AF447

[DC-ATE]

Don't know who wrote this: -
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.


I'll ask this again: WHY are you messing with the rudder in cruise with or without turbulence? [Transport pilots only, please] Or, is this an Airbus technique? While it is 'proper' to try and keep the wings level, it is not necessary to keep the heading constant. Trying to maintain heading can lead to serious overloads.

[parabellum]

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.

[Paul2412]

stadedelafougere:

I understand that a large amount of data would be worthless, and as a result when the aircraft parks up at the gate successfully a simple signal to identify the end of the flight is sent and the airline can choose to delete the data while possibly keeping anything flagged as unusual so the maintenance guys can take a look.

Also, if the data was kept it would be easier to diagnose the start of a problem that may eventually become serious enough to cause concern. For example, a problem develops in flight for some reason, that information is now logged with the airline. If 7 days later a flight is forced to make an emergency landing, or worse still is lost the investigators can see clearly that a problem occurred at a particular time. As I understand it, the FDR overwrites itself every 30 minutes so at the moment, that particular fault would never be detected.

The argument regarding data size and cost is not relevant, I work in the IT industry and can assure you that storing TB's of information does not cost a great deal at all.

Basically, the point is that if the technology already exists for the airplane to send messages to the ground, why not take all messages that the FDR flags as unusual straight to the ground regardless of whether it caused a problem or not? Prevention is better than cure.

In response to the tombstone mentality, I understand that its a risk vs cost industry as is every industry. However, I run an IT business hosting many clients valuable data. If I receive an advisory that may cost me in the short term but will protect me in the long term I'll take it and implement it straight away as I know a total failure of my system could cost me dear. You would think that when your talking human life that could be lost it would be the same!

[TP-51]

I know little about IT, but as you say, there MUST be a way that modern aircraft can transmit "burst" transmissions on a regular basis (say every 20min) to home base including ALL the info that would normally be stored on the FDR/CVR?

OK a lot can happen in the 20min between transmissions, but surely a pattern may emerge leading up to a serious incident?

Great idea, but as long at the Pilot Unions are worried about airlines reviewing this data and then taking action against pilots after flights - this will never happen.

Perhaps all data could be sent to a '3-party' organisation such as IATA for storage for a period of say 24 hours or 7 days then automatically destroyed.

[lgw-morph]

Air France Probe Suggests Plane Broke Up in Air, Estado Says





By Laura Price
June 12 (Bloomberg) -- The Air France plane that crashed June 1 may have partly broken up in the air before hitting the Atlantic Ocean, O Estado de S. Paulo reported, citing investigators it didn’t identify.
Most of the 16 bodies examined in preliminary stages of the probe into the flight from Rio de Janeiro to Paris were found naked or with minimal clothing, suggesting the wind may have removed the garments, the newspaper said. The possibility of an explosion or fire in the jet is also unlikely because the bodies showed no sign of burns, Estado said.
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.
Representatives from Brazil’s legal medical institute, which is conducting the body examinations in the northeastern city of Recife, weren’t immediately reachable when Bloomberg News called for comment before regular working hours.
To contact the reporter on this story: Laura Price in London at [email protected] ([email protected])
Last Updated: June 12, 2009 07:09 EDT

[BOAC]

Bodies were found 85 kilometers (53 miles) apart, which may also indicate the Airbus A330-200 broke up before reaching the ocean, - to me it does not 'indicate' this at all. I keep on seeing this - can someone explain how an aircraft, supposedly 'breaking up' badly enough to spill passengers, can travel on for 85k? We are looking at around 6-7 minutes in a straight line, and I would suggest we should assume the ocean has spread this debris. Case remains open for me.

[Towhee]

Thanks for the diagram of antenna locations, Saigon Lost. It gives evidence that the vertical fin was intact throughout the period of the ACARS reports, else there would have been HF Fail reports, too. The VOR antennas are not monitored, but the HF antenna couplers, in the leading edge of the vertical fin, are active LRU, Line Replaceable Units, that are powered, and provide fault reporting to the transceivers, which would, in turn, report to the ACMS, and from there to ACARS.

Awesome post. A perfect example of why this board rocks! You just crossed the early breakup hypothesis off the list

only assuming ACARS reports are complete

[positive climb gear]

Apologies,I am an A320 driver but was wondering if any A330 pilots might comment on this:
FCOM 1 states
For the A320 the deflection of the rudder and the pedals is limited as a function of speed. Each channel of the limiter is controlled and monitored by its associated FAC. If both FACs fail, maximum deflection is available when slats are extended.
Hence, up to 160 Kts CAS, the maximum rudder deflection of 25 degress is available. This then reduces (non linearly) to a maximum deflection of 3.4 degrees for speeds greater than 380 Kts.
One rudder surface controls Yaw. The yaw damping and turn coordination functions are automatic. The ELACs compute yaw orders for coordinating turns and damping yaw oscillations, and transmit them to the FACs.

As it seems on general concensus that there was a problem with the probes leading to erroneous speed indications, what if the FACs allowed a greater rudder deflection during their normal dutch roll damping manoeuvre, since they sensed a much lower erroneous speed?

If the speed then did increase (possibly as quickly as it dropped), the FACs would recognise that the rudder deflection was greater than allowed, would the computers assume a FAC failure? Of course the secondary effects of rudder are roll, thus making handling even more difficult.

Hence I hope the previous response for transport pilots to comment on their use of rudder- in the A320 the rudder is being operated by the FACs without your knowledge- as there is no feedback on the pedals!

Is it a similar design on the A330.....?

[Gergely Varju]

ILS27LEFT: I tried to avoid unncessary posting there, since the thread is a bit chaotic as is, and if admins decided to keep it as thread and not as a temporary subforum where theories can be discussed in an organized way (and merged into a thread at later point, and moved back to this part of forum), I think it is easy to reduce their workload by posting less. Yet, your post makes me wonder, if it is a good decision or not.

