AF 447 Search to resume (part2)
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Back to the Facts
Hi,
Browsing again the old BEA reports, I found this quote which should have been taken into consideration much earlier by most of us as for the initial state of the recovered floating bodies, next, enlightnig someway the nuisance of the various rumors circulating from "tabloids" reporting sources:
This would contradict most of the press releases (still today summaries):
1. Many bodies were recovered by the French Navy (about 3/5th by Ventôse);
2. They were clothed and well preserved;
S~
Olivier
Browsing again the old BEA reports, I found this quote which should have been taken into consideration much earlier by most of us as for the initial state of the recovered floating bodies, next, enlightnig someway the nuisance of the various rumors circulating from "tabloids" reporting sources:
Originally Posted by BEA first interim report, page 40
1.13 Medical and Pathological Information
Sailors from the Frigate Ventôse recovered about thirty bodies. A visual examination of the bodies showed that they were clothed and relatively well preserved. All of them were handed over to the Brazilian Navy to be transferred to the Recife morgue.
Sailors from the Frigate Ventôse recovered about thirty bodies. A visual examination of the bodies showed that they were clothed and relatively well preserved. All of them were handed over to the Brazilian Navy to be transferred to the Recife morgue.
1. Many bodies were recovered by the French Navy (about 3/5th by Ventôse);
2. They were clothed and well preserved;
S~
Olivier
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Some BEA photo isolations from today's briefing:
An A330 avionics rack (hat tip to PJ2):
AF447's rack being hoisted aboard:
Recovered rack components:
An A330 avionics rack (hat tip to PJ2):
AF447's rack being hoisted aboard:
Recovered rack components:
Machaca;
Many thanks once again.
With the Avionics Bay comes the memory boards/chips of the FCPCs, FCSCs and possibly the QAR. If a card, (and I now suspect it is), it may be readable if not shattered. The card is placed in a slot so is somewhat "protected" unless the unit itself was crushed. What we see of condition of the boxes is encouraging. Let us hope for the best here as well.
I see from the photograph of the engine that half the stator-blade section is missing, confirming what was seen in the original photographs.
Many thanks once again.
With the Avionics Bay comes the memory boards/chips of the FCPCs, FCSCs and possibly the QAR. If a card, (and I now suspect it is), it may be readable if not shattered. The card is placed in a slot so is somewhat "protected" unless the unit itself was crushed. What we see of condition of the boxes is encouraging. Let us hope for the best here as well.
I see from the photograph of the engine that half the stator-blade section is missing, confirming what was seen in the original photographs.
auv-ee:
Thank you for pointing me to your previous very interesting post on the subject.
Can we assume that a 20db signal to noise ratio is about the detection capability of TPLs ?
Since we are in the ITCZ intermittent heavy showers have a significant probability of occurring at any time. I read in a US Navy paper that rain drops impacting sea surface and implosion of air bubbles caused by rain produce noise in the 1-100 kHz band with max SL @ 20 kHz and SL can be up to 30 dB above sea surface noise though I think the intensity is lower at great depths. It seems that if the TPLs were flown at, say 1700 m from the nearest pinger a simple shower occurring at the same time would have prevented detection. As I understand phase I, any area was swept only once so perhaps the failure was only bad luck.
OTOH, it is very possible that both ULB failed in the crash.
Thank you for pointing me to your previous very interesting post on the subject.
Can we assume that a 20db signal to noise ratio is about the detection capability of TPLs ?
Since we are in the ITCZ intermittent heavy showers have a significant probability of occurring at any time. I read in a US Navy paper that rain drops impacting sea surface and implosion of air bubbles caused by rain produce noise in the 1-100 kHz band with max SL @ 20 kHz and SL can be up to 30 dB above sea surface noise though I think the intensity is lower at great depths. It seems that if the TPLs were flown at, say 1700 m from the nearest pinger a simple shower occurring at the same time would have prevented detection. As I understand phase I, any area was swept only once so perhaps the failure was only bad luck.
OTOH, it is very possible that both ULB failed in the crash.
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Originally Posted by DJ77
Can we assume that a 20db signal to noise ratio is about the detection capability of TPLs ?
Since we are in the ITCZ intermittent heavy showers have a significant probability of occurring at any time. I read in a US Navy paper that rain drops impacting sea surface and implosion of air bubbles caused by rain produce noise in the 1-100 kHz band with max SL @ 20 kHz and SL can be up to 30 dB above sea surface noise though I think the intensity is lower at great depths.
