AF447
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?
Comments?
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Assuming that the accident came about because of extreme weather conditions (and that's still conjecture, I know), and given that other flights made the journey safely, at roughly the same time, I can only see the following possibilities:
1. AF447 was acting with the same caution as other operators, but experienced freak conditions (eg, lightning at a distance from the storm cell, or an unusually fast-developing cell).
2. AF447 was acting with the same caution as other operators, but did not have access to the same information about weather problems in front of them. (eg, inoperative weather radar).
3. AF447 was not acting with the same caution as other operators.
No.3 is the one that this community could usefully explore, I think.
Presumably, when approaching areas of difficult weather, there is a level of severity where the decision is to fly around the area rather than grit one's teeth and plunge through? This has to be the captain's decision, ultimately, but to what extent is the assessment affected by company expectations, or peer-group culture? How does the decision get made?
To what extent might exaggerated trust in the robustness of the airframe affect the decision? (Air France, Airbus, after all).
Please note: I'm not suggesting irresponsibility on the part of the operator or the crew. But I'd be interested to know how pilots here - who I assume are from a wide range of operators, of different ages, different locales - go about the business of deciding what to do about dodgy weather ahead.
1. AF447 was acting with the same caution as other operators, but experienced freak conditions (eg, lightning at a distance from the storm cell, or an unusually fast-developing cell).
2. AF447 was acting with the same caution as other operators, but did not have access to the same information about weather problems in front of them. (eg, inoperative weather radar).
3. AF447 was not acting with the same caution as other operators.
No.3 is the one that this community could usefully explore, I think.
Presumably, when approaching areas of difficult weather, there is a level of severity where the decision is to fly around the area rather than grit one's teeth and plunge through? This has to be the captain's decision, ultimately, but to what extent is the assessment affected by company expectations, or peer-group culture? How does the decision get made?
To what extent might exaggerated trust in the robustness of the airframe affect the decision? (Air France, Airbus, after all).
Please note: I'm not suggesting irresponsibility on the part of the operator or the crew. But I'd be interested to know how pilots here - who I assume are from a wide range of operators, of different ages, different locales - go about the business of deciding what to do about dodgy weather ahead.
I discovered the following document on smart cockpit:
SmartCockpit - Airline training guides, Aviation, Operations, Safety
It is an Airbus presentation about Unreliable Airspeed from 2006.The document does not appear to be complete as some videos are missing but it does show that Airbus offer a backup speed scale rather like a traditional fast slow indicator. to cater for air data problems.
I wonder if the AF aircraft had this mod fitted?Has anybody got any experience of using this Airbus mod?
SmartCockpit - Airline training guides, Aviation, Operations, Safety
It is an Airbus presentation about Unreliable Airspeed from 2006.The document does not appear to be complete as some videos are missing but it does show that Airbus offer a backup speed scale rather like a traditional fast slow indicator. to cater for air data problems.
I wonder if the AF aircraft had this mod fitted?Has anybody got any experience of using this Airbus mod?
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Thanks for the constructive comments, guys.
As to why not make the changes mandatory instead of advisory, my guess is that there was an accountant sitting at the table. No disrespect to accountants - they're there to remind you that if you stop making a profit you'll end up on the dole.
My guess is that Airbus reasoned that all that had happened so far was that a few pilots (maybe ten crews, 6 Air France, 2 Air Caraibes, maybe 2 Qantas) pilots had got a fright - but they'd managed to recover and land safely.
An 'advisory' means that the airlines pay - if they care to. A 'mandatory' means that the manufacturers do.
I LIKE to think that in my own business - which was equally concerned with safety - I'd have been the 'White Knight' yelling for us to 'do the right thing.' I probably would have been in this case - but, as a director, you only have one vote, and I never got to be a CEO.
As to 'why use the rudder?,' the only things I ever flew were 'toy' aeroplanes and gliders. I never flew in bad visibility, leave alone thunderstorms. I'm pretty sure that, if I was in the circumstances those guys were probably facing, I'd have used anything within reach (even including sensitive parts of the guy in the other seat's anatomy) to regain control. I know one other thing, too - if I'd ever been thrown into say a 45-degree bank while losing height, I'd have remembered in particular that the rudder, geometrically speaking, was 'half of the elevator' in that attitude - and vice versa - and therefore I'd have made a balanced input of both..........
