AF 447 Search to resume
henra: thanks. 
~15-20,000 fpm.
I suppose I ought to do the stubby pencil math and see how that fits in with BEA's estimated g-loads at impact.
~15-20,000 fpm. I suppose I ought to do the stubby pencil math and see how that fits in with BEA's estimated g-loads at impact.
Originally Posted by from the BEA report as posted by BJ-ENG
Pelvic fracture is one of the classifications used by accident investigation pathologists (Naval Flight Injury Manual) to correlate the most serious injury sustained against deceleration and corresponds to a deceleration force in the range 100G to 200G.
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The Recorders to Provide the details
“Lets wait until the recorders are recovered. Then we will know.” That statement has been made ad nauseum during this thread, and the original one.
I fear however this may not be the case.
I do agree, the recorders will provide information which will help determine the reason(s) and provide the cause(s). PROVIDED they are readable after two years at a deep submerged depth. That is a big question. Another, and more important, if they are readable, that the actual true information discovered is provided, and not altered as has been suspected in past accidents. I share the stated concern of others, and I am not comfortable with the sole custody of the recorders being granted to the BEA, who have a vested interest in the outcome of the investigation. Two French Companies and the French Government to name but three will no doubt be a great temptation to mold the cause. There seems to be a protocol being established now which prohibits any other party or government, other than the BEA, from obtaining and controlling any and all recovered info from the crash site. I don’t know if this is good or not given the results of previous investigations.
I fear however this may not be the case.
I do agree, the recorders will provide information which will help determine the reason(s) and provide the cause(s). PROVIDED they are readable after two years at a deep submerged depth. That is a big question. Another, and more important, if they are readable, that the actual true information discovered is provided, and not altered as has been suspected in past accidents. I share the stated concern of others, and I am not comfortable with the sole custody of the recorders being granted to the BEA, who have a vested interest in the outcome of the investigation. Two French Companies and the French Government to name but three will no doubt be a great temptation to mold the cause. There seems to be a protocol being established now which prohibits any other party or government, other than the BEA, from obtaining and controlling any and all recovered info from the crash site. I don’t know if this is good or not given the results of previous investigations.
With all protections off could you fly it ?
A question from a non-pilot. Given that at some time near 2:10 the aircraft was trimmed and at an appropriate speed and altitude, and that at some time around about 2:15 the a/c was in 'line of flight' with low forward speed and high ROD but more or less level and engines at idle, is there any plausible configuration of the aircraft with limited roll excursion and plausible constant pitch angle (say less than 25 degrees) which if held which would execute the dynamics ?
If you have to invoke a multi-episode history with interludes of dramatic energy loss but with (almost) recovery of attitude at the end, the permutations must run wild. If you have to assume a turn, then the plausibility of that action in the circumstances, and the cruelty of fate which left the a/c in an ambiguous location must be accepted. If the sequence started somewhat later then the timeline gets even yet more demanding.
If you have to invoke a multi-episode history with interludes of dramatic energy loss but with (almost) recovery of attitude at the end, the permutations must run wild. If you have to assume a turn, then the plausibility of that action in the circumstances, and the cruelty of fate which left the a/c in an ambiguous location must be accepted. If the sequence started somewhat later then the timeline gets even yet more demanding.
Quote from mm43:
A caution regarding the A/P and A/THR; an ACARS warning is not generated each time they suffer a manual disconnection. The warning is due to an automatic disconnection due to their operating parameters having been exceeded.
Your first sentence is correct. But my understanding (and experience on the A320) is that knocking the sidestick (possibly accidentally) produces the AP disconnect warning, and closing the throttles in A/THR produces the A/THR disconnect warning.
Quote:
There is one non F/Ctl warning timestamped at 0210, i.e. FCPC2 (2CE) WRG: ADIRU 1 BUS ADR1-2 TO FCPC2,HARD which is a systems warning, but we also have PROBE-PITOT 1X2 / 2X3 / 1X3 (9DA),HARD. What came first, the chicken or the egg??
I saw your discussion on wiring earlier, but haven't got my head around the implications yet. Are you suggesting that the ASIs might not have been giving erroneous indications? If they were, my argument stands; if there's doubt in that area, I'll need to review part of my argument. Please advise, mm43.
