AF 447 Search to resume
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Hi,
Mr Optimistic
Google Vertaling
Mr Optimistic
Whatever happened to the oilsick ? Was it ever taken seriously in choosing the search area ? Not saying it should have been but just wondering.
We have good reason to believe that the fourth phase should allow this time to locate the aircraft. The area determined by the BEA as part of this new phase is identical to the area determined by the association to find a circle of 20Mn (yellow circle inside the circle of 40mn).
Sea research area late 2010 circles
Note: The green circle (top inside the yellow circle of 20Mn), includes 3 debris located about 5 kms from LKP, the red circle (bottom inside the yellow circle of 20Mn), includes the water kerosene.
Sea research area late 2010 circles
Note: The green circle (top inside the yellow circle of 20Mn), includes 3 debris located about 5 kms from LKP, the red circle (bottom inside the yellow circle of 20Mn), includes the water kerosene.
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Hi,
NeoFit
Flight data recorder - Wikipedia, the free encyclopedia
NeoFit
Yes, of course... but CVR/DFR solid state memory cards data are granted only thirty days at 16,000 feet deep water.
FDRs are usually located in the rear of the aircraft, typically in the tail. In this position, the entire front of the aircraft is expected to act as a "crush zone" to reduce the shock that reaches the recorder. Also, modern FDRs are typically double wrapped, in strong corrosion-resistant stainless steel or titanium, with high-temperature insulation inside. They are usually bright orange. They are designed to emit a locator beacon for up to 30 days, and can operate immersed to a depth of up to 6,000 meters (20,000 ft).[11][12]
Flight data recorder - Wikipedia, the free encyclopedia
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jcjeant
Hello,
I agree with 6,000 meters (20,000 ft)
But in the Wiki link yo gave us, I noticed at the end
12 - "SSFDR Solid State Flight Data Recorder, ARINC 747 - TSO C 124 - ED 55". [quote]
Regards
Hello,
I agree with 6,000 meters (20,000 ft)
But in the Wiki link yo gave us, I noticed at the end
12 - "SSFDR Solid State Flight Data Recorder, ARINC 747 - TSO C 124 - ED 55". [quote]
Resistance to immersion in seawater: 30 days at depth of 6000 m
Not 2 years.
(it seems to me that BEA was unable to read D-AXLA records, after only a few days immersed in fourty meters deep. See: 1.11.3 Data readout )So, I am asking myself if ...
Regards
Last edited by NeoFit; 14th Feb 2011 at 01:11. Reason: PickyPerkins is faster than me !
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Life at Depth
Reason: PickyPerkins is faster than me !
Last edited by PickyPerkins; 14th Feb 2011 at 01:38. Reason: Add Regards and title
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Hi,
They were read ! (Not important that the BEA was not able to read it .. other were able .. )
(it seems to me that BEA was unable to read D-AXLA records, after only a few days immersed in fourty meters deep. See: 1.11.3 Data readout )
They were read ! (Not important that the BEA was not able to read it .. other were able .. )
1.11.3 Data readout
The CVR and the FDR, under judicial seals, were handed over to the BEA by a senior police
officer on Sunday 30 November.
The electronic cards from the protected modules containing the recorded data were
extracted. These cards were cleaned and then dried. Attempts to read them out using
several types of independent equipment did not make it possible to recover the recorded
data.
The electronic cards were placed under judicial seal again following these operations. They
were examined at Honeywell, manufacturer of the recorders, in the United States on the 5th
and 6th
of January 2009 in the context of an International Commission of Inquiry. Some short-
circuits were discovered on the cards. Eliminating the short-circuits allowed a complete
readout of the data. The recordings were of good quality and the whole flight was included.
The graphs of the flight parameters are in appendix 1.
The CVR and the FDR, under judicial seals, were handed over to the BEA by a senior police
officer on Sunday 30 November.
The electronic cards from the protected modules containing the recorded data were
extracted. These cards were cleaned and then dried. Attempts to read them out using
several types of independent equipment did not make it possible to recover the recorded
data.