Maybe worth mentioning too that one accident I researched thoroughly (because I visited NYC shortly afterwards) was AA587. Believe it or not - because Airbus favour 'variable stop' rudder limiters (that is, the pedal travel is restricted instead of the rudder movement) a mere 1.2-inch pedal movement will produce full permissible rudder movement on an A300 doing only 250 knots.......
'Pilots aren't concert pianists,' you might say........
As to why not make the changes mandatory instead of advisory, my guess is that there was an accountant sitting at the table. No disrespect to accountants - they're there to remind you that if you stop making a profit you'll end up on the dole.
My guess is that Airbus reasoned that all that had happened so far was that a few pilots (maybe ten crews, 6 Air France, 2 Air Caraibes, maybe 2 Qantas) pilots had got a fright - but they'd managed to recover and land safely.
An 'advisory' means that the airlines pay - if they care to. A 'mandatory' means that the manufacturers do.
I LIKE to think that in my own business - which was equally concerned with safety - I'd have been the 'White Knight' yelling for us to 'do the right thing.' I probably would have been in this case - but, as a director, you only have one vote, and I never got to be a CEO.
As to 'why use the rudder?,' the only things I ever flew were 'toy' aeroplanes and gliders. I never flew in bad visibility, leave alone thunderstorms. I'm pretty sure that, if I was in the circumstances those guys were probably facing, I'd have used anything within reach (even including sensitive parts of the guy in the other seat's anatomy) to regain control. I know one other thing, too - if I'd ever been thrown into say a 45-degree bank while losing height, I'd have remembered in particular that the rudder, geometrically speaking, was 'half of the elevator' in that attitude - and vice versa - and therefore I'd have made a balanced input of both..........
Maybe worth mentioning too that one accident I researched thoroughly (because I visited NYC shortly afterwards) was AA587. Believe it or not - because Airbus favour 'variable stop' rudder limiters (that is, the pedal travel is restricted instead of the rudder movement) a mere 1.2-inch pedal movement will produce full permissible rudder movement on an A300 doing only 250 knots.......
'Pilots aren't concert pianists,' you might say........
Last edited by RWA; 12th Jun 2009 at 13:49.
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From the first post on this thread:
but many posts that try and bring people back to real events and reality with rational explanations are deleted.
So, why, where we try and use real facts, including oceanographic data to either support or refute other posts are they deleted?
this was a real aircraft carrying real people which really crashed in a real ocean due to some real cause - while flying in the vicinity of real weather.
. . . there is no jury to persuade, and a "convincing" argument will still carry no water if, in the end, it does not match up with the real event.
. . . there is no jury to persuade, and a "convincing" argument will still carry no water if, in the end, it does not match up with the real event.
"No Captain is going to . . . . Never say never....
At this point, almost anything is "possible", far fewer things are "probable" consistent with the limited evidence, and only one is "correct".
At this point, almost anything is "possible", far fewer things are "probable" consistent with the limited evidence, and only one is "correct".
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Yes, captainflame. The pathologists will likely tell us quite soon whether she hit the water in one piece, or broke up in the air.
But not WHY she did.....
But not WHY she did.....
Last edited by RWA; 12th Jun 2009 at 14:04.
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On the Boeing's that I have flown the only time you touch the rudder at cruise speeds is during the recovery from unusual attitudes, top rudder to compensate for extreme bank angle, other wise, once past, at the latest, 210kts, leave the rudder alone. It would appear that somewhere in the transition from general aviation to jets the lessons about the rudder, it's uses etc. and how to apply it are being forgotten.
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Rudder still attached...
I'm puzzled with the bit about in flight break off of the VS because the rudder is still nicely attached to it.