First of all, you ignore some key thing. GPS wasn't lost, since the a/c knew its own coordinates.
GPS isn't useful to calculate airspeed, since you don't know about wings, so GPS signal has nothing to do with airspeed data.
(Even trying to track something that moves with the air would be better indicator for speed... but sadly it would be pretty hard to say the least)
Some people on a hungarian forum suggested, that if you have attitude data and EPR you can calculate the speed, but it would again ignore some of the effects of weather...
Some people suggested metal plates and various devices to determine airspeed, such devices aren't tested or installed, so it doesn't work.

While it is theoretically possible for a computer to calculate some estimated airspeed from various data, and try to help the pilot to keep the a/c in safe limits, it would require some pretty complex computer software, which isn't tested or installed yet. Worst of all: It isn't even implemented in a way that would let us use it on an Airbus FBW aircraft. And measuring if you are withing safe limits can be easier anyway.

The serious faults you speak about are consequences of each other. You also ignore what kind of "serious faults" we are speaking about. If you count the alternate law message, the autopilot and autothrottle messages, etc. as serious faults, not simple consequences of pitot icing, then it could make sense.

But you also gladly ignore the fact, that weather, etc. can be considered common, yet many flights cross the atlantic safely. Why? We can say, pilots try to avoid Thunderstorms. We can say, that the aircraft are certified and should be safe on such trips. We can also say there are many options to avoid such events.

About Coffin corner aviation: We can speak about Coffin Corner aviation for many pages, and about how various systems on the aircraft can determine what speed is safe, and how various factors like any "obstacle" under the aircraft (terrain, CB, traffic) can influence what can be safe, but it isn't that simple as you want to portray it.

[matkat]

Paul2412, It is not for the manufacturer ie Airbus to mandate a service bulletin and in fact they cannot in any case it is for the state of design to do this so only EASA would have been able to mandate a change from a SB to an AD. In earlier posts I have seen the term "mandatory service bulletin" used though manufactures often use this term only the state of design can change this from an optional SB to a mandatory airworthiness directive, so in summary from a legal standpoint Airbus did issue an SB but EASA never mandated it so I cannot see why there would be an issue as in reality AF really did not have to change anything as all service bulletins are optional until changed to an AD.

[lomapaseo]

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?


Its really a chicken and the egg issue. For cascading failures you need to consider which direction they are progressing

[overthewing]

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.

[tubby linton]

I discovered the following document on smart cockpit:
SmartCockpit - Airline training guides, Aviation, Operations, Safety (http://www.smartcockpit.com/pdf/flightops/flyingtechnique/34)

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?

[RWA]

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........

[Wader2]

From the first post on this thread:

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.

but many posts that try and bring people back to real events and reality with rational explanations are deleted.

"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".

So, why, where we try and use real facts, including oceanographic data to either support or refute other posts are they deleted?

[captainflame]

If they had NO water in the lungs, they didn't drown, did they !?!?
:=

[RWA]

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.....

[vapilot2004]

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.

At least in these threads.....among many other lessons. :ok:

[captainflame]

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)
:confused:

[RWA]

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 (http://www.bloomberg.com/apps/news?pid=20601086&sid=as_IAXADNn1c)

[JRBarrett]

Someone please tell me WHY, if true, there is an "Automatic" position on the Pitot Heat Switch on this, or any aircraft.

Avionics maintenance engineer here, specializing in air data systems.

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

[elch]

No. It is different, no FACs no ELACS
Just 3 PRIMS, 2 SECs, 2 RPTLs and 2 RTLs, 1 BCM for either Blue or yellow HYD.

[Safety Concerns]

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.

[Mr Optimistic]

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.

[elch]

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

[Gergely Varju]

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.

[Mr Optimistic]

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.

[Professorrah]

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??????

[connector]

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"?

[Gringobr]

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 (http://www.clicrbs.com.br/anoticia/jsp/default.jsp?uf=2&local=18&section=Geral&newsID=a2543209.htm)

[captainflame]

:p
Funnilly enough, Mr Pitot invented a tube to measure fluid speeds,
and a Pitot tube measures "P tot "
ie total pressure = P Dynamic + P static !! :D
Year: 1732

[Graybeard]

Per Bloomberg, AF had the new pitot tubes in hand, and I'm sure I read early in the other thread that the accident plane was scheduled to get them on the next C check (approximate annual inspection.) IIRC, this plane had over 18,000 hours in about 4 years, an incredibly high rate of utilization. This leaves precious little time for non-routine maintenance at home base, such as changing pitot tubes.

You don't just change the pitot tubes and walk away; you then have to perform a full pressure-static check, including pneumatically pumping up the altitude to above max altitude, so you leave those changes for the C check if you can.

It must be quite a serious flaw in the pitot tubes that they have to be replaced with new ones, rather than re-worked. Safety review teams at Thales, Airbus and AF apparently did a cost/benefit analysis and came up with the wrong answer, if erroneous airspeed was the initial event.

GB

[gillesf]

I am also very curious about the temperature "cliff" coming out of 3 updrafts in the turbuence. Could there have been a combination of wrong speed (pitot) and stall/fall with that cliff getting out of the turbulence? Isn't it really an exceptional situation (may be not weather wise, but flying wise since CBs are usually avoided), an hence not taken into account by computer/checklists? As for the "criminal investigation", it is an automatic administrative procedure here in France and does not imply that criminal behaviour is being suspected. Thanks - Gilles

[lomapaseo]

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.

.......................

An 'advisory' means that the airlines pay - if they care to. A 'mandatory' means that the manufacturers do.


a guess is one thing, but your supporting statement is not true. Cost between the manufacturer and the customer is a negotiated contractual issue.

