Metrojet crash Eygpt
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the blast appears to have caused an instantaneous transverse failure across the crown of the fuselage at a frame forward of the aft doors
As part of my job, I've looked at dozens of DFDR readouts. It is very uncommon for any parameter on the DFDR to be recorded at more than once per second.
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Highly unbelievably that 1 kg of TNT can cause such thing in less then 1 sec (and in 1 sec frame there will be at least dozen readouts at FDR).
I think you could stop the FDR with 10ozs if you put it in the right place, i.e next to the power supply. The fact that the FDR reportedly stopped after 1 second would suggest to me that the power supply was immediately interupted by the initial explosion. What happened after that was chain of events, leading to the liberation of the tail section etc. etc.
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I think you could stop the FDR with 10ozs if you put it in the right place, i.e next to the power supply. The fact that the FDR reportedly stopped after 1 second would suggest to me that the power supply was immediately interupted by the initial explosion.
Not the first time a bomb has been planted in the same hiding spot.
History repeats.
Philippine Airlines 434.
Aircraft survived with serious damage, 1 pax died and several others injured.
History repeats.
Philippine Airlines 434.
Aircraft survived with serious damage, 1 pax died and several others injured.
from wikipedia
"Yousef removed an altered Casio digital watch from his wrist to be used as a timer, unpacked the remaining materials from his dopp kit, and assembled his bomb. He set the timer for four hours later, which was approximately the time at which the plane would be far out over the ocean en route to Tokyo, put the entire bomb back into his dopp kit, and returned to his current seat.
After asking a flight attendant for permission to move to seat 26K, saying he could get a better view from that seat, Yousef moved to that seat and tucked the assembled bomb into the life vest pocket under that seat."
I wouldn't be surprised if terrorists got their idea from wiki(or some other Internet source), this sounds very spooky...
"Yousef removed an altered Casio digital watch from his wrist to be used as a timer, unpacked the remaining materials from his dopp kit, and assembled his bomb. He set the timer for four hours later, which was approximately the time at which the plane would be far out over the ocean en route to Tokyo, put the entire bomb back into his dopp kit, and returned to his current seat.
After asking a flight attendant for permission to move to seat 26K, saying he could get a better view from that seat, Yousef moved to that seat and tucked the assembled bomb into the life vest pocket under that seat."
I wouldn't be surprised if terrorists got their idea from wiki(or some other Internet source), this sounds very spooky...
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I do as well.
Once I found the container dangling down and contacted the FA. Comment was only "we do not fly over water today, Sir". They were not interested in somebody potentially messing with it, and probably did no write-up for maintenance to fix it...
On some aircraft it is a hard container, sometimes it is a soft bag.
Once I found the container dangling down and contacted the FA. Comment was only "we do not fly over water today, Sir". They were not interested in somebody potentially messing with it, and probably did no write-up for maintenance to fix it...
On some aircraft it is a hard container, sometimes it is a soft bag.
Only half a speed-brake
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I disagree, though not importantly, with tdracer that frame rates greater than one-second are uncommon. CARS 625.33, Schedule 3 specifies rates which are essentially the same as U.S. standards.
There are a number of parameters which are sampled at 1/2", 1/4" and higher, (1/8", 1/10" (B777) & 1/16" (later Airbus)) rates. The reason is logical - Vertical/longitudinal/lateral 'g' for example, change rapidly, as do flight controls positions, aircraft attitudes and some engine parameters.
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The number of parameters recorded, the interval and the resolution are in function of year of production.
For a 1997 made:
There are some parameters with interval below 1 second, as g factors and flight controls position, in Appendix M
For a 1997 made:
CFR 14 §121.344 Digital flight data recorders for transport category airplanes:
(d) For all turbine-engine-powered transport category airplanes that were manufactured after October 11, 1991—
(1) The parameters listed in paragraph (a)(1) through (a)(34) of this section must be recorded within the ranges, accuracies, resolutions, and recording intervals specified in Appendix M
(d) For all turbine-engine-powered transport category airplanes that were manufactured after October 11, 1991—
(1) The parameters listed in paragraph (a)(1) through (a)(34) of this section must be recorded within the ranges, accuracies, resolutions, and recording intervals specified in Appendix M
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Yet Another AD
AD 2015-23-13. All A-318, 319, 320, and A321 series airplanes. Allowable load limits on the vertical tail plane could be reached and possibly exceeded. Exceeding allowable load could result in detachment of the vertical tail plane.
