much less likely to break off.
A possible scenario is that there were multiple explosions because of the fuel and that the first one blew off the APU cone. Problem is that the damage pattern offers only weak support for it. I think this is the puzzle at the moment.
The interesting part is that after the tail breaks off, HS failure and APU cone breakaway become much less likely. A HS failure on the other hand can result in APU cone break away but after the HS is gone the tail breakaway is much less likely. Even a scenario where a 'pressure event' causes both the APU cone ejection and a HS damage, one expects that this causes either the tail to break after which HS failure is less likely or one expects the HS to break off fully, after which the tail is much less likely to break off.
A possible scenario is that there were multiple explosions because of the fuel and that the first one blew off the APU cone. Problem is that the damage pattern offers only weak support for it. I think this is the puzzle at the moment.
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Mode of failure explained again
#1548 (permalink) and #1493 (permalink) is IMO the closest realistic explanation of the sequence of events involved.
IMO it does not exclude explosive initiation- but it does cover the most probable sequence.
I note as many have- the loud noise on the CVR may resolve the structural failure/HS flapping or explosive initiation
Even so one wonders how or why the jackscrew- HS wing box has yet to be found since both cvr and fdr are located very close.
Please lets drop the video issue and the center wing tank issues as an initiating event. Way too many things simply do not fit either.
IMO it does not exclude explosive initiation- but it does cover the most probable sequence.
I note as many have- the loud noise on the CVR may resolve the structural failure/HS flapping or explosive initiation
Even so one wonders how or why the jackscrew- HS wing box has yet to be found since both cvr and fdr are located very close.
Please lets drop the video issue and the center wing tank issues as an initiating event. Way too many things simply do not fit either.
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RTM Boy wrote, "I can't think of a single example of serious structural failure and/or decompression that resulted in a mid-air fire. Loss of control, yes. Fire, no", and gave an impressive list of 11 cases.
However, in five of the cases, the fuselage substantially remained connected:
AA 96 (USA 1972) no mid-air fire - landed!
Turkish 981 (France 1974) no mid-air fire
AA 191 (USA 1979) no mid-air fire (despite huge fuel stream from port wing at low altitude) (engine loss and impact damage)
United 811 (over Pacific 1988) no mid-air fire - landed!
El Al 1862 (Netherlands 1992) no mid-air fire (engine loss and impact damage)
The NTSB report records a mid air fire for:
Braniff 250 (USA 1966) 'tumbled down in flames' (to quote Wikipedia)
In the case of Braniff 250, one of the wings was torn off, and the mid-air fire is attributed to the consequent tank rupture.
Wikipedia agrees with the absence of mid-air fire in five cases:
Speedbird 911 (Japan 1966) no mid-air fire
Lake Central 527 [emended from 250] (USA 1967) no mid-air fire - severed at cockpit
BEA 706 (Belgium 1971) no mid-air fire
JAL 123 (Japan 1985) no mid-air fire - notorious for being semicontrollable
China Air 611 (Taiwan 2002) no mid-air fire
However, in five of the cases, the fuselage substantially remained connected:
AA 96 (USA 1972) no mid-air fire - landed!
Turkish 981 (France 1974) no mid-air fire
AA 191 (USA 1979) no mid-air fire (despite huge fuel stream from port wing at low altitude) (engine loss and impact damage)
United 811 (over Pacific 1988) no mid-air fire - landed!
El Al 1862 (Netherlands 1992) no mid-air fire (engine loss and impact damage)
The NTSB report records a mid air fire for:
Braniff 250 (USA 1966) 'tumbled down in flames' (to quote Wikipedia)
In the case of Braniff 250, one of the wings was torn off, and the mid-air fire is attributed to the consequent tank rupture.
Wikipedia agrees with the absence of mid-air fire in five cases:
Speedbird 911 (Japan 1966) no mid-air fire
Lake Central 527 [emended from 250] (USA 1967) no mid-air fire - severed at cockpit
BEA 706 (Belgium 1971) no mid-air fire
JAL 123 (Japan 1985) no mid-air fire - notorious for being semicontrollable
China Air 611 (Taiwan 2002) no mid-air fire
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@StuntPilot
after the tail breaks off , HS failure and APU cone breakaway become much less likely.
A HS failure on the other hand can result in APU cone break away but after the HS is gone the tail breakaway is much less likely.
A HS failure on the other hand can result in APU cone break away but after the HS is gone the tail breakaway is much less likely.
First one. After the tail breaks-off (cause unknown), while considering the beefy 6-point tailmount, will probably leave intact the 'basically strong' cylinder of the tailcone. So immediate THS break-up appears to have lower probablility. The plane only starts rotating a while later. Losing the THS comes only after an increase of the aerodynamic loads.
Second one. If the THS is wrung out of position (cause still unknown), and one side breaks-off as a consequence of that. It could well take away immediately the 'double-paperclip' connection rod that spans the THS 'manufacturing insertion opening' on that side. Which immediately and severely degredates the strength and stiffness of that cylindrical area. Which then would at almost the same time, put the tail and other side of the THS out of position. With severe consequences. Which could well lead to a parallel departure of both tail and THS box and other half of the THS. This scenario appears to run faster than your first one.
It is not even necessary for this to push out the APU unit ... there is a possibility that the APU is still inside the cone.
So at first sight i think the tail could still come off. And consider your second option more likely at this stage and with the 'evidence' we have at this stage in time.
Confirmation or rejection of these scenario's of course requires checking and matching of the sequence with the pattern of the wreckage on the ground.
The most probable scenario could then be used to point back at the originating events.
+++
My impression was that we see only one half of the double paperclip in the structure. But i have to go back to the pictures to look at that.
Last edited by A0283; 7th Nov 2015 at 23:49. Reason: +++ added