Seems to me that overloads there would have ripped it (the rudder) off too ? (see AA)
Where if VS broke off when hitting water, it's still attached. (see NWA and ANZ 320)
Seems to me that overloads there would have ripped it (the rudder) off too ? (see AA)
Where if VS broke off when hitting water, it's still attached. (see NWA and ANZ 320)
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Right on cue - she broke up in the air.......
"Almost all of the bodies had multiple fractures, the paper reported. Investigators haven’t found water in the victims’ lungs, which would indicate drowning, Estado said. Bodies were found 85 kilometers (53 miles) apart, which may also indicate the Airbus A330-200 broke up before reaching the ocean, Estado reported."
Air France Probe Suggests Plane Broke Up in Air, Estado Says - Bloomberg.com
"Almost all of the bodies had multiple fractures, the paper reported. Investigators haven’t found water in the victims’ lungs, which would indicate drowning, Estado said. Bodies were found 85 kilometers (53 miles) apart, which may also indicate the Airbus A330-200 broke up before reaching the ocean, Estado reported."
Air France Probe Suggests Plane Broke Up in Air, Estado Says - Bloomberg.com
Someone please tell me WHY, if true, there is an "Automatic" position on the Pitot Heat Switch on this, or any aircraft.
The "automatic" mode is used to prevent electrically-heated sensors (pitot probes, AOA vanes, TAT probes etc.) from being switched "on" when the aircraft is on the ground.
The system is activated by the weight-on-wheels sensors, permitting electrical current flow to the probe heating elements only after the aircraft is airborne.
Without the cooling effect provided by airflow, the pitot probes in particular can reach a temperature of several hundred degrees in very short order, which can quickly cause the heating elements to burn out (at the very least), to say nothing of possible damage to surrounding aircraft structure.
A manual mode must be available, however, as there are occasions where it would be necessary to power the heaters on the ground - i.e. on a cold day where frozen precip (snow, sleet, freezing rain) is present.
A significant amount of electrical current flows through the heating elements when they are activated. If sensors detect no (or inadequate) current flow in a situation where the heater should be on, it will trigger a "fail" annunciator or EICAS message for the associated probe.
Many "vintage" Boeing aircraft (737, 727 etc.) had a switch-selectable ammeter so that the crew could actually see the amount of electrical current being delivered to each probe's heating element. More modern airframes depend solely on annuciators to detect heater failure.
However, none of these monitoring systems can detect a situation where the heater might be working perfectly, and yet unable to keep up with ice accretion in a particular environmental scenario due to a design flaw.
JR Barrett
Last edited by JRBarrett; 12th Jun 2009 at 14:39.
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nice sentiment notpilotatall but doesn't match the real world.
The real world takes it for granted that "it won't happen to them" and due to some fantastic design and advances in technology they will most probably be right.
The real world takes it for granted that "it won't happen to them" and due to some fantastic design and advances in technology they will most probably be right.
Re: Overthewing, there is still the possibility that the conjecture is wrong and that the weather was not extreme to the point of loss of all hope of recovery. Need the recorders to know that and given the likelihood of wide dispersal, recovery of them will be a miracle. Lingering doubts will remain over the robustness of the systems until the environment is known.
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Rudder and vma
When the upset recovery training came up we heavily contested the military derived rudder recovery usage ( sky rudder they said ). Best way to loose an aircraft by control inputs beyond FAR certification:
Code of Federal Regulations
Sec. 25.351
Part 25 AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES
Subpart C--Structure
Flight Maneuver and Gust Conditions
Sec. 25.351
[Yaw maneuver] conditions.
[The airplane must be designed for loads resulting from yaw maneuver conditions specified in paragraphs (a) through (d) of this section at speeds from VMC to VD. Unbalanced aerodynamic moments about the center of gravity must be reacted in a rational or conservative manner considering the airplane inertia forces. In computing the tail loads the yawing velocity may be assumed to be zero.
(a) With the airplane in unaccelerated flight at zero yaw, it is assumed that the cockpit rudder control is suddenly displaced to achieve the resulting rudder deflection, as limited by:
(1) The control system on control surface stops; or
(2) A limit pilot force of 300 pounds from VMC to VA and 200 pounds from VC / MC to VD / MD, with a linear variation between VA and VC / MC.