SUMMARY: “This AD was prompted by a determination that, in specific flight conditions, the allowable load limits on the vertical tail plane could be reached and possibly exceeded. Exceeding allowable load could result in detachment of the vertical tail plane. This AD requires modification of the pin programming flight warning computer (FWC) to activate the stop rudder input warning (SRIW) logic; and an inspection to determine the part numbers of the FWC and the flight augmentation computer (FAC), and replacement of the FWC and FAC if necessary. We are issuing this AD to prevent detachment of the vertical tail plane and consequent loss of control of the airplane.Effective December 29, 2015.” Compliance within 48 months.
“We estimate that this AD affects 953 airplanes of U.S. registry. We also estimate that it will take about 3 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD on U.S. operators to be $243,015, or $255 per product.”
FAA AD Link > http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/41103a24e0131b2286257f0700529ecf/$FILE/2015-23-13.pdf
ALSO REFERENCED IN THIS AD.
“EASA Airworthiness Directive 2014-0217R1, dated February 26, 2015 (referred to after this as the Mandatory Continuing Airworthiness Information, or ''the MCAI''), to correct an unsafe condition.The MCAI states: During design reviews that were conducted following safety recommendations related to in-service incidents and one accident on another aircraft type, it has been determined that, in specific flight conditions, the allowable load limits on the vertical tail plane could be reached and possibly exceeded.This condition, if not corrected, could lead, in the worst case, to detachment of the vertical tail plane in flight and consequent loss of the aeroplane.To prevent such a possibility, Airbus has developed modifications within the flight augmentation computer (FAC) to reduce the vertical tail plane stress and to activate a conditional aural warning within the flight warning computer (FWC) to further protect against pilot induced rudder doublets.”
“Consequently, EASA issued AD 2014-0217 to require installation and activation of the stop rudder input warning (SRIW) logic. In addition, that [EASA] AD required, prior to or concurrent with modification of an aeroplane with the activation of the SRIW, upgrades of the FAC and FWC, to introduce the SRIW logic and SRIW aural capability, respectively. After modification, the [EASA] AD prohibited installation of certain Part Number (P/N) FWC and FAC.”
“Since that [EASA] AD was issued, an additional previously-published Airbus Service Bulletin (SB) was identified, and a new SB was published, for the concurrent requirement to replace the FAC with a unit having a P/N as listed in Table 3 of Appendix 1 of the AD.”
NTSB SAFETY RECCOMMENDATIONS A-04-56 through -62.
See Letter to FAA Administrator Marion C. Blakey, November 10, 2004 which addressed the loss of American Airlines Flight 587 on Nov 12, 2001.
NTSB Letter Link > http://www.ntsb.gov/safety/safety-recs/recletters/A04_56_62.pdf
SUMMARY: “This AD was prompted by a determination that, in specific flight conditions, the allowable load limits on the vertical tail plane could be reached and possibly exceeded. Exceeding allowable load could result in detachment of the vertical tail plane. This AD requires modification of the pin programming flight warning computer (FWC) to activate the stop rudder input warning (SRIW) logic; and an inspection to determine the part numbers of the FWC and the flight augmentation computer (FAC), and replacement of the FWC and FAC if necessary. We are issuing this AD to prevent detachment of the vertical tail plane and consequent loss of control of the airplane.Effective December 29, 2015.” Compliance within 48 months.
“We estimate that this AD affects 953 airplanes of U.S. registry. We also estimate that it will take about 3 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $85 per work-hour. Based on these figures, we estimate the cost of this AD on U.S. operators to be $243,015, or $255 per product.”
FAA AD Link > http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgad.nsf/0/41103a24e0131b2286257f0700529ecf/$FILE/2015-23-13.pdf
ALSO REFERENCED IN THIS AD.
