AF447
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Picture of an A310 vertical stabilizer, after impact with water at approx. 215 KIAS, can be found on page 98.
Looks indentical to the AF 447 vertical stabilizer.
http://www.bea-fr.org/docspa/2000/5y-n000130a/pdf/5y-n000130a.pdf
Looks indentical to the AF 447 vertical stabilizer.
http://www.bea-fr.org/docspa/2000/5y-n000130a/pdf/5y-n000130a.pdf
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Originally Posted by barit1
Yes - NWA 727 on ferry out of NYC had exactly this problem (1 Dec 74) and the outcome was as PTH and NimSim described. If anyone has access to full NTSB reports, the # is NYC75AN070.
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To Captain Crunch
(lapsed student pilot here, but lots of computerized embedded systems expertise)
Regarding the "The granularity of the data is very high" statement, I interpreted this as saying "We don't know if or how the ACARS system batches transmissions".
In communications systems there is an overhead associated with obtaining the channel to communicate data, and to maximize utilization of the channel its appropriate to make the overhead (from a overall channel perspective) as minimal as possible. So the ACARS system might not transmit a single notification as soon as it receives it from the onboard systems... Hypothetical: Upon getting a notification it could set a countdown timer for 2 minutes, and when that 2 minute timer expires it transmits the original notification and anything else it receives in that two minute period. This is perfectly acceptable given what ACARS is intended for, and makes the overall communications system more efficient, but it also means that: a) The timestamps might not reflect the *exact* moment something was detected, rather it's a close approximation to the time. and b) There might have been unsent notifications in the ACARS system that never got transmitted (even if the transmitter and antenna stayed intact all the way til the end)
-RB
Regarding the "The granularity of the data is very high" statement, I interpreted this as saying "We don't know if or how the ACARS system batches transmissions".
In communications systems there is an overhead associated with obtaining the channel to communicate data, and to maximize utilization of the channel its appropriate to make the overhead (from a overall channel perspective) as minimal as possible. So the ACARS system might not transmit a single notification as soon as it receives it from the onboard systems... Hypothetical: Upon getting a notification it could set a countdown timer for 2 minutes, and when that 2 minute timer expires it transmits the original notification and anything else it receives in that two minute period. This is perfectly acceptable given what ACARS is intended for, and makes the overall communications system more efficient, but it also means that: a) The timestamps might not reflect the *exact* moment something was detected, rather it's a close approximation to the time. and b) There might have been unsent notifications in the ACARS system that never got transmitted (even if the transmitter and antenna stayed intact all the way til the end)
-RB
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Picture of an A310 vertical stabilizer, after impact with water at approx. 215 KIAS, can be found on page 98.
Looks indentical to the AF 447 vertical stabilizer.
http://www.bea-fr.org/docspa/2000/5y...y-n000130a.pdf
Looks indentical to the AF 447 vertical stabilizer.
http://www.bea-fr.org/docspa/2000/5y...y-n000130a.pdf
It's on page 122 and it looks nothing like the AF447.
Last edited by FE Hoppy; 12th Jun 2009 at 05:29.
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CC: "I suspect it's really the A330's interpretation of a complete loss of all air data that caused this accident."
The ACARS reported ADR fail, which could mean any one or more of the outputs of the ADR: airspeed, altitude, CAS, TAT, etc. . The pitot tubes on the A330 feed only airspeed computation, and airspeed is all that had to fail to lead to this accident. Altitude Fail in addition to airspeed fail is really, really tough to overcome. There was probably not a loss of altitude data, and I see no indication there was, except for the TCAS, which could be explained differently.
Do you see any other evidence of Altitude Fail?
GB
The ACARS reported ADR fail, which could mean any one or more of the outputs of the ADR: airspeed, altitude, CAS, TAT, etc. . The pitot tubes on the A330 feed only airspeed computation, and airspeed is all that had to fail to lead to this accident. Altitude Fail in addition to airspeed fail is really, really tough to overcome. There was probably not a loss of altitude data, and I see no indication there was, except for the TCAS, which could be explained differently.
Do you see any other evidence of Altitude Fail?
GB
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Checked the thread as best I could, apologies if this has already been covered.
On the Aviation Herald site, referring to this accident, there's a passage about two Air France A340s that had similar problems (thankfully without such a tragic ending) which says:-
"The captain released control of the airplane to the first officer and tried to switch his display from ADIRU1 to ADIRU3. 2 minutes later autopilot and autothrust disconnected and the fly by wire changed into alternate law. The crew noticed icing conditions (static air temperature [SAT] -29 degrees Centigrade) and switched anti ice including pitot heating systems from automatic to on. The speed indications became normal again and agreed again.........
'From automatic to on.' I'd heard that the A330/A340 have automatic pitot heating, don't know if all airliners do nowadays? But if there's an automated system controlling the pitot heaters, could it be possible that the whole cascade of 'computer malfunctions' was caused by.......a computer malfunction........?