A caution regarding the A/P and A/THR; an ACARS warning is not generated each time they suffer a manual disconnection. The warning is due to an automatic disconnection due to their operating parameters having been exceeded.
Your first sentence is correct. But my understanding (and experience on the A320) is that knocking the sidestick (possibly accidentally) produces the AP disconnect warning, and closing the throttles in A/THR produces the A/THR disconnect warning.
Quote:
There is one non F/Ctl warning timestamped at 0210, i.e. FCPC2 (2CE) WRG: ADIRU 1 BUS ADR1-2 TO FCPC2,HARD which is a systems warning, but we also have PROBE-PITOT 1X2 / 2X3 / 1X3 (9DA),HARD. What came first, the chicken or the egg??
I saw your discussion on wiring earlier, but haven't got my head around the implications yet. Are you suggesting that the ASIs might not have been giving erroneous indications? If they were, my argument stands; if there's doubt in that area, I'll need to review part of my argument. Please advise, mm43.
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15~20,000 ft/min: I suppose I ought to do the stubby pencil math and see how that fits in with BEA's estimated g-loads at impact.
=================
Whilst we can postulate a few descent profiles, that seem to fit, there surely are too many unknown still to bother with more than say 2 or 3 basic likelihoods. Must say though, that a deliberate turn or serious wing-drop (with recovery in the same sense, being the easiest thing to do) does seem part of the picture
Quote from Mr Optimistic:
Given that at some time near 2:10 the aircraft was trimmed and at an appropriate speed and altitude, and that at some time around about 2:15 the a/c was in 'line of flight' with low forward speed and high ROD but more or less level and engines at idle, is there any plausible configuration of the aircraft with limited roll excursion and plausible constant pitch angle (say less than 25 degrees) which if held which would execute the dynamics ?
I'm inclined to think that a considerable turn or turns must have been involved, particularly in view of the alleged proximity of the debris field to the LKP. Don't follow why you stipulate a constant pitch angle, though.
Given that at some time near 2:10 the aircraft was trimmed and at an appropriate speed and altitude, and that at some time around about 2:15 the a/c was in 'line of flight' with low forward speed and high ROD but more or less level and engines at idle, is there any plausible configuration of the aircraft with limited roll excursion and plausible constant pitch angle (say less than 25 degrees) which if held which would execute the dynamics ?
I'm inclined to think that a considerable turn or turns must have been involved, particularly in view of the alleged proximity of the debris field to the LKP. Don't follow why you stipulate a constant pitch angle, though.
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Lonewolf 50
There was a briefing given to the Royal Aero Society by Boeing Chief Test Pilot Capt. Frank Santoni regarding progress in certification programs for Boeing 748 and 787.
It is an hour long briefing and for you television addicts-contains no video
but some very interesting audio. Among the topics discussed was stall testing of these aircraft. I have not re-listened to the briefing, but I recall the description of testing the stall characteristics of these aircraft. From my recollection, he described stall behavior of these aircraft as a low frequency vibration with increasing motion on the flight deck until it reached the point that was mandatory that the crew be strapped in or else they would be thrown from their seats. This type behavior would likely be also relevant to the A332.
Boeing Flight Test Update on the 747-8 and 787 | Aero Society Channel | The Royal Aeronautical Society
Could stall buffet be mistaken for turbulence associated with a CB? 
If so, how long would it take an aircrew to realize "Hey, this is a stall, not heavy turbulence" and begin to initiate corrective action?
could a crew mistake a stall for turbulence.
If so, how long would it take an aircrew to realize "Hey, this is a stall, not heavy turbulence" and begin to initiate corrective action? could a crew mistake a stall for turbulence.
It is an hour long briefing and for you television addicts-contains no video
but some very interesting audio. Among the topics discussed was stall testing of these aircraft. I have not re-listened to the briefing, but I recall the description of testing the stall characteristics of these aircraft. From my recollection, he described stall behavior of these aircraft as a low frequency vibration with increasing motion on the flight deck until it reached the point that was mandatory that the crew be strapped in or else they would be thrown from their seats. This type behavior would likely be also relevant to the A332.Boeing Flight Test Update on the 747-8 and 787 | Aero Society Channel | The Royal Aeronautical Society
Auraflyer
It will be interesting to see where the wreckage really is when the location is finally disclosed. I have long believed it is to the S of LKP based on drift analysis - although I am the first to admit that there are a lot of assumptions inherent in this.