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Weak signals detection
If the half buried SSCVR ULB was transmitting as specified the chances to be detected with available techniques and adequate methodology were very high.
I am very familiar with "weak signals detection" using DSP techniques, intrinsically quite insensitive to noise.
In the picture below:
You have a signal that could be IMPOSSIBLE to be heard and with proper techniques can be CLEARLY detectable in the computer screen (High Signal to Noise ratio) using widely available FREE software PC (Win) compatible.
For example:
With this setup you could tune in a distant NDB (impossible to be heard, even it´s carrier) and it will come up "loud" and CLEAR in your screen
Another example:
You could have a CW 10W HF carrier operating in the 5 MHz* aeronautical band (dark hours) in the a/c, being monitored in DKR or REC with near 100% chances to tell you when disappear triggering an alert.
(*) 8 MHz in daylight.
Even with the current HF antennas (a/c and ground stations) very poor compared to the ones used by dedicated amateur radio in their stations.
PS
I will investigate what kind of Receiver they used in order to understand on their capability to succeed in cases like AF447.
And if the wreckage did fall in a hilly region it would be more difficult.
I am very familiar with "weak signals detection" using DSP techniques, intrinsically quite insensitive to noise.
In the picture below:
You have a signal that could be IMPOSSIBLE to be heard and with proper techniques can be CLEARLY detectable in the computer screen (High Signal to Noise ratio) using widely available FREE software PC (Win) compatible.
For example:
With this setup you could tune in a distant NDB (impossible to be heard, even it´s carrier) and it will come up "loud" and CLEAR in your screen
Another example:
You could have a CW 10W HF carrier operating in the 5 MHz* aeronautical band (dark hours) in the a/c, being monitored in DKR or REC with near 100% chances to tell you when disappear triggering an alert.
(*) 8 MHz in daylight.
Even with the current HF antennas (a/c and ground stations) very poor compared to the ones used by dedicated amateur radio in their stations.
PS
I will investigate what kind of Receiver they used in order to understand on their capability to succeed in cases like AF447.
And if the wreckage did fall in a hilly region it would be more difficult.
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I recall from the NASA Columbia investigation that bodies recovered from in-flight breakups, or from the failure of a pressure vessel at a significant height, the bodies in all previous recoveries were denuded; this was the case in Air India 182 and Pan Am 103.
The fact that bodies from the AF447 are fully clothed, I assume, rules out any in-flight breakup and explosive decompression?
The fact that bodies from the AF447 are fully clothed, I assume, rules out any in-flight breakup and explosive decompression?
From the PDF
One hopes that this apparent hubris has been mitigated in the interim. (Report is 15 years old, yes?) I say this fully acknowledging that the author is a better pilot than I.
The difference between education and training. 
I applaud the approach advocated.
A boilerplate "unusual attitudes" recovery technique.
As discussed previously in various AF 447 posts ... and as seen in stall training in small single engine trainers.
JD-EE
If your suggestion is to be considered, there is likely a cultural (industry and/or corporate) issue that may be non-trivial to address .
I think you mean "for other flight duties" but I see what you are headed towards.
I learned radar work on a scope with more or less raw video (ship board radar) and was disappointed in later graduating to the APS-124, which only providing processed video to my cockpit display in the (then new) SH-60B. One factor that drove this choice was that the data from the radar had to be in a form that would easily go down a directional data link to the ship's Combat Information Center. That tech and design decision allowed the radar to share space in the cockpit with our other tactical displays, via a selection toggle, but it constrained how much one could get out of the radar itself. It also allowed either the pilot, or the crewman, to work the radar.
While I share your position on giving the pilot the choices to tweak the display and input, there is the design problem of competing with other capability for real estate in the finite amount of space provided for pilot attention on any flight deck.
Ergonomics at its most interesting.
Some of the folks who operate that radar have, in various posts over the past two years, pointed out that there is some room to "tweak" the display during a given trip. It may be "good enough" with enough operator training, habit, and familiarity. This points again to a cultural issue, possibly moreso than a design issue.
The end result of two years work is a training package including a video and a CD-ROM, giving an airplane upset recovery training aid.
However, all members of the joint industry group agreed that the package is aimed at preventing loss of control accidents on conventional aircraft. It is not aimed at protected Fly-by-Wire aircraft. There is no need for this type of continuation training on protected aircraft, although a general knowledge of the principles involved is useful for every pilot.
However, all members of the joint industry group agreed that the package is aimed at preventing loss of control accidents on conventional aircraft. It is not aimed at protected Fly-by-Wire aircraft. There is no need for this type of continuation training on protected aircraft, although a general knowledge of the principles involved is useful for every pilot.