(b) With the cockpit rudder control deflected so as always to maintain the maximum rudder deflection available within the limitations specified in paragraph (a) of this section, it is assumed that the airplane yaws to the overswing sideslip angle.
(c) With the airplane yawed to the static equilibrium sideslip angle, it is assumed that the cockpit rudder control is held so as to achieve the maximum rudder deflection available within the limitations specified in paragraph (a) of this section.
(d) With the airplane yawed to the static equilibrium sideslip angle of paragraph (c) of this section, it is assumed that the cockpit rudder control is suddenly returned to neutral.]
Amdt. 25-91, Eff. 7/29/97
Code of Federal Regulations
Sec. 25.351
Part 25 AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES
Subpart C--Structure
Flight Maneuver and Gust Conditions
Sec. 25.351
[Yaw maneuver] conditions.
[The airplane must be designed for loads resulting from yaw maneuver conditions specified in paragraphs (a) through (d) of this section at speeds from VMC to VD. Unbalanced aerodynamic moments about the center of gravity must be reacted in a rational or conservative manner considering the airplane inertia forces. In computing the tail loads the yawing velocity may be assumed to be zero.
(a) With the airplane in unaccelerated flight at zero yaw, it is assumed that the cockpit rudder control is suddenly displaced to achieve the resulting rudder deflection, as limited by:
(1) The control system on control surface stops; or
(2) A limit pilot force of 300 pounds from VMC to VA and 200 pounds from VC / MC to VD / MD, with a linear variation between VA and VC / MC.
(b) With the cockpit rudder control deflected so as always to maintain the maximum rudder deflection available within the limitations specified in paragraph (a) of this section, it is assumed that the airplane yaws to the overswing sideslip angle.
(c) With the airplane yawed to the static equilibrium sideslip angle, it is assumed that the cockpit rudder control is held so as to achieve the maximum rudder deflection available within the limitations specified in paragraph (a) of this section.
(d) With the airplane yawed to the static equilibrium sideslip angle of paragraph (c) of this section, it is assumed that the cockpit rudder control is suddenly returned to neutral.]
Amdt. 25-91, Eff. 7/29/97
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Safety Concerns: Sorry if it is a bit offtopic, etc. I agree with what you say, but I think it is a responsibilty of both our politicans and the self loading freight.
Why? Safe operation is mandatory, but if the management knows their aircraft isn't safe and people die, noone from the management is charged for it. No personal consequences for unsafe operations, but more premiums from extra profit if you ignore safety? It invites disaster to happen.
But the problem isn't here. If pax decides: if AF ignores SBs and some planes aren't that safe then we don't fly with them, because the contract is for a safe flight, etc. then AF wouldn't ignore SBs.
I am not sure how it works in your country, but in Hungary the generic population is less interested in which airline is safe, and more interested, if some package for a celebrity (who became one without any merit or real talent) was lost somehow. Or the "drama" or anything else, but not their safety.
Even if pax can raise stupid questions there, they vote with their money about safety, and their vote can determine the safety for pilots as well.
I don't want to start another Airbus - Boeing argument here. Probably we don't know what is better.
But most pax have an assumption about which is safer. Yet most of them ignore it when they can save an euro or two this way. If they ignore their assumption, they won't care about SBs they don't even know about.
And most companies simply do what customers want.
For them GSM on board, a few cents worth of discount, etc. are all more important than safety and this is why companies spend money to provide GMS service and not on reliable communication with ATC, following SBs, etc.
We decided to keep SLF discussion on this topic at minimum, since it is easier to moderate a single thread this way. If we would use the public exposure, would have a subforum, where SLF can learn and they would next vote for safety with their money? Then the picture would be different.
Our choices are part of the real world that makes ignoring SBs profitable. And even if it is a small part of picture, and our influence is pretty hard to notice, we should make sure our decisions contribute to safety and not to any future accident. Because if we don't follow this "example" then why would anyone else do it? But if many people decides even if his individual influence doesn't matter he stay security conscious that can have some effect.