“EASA Airworthiness Directive 2014-0217R1, dated February 26, 2015 (referred to after this as the Mandatory Continuing Airworthiness Information, or ''the MCAI''), to correct an unsafe condition.The MCAI states: During design reviews that were conducted following safety recommendations related to in-service incidents and one accident on another aircraft type, it has been determined that, in specific flight conditions, the allowable load limits on the vertical tail plane could be reached and possibly exceeded.This condition, if not corrected, could lead, in the worst case, to detachment of the vertical tail plane in flight and consequent loss of the aeroplane.To prevent such a possibility, Airbus has developed modifications within the flight augmentation computer (FAC) to reduce the vertical tail plane stress and to activate a conditional aural warning within the flight warning computer (FWC) to further protect against pilot induced rudder doublets.”
“Consequently, EASA issued AD 2014-0217 to require installation and activation of the stop rudder input warning (SRIW) logic. In addition, that [EASA] AD required, prior to or concurrent with modification of an aeroplane with the activation of the SRIW, upgrades of the FAC and FWC, to introduce the SRIW logic and SRIW aural capability, respectively. After modification, the [EASA] AD prohibited installation of certain Part Number (P/N) FWC and FAC.”
“Since that [EASA] AD was issued, an additional previously-published Airbus Service Bulletin (SB) was identified, and a new SB was published, for the concurrent requirement to replace the FAC with a unit having a P/N as listed in Table 3 of Appendix 1 of the AD.”
NTSB SAFETY RECCOMMENDATIONS A-04-56 through -62.
See Letter to FAA Administrator Marion C. Blakey, November 10, 2004 which addressed the loss of American Airlines Flight 587 on Nov 12, 2001.
NTSB Letter Link > http://www.ntsb.gov/safety/safety-recs/recletters/A04_56_62.pdf
Only half a speed-brake
There are some parameters with interval below 1 second, as g factors and flight controls position, in Appendix M
take care,
FD.
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@Data guy... AD
Thanks for posting that 
. The AD refers to pilot induced rudder doublets. Just one of the boxes to tick off in the Metrojet case. Even when a bomb is officially reported to be 100% certain, knowledge from doublet damages might be used to better understand the Metrojet break up sequence.
To be able to better understand and compare this aspect I wonder if anyone here has information on commercial or test pilots actually performing rudder doublets on Boeing aircraft and their resilience to that kind of pilot action. Condition being Inflight and above 200 knots.
In the AAL587 case it went over Ultimate Load to about 193% of Limit Load at 250knots after about two and a half doublets. In the AAL587 docket there is some information on Boeing design aspects but not surprisingly on doublet statistics (or cases) in Boeing test or operational service (as far as i have read it till now).
I think this is within, but almost at, the 'border' of the Metrojet case. In order not to lose a response, if you have some (deep or detailed) info on this you can also privmail me.
. The AD refers to pilot induced rudder doublets. Just one of the boxes to tick off in the Metrojet case. Even when a bomb is officially reported to be 100% certain, knowledge from doublet damages might be used to better understand the Metrojet break up sequence.To be able to better understand and compare this aspect I wonder if anyone here has information on commercial or test pilots actually performing rudder doublets on Boeing aircraft and their resilience to that kind of pilot action. Condition being Inflight and above 200 knots.
In the AAL587 case it went over Ultimate Load to about 193% of Limit Load at 250knots after about two and a half doublets. In the AAL587 docket there is some information on Boeing design aspects but not surprisingly on doublet statistics (or cases) in Boeing test or operational service (as far as i have read it till now).
I think this is within, but almost at, the 'border' of the Metrojet case. In order not to lose a response, if you have some (deep or detailed) info on this you can also privmail me.
Last edited by A0283; 26th Nov 2015 at 12:40. Reason: Add condition
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I recently had an interesting conversation with a Russian engineer I've known for a number of years; according to him, he knows at least one of the investigators into this crash and apparently the bomb theory is not universally accepted.
