BREAKING NEWS: airliner missing within Egyptian FIR
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. . . I have a good idea of how explosions are imaged by video cameras.
The disperancy in the black level of smoke versus the airframe is my main issue.
Yes if the video is real the smoke could have been processed separately to alter its black level for dramatic effect. . . .
However a common trick to help marry composite elements is to leave or make the frame wobbly.
The disperancy in the black level of smoke versus the airframe is my main issue.
Yes if the video is real the smoke could have been processed separately to alter its black level for dramatic effect. . . .
However a common trick to help marry composite elements is to leave or make the frame wobbly.
An aircraft in flight
An explosion
A smoke trail
That the first two are genuine but independent and that all three have been fused in to one video?
I would not disagree with that.
My initial post was only to cast doubt on the assertion that the explosion was FAKE as opposed to the whole composition being fake.
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CVR Bandwidth
I looked at specs for a couple of CVR's. One had a bandwidth of 3kHz and the other 5kHz. The microphone bandwidth would likely have been higher.
This means that a sample of the sound (think "relative" pressure) was recorded about every 100 microseconds. In that time, a sound wave travels about a couple of centimeters in air, and quite a bit more in metal. This means that the differential between microphones gives some information about the direction of arrival of an impulse, and its speed of propagation.
If the initial event was a low velocity explosion (such as a fuel tank) or an explosive decompression, there might be time for sound to get to the cockpit before the signal carrying cable was severed. If it was a high velocity explosion (C4, SEMTEX, PETN, ANFO), that sound could get there only if the explosion shock wave itself did not sever the cable, but rather just weakened the fuselage structure leading to an eventual breakup (milliseconds to seconds later).
Whether the fast rise time characteristic of a high velocity explosion shock wave could be distinguished is another question. A lot of material would be filtering out the high frequency components as the shock wave traveled from aft to the cockpit, although it might be conducted through the metal of the airframe, which would better preserve it.
Finally, the "sound" at the end of the CVR might just be the electrical transient from the cable being severed, and perhaps also from power being removed.
All of which brings up a question I've had during this very interesting thread: is there a reason we are not discussing a center fuel tank explosion? There have been a some of these in commercial jet aviation history, most notably TWA-800.
This means that a sample of the sound (think "relative" pressure) was recorded about every 100 microseconds. In that time, a sound wave travels about a couple of centimeters in air, and quite a bit more in metal. This means that the differential between microphones gives some information about the direction of arrival of an impulse, and its speed of propagation.
If the initial event was a low velocity explosion (such as a fuel tank) or an explosive decompression, there might be time for sound to get to the cockpit before the signal carrying cable was severed. If it was a high velocity explosion (C4, SEMTEX, PETN, ANFO), that sound could get there only if the explosion shock wave itself did not sever the cable, but rather just weakened the fuselage structure leading to an eventual breakup (milliseconds to seconds later).
Whether the fast rise time characteristic of a high velocity explosion shock wave could be distinguished is another question. A lot of material would be filtering out the high frequency components as the shock wave traveled from aft to the cockpit, although it might be conducted through the metal of the airframe, which would better preserve it.
Finally, the "sound" at the end of the CVR might just be the electrical transient from the cable being severed, and perhaps also from power being removed.
All of which brings up a question I've had during this very interesting thread: is there a reason we are not discussing a center fuel tank explosion? There have been a some of these in commercial jet aviation history, most notably TWA-800.
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Oxygen
There have been several mentions of lack of oxygen being responsible for the thick black smoke which appears in the videos.
The relative mixture of atmospheric gases is the same at 30,000 feet as it is at sea level, only the pressure is lower.
Cabin pressure in a high flying aircraft is maintained by outside air being compressed and vented into the cabin. If there were less oxygen at altitude, then this technique wouldn't work.
In event of depressurisation occuring, supplementary oxygen masks are deployed for passengers because the human body can't extract sufficient oxygen from low pressure air, not because the air itself has any less oxygen.
Sufficiently fit and acclimatised individuals are capable of surviving at equivalent altitudes for several hours without supplementary oxygen as proved by unassisted ascents of Mount Everest.
The relative mixture of atmospheric gases is the same at 30,000 feet as it is at sea level, only the pressure is lower.
Cabin pressure in a high flying aircraft is maintained by outside air being compressed and vented into the cabin. If there were less oxygen at altitude, then this technique wouldn't work.
In event of depressurisation occuring, supplementary oxygen masks are deployed for passengers because the human body can't extract sufficient oxygen from low pressure air, not because the air itself has any less oxygen.
Sufficiently fit and acclimatised individuals are capable of surviving at equivalent altitudes for several hours without supplementary oxygen as proved by unassisted ascents of Mount Everest.