The electronic cards were placed under judicial seal again following these operations. They
were examined at Honeywell, manufacturer of the recorders, in the United States on the 5th
and 6th
of January 2009 in the context of an International Commission of Inquiry. Some short-
circuits were discovered on the cards. Eliminating the short-circuits allowed a complete
readout of the data. The recordings were of good quality and the whole flight was included.
The graphs of the flight parameters are in appendix 1.
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Having repaired miniature electronic circuits after a ~ a day in salt water (while energized) I wouldn't hold out much hope for the cards in the recorders long after they have flooded. Pieces of the circuit trace just vanish. I wouldn't be surprised if individual chips lose their leads and corrode internally at that depth/pressure. All we can do is hope that the seals hold, that data is recoverable, and that the people designing the protective case generously over-designed the enclosure.
Those lost in AF447 deserve the chance to have their story told.
Those lost in AF447 deserve the chance to have their story told.
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Corrosion by seawater
Having repaired miniature electronic circuits after a ~ a day in salt water (while energized) I wouldn't hold out much hope for the cards
If the impact switch is subjected to a 2.5 G shock, the recorder is electrically disconnected to prevent further recording and erasure. ....."
From Ref. 11 of the Wikipedia link posted by jcjeant.
And maybe to minimise corrosion? Regards,
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Picky, got any information on the pinger circuit location relative to the memory circuits? There would be a current field in the sea water if adjacent to memory. Current= accelerated corrosion. If in the same compartment, not good.
In any case, very high pressure seawater is likely to intrude into chips by way of the leads over time, although potting may delay intrusion. Circuit immersion for any long period of time is not good. Lets hope for success, but understand we may be too late.
In any case, very high pressure seawater is likely to intrude into chips by way of the leads over time, although potting may delay intrusion. Circuit immersion for any long period of time is not good. Lets hope for success, but understand we may be too late.
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For those interested there is an interview with David Gallo, director of special projects at Woods Hole Oceanographic Institution who are handling the search. Begins at 12:55
The Monocle Weekly [Monocle]
The Monocle Weekly [Monocle]
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The ULB is a standalone item. It is attached physically to the CVR/DFDR by a double 'u' clamp arrangment. It has been known to get separated from the recorder, sometimes under strange circumstances. The most recent was a Yemenia Airways A310 that went down on its approach to Moroni Airport in the Comoros Islands - 30 June 2009. There was one recovered survivor (others survived the crash but drowned), and IIRC the a/c was stalled making a turn during the approach.
The data recorders are contained within the Crash Survivable Memory Unit (CSMU), and are expected survive a 3400g + impact, 1,100 degree Celsius fire for 1 hour, a 227kg steel ball with 6.3mm protruding pin drop test from height of 3m, 5000 psi dry pressure test on each side for 6 minutes, a similar water tank pressure test for 24 hours, and salt-water immersion for 30 days. These are the "minimums".
All electrical contact with the CSMU is severed when the acceleration on a multi-axis switch exceeds 2.5g. The non volitile memory can usually be recovered by the manufacturers even after some or all of the design conditions have been exceeded. The Nixon tapes didn't quite meet these standards!
The data recorders are contained within the Crash Survivable Memory Unit (CSMU), and are expected survive a 3400g + impact, 1,100 degree Celsius fire for 1 hour, a 227kg steel ball with 6.3mm protruding pin drop test from height of 3m, 5000 psi dry pressure test on each side for 6 minutes, a similar water tank pressure test for 24 hours, and salt-water immersion for 30 days. These are the "minimums".
All electrical contact with the CSMU is severed when the acceleration on a multi-axis switch exceeds 2.5g. The non volitile memory can usually be recovered by the manufacturers even after some or all of the design conditions have been exceeded. The Nixon tapes didn't quite meet these standards!
Last edited by mm43; 14th Feb 2011 at 22:22.
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FDR and ULB
MM43 already described the arrangement of the ULB on the FDR. An image is seen here:
https://commerce.honeywell.com/webap...tegoryId=39509
If a pressure housing does not implode on initial exposure to high pressure, it is unlikely (though not impossible) to do so at a later time, from a structural standpoint. What can cause a time-delayed failure is perforation of a housing or sealing surface due to poor material choice.
I have seen a stainless-steel housing in, seawater, fail from perforation where an adhesive label was applied. The label excluded oxygen from the surface, and thus allowed crevice corrosion to proceed.