Crash: Air France A332 over Atlantic on June 1st 2009, aircraft impacted ocean
Also - I looked through Airbus's 'advisories' as best I could, and don't recall seeing any mention of 'Check Pitot Heat ON.'
On the Aviation Herald site, referring to this accident, there's a passage about two Air France A340s that had similar problems (thankfully without such a tragic ending) which says:-
"The captain released control of the airplane to the first officer and tried to switch his display from ADIRU1 to ADIRU3. 2 minutes later autopilot and autothrust disconnected and the fly by wire changed into alternate law. The crew noticed icing conditions (static air temperature [SAT] -29 degrees Centigrade) and switched anti ice including pitot heating systems from automatic to on. The speed indications became normal again and agreed again.........
'From automatic to on.' I'd heard that the A330/A340 have automatic pitot heating, don't know if all airliners do nowadays? But if there's an automated system controlling the pitot heaters, could it be possible that the whole cascade of 'computer malfunctions' was caused by.......a computer malfunction........?
Crash: Air France A332 over Atlantic on June 1st 2009, aircraft impacted ocean
Also - I looked through Airbus's 'advisories' as best I could, and don't recall seeing any mention of 'Check Pitot Heat ON.'
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Greybeard,
I have to defer to the A330 techs to tell me the likelihood of that. I'm just going on the experience that on the early bus where all three altimeters sprung into very different readings, and began to drift, so we were unsure of our altitude. We lost all air data for a time imho, and I suspected at the time that it got the static ports and tats as well.
Moral of the Story: Don't fly within 100 nm's of a typhoon near the equator or in the ITCZ with a bus. The ice won't show up on the radar and even benign looking stuff in the arm of cyclonic weather can take everything out for a short time.
And it's important to point out that this was a lot of years ago, and I'm retired now. A check pilot who did work for Boeing told me of the B-747 engine structure mistakes. Chalk it up to Test Pilot Urban Legend if you will:
I have to defer to the A330 techs to tell me the likelihood of that. I'm just going on the experience that on the early bus where all three altimeters sprung into very different readings, and began to drift, so we were unsure of our altitude. We lost all air data for a time imho, and I suspected at the time that it got the static ports and tats as well.
Moral of the Story: Don't fly within 100 nm's of a typhoon near the equator or in the ITCZ with a bus. The ice won't show up on the radar and even benign looking stuff in the arm of cyclonic weather can take everything out for a short time.
And it's important to point out that this was a lot of years ago, and I'm retired now. A check pilot who did work for Boeing told me of the B-747 engine structure mistakes. Chalk it up to Test Pilot Urban Legend if you will:
Last edited by Captain-Crunch; 12th Jun 2009 at 07:10. Reason: deleted off-topic 747 proof
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If the VS failed in a downward compression direction as has been intimated in preceding writings, I would think that it is quite possible that this caused deformation and damage of the aft pressure bulkhead and the speculated subsequent pressurization failure.
Comments?
KW
Comments?
KW
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SATCOM AE operation
From the RC OPtion Data (SDU-906)
The Anetnna is a phased arraray type It needs to know which Active elements to activate to 'Steer the beam; ( done electronically, no moving components)
If anyone knows AF's fit Manufacturer &/or High Gain/Low Gain Antenna(s) please let me know
The SDU receives airplane heading and attitude data from the inertial reference unit (IRU). The SDU system processor determines the elevation and azimuth angle necessary to point the high gain antenna beam at the applicable satellite. The SDU sends this data to the beam steering unit (BSU).
If anyone knows AF's fit Manufacturer &/or High Gain/Low Gain Antenna(s) please let me know
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re rudder:
We tried this in the sim:
FL 350 M .81 normal law,
Quickly apply full rudder, the a/c rapidly banks to 50-60 degrees bank, with only 4 degrees of rudder travel available.
Conversely, an engine failure in cruise is counteracted with the lightest touch of rudder, maybe 1 inch and can barely be seen on the flt controls page.
Respect the rudder, it is a very powerful control.
FL 350 M .81 normal law,
Quickly apply full rudder, the a/c rapidly banks to 50-60 degrees bank, with only 4 degrees of rudder travel available.
Conversely, an engine failure in cruise is counteracted with the lightest touch of rudder, maybe 1 inch and can barely be seen on the flt controls page.
Respect the rudder, it is a very powerful control.
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pj, safety concerns
concerning the VS issue - you cannot tell if there were other "1001 msg" or not because you cannot be sure that the 02:14Z msg was the last one, or are you?
do some of the experts present here consider the backloops between adirus and computers?
do some of the experts present here consider the backloops between adirus and computers?
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As I understand it, cpdlcads, the Rudder Travel Limiter does indeed restrict rudder movement to 4 degrees or so at high speed. As opposed to 30 degrees or so at low speed.