It will be interesting to see where the wreckage really is when the location is finally disclosed. I have long believed it is to the S of LKP based on drift analysis - although I am the first to admit that there are a lot of assumptions inherent in this.
This suggests they found it nearish their starting point.
I would have assumed they would start south, since that was the "red" (most likely) area in both their "everything taken account of" search area (fig #32) and their "everything except ping-only searches taken account of" search area (fig #33) (to paraphrase somewhat inaccurately).
I would assume that only once you had finished there, would you search the area north, since (a) that area had already been searched (albeit "ping-only") and (b) it would only be necessary to go there if both pingers had not activated AND nothing turned up in the south.
However mm43 noted this a while back:
The "Alucia" has arrived in the proposed search area, and my interpretation of press releases is that the search will commence in the north sector of the 20NM radius circle and progress southwards. A reposting of a previous BEA graphic with additional enhancements will provide a general indication of the area the "Alucia" will now be working in.
This time there is no AIS and they have not disclosed the location. Is it just coincidence, or did they make a conscious decision to deny the public this information in phase 4. If a conscious decision, why the change in policy? I guess I can understand the reasons not to disclose the location. But then why is it they apparently didn't care in the earlier searches?
sensor_validation;
If for any reason the engines rolled back, level flight is not possible, but forward flight is, and at the same airspeed as before or, more likely a slower, gliding speed. The A330 glides extremely well, far better than any Cessna, (but at a lot faster speed in the glide - best L/D for the A330 at 205T would have been about 245kts), and a heavier aircraft glides further than a light aircraft and takes longer to get down. A glide from FL350 to sea level with no engine power would take about 20 - 25 minutes and cover from 80 to 120nm depending upon weight, wind and some other factors. For comparison, under idle thrust, 30 - 35 minutes, 110 to 150nm to lose 35,000ft. The shorter distance with engine failure is due in part to the large windmilling frontal surfaces presented to the airflow by the N1's.
With dual engine failure you still have pitch of course so you have speed control, (governed, really, by AoA). The QRH Unreliable airspeed drill has the pitch-for-airspeed tables, and the QRH Dual Engine Failure (With Fuel) has airspeed to glide at. The ditching would be done with Config FULL, if available, (windmilling engines will power the hydraulics to some extent) and gear up and, as Sully showed us all, could be survivable under the right conditions.
I'm pretty sure this didn't occur and have written what I thought happened, but the recorders may mock us all...
wes_wall;
Regarding altering the SSFDR and SSCVR to suit certain interests, can you describe for me how that could be done and how it would avoid detection by those who do flight data analysis and sound spectrometry in their sleep? Thanks.
Not mentioned for a while - but if initial problem was caused by icing - what about the effect of ice crystals on the engines, did they somehow "roll back" meaning level flight with "pitch and power" not an option? This phenomena still subject to research
With dual engine failure you still have pitch of course so you have speed control, (governed, really, by AoA). The QRH Unreliable airspeed drill has the pitch-for-airspeed tables, and the QRH Dual Engine Failure (With Fuel) has airspeed to glide at. The ditching would be done with Config FULL, if available, (windmilling engines will power the hydraulics to some extent) and gear up and, as Sully showed us all, could be survivable under the right conditions.
I'm pretty sure this didn't occur and have written what I thought happened, but the recorders may mock us all...
wes_wall;
Regarding altering the SSFDR and SSCVR to suit certain interests, can you describe for me how that could be done and how it would avoid detection by those who do flight data analysis and sound spectrometry in their sleep? Thanks.
Last edited by PJ2; 15th Apr 2011 at 06:04.
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Originally Posted by auraflyer
So if that's right, again suggests possibly in the north?
In any case, the BEA has drawn a nice picture of the approximate location (last page, below), in the abyssal plain to the north and west of LKP, and they said that the debris field was within this (dark blue) area; though their arrow identifies the abyssal plain, not the wreck within it.
http://www.bea.aero/fr/enquetes/vol....4avril2011.pdf
Are you still uncertain as to the approximate location of the debris? The plan was to work north to south across the area not searched in Phase 2/3 that is within the 20nm radius, then to proceed outward, as required.
searching the remaining north sector doesn't take a long time (2 weeks?) and they would then be better positioned to expand the search south, without having to run north, again.