Without supporting data it is useless to denigrate a party or person just to support a supposition.

Under continued airworthiness cost is not an issue (alternate means of compliance etc. accomodates this). The facts supporting the product safety issue are not yet in evidence to us although presumably they were to EASA. Just because a system may malfunction does not mean the aircraft is unsafe.

[deSitter]

FEHoppy, RE p. 122 BEA report

No that looks nothing like AF447, the rudder is damaged mid-section and is surrounded by leaked oil and hydro fluid from the rudder acuators likely. It appears to be cracked side to side about midway as well. IOW severe damage as expected to the structure of the tail section.

-drl

[petermcleland]

Quote:-

"I'll ask this again: WHY are you messing with the rudder in cruise with or without turbulence? [Transport pilots only, please] Or, is this an Airbus technique? While it is 'proper' to try and keep the wings level, it is not necessary to keep the heading constant. Trying to maintain heading can lead to serious overloads."

I would hope that nobody here changes or maintains heading with the rudder...This would be done with aileron. The rudder pedals in jet airliners are just footrests in normal flight and should only be moved to push the ball back to the middle after engine failure, kicking off drift for landing and keeping straight on the runway centreline.

[SteveMRobson]

Ice has been a problem for aircraft since the early days. More recently the B777 at Heathrow and now A/B330. Perhaps in this high technology world the basics are not treated with due reverence or simply that mother nature continues to teach us not to lose sight of the rules.
On exercise away from base a pitot had a heater problem which was a no go item, one was robbed from an aircraft undergoing maintenance and fitted in the evening. The main problem was the curing time for the sealant during October in Scotland.
Despite only circumstantial evidence pointing to the pitot system, the evidence has been building up and it should not need the threat of pilot action to accelerate at least a minimum update fit. The balance between costs and safety has always been a tight rope but once a reasonable amount of evidence is there the right action should be taken - the consequences are far more serious.

[JRBarrett]

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"?

Quite possible re: variable current flow for ground vs. air modes on an Airbus.

I can't answer that one way or the other, as my own experience is on Hawkers, Gulfstreams, (older) Boeings and Lears - which either have fully manual control of probe heat - or weight-on-wheels coupled automatic heater on/off. (With manual overide available).

Windscreen heat is another matter - all electrical windscreen heating systems I've encountered do employ variable current controllers regulated by temperature feedback from thermistors embedded in the glass.

If I were a pilot, I think I'd much prefer to have full control of each probe's heater circuit individually (via dedicated switches) rather than a single anti-ice switch controlling multiple probes.

In any case, I leave it to an engineer with Airbus experience to shed light on the specifics of the AUTO mode on that airframe.

JR Barrett

[DC-ATE]

JRBarrett -
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.

There we go again....."automatic". I never flew an airplane that had that. We had a Checklist that had Pitot Heat on it. Simple. In other words, no problem having it on while on the ground. And the 'automatic' portion (which there was none) couldn't fail.

[Safety Concerns]

For those who are interested in the basics behind a330 probe heating

Monitoring

The PHC monitors heating of the static probes, AOA sensor, pitot probes and TAT sensor. Current detection with a preset threshold is provided for monitoring purposes.

Low heating or overcurrent or heating loss triggers a warning.
Monitoring of the TAT sensors is inhibited on the ground.
A monitoring system activates a warning when heating is incorrect. Warning is triggered as follows:
(a)
For pitot probe
-
in flight when the current I is lower than 0.9A or greater than 6A
-
on ground when the current I is lower than 0.4A or greater than 4A.
(b)
For TAT sensor

When the current I is lower than 0.8A or greater than 4A.
(c)
For AOA sensor

When the current I is lower than 0.12A or greater than 5A.
(d)
For L and R static probes

When the current is lower than 1.3A or greater than 4A.
The PHC serves to:

-
identify the faulty element(s),
-
memorize the faulty element.
(2)
Indication

The PHC continuously emits signals via the ARINC 429 bus (low speed).
A discrete output (one per probe) informs the ADIRU of associated probe channel of the heating fault. Then, the ADIRU informs the Flight Warning Computer (FWC).

[grebllaw123d]

There is a description of the mentioned system on smartcockpit.com AIRBUS330, section ICE and RAIN 1.30.50 pages 1-3.

[einhverfr]

> Great idea, but as long at the Pilot Unions are worried about airlines reviewing this data and then taking action against pilots after flights - this will never happen.

Yeah, sending cvr/fdr data at 20 min. intervals would seem like a big privacy problem with little practical gain. After all, I would think that the 5-10 minutes before an incident is where the most important info tends to be found. Hence one can generally send all of the ROUTINE info but none of the important stuff.

Furthermore, the costs of such a thing would be very large for dubious benefit. :ugh:

[JD-EE]

I've noticed a fair number of non-pilots mumbling about GPS as if they think it tells you everything about where the plane is and how fast it's going. It's time to put some details on the record.

First, GPS tells you nothing about where you are. It tells you where you were at the time of the last measurement. With an automobile we're speaking of discrepancies that are not worth thinking about. With a high dynamics aircraft (fighter) the difference between where you are and where GPS alone tells you can be more than slightly significant. GPS alone even has difficulty tracking through typical military fighter aircraft moves. With C/A code tracking it's just about worthless. That is why the military has its P-code (and encrypted Y-code).

This lag and inability to track is mitigated to a high degree via software and other inputs, the IMU and IRU for example. Kalman filters can generate enough accuracy to feed back a position estimate to the GPS receiver that the receiver can maintain lock, if not accuracy.

Still, the whole system tells you where you were and where it thinks you might be based on projections not where you are.