This is proper rumour and should be treated as such; anyway, the story goes that, firstly, the cabin pressure did not spike before falling as one might expect from an internal explosion and, secondly, the sober assessment is one of catastrophic engine failure, hull breach, fuel fire and of course the tail falling off.
Looking at the pictures here (and the video on that page) http://www.pprune.org/rumours-news/5...an-fir-46.html how does this alternative take on events pan out? It's frustrating being unable to see each piece of wreckage in the wider context; the engines and their parts do look very separated from the wings.
I'll leave it to those who know their stuff to dismiss this idea.
This is proper rumour and should be treated as such; anyway, the story goes that, firstly, the cabin pressure did not spike before falling as one might expect from an internal explosion and, secondly, the sober assessment is one of catastrophic engine failure, hull breach, fuel fire and of course the tail falling off.
Looking at the pictures here (and the video on that page) http://www.pprune.org/rumours-news/5...an-fir-46.html how does this alternative take on events pan out? It's frustrating being unable to see each piece of wreckage in the wider context; the engines and their parts do look very separated from the wings.
I'll leave it to those who know their stuff to dismiss this idea.
To be able to better understand and compare this aspect I wonder if anyone here has information on commercial or test pilots actually performing rudder doublets on Boeing aircraft and their resilience to that kind of pilot action. Condition being inflight and above 200 knots.
Such tests are not done without much forethought and a careful briefing..
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I have seen many photos of plane crashes with the engines heavily damaged, but have I don't remember seeing any with a broken fwd fan shaft. Usually what is seen is the main fan disk still attached and heavy damage on all the fan blades.
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the sober assessment is one of catastrophic engine failure, hull breach, fuel fire and of course the tail falling off.
Whatever happened 'severed' the data/power lines very early on.
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Still missing 11 and remarks on other posts
Major items still missing in pictures in the public domain...
A. Fuselage barrel section between wing and tail... (two window rows aft connected to the tail section),
B. Substantial part of the vertical tail and rudder,
C. A large number of seats,
D. ....
As far as i have seen ... No clear evidence of bomb damage on any available picture...
No pictures of burned seats than can shed any light on the direction and extent of the fire in the aft section (point A.)...
From what is published you would expect quite a flash or short flashfire... In what appears to be a very short time. So how would a small bomb explain that. Cutting the APU fuel line of a shut off APU, does not deliver that ? ... Wings and cwt seem pretty complete? ... Did this specific plane configuration indeed carry fuselage tanks apart from the cwt, then these would be a more likely source?
Bomb versus fuel-tank explosion scenario discussions are not new. And appear to be never ending even years after final reports are published.
The engines are pretty close to the wing ... You can see them in a number of pictures taken from the main impact site. They separated rather late. They look pretty clean... and not like having had a catastrophic failure... Kicking out (both) fans is indeed quite unusual...
Another thing is, that we do not know what the site looked like just after the crash. Recovery of the victims has of course been a priority in the early stages.
Too many possible scenarios open at this stage... Is my impression... Which statistically speaking is no surprise
A. Fuselage barrel section between wing and tail... (two window rows aft connected to the tail section),
B. Substantial part of the vertical tail and rudder,
C. A large number of seats,
D. ....
As far as i have seen ... No clear evidence of bomb damage on any available picture...
No pictures of burned seats than can shed any light on the direction and extent of the fire in the aft section (point A.)...
From what is published you would expect quite a flash or short flashfire... In what appears to be a very short time. So how would a small bomb explain that. Cutting the APU fuel line of a shut off APU, does not deliver that ? ... Wings and cwt seem pretty complete? ... Did this specific plane configuration indeed carry fuselage tanks apart from the cwt, then these would be a more likely source?
Bomb versus fuel-tank explosion scenario discussions are not new. And appear to be never ending even years after final reports are published.
The engines are pretty close to the wing ... You can see them in a number of pictures taken from the main impact site. They separated rather late. They look pretty clean... and not like having had a catastrophic failure... Kicking out (both) fans is indeed quite unusual...
Another thing is, that we do not know what the site looked like just after the crash. Recovery of the victims has of course been a priority in the early stages.
Too many possible scenarios open at this stage... Is my impression... Which statistically speaking is no surprise