Why? Safe operation is mandatory, but if the management knows their aircraft isn't safe and people die, noone from the management is charged for it. No personal consequences for unsafe operations, but more premiums from extra profit if you ignore safety? It invites disaster to happen.
But the problem isn't here. If pax decides: if AF ignores SBs and some planes aren't that safe then we don't fly with them, because the contract is for a safe flight, etc. then AF wouldn't ignore SBs.
I am not sure how it works in your country, but in Hungary the generic population is less interested in which airline is safe, and more interested, if some package for a celebrity (who became one without any merit or real talent) was lost somehow. Or the "drama" or anything else, but not their safety.
Even if pax can raise stupid questions there, they vote with their money about safety, and their vote can determine the safety for pilots as well.
I don't want to start another Airbus - Boeing argument here. Probably we don't know what is better.
But most pax have an assumption about which is safer. Yet most of them ignore it when they can save an euro or two this way. If they ignore their assumption, they won't care about SBs they don't even know about.
And most companies simply do what customers want.
For them GSM on board, a few cents worth of discount, etc. are all more important than safety and this is why companies spend money to provide GMS service and not on reliable communication with ATC, following SBs, etc.
We decided to keep SLF discussion on this topic at minimum, since it is easier to moderate a single thread this way. If we would use the public exposure, would have a subforum, where SLF can learn and they would next vote for safety with their money? Then the picture would be different.
Our choices are part of the real world that makes ignoring SBs profitable. And even if it is a small part of picture, and our influence is pretty hard to notice, we should make sure our decisions contribute to safety and not to any future accident. Because if we don't follow this "example" then why would anyone else do it? But if many people decides even if his individual influence doesn't matter he stay security conscious that can have some effect.
Public perception
Air transport needs to be considered so safe that safety isn't a purchasing choice. The DC 10 had a hard time in the '80's when it cropped up to often in the headlines. If, by unfortunate chance, another large loss was experienced whilst AF is still in the headlines I think public confidence in the industry would become an issue. So yes, safety is either irrelevant to choice or the only factor worth considering depending on public sentiment.
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Quote:
However, none of these monitoring systems can detect a situation where the heater might be working perfectly, and yet unable to keep up with ice accretion in a particular environmental scenario due to a design flaw.
I find this hard to believe, as the aircraft clearly has to be certified for "flight into known icing" for a given specification. The entire airframe would have iced before the Pitot if the heater was actually working??????
However, none of these monitoring systems can detect a situation where the heater might be working perfectly, and yet unable to keep up with ice accretion in a particular environmental scenario due to a design flaw.
I find this hard to believe, as the aircraft clearly has to be certified for "flight into known icing" for a given specification. The entire airframe would have iced before the Pitot if the heater was actually working??????
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Sensors
JR
Isnt it this way on the 330:
One engine running, low current flow.
Airborne : high current flow,
provided by controllers.
What is the reason to use controllers,
when a simple "current relay" could do it,
like on all "vintage" aircrafts.
There is no "temp-feedback" from the sensors,
so why "controllers"?
Isnt it this way on the 330:
One engine running, low current flow.
Airborne : high current flow,
provided by controllers.
What is the reason to use controllers,
when a simple "current relay" could do it,
like on all "vintage" aircrafts.
There is no "temp-feedback" from the sensors,
so why "controllers"?
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autopsies
first results show no signs of burning or explosion (bomb, fire etc)
Most of the bodies were without clothes, the IML here says that indictaes the plane broke up in flight
none died by drowing, ie none had water in their lungs
Most suffered severe head injuries, impact with water
Bodies were found in two separate lines, indicating the possiblity the plane broke up in the air
Voo 447: perícia reforça hipótese de que avião se partiu | Geral
Most of the bodies were without clothes, the IML here says that indictaes the plane broke up in flight
none died by drowing, ie none had water in their lungs
Most suffered severe head injuries, impact with water
Bodies were found in two separate lines, indicating the possiblity the plane broke up in the air
Voo 447: perícia reforça hipótese de que avião se partiu | Geral