GPS is even worse at telling you your speed, although it can do so. It can take where you were at two times and divide by the time to get a velocity vector. If it smooths that over time it can be reasonably accurate.

That brings up "time" as your enemy. The longer you integrate the GPS tracking feedback loops (the lower their bandwidth) the more accurate the data. Noise is the enemy. Fortunately GPS is designed to work WITH jamming efforts. And jamming is just another word for noise. So there is a potentially very large margin for unjammed GPS to be very accurate, especially in relative positions over a short time frame.

Now consider the plane is in heavy turbulence. The filters are prepared to handle this. Civilian aircraft don't do aerobatics. They fly sanely, even in turbulence the flight is fairly sane, it cannot be called aerobatics with spins. rolls, and other rapid motion changes. So far the GPS plus other information sources can give you reasonably good estimates of where you're going, how fast, and where you are. To be sure it's accuracy is fading. But you are within the design parameters for all the instruments and software involved.

Note that I've not said a thing about heading, yaw, or pitch of the plane itself. GPS CAN make an estimate if you have antennas on the nose, tail, and both wing tips. It might even be a good guess using phase tracking tricks. Theoretically it's possible. And with computers these days it may even be practical if calibration tables for cable measured temperature versus delay time is carried and usable. I'd not bet on it.

Now throw the plane into a spiral dive or a flat spin or almost any other controlled or uncontrolled aerobatic movement. Civilian GPS is not designed to handle this very well. The nav computer can make some estimates. But I question whether the dynamic ranges of the instruments, including GPS, can handle the uncontrolled "aerobatics" situation. I'd also be surprised if the SatCom antenna aiming algorithms can adapt quickly enough to the questionable data to keep the antenna aimed on the satellite.

That's as far as I can take it. This is stuff I know about. It is far enough to suggest strongly, but not conclusively, that the plane was still relatively speaking straight and level at 0214Z, the time of its last transmission. Now, the time gap MIGHT mean it was more or less out of control and the antenna aligned for a few hundred milliseconds, long enough to spit out a burst of trouble reports. But that magic lineup seems to me to be to low a probability to worry OUR minds about. The accident investigators might just to kill even the remote possibilities.

{^_^} Joanne - worked on GPS satellite hardware and software and worked on some GPS receiver software in her years at Rockwell and Magnavox (military) in Torrance.

(It's Kalman not Jalman, you bimbo. {^_-} Typo fixed.)

[ClippedCub]

I keep on seeing this - can someone explain how an aircraft, supposedly 'breaking up' badly enough to spill passengers, can travel on for 85k?It doesn't. Dispersion can be explained by ballistic trajectories.

http://www.asc.gov.tw/author_files/Ballistic.pdf

[Mad (Flt) Scientist]

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.So is there any work being/can be done to address ?

The heater controller maybe can't tell when it's being overwhelmed by outside spec icing conditions (or an undetected heater failure or a "design flaw") but there is a system which can detect the consequences - the ADIRU miscompare messages are telling you that the data is beoming unreliable. Since there's not a lot you can do to rectify the situation other than switch to (hopefully functional) alternate sources.

[JD-EE]

ClippedCub (http://www.pprune.org/members/302559-clippedcub)

All the plane has to do is disperse the bodies over a fraction of a km.

Differential drift rates in the prevailing Westerly currents would take care of the rest of the dispersion.

{^_-}

[Towhee]

Are you sure that 'any other professional pilots' would have been flying through that weather, and not around it?

Is it an established fact or only an assumption that the AF
pilots were 'flying through that weather'?

After reading numerous posts by extremely knowledgeable
pilots, meteorologists, engineers, mechanics, and assorted other
professionals, it appears as if it's not been proven that the AF pilots
did not deviate around the worst of the WX.

Many attest that they may have deviated, and communications
to that effect may have been affected by WX, etc. So received
communications or lack thereof aren't evidence that they were flying through that weather.

Also, knowledgeable sources report that, whether they did or
did not deviate, decision making about this may have been
affected by inadequate WX information, including radar, and by the
fact that newly developing convective forces can form and rise rapidly
from the ocean surface and be nearly indetectable.

[einhverfr]

Is it an established fact or only an assumption that the AF
pilots were 'flying through that weather'?


Established fact? Not yet.

However, I think it is probable because the projections of the plane flying through the MCS explain the 0200Z manual message and fit in well with the projections of Tim Vasquez. Maps suggesting deviation do not do this as well, so I would suggest that the general weight of the evidence suggests that the plane was probably flying through the mesoscale convective system.

This makes it more than an assumption and a bit less than an established fact.

[deSitter]

Application of rudder, instinctual -

what has been said of rudder input in normal flight is very interesting and telling. One should consider the animations the NTSB often publish as part of their public dockets. It would seem that a sudden upset almost always leads to rapid, one would say instinctual, rudder input from the PF. Sometimes this may be justified but from what has been said by pilots here, not often. Perhaps this goes back to training days in small aircraft where more rudder authority is required to escape an upset or establish stable flight in turbulence - the ideas imprinted there could somehow just become part of the airman's natural skills.

This aircraft had already accumulated 18000 hours in 4 years - that's a lot of flying. There are many unknowns about how fatigue accumulates in composite structures. We know in one case that the VS mounting lugs failed laterally, all at once, across many layers of composite material, in AA587. This must have taken the structural engineers somewhat by surprise. These things have not been around long enough to know all their properties under heavy use. One thing is sure, they don't respond well to rapidly changing stress like aluminum does, and they tend to fail collectively and not along easily identifiable cracks. One can point out here the failure of the carbon-carbon reinforced leading edge panels in the Columbia orbiter. The collected engineers gasped in amazement as a piece of foam smashed a 50cm hole in that panel - I don't think anyone expected this collective failure mode where a crack develops and propagates at such speed. One thing that may be important to consider is that these structures come out of fabrication with a lot of frozen-in stress that gets released almost explosively on failure.