I don't own this space under my name. I should have leased it while I still could
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"When that bizjet crashed at Blackbushe in the UK a few months ago the AAIB's initial statement of known facts a few weeks later mentioned a change in the circuit pattern by the jet to accommodate a slow flying microlight.
This was the first anyone had heard of the presence of a microlight and those flying it have never made any public statements - though I'm sure they have made one to the AAIB."
IIRC, It was well reported and discussed at an early stage as a possible indicator that the private jet pilot was cutting corners.
This was the first anyone had heard of the presence of a microlight and those flying it have never made any public statements - though I'm sure they have made one to the AAIB."
IIRC, It was well reported and discussed at an early stage as a possible indicator that the private jet pilot was cutting corners.
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Aircraft ID
I was intrigued about the video, I have been away and started piling through this at about page 60 not realising a video had been released.
I have no idea whether it is true of fake but what struck me was that right from the off it looked like a high wing four engined aircraft (C-17, Il 76, A400) and if you freeze the video at 1 second, to me there are 4 lines which could look like engines.
Certainly did not look obviously airbussy to me but it's not the greatest video.
(By the way I was the UK Air Cadet individual champion at aircraft recognition...........in 1973-74
true, so either I am spot on, or lost my touch!)
I have no idea whether it is true of fake but what struck me was that right from the off it looked like a high wing four engined aircraft (C-17, Il 76, A400) and if you freeze the video at 1 second, to me there are 4 lines which could look like engines.
Certainly did not look obviously airbussy to me but it's not the greatest video.
(By the way I was the UK Air Cadet individual champion at aircraft recognition...........in 1973-74
true, so either I am spot on, or lost my touch!)
search area
seems the wreckage trail has been mentioned in the press conference at 13km
The tail section of the aircraft was found at coordinates N30.1527 E34.1858, 2230 meters/1.2nm south of the main wreckage and south of the last radar position
On Nov 7th 2015 Egypt's Air Accident Investigation Commission (EAAIC) reported in a press conference, that:
- the wreckage is distributed over a length of more than 13km consistent with in-flight breakup, several parts of the wreckage are missing.
- Initial observation of the wreckage does not yet allow to determine the cause of the inflight break up.
- The FDR was successfully downloaded, preliminary review of the data suggests the recording stopped 23 minutes 14 seconds after becoming airborne, last recorded altitude was 30,888 feet MSL, last recorded airspeed was 281 knots IAS, autopilot 1 was engaged, the aircraft was still climbing.
- The CVR was successfully downloaded and a first listening was done, the transcript is currently being compiled, a noise was heard in the last second of the recording. Spectral analysis is trying to determine the nature of this noise.
- Parties reporting facts outside of the investigation should provide their evidence to the accident investigation commission ( this appears to be a reference to British and US Intelligence heard chatter suggesting the aircraft was brought down by a bomb).
The tail section of the aircraft was found at coordinates N30.1527 E34.1858, 2230 meters/1.2nm south of the main wreckage and south of the last radar position
On Nov 7th 2015 Egypt's Air Accident Investigation Commission (EAAIC) reported in a press conference, that:
- the wreckage is distributed over a length of more than 13km consistent with in-flight breakup, several parts of the wreckage are missing.
- Initial observation of the wreckage does not yet allow to determine the cause of the inflight break up.
- The FDR was successfully downloaded, preliminary review of the data suggests the recording stopped 23 minutes 14 seconds after becoming airborne, last recorded altitude was 30,888 feet MSL, last recorded airspeed was 281 knots IAS, autopilot 1 was engaged, the aircraft was still climbing.
- The CVR was successfully downloaded and a first listening was done, the transcript is currently being compiled, a noise was heard in the last second of the recording. Spectral analysis is trying to determine the nature of this noise.
- Parties reporting facts outside of the investigation should provide their evidence to the accident investigation commission ( this appears to be a reference to British and US Intelligence heard chatter suggesting the aircraft was brought down by a bomb).
Last edited by rog747; 7th Nov 2015 at 16:56. Reason: source avh
Thick black smoke which p!umes and billows? Looks like the smoke rising vertically from a oil fuelled fire in still air turned through 90 degrees and overlaid. Just sayin'.
Tdracer and Mesoman. Very good contributions from the both of you (as well as others) on the characterists of sound propogation. This has really assisted in learning/understanding of what might have been on the CVR. This is where Pprune is quite the worthwhile read. Keep up the intelligent discussion.
Frankly this has been one of the most reasonable threads in a long time.
Frankly this has been one of the most reasonable threads in a long time.
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CVR - no alarms after the explosion?
After the ISIS video shows the explosion, the aircraft continues flying for an additional 15 seconds before the video ends with the fuselage relatively still in one piece.