One other thing I had missed until now (and I don't recall seeing it in the thread already) -- look at the sonar image in the BEA 4/4 report (p2):
The red arrow at the top points north. I'm no expert on sidescan sonar, but doesn't it look like the wreckage & the debris field runs approximately along the east/west axis?
Would correlate with being left of planned course - but I suppose there may well be little correlation between final resting orientation and orientation at impact for such a deep descent?
Occam's razor: they might not have realised it was active the first time (or publicly available enough), and so disabled it this time (because they want to keep the location secret)? ie a simple oversight?
At one level I can understand not disclosing the location right now. It would inevitably promote more speculation about what caused the crash - while such speculation is happening anyway, I can appreciate they have no desire to encourage it. It would almost certainly generate criticism of the previous search efforts if they were seen to be fairly wide of the mark (yes such criticism would be unwarrented and would be ignorant of the substantial difficulties involved, but we all know that such criticism would be forthcoming).
I hope that this is the only reason, and that there are not other agendas at play. I believe we should give the authorities the benefit of the doubt that justice is being done. Equally, those authorities need to be realistic and understand that justice also has to be seen to be done. Fairly or unfairly, there are already plenty of questions being asked about many aspects of this investigation. Against that background, the authorities need to appreciate that the lack of of communication and insufficient transparency do not help this cause.
And I am still not convinced about the location. On balance, I suspect the graphic produced is honest. But the language used is loose enough to be ambiguous - possibly deliberately so.
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Originally Posted by auraflyer
The red arrow at the top points north. I'm no expert on sidescan sonar, but doesn't it look like the wreckage & the debris field runs approximately along the east/west axis?
Would correlate with being left of planned course - but I suppose there may well be little correlation between final resting orientation and orientation at impact for such a deep descent?
wes_wall,
As part of a post wherein you expressed doubt as to the objectivity of the BEA, you said the BEA has "a vested interest in the outcome".
Can you explain what you meant?
As part of a post wherein you expressed doubt as to the objectivity of the BEA, you said the BEA has "a vested interest in the outcome".
Can you explain what you meant?
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Originally Posted by PJ2
The ditching would be done with Config FULL, if available, (windmilling engines will power the hydraulics to some extent) and gear up
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Blame?
It's a nominally French airplane flown by a nominally French airline certified and investigated by a French authority, with nominally French pitot probes that are suspect..
Who would they blame - Brazil?
No, I don't expect a coverup.
Who would they blame - Brazil?
No, I don't expect a coverup.
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Ice
Is it possible that the failed pitot tubes where actually a symptom of what was going on and not the cause of the crash? If the pitot tubes were coated in ice would it be possible for other parts of the A330 to be coated in ice as well, causing the flight upset (stall?)?
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WRG
Svarin on 12Apr 10:54
One interpretation is PRIM2 loses connection with ADR1 (part of ADIRU1) through a failed bus. BEA exlained it away with "PRIM2 rejects ADR1"... However, this particular failure does not seem to have anything to do with unreliable airspeed and ADR comparison, it is quite obviously an electronics connectivity issue : WRG means wiring, gentlemen. Airbusese for "warning" is WRN.
One interpretation is PRIM2 loses connection with ADR1 (part of ADIRU1) through a failed bus. BEA exlained it away with "PRIM2 rejects ADR1"... However, this particular failure does not seem to have anything to do with unreliable airspeed and ADR comparison, it is quite obviously an electronics connectivity issue : WRG means wiring, gentlemen. Airbusese for "warning" is WRN.
This does not make it a wiring fault, although that's a possibility. It was much more likely an issue with erratic airspeed being captured at slightly different times by two computers.
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Mr. Optomistic - you have me scratching my head. I'm not and never have been a pilot. (Near Mr. Magoo eyes pretty much guaranteed that. But I could focus on 1 mil gold wires on integrated circuits just fine.)
Seriously, discussions in this forum and one of its predecessors has led me to believe that one of the people in the cockpit is supposed to have his mask on at all times. Is that an incorrect understanding on my part?
Seriously, discussions in this forum and one of its predecessors has led me to believe that one of the people in the cockpit is supposed to have his mask on at all times. Is that an incorrect understanding on my part?