-drl

[lomapaseo]

Towhee
Pretty good post for a newbie.

Succinct and logical without speculation :ok:

[ILS27LEFT]

Yes mine was certainly a very strong assumption based on established facts regarding the weather, documented also on this forum. The pilot of AF 447 also radio-communicated the turbulence shortly before the series of faults kicked in.
All Weather radars were showing serious weather indeed, I am not talking about the radar on board this specific a/c, nobody knows if that was fully working in fact, but I am referring to the numerous public weather radars fully available on the web for that area at that time. Plenty of screenshots available online. Definitely serious weather but absolutely average and forecasted for the area and they were flying through it or very close to it, this alone would have never brought the plane down. We all know this.
I have never said that the weather caused this accident, what I have "rumoured" in my previous post instead is that established bad weather (fact) associated to the "apparently confirmed" pitot problem (nearly a fact) is a recipe for disaster, in my opinion, due to coffin corner and total:mad: lack of air speed data.
I do not think anybody can deny this.:mad:
Can anybody fly through coffin corner without airspeed data and survive?
As I said I also believe that ground speed data lost signal from satellite due to weather which normally is not an issue at all.
Again, a combination of factors but AF did not change pitot on this A/C as per AirBus notice. Coincidence or possible cause?

[Interflug]

The pilot of AF 447 also radio-communicated the turbulence shortly before the series of faults kicked in.No factual information exists about this claimed communication (in public). It might be just a myth.

[etsd0001]

We know in one case that the VS mounting lugs failed laterally, all at once, across many layers of composite material, in AA587. This must have taken the structural engineers somewhat by surprise.

Not so.

From the Airbus FCOM Bulletin 815/1

The Rudder should not be used:

- To induce roll
- To counter roll induced by any type of turbulance

Whatever the airborne flight conditions may be, full or nearly full opposite rudder pedal inputs must not be applied. Such inputs can lead to loads higher than the limit, and can result in structural damage or failure

The rudder travel limiter system is not designed to prevent structural damage or failure in the event of such rudder system inputs

[HarryMann]

Can anybody fly through coffin corner without airspeed data and survive?This term seems to be acquiring a life of its own... Coffin Corner. Goodness knows what any lay members of the public would think reading 'that' statement.

1) You don't fly 'through' that region, as if it's a part of the sky, you fly 'within' an altitide speed band, a regime, tight or wide in extent, as explained 100's of posts ago, probably +/- 25 kts plus other 'certificated' margins on top of that.

2) We don't know for sure that ALL airspeed and attitude data was lost, do we?

3) It's the turbulence that would be the primary difficulty, rather than being within a restrictive flight regime per se, if all airspeed data was lost, since a default attitude and power setting is the recommended 'exit strategy'

I agree a very serious situation would exist when losing airpseed data when 'way up there', and would be amplified by manifold issues at night in turbulence/ice/preciptation/lightning...

But saying flying 'through coffin corner' without airspeed data gives totally the wrong impression...

[ILS27LEFT]

I am quite sure I read it somewhere on an official source, I could be wrong of course but I think it is irrelevant because the fact that significant weather was in the proximity of this A/C I still see it as a clear FACT.:ok:
I think it is also a proven FACT that pitots had not been changed by AF on this specific machine.
Anything else is rumours and speculation of course but the two FACTS above "could" have been the initial trigger of a full loss of control with all consequences associated to this.
If the pitot issue will be confirmed as main trigger nobody can blame the two or 3 professional pilots in the cockpit.
I say this because I am also sure they knew very well about this pitot problem and they were all well trained on how to react to loss of airspeed data at altitude and in turbulence, but again real weather could have made it impossible. Sims, unfortunately, cannot fully replicate reality.
Reminder: it is not always easy to avoid those massive CB, sometimes you have no choice and go back, sometimes something strong, thick and black just comes out of nowhere, plus nobody knows if their wx radar was working and telling the truth.
Only this.

[HarryMann]

Definitely serious weather but absolutely average and forecasted for the area and they were flying through it or very close to it, this alone would have never brought the plane down. We all know this.

We don't, flying through very serious weather can bring aircraft down if control is lost - fact - which is why a/c have weather radar and pilots everywhere avoid the worst, even with fully operational air data displays - because you just don't know what is inside! Nature is not just incredibly powerful, but incredibly unpredicatble...

[Bearcat]

Harry, unfortunetly coffin corner could be a very signicient part of this accident if the data is retrieved to show that the aircraft flew through an area of ISA+45 due convective lifting from the CB's in this ITCZ area. An A330 with 1.3G protection flying at max alt then going through this warm patch....well red bars will be meeting red bars on the speed tape.....

[eliptic]

i guess this thread did not leave out any form of possible reason of the accident ,,maybe the only missing link would be the lockness (http://images.google.se/images?hl=sv&rlz=1G1GGLQ_SVSE265&q=lockness&um=1&ie=UTF-8&ei=edcySsa3AYasjAegvPyJCg&sa=X&oi=image_result_group&resnum=1&ct=title)

Regards to the Crew i think the majority of pilots would face the same destiny as the AF 447 guys did,, thinking of collected experience

it is very sad when speculations start depending on clothes on or not, especially for the relatives to the victims ,, get that box recover now!!

[HarryMann]

Thanks Bearcat, well aware...

I just think the post was adding little to what has been said ad infinitum so far, and sounded 'alarmist' in it's use of phraseology..

Flying 'through coffin corner without airspeed data'...The a/c was probably flying up in that region and then lost airspeed data (probably)...

A very different emphasis, no ?