According to the authorities, the CVR records a loud noise of some sort and then nothing. No aural warnings or alarms after that. The CVR is powered from the essential bus so shouldn't we expect alarms and bells after the explosion if that video is real.
According to the authorities, the CVR records a loud noise of some sort and then nothing. No aural warnings or alarms after that. The CVR is powered from the essential bus so shouldn't we expect alarms and bells after the explosion if that video is real.
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All of which brings up a question I've had during this very interesting thread: is there a reason we are not discussing a center fuel tank explosion? There have been a some of these in commercial jet aviation history, most notably TWA-800.
Must admit the similarities with TWA circumstances are notable.
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Possibly a stupid question!
Forgive me if its stupid but if the screw jack was deliberately tampered with would the possible result be the same as structural defect and the tail detaching from the rest of the aircraft ?If so wouldn't that obviate the need for explosives and account for, as far as I have heard, no residue being found.
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videos plural!
Note that a lot of post here a referring to "the video" but most posts do not provide a link to the video they are talking about. Even if responding directly to a particular post, they do not reference that poster by name. This only causes confusion which escalates in further responses. 
The web is now a source of multiple versions of these videos, both as copies/part copies of the earliest ones or newer ones.
From back posts at least 4 different videos have been mentioned. One at the beginning which I believe from some posts only showed wreckage. This caused some confusion then. At another point more recently in the thread videos were again being discussed and 2 different ones were weblinked. I cannot find them now. Both showed 2 different recordings (videoed by 2 different sources) of a plane, losing its tail then exploding and continuing to come down on fire but with wings attached. So, 2 videos, each with 2 different recordings. In each of these 2 videos, one recording was duplicated, but that still gave us 3 different recordings of the same incident.
It would be very helpful if those posting further comments on video content could include the link they are referring to. This should be simple enough, as presumably they will have recently watched it and have the weblink open.
I think a lot of readers would appreciated that. Thank you.
The web is now a source of multiple versions of these videos, both as copies/part copies of the earliest ones or newer ones.
From back posts at least 4 different videos have been mentioned. One at the beginning which I believe from some posts only showed wreckage. This caused some confusion then. At another point more recently in the thread videos were again being discussed and 2 different ones were weblinked. I cannot find them now. Both showed 2 different recordings (videoed by 2 different sources) of a plane, losing its tail then exploding and continuing to come down on fire but with wings attached. So, 2 videos, each with 2 different recordings. In each of these 2 videos, one recording was duplicated, but that still gave us 3 different recordings of the same incident.
It would be very helpful if those posting further comments on video content could include the link they are referring to. This should be simple enough, as presumably they will have recently watched it and have the weblink open.
I think a lot of readers would appreciated that. Thank you.
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Originally Posted by mitrosft
There is no time stamp in twitter pic. Assume Nordwind passed KG before event.
Originally Posted by theron
And FR24 data shows flight disruption starts at around 4:13:00.
Given this was an official FR24 receiver, the time should be GPS synched. I don't know anything about the clocks in the FDR and CVR.
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I don't own this space under my name. I should have leased it while I still could
gawbc that video is the same as on the Daily Express web link. The last section of the video does not seem to relate to the initial bit.
It also strikes me that something is missing from that aircraft at 33,000 feet. There are no contrails or even visages of one starting.
What was the contrail height that day?
It also strikes me that something is missing from that aircraft at 33,000 feet. There are no contrails or even visages of one starting.
What was the contrail height that day?
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@mickjoebill
"Having filmed 3 airframes being blown up as well as gas, petroleum, dust explosions, flashovers and numerous controlled demolitions for science docs I have a good idea of how explosions are imaged by video cameras."
My mispent youth in fire research agrees 100% with your conclusions. Having also worked in photo manipulation and other graphic artistry my first reaction to the video was to laugh.
I remember a documentary by an NTSB expert who said if you don't have recorded data then find all four corners and start from there. As far as I can see they haven't found all four corners yet.
"Having filmed 3 airframes being blown up as well as gas, petroleum, dust explosions, flashovers and numerous controlled demolitions for science docs I have a good idea of how explosions are imaged by video cameras."
My mispent youth in fire research agrees 100% with your conclusions. Having also worked in photo manipulation and other graphic artistry my first reaction to the video was to laugh.
I remember a documentary by an NTSB expert who said if you don't have recorded data then find all four corners and start from there. As far as I can see they haven't found all four corners yet.
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"First" video quite possible from somebody reaching site before rescue team, I read complains that place was looted before investigators begin secure it.
It's also not improbable that some of soldiers who arrive at the place first make video with their phones and post it in social media.
It's also not improbable that some of soldiers who arrive at the place first make video with their phones and post it in social media.