We wanted a general knowledge based approach, as opposed to a rule based one. For this, after proposing some initial actions, we talk about “additional techniques which may be tried”. This obviously is more difficult to teach
I applaud the approach advocated.
When we started our discussions, the training being given in the airlines to recover from excessive nose-up pitch attitudes emphasised rolling rapidly towards 90° of bank.
Based on our experience as test pilots we are very wary of using rudder close to the stall. It is the best way to provoke a loss of control if not used very carefully, particularly with flaps out.
JD-EE
If you are going to design an aircraft that gives up control when the automation gets confused but not before then you need the pilots to have the most wide open control possible. Maybe that will be a takeaway from AF-447.
Meantime, lobby for a switch on the radar front panel that may involve an "ARE YOU REALLY SURE?" interaction with the pilot that enables full control of the display including any raw mode that could exist. The pilots are being offloaded for other flight controls. So they have time to operate the radar in detail modes; and, they have time to learn how.
I learned radar work on a scope with more or less raw video (ship board radar) and was disappointed in later graduating to the APS-124, which only providing processed video to my cockpit display in the (then new) SH-60B. One factor that drove this choice was that the data from the radar had to be in a form that would easily go down a directional data link to the ship's Combat Information Center. That tech and design decision allowed the radar to share space in the cockpit with our other tactical displays, via a selection toggle, but it constrained how much one could get out of the radar itself. It also allowed either the pilot, or the crewman, to work the radar.
While I share your position on giving the pilot the choices to tweak the display and input, there is the design problem of competing with other capability for real estate in the finite amount of space provided for pilot attention on any flight deck.
Ergonomics at its most interesting.
Some of the folks who operate that radar have, in various posts over the past two years, pointed out that there is some room to "tweak" the display during a given trip. It may be "good enough" with enough operator training, habit, and familiarity. This points again to a cultural issue, possibly moreso than a design issue.
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QAR media
What we see of condition of the boxes is encouraging
Surprisingly in better condition than i first thought. Considering the bay location in the a/c.
Last edited by RR_NDB; 9th May 2011 at 17:44. Reason: Comm. impvmt.
zoom-boom scenario
I´m somewhat astonished concerning this scenario.
Flying at FL 350 with a still heavy aircraft, how much climb could be produced even with full power? Is there enough elevator authority available to get the climb rate going to reach such an AOA and how fast would airspeed degrade? Gums with his F16 could have done it, my F4 would just have produced a lot of drag on such an elevator input and would have picked up a descent rate instead of a climb rate.
Next question is, at what point of the events and with what kind of airspeed could this pitchup have started? Icing of pitots, therefore unreliable airspeed (not known to the crew jet), turbulence and autothrust of, stall onset at the low speed region (not clearly identified by the crew yet, might be mixed up with turbulence issues). Crew-action increase thrust leading to pitchup (underslung engines, unfavorable CG), with slowing down descent rate, but not curing the pitch problem (correct speed still not known to the crew, work overload, turbulence.....). Nose stays up crew reduces thrust again..........
At what forward speed would we define the upset (if it happened) from FL 350 to FL100 and then on down to the water? If the normal flying speed is 470 KTAS in FL 350, is the thing still flying with 300 KTAS? Per my definition the aircraft would be out of flying speed way before the previous mentioned 60 KIAS from other posters.
The going down in a upset condition would probably never be in a straight line, struggling with a falling aircraft in free airspace directional control would be my last worries. It might have done one or more turning/ yawing motions around the vertical axis, it is at least more probable in an upset than a straight line. That sums up for the missing time. And it might not have been a continuous upset, secondary stalls are quite a common encounter in well controlled training environment (planned, briefed, prepared and good weather).
I´m not saying, that´s what it was.
franzl
Flying at FL 350 with a still heavy aircraft, how much climb could be produced even with full power? Is there enough elevator authority available to get the climb rate going to reach such an AOA and how fast would airspeed degrade? Gums with his F16 could have done it, my F4 would just have produced a lot of drag on such an elevator input and would have picked up a descent rate instead of a climb rate.
Next question is, at what point of the events and with what kind of airspeed could this pitchup have started? Icing of pitots, therefore unreliable airspeed (not known to the crew jet), turbulence and autothrust of, stall onset at the low speed region (not clearly identified by the crew yet, might be mixed up with turbulence issues). Crew-action increase thrust leading to pitchup (underslung engines, unfavorable CG), with slowing down descent rate, but not curing the pitch problem (correct speed still not known to the crew, work overload, turbulence.....). Nose stays up crew reduces thrust again..........