PS. We also don't know it was at max alt for its weight at the point

[Farfrompuken]

ILS27L et al.

All this talk of wx avoidance and turning back etc. is all very 'armchair'.

Having flown through that region on many nights, sometimes you have to thread your way through the best (but no means nice) way possible using radar and eyes to guide you.

Turning around wasn't an option for me for 2 reasons: 1) past LPD to an island destination and 2) you'd be flying back through precisely the weather you were trying to avoid in the first place!!

Not been on AF447, I can't comment too much on their options, however stooging through the ITCZ isn't enjoyable, less so if you're facing failures many hours from a safe haven. Turning around may not have been an option.

I suggest we all await the official reports before spouting any more waffle.

[eliptic]

Grrr,

I can not for 1 second understand WHY in 2009 a so critical item as a black box should be aloud to follow a A/C down to the bottom of the sea

Thats totally insane,atleast they could put it in the v/s!! that one seams to exit and float most of the :ugh:times

[Gringobr]

Oxygen masks have been found from AF 447
No comment......
Peças e objetos do voo AF 447 - Álbum de Fotos - UOL Notícias (http://noticias.uol.com.br/album/090612pecas_album.jhtm?abrefoto=4)

[grizzled]

More Pix.

This was published today. As it was taken at a photo session arranged by Brasilian authorities at Recife, one might assume more specific photos of the items will soon show up online.

http://i602.photobucket.com/albums/tt110/grizzled/AF447Recife_Jun12.jpg?t=1244849276

[kilomikedelta]

They're all aat: FORÇA AÉREA BRASILEIRA - Asas de um povo soberano (http://www.fab.mil.br/portal/voo447/fotos.php)

[Gringobr]

Although this has been on the news here in Brazil for hours, I have not yet seen it mentioned here, I sent a post but did not get published here
basically most of the bodies had severe head injuries, none died from drowning..
No trace of fire or explosion was found on any bodies.
they were found in two separate areas, suggesting, only possibly, breakup in flight

[J.S.]

Hello all, I´ve followed and read all postings from 1st (closed) to this topic, many interesting things I´ve read since then.

Just 30 minutes ago, in the daily night-news-program on the brazilian TV channel "Band", the leader of the IML in Recife said (Institute for autopsies):
"The 16 bodies we´ve pre-autopsied, so far, can´t be recognized and or identified by parents/related persons. No one of the recovered bodies had clothes on. No one of the bodies had water in their lungs nor signs of smoke. No one of the bodies apresented any kind of fire/heat exposure. Allmost all bodies show middle to heavy internal contusions."

The conclusion from the news-reporter was for then, as he said:
"The theory comes near that the AF 447 suffered a quick decompression while in almost cruising altitude with or without total desintegration of the a/c and that the passengers and crew may have died before the impact on the ocean."

Sorry if my portuguese > english translation isn´t 100%, at least I din´t used some auto-translators...btw. I´m german.

Actual images of found debris you´ll find here: gallery on brazilian news-site: G1 > Mundo - NOTÍCIAS - Air France voo 447: galeria de fotos (http://g1.globo.com/Noticias/Mundo/0,,MUL1184390-5602,00.html)

[zak0r]

No one of the recovered bodies had clothes on.

A very large percentage of accident victims in the Alps who slip/fall/tumble down mountains and experience a strong impact falling or multiple tumbling falls are stripped of their clothing. I'd like to point that climbers in the Alps dont(cant!) suffer Rapid Decompression yet often end up without clothing when falling down the hill.

[Backoffice]

Just to throw another thought in here.
I wonder what was in the hold apart from containerised baggage..i.e. any large bulk cargo items that may or may not have been tied down and, might in the turbulence attain enough momentum to punch a hole in the skin.

[YRP]

I know little about IT, but as you say, there MUST be a way that modern aircraft can transmit "burst" transmissions on a regular basis (say every 20min) to home base including ALL the info that would normally be stored on the FDR/CVR?

OK a lot can happen in the 20min between transmissions, but surely a pattern may emerge leading up to a serious incident?


Of course there is a way, 747guru. The technology exists - satcom/phone link. But it would have to be way more frequent that 20 minutes to be useful. Back of the envelope calculation, you're talking a couple of satphone voice calls worth of bandwidth, continuous.

Not an expert, but the cost would be approximately equal to the pilots' salaries for the flight.

If you were going to spend that kind of money to improve safety, is that really the most effective way to do it? What do you really get out of it?

(Standing by to be flamed)

[DC-ATE]

etsd0001 -
The rudder travel limiter system is not designed to prevent structural damage or failure in the event of such rudder system inputs

Huh? Explain please. If it's not designed to prevent damage, what is its purpose?

[ClippedCub]

Excellent points deSitter (http://www.pprune.org/members/218316-desitter) on composite structures.

Composite structures gradually bought their way on the airframe over the decades, and it's true, they don't deflect much before failure. Would like to know when they do the fatigue testing, whether they expose the sample to temperature and humidity cycles too. The pilots can answer here, but would assume an intercontinental plane spends its whole life on one line. Swampy England, high alt cold, hot Rio and back.

For 447 however, the photographic evidence of the vertical wouldn't necessarily support THAT structure failed below design load with margin. The empennage could have been peeled from the VS for instance. In the case where the horizontal failed downward, it would have dragged the two mounting points of the VS down with it in that area of dense supporting structure, explaining the rudder corner damage, since the VS would have rotated te down. The VS would have been only momentarily attached at the front after that. Or course this would have happened very rapidly.

Either way, VS first or HS first, would indicate an overload.

[ClippedCub]

The water bottles don't point to a decompression - they would have ruptured. Appear to be intact in the photo. Either there wasn't a rapid decompression, or they are sea trash.

[Will Fraser]

Are those FA jumps on a bulkhead veneer, belts stowed?