BUT, it surely relies on the ASIs for the speed? If the pitot tubes were partially blocked, presumably the ASIs would understate that speed?
So could the RTL, in those circumstances, have permitted a much greater rudder deflection than was safe?
BUT, it surely relies on the ASIs for the speed? If the pitot tubes were partially blocked, presumably the ASIs would understate that speed?
So could the RTL, in those circumstances, have permitted a much greater rudder deflection than was safe?
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avspook
It is possible, that SAT antenna was smcelectronic CMA-2102 SATCOM High Gain Antenna System.
http://www.cmcelectronics.ca/pdf/satcom2102.pdf
No build in GPS, electronically steerable, phased-array antenna, 12-17 dB gain.
It is possible, that SAT antenna was smcelectronic CMA-2102 SATCOM High Gain Antenna System.
http://www.cmcelectronics.ca/pdf/satcom2102.pdf
No build in GPS, electronically steerable, phased-array antenna, 12-17 dB gain.
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Should we care ?
Yes thats why with rud trvl limit fault ecam says rudder: handle with care
CARE ON .................. CHECKED
Who has experience with careful rudder inputs flying manually at altitude at M 0.80 in alternate law?...in severe turbulence...
Test pilot territory I guess...
Not saying this is relevant. We are fishing in the dark.
Last edited by Interflug; 12th Jun 2009 at 10:35. Reason: spelling
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I have my own idea
I have read quite a bit about this incident.
It is my personal opinion, according to the facts available at this precise time, that any other professional pilots who would have been on duty in that cockpit at that precise time, left exactly in the same scenario as the AF447 flying through that weather, would have done all possible to find a solution and fly the damn thing but whatever action would have been taken this would have resulted in a guaranteed disaster:
-Coffin corner and loss of all speed data (including GPS due to bad signal) is a recipe for disaster whatever the pilots on board.
Combine the above with a sudden and multiple list of serious faults and the plane very quickly either goes too fast or too slow, whatever corrective action is taken.
In both cases the plane would destroy pretty quickly.
If they could have precisely controlled their speed nothing would have happened. They could not guess their speed.
I am sure excellent pilots were dealing with an impossible event.
Airbus vs Boeing does not apply, any aircraft, whatever the make and model, would have gone beyond the coffin corner speed limits if flown without speed data.
Airbus was fully aware of the pitot tube problem, AF did not react.
Corners can never be cut in aviation especially when dealing with essential flying data, speed is everything. GPS signal in weather is lost.
It is my personal opinion, according to the facts available at this precise time, that any other professional pilots who would have been on duty in that cockpit at that precise time, left exactly in the same scenario as the AF447 flying through that weather, would have done all possible to find a solution and fly the damn thing but whatever action would have been taken this would have resulted in a guaranteed disaster:
-Coffin corner and loss of all speed data (including GPS due to bad signal) is a recipe for disaster whatever the pilots on board.
Combine the above with a sudden and multiple list of serious faults and the plane very quickly either goes too fast or too slow, whatever corrective action is taken.
In both cases the plane would destroy pretty quickly.
If they could have precisely controlled their speed nothing would have happened. They could not guess their speed.
I am sure excellent pilots were dealing with an impossible event.
Airbus vs Boeing does not apply, any aircraft, whatever the make and model, would have gone beyond the coffin corner speed limits if flown without speed data.
Airbus was fully aware of the pitot tube problem, AF did not react.
Corners can never be cut in aviation especially when dealing with essential flying data, speed is everything. GPS signal in weather is lost.
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Dysag
I'm not sure because I wasn't there. From the information that is available so far, you really would need to be there to come to any conclusion of whether their actions were the right ones or not. What I would assume is that they were professional pilots acting in a professional manner to ensure the safe operation of the flight. If you have the specific details of the information that the pilots had in front of them and would care to share that with us, then we may be able to answer your question....
I'm not sure because I wasn't there. From the information that is available so far, you really would need to be there to come to any conclusion of whether their actions were the right ones or not. What I would assume is that they were professional pilots acting in a professional manner to ensure the safe operation of the flight. If you have the specific details of the information that the pilots had in front of them and would care to share that with us, then we may be able to answer your question....
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Criminal Investigation
I suppose it was inevitable, but Agence Presse, Reuters and others are reporting that a criminal Investigation has commenced, with focus on the pitots, and why they were not replaced.
Apparantly this is standard procedure in France if French citizens die outside the country, but we are all aware of the regrettable effects of a criminal investigation mingling with, or worse, hindring an accident investigation: many people who might have something to contribute retreat into the woodwork.
A shame, really.
Regards, OORW
Apparantly this is standard procedure in France if French citizens die outside the country, but we are all aware of the regrettable effects of a criminal investigation mingling with, or worse, hindring an accident investigation: many people who might have something to contribute retreat into the woodwork.
A shame, really.
Regards, OORW