At what forward speed would we define the upset (if it happened) from FL 350 to FL100 and then on down to the water? If the normal flying speed is 470 KTAS in FL 350, is the thing still flying with 300 KTAS? Per my definition the aircraft would be out of flying speed way before the previous mentioned 60 KIAS from other posters.
The going down in a upset condition would probably never be in a straight line, struggling with a falling aircraft in free airspace directional control would be my last worries. It might have done one or more turning/ yawing motions around the vertical axis, it is at least more probable in an upset than a straight line. That sums up for the missing time. And it might not have been a continuous upset, secondary stalls are quite a common encounter in well controlled training environment (planned, briefed, prepared and good weather).
I´m not saying, that´s what it was.
franzl
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The aera phase 1 the very first research .. (with ASSUMPTION of working pingers) was not a large one !
And phase 4 included the crash site.
The difference is they used appropriate tools for this search and they assumed (this time) that the pingers were no more working !
The difference is they used appropriate tools for this search and they assumed (this time) that the pingers were no more working !
At the first search .. they have two doors to open ....
One with the pingers in the room .. the other with no pingers ...
They opened only one door .
One with the pingers in the room .. the other with no pingers ...
They opened only one door .
It's easy to use hindsight to say they should have bet on the 100:1 outsider after you know the result.
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From Tim Vasquez's excellent meteorology of nearly two years ago.
IMO, the possibility of a downdraft beneath the anvil contributing to the rate of descent ought to be considered.
Vasquez's site for his AF447 work.
Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data
IMO, the possibility of a downdraft beneath the anvil contributing to the rate of descent ought to be considered.
Vasquez's site for his AF447 work.
Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data
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IMO, the possibility of a downdraft beneath the anvil contributing to the rate of descent ought to be considered.
Vasquez's site for his AF447 work.
Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data
Vasquez's site for his AF447 work.
Air France 447 - AFR447 - A detailed meteorological analysis - Satellite and weather data
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That's a terrific picture of the engine! You can see the 12 o'clock position facing the camera --their sling is hanging it from it's 9:00 -- and the fwd eng mount quite well... [*edit*Clearly*] it appears** the bottom forward half of the engine took the brunt, pulling the forward mount down, shearing those mount bolts and pushing the aft upper portion of the engine upward... Can't see what failed there, because the aft mount is gone.
Last edited by 3holelover; 9th May 2011 at 18:33.
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RR_NDB
I believe the technique you are referring to is a phase lock loop system.
Phase-locked loop - Wikipedia, the free encyclopedia
Real electronic black magic. No doubt the EE folk will have more to say.
You have a signal that could be IMPOSSIBLE to be heard and with proper techniques can be CLEARLY detectable in the computer screen (High Signal to Noise ratio) using widely available FREE software PC (Win) compatible.
Phase-locked loop - Wikipedia, the free encyclopedia
Real electronic black magic. No doubt the EE folk will have more to say.
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Hi,
Sorry for the big size (so I post only the URL) .. but this give a better view (engine) of what explained above ... (magnified 150 % of the original BEA pic)
http://i.imgur.com/F0cQX.jpg
That's a terrific picture of the engine!
http://i.imgur.com/F0cQX.jpg
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Digital Signal Processing
Machinbird,
PLL is just a "building block" that can be "hardware based". And are powerful.
DSP systems are IMPRESSIVE. You use the "computing power" to "remove" the noise (that is ramdom) to detect the signal (that is coherent) using Redundancy.
The results i observed are simply unbelievable. So i designed a "Propagation Tester" using it that can be understood in my PY2CW mobile Ham Station website.
Using the synergy between HF and Internet in "near real time".
I am curious to known what kind of Receiving Technique they used in the failed ULB location.
Real electronic black magic
DSP systems are IMPRESSIVE. You use the "computing power" to "remove" the noise (that is ramdom) to detect the signal (that is coherent) using Redundancy.
The results i observed are simply unbelievable. So i designed a "Propagation Tester" using it that can be understood in my PY2CW mobile Ham Station website.
Using the synergy between HF and Internet in "near real time".
I am curious to known what kind of Receiving Technique they used in the failed ULB location.
Last edited by Jetdriver; 10th May 2011 at 02:55.
Dog Tired
It's all very well for you experts to pontificate about the several sciences involved but I am simply amazed that they have got an engine up from that depth.
I know how big that engine is and I applaud their efforts.
I know how big that engine is and I applaud their efforts.