Bullet, ditto, linear text?

[Chomolungma]

sounds reasonable?

June 12, 2009
'Black box' obsolete
PARIS - WHETHER or not the black boxes from Air France flight 447 are found, the crash has shown that new technology is needed to record a flight's last moments in real-time, an aviation expert argues. Former Air Canada chief executive and ex-head of the International Air Transport Association, Pierre Jeanniot helped pioneer flight data recorders 40 years ago but now says the 'black boxes' are obsolete.
'Technology has evolved,' Mr Jeanniot told AFP. 'Real-time data transmission from the cockpit by satellite is a lot less costly than it was ten years ago. It is now possible to transmit everything directly during the flight if there is a problem.'
Mr Jeanniot said an automatic system for data transmission of flight information by satellite exists and should now become the norm in the industry. It would put an end to painstaking searches like the one taking place off the coast of Brazil for AF 447's flight recorders, and allow investigators to reconstruct events in only a few clicks of a mouse.
'The plan would begin to transmit data only from the time that a malfunction occurs,' said Mr Jeanniot. 'The system can be programmed so that in the event of a serious malfunction, it transmits all data and cockpit communications non-stop. It's quite simple.'
The new advanced technology would eliminate the need for costly and often futile searches for black boxes at the bottom of the ocean or deep in the jungle, using helicopters, submarines and mobilising rescue teams.
'Through satellite transmission, everything can be collected instantly. We can know exactly where the aircraft has dropped,' Mr Jeanniot said.
More importantly, the valuable data would help grieving families. 'Can you imagine how hard it is for families to be left not knowing what happened for months, some times years?' he said.
A small Toronto-based firm StarNav is developing the state-of-the-art system to provide the real-time connection between the aircraft and the ground, said Jeanniot.
As the data would only be monitored in the event of a problem, most of the flights would not be transmitting anything at all, and there would be no risk of overloading the satellite linkups, said Mr Jeanniot. -- AFP

[Will Fraser]

They look like jump seats to me, with the harness/belt stowed. How many FAs aboard, how many jumps, and were they up and about? Rather than seated due to Turbulence?

Clipped Cub couple of those bottles look like they recompressed from Cabin altitude to sea level P. If the cabin was at ~8k feet, prior to upset
and descent, if there was disint. airborne, it may have happened low enough below cruise to protect the plastic, allowing it to contain 8k air, capped, and crinkled at SL.

[WhyIsThereAir]

There is a hunk of skin in one of the images with "FWD" in the lower front corner of what is left. Can anyone recognize where this might have been on the plane?

[CONF iture]

I say this because I am also sure they knew very well about this pitot problem and they were all well trained on how to react to loss of airspeed data at altitude and in turbulence
Not so sure ... Unreliable Airspeed exercises are usually practiced anytime during the 10 first minutes after takeoff. I have personally never seen this practice above 15000 feet.

It is true I'm not an AF pilot, but before 447 I had never heard about these pitot malfunctions at cruise Flight Level ... or I simply can't remember.

I am quite sure I read it somewhere on an official source, I could be wrong of course but I think it is irrelevant because the fact that significant weather was in the proximity of this A/C I still see it as a clear FACT
Understand your point, but if you're not able to quote your source, better not to mention anything.

[The Chaser]

W.I.T.A possibly part of the crew container exterior wall???

I am somewhat suprised by the size of some of this fuselage (or contained within) debris. It has either lost a lot of its inertia and speed at altitude (following ejection from the aircraft structure), descending individually at comparatively slow speeds; OR

Spilt out of the aircraft following a comparatively slow speed water impact and break up.

The information posted on the condition of those recovered so far would not necessarily fit with the second scenario, particularly the absence of other large bits of floating debris (non-metallic cabin bits etc).

High speed (near vertical) impact of any surface (land or water) would almost certainly destroy most parts into an amalgum of very small, highly compressed ejecta (more likely to sink).

The two fold down crew seats, any views on what cabin partition bulkhead they are from (forward or aft area of the fuse)??

[Will Fraser]

The jumpseats are most likely aft, since the radius of the perimeter of the bulkhead is small, and if that is a passage to the left of #3, that is a pair, possibly even on the aft pres bulkhead. (~unfamiliar 330) I'd like to again point out the stowed harness/belts, they were not occupied if Captain had ordered seatbelts and FAs to sit secured in the turbulence.

[JD-EE]

Chomolungma (http://www.pprune.org/members/302857-chomolungma)
June 12, 2009
'Black box' obsolete
PARIS - WHETHER or not the black boxes from Air France flight 447 are found, the crash has shown that new technology is needed to record a flight's last moments in real-time, an aviation expert argues. Former Air Canada chief executive and ex-head of the International Air Transport Association, Pierre Jeanniot helped pioneer flight data recorders 40 years ago but now says the 'black boxes' are obsolete.

Now, maybe I am nuts and maybe I'm not. Bit CVR and FDR tools record continuously overwriting the old data with new data continuously. You get a couple hour record or more. The bit about wait until we're in trouble to transmit does not tell a pickled thing about how they got there. What would be needed is bandwidth sufficient to squirt up the data from the last couple of hours and then continue the data transmission until conditions return to normal or LOS (Loss Of Signal.) That initial squrt of a couple hours of data would require a TV signal sort of bandwidth to make it happen fast enough, and even then it might not all get there. Then maintaining the flow would require a narrow voice channel and a slow data channel at most. So you'd be wasting an expensive TV bandwidth channel. But it's wasted anyway because it has to be available at all times. And to make sure the most valuable data gets there first you'd have to use uncompressed data or data with a compression format that works in reverse. Send the newest data first working back to the oldest data. Ugh - the solution seems ugly to me as a communications engineer.