This sort of failure can be avoided by appropriate choice of material and and/or by correctly sizing sacrificial anodes for the surface area and duration to be protected. Let's hope that Honeywell's design will exceed the minimum requirement.
As others have pointed out, solid state memories may be adequately protected, by their encapsulation, from direct exposure to high pressure seawater for a significant duration. It is possible to remove the encapsulation and gain access to the chip even if the external contacts have corroded away.
https://commerce.honeywell.com/webap...tegoryId=39509
If a pressure housing does not implode on initial exposure to high pressure, it is unlikely (though not impossible) to do so at a later time, from a structural standpoint. What can cause a time-delayed failure is perforation of a housing or sealing surface due to poor material choice.
I have seen a stainless-steel housing in, seawater, fail from perforation where an adhesive label was applied. The label excluded oxygen from the surface, and thus allowed crevice corrosion to proceed.
This sort of failure can be avoided by appropriate choice of material and and/or by correctly sizing sacrificial anodes for the surface area and duration to be protected. Let's hope that Honeywell's design will exceed the minimum requirement.
As others have pointed out, solid state memories may be adequately protected, by their encapsulation, from direct exposure to high pressure seawater for a significant duration. It is possible to remove the encapsulation and gain access to the chip even if the external contacts have corroded away.
Last edited by auv-ee; 14th Feb 2011 at 19:56.
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A/P disengagement
Originally posted by HN39;
Both explanations don't quite line up with the diagram posted by PJ2. If ADR DISAGREE does not cause A/P disengagement, then it was probably caused by DOUBLE ADR FAULT due to a rapid change of CAS and Mach in at least two ADR's.
Both explanations don't quite line up with the diagram posted by PJ2. If ADR DISAGREE does not cause A/P disengagement, then it was probably caused by DOUBLE ADR FAULT due to a rapid change of CAS and Mach in at least two ADR's.
On the subject of the 0.45 sec period; I assume that the actual data acquisition rate is 0.15 sec (150ms). Can you confirm that figure?
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Originally Posted by mm43
On the subject of the 0.45 sec period; I assume that the actual data acquisition rate is 0.15 sec (150ms). Can you confirm that figure?
Regarding your first sentence, I'm inclined to believe that the FCOM is correct - <deleted>.
regards,
HN39
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A/P disconnect vs A/P lost
HN39 wrote :
Beware : A/P disconnect will occur on all reversions shown in PJ2 table.
But A/P is lost, meaning it cannot be reengaged, in certain conditons only. ADR DISAGREE is one condition that could allow A/P reengagement. In other words, one could say A/P disconnect condition can be either latched or not latched depending on the type of failure, and ADR DISAGREE does not latch.
Beware : ADR DISAGREE means one ADR is rejected and the remaining two disagree. If 2 ADRs are lost/faulted, the failures shown on ECAM and sent by ACARS will not be those we have here (but something like ADR1+2 FAULT)
If ADR DISAGREE does not cause A/P disengagement, [...]
But A/P is lost, meaning it cannot be reengaged, in certain conditons only. ADR DISAGREE is one condition that could allow A/P reengagement. In other words, one could say A/P disconnect condition can be either latched or not latched depending on the type of failure, and ADR DISAGREE does not latch.
Beware : ADR DISAGREE means one ADR is rejected and the remaining two disagree. If 2 ADRs are lost/faulted, the failures shown on ECAM and sent by ACARS will not be those we have here (but something like ADR1+2 FAULT)
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AP Lost
I am still wondering whether the AP could be reconnected?
Would the 2:11 message bring the situation inside the AP lost box as a double ADR or IR Fault. See post 2705
See also BEA Report No. 2 at bottom of p. 37 and top of p. 38.
Would the 2:11 message bring the situation inside the AP lost box as a double ADR or IR Fault. See post 2705
See also BEA Report No. 2 at bottom of p. 37 and top of p. 38.
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AF447 dissections
Three recent AF447 related articles worth reading. In relation to the third article, it should be noted that Ex-NTSB Chair Jim Hall has links to a deployable recorders firm - and is therefore somewhat biased.
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link one
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link two
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link three
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link one
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link two
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link three
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