What MIGHT help for locating FDR and CVR is a means of automatically triggering a stream of flight data including the navigation system's estimates of position, velocity (speed and direction), and flight control settings. Cockpit voice can wait for recovery. The data would be designed to put the search as close as possible to the right place.

As many others want to do if we elected to send CVR and data with enough fidelity to get the voices well but compressed almost to death there is a good algorithm that gets it all through a 2400 bps (300 BYTES/sec) or so channel. The algorithm even tends to mute ambient noise. Somebody else mentioned the FDR stream is about 2 k BYTES a second or so. So you get a total bandwidth of about 2 to 3 k BYTES per second per plane with 10,000 planes in the air. That's an agregate data rate of 20 to 30 megabytes per second or a good two digital TV channels worth - if it's all collected and transmitted at one place.

Planes aren't all neatly packed in one place. So each is transmitting its own data. That means each one uses about 10 kHz of bandwidth, continuously, if you want reasonable error rates for a first cut round figure. That's 100 megabytes bandwidth, a piddly 17 TV signals wide or so.

Off hand that sounds terribly expensive. I'd stick to simply trying to make finding the recorders a little easier. And even that may not be worth it for a deep ocean recovery once every few years. The $100 million or even gigabuck SAR may be cheaper in the long run.

{o.o} (It would be fun to have that much bandwidth to play with. But it might also be fun to have that much money to play with.)

[jeremiahrex]

I just thought I'd put a small chime in on the time stamping of the ACARS data. There are many unknowns given the particular system, but we can make some very reasonable assumptions. The incoming faults are timestamped and then the delay the manual talks about is most likely to prevent multiple logging of a single signal that may chatter erroneously from it's intended state. Since the faults are logged on a state of change this is a practical necessity of any system. That delay probably doesn't change the time stamp of the original fault. Theoretically the faults should all be logged in order then, even if different messages have different delay times. Upon being transmitted to the ACARS system, it probably doesn't retimestamp the messages. It could I suppose but it would serve no purpose.

[Will Fraser]

If those are aft jumpseats, it would be nice to know where in the Ocean they were found relative to the VS. If close together, it may suggest an aft fuselage failure in concert with loss of VS and aft bulkhead. Were there nine FAs aboard?

[ClippedCub]

it may have happened low enough below cruise to protect the plastic, allowing it to contain 8k air, capped, and crinkled at SL.

The bottles don't look like they've spent months at sea, possibly from the plane. Could be a sign the breakup occurred at a lower altitude, down to and including SL, which would rule out rupture of the pressure vessel causing the breakup.

[Will Fraser]

It is unlikely any loss of cabin pressurization caused a total failure of the fuselage. If the hull breached, the loss of pressure is a given. If the pressure was lost, one is forced to assume a small opening, because if it was a major opening, that would qualify it is a disintegration. Sounds confusing, and mostly semantics, but technically it isn't. Whatever pressure issue the ACARS message indicated, it is most unlikely to be a hull 'disintegration'; that would be expected to have engendered earlier and more critical ACARS data, meaning aerodynamic loads that were unsustainable. So it seems more likely that hull fragmentation occurred first, with an obvious loss of all pressure difference (perhaps gain?) immediately. Depending on a/c altitude at failure.

[RWA]

There are many unknowns about how fatigue accumulates in composite structures. We know in one case that the VS mounting lugs failed laterally, all at once, across many layers of composite material, in AA587. This must have taken the structural engineers somewhat by surprise.

Composite structures gradually bought their way on the airframe over the decades, and it's true, they don't deflect much before failure.

DeSitter, ClippedCub, just in fairness to the pilots of AA587, in 2005/6 the Canadian Board and the NTSB jointly investigated two more rudder incidents on aircraft of the same vintage.

The first being the Air Transat case of a rudder oscillating violently and breaking off while cruising on autopilot, and the second a Fedex aircraft in which severe delaminations had been found - thankfully before it misbehaved.

To quote the Canadian report, "The NTSB investigation into this occurrence has determined that the initial delamination was the result of the infiltration of hydraulic fluid in the honeycomb material of the rudder, which appears to be linked to the vulnerability of rudders built before modification 8827, affecting about 370 Airbus A300-600/A310 and 40 Airbus A330/A340. Tests of this rudder in a depressurisation chamber resulted in significant further growth in the damage. Although a direct correlation between the Air Transat and the FedEx event has not been established at this time, the event confirms that significant delamination of these rudders can progress unnoticed, in spite of the present maintenance standards in place."

Transportation Safety Board of Canada | Transportation Safety Board of Canada - Aviation Safety Recommendation A06-05 (http://www.tsb.gc.ca/eng/medias-media/fiches-facts/A05F0047/recs_a0605_cannon.asp)

It turned out that such tap tests as had been carried out up to that time were on the wrong parts of the rudder/fin assembly.

So the good news is that the A300/A310 problem has now been found and rectified, and should not recur; and that it was not the direct result of composite construction. The other 'news' is that (since the FDRs of the time recorded pedal movement and rudder movement, but were not able to 'say' whether the pedals moved the rudder or vice versa) AA587 may well not have been pilot error at all.

[INTEL101]

ok - I do know something about IT and can confirm that satellite internet connections are available with downlink speeds of 400 Mb/sec. If you could do uplink ASCII bursts to relay geostationary satellites you could transmit all your FDR and FVR data in sub second UHF bursts every few mins or so and it probably would not require that many frequencies to cover half a hemisphere's flights.

Of course it all comes down to the filthy lucre in the end as it would require at least eight satellites and a few automated ground stations. But then you could do away with your black HMV boxes.

Given the fact that some airlines are now offering inflight broadband connections, you might think that the voice and data recorders would get access to the same technology.

[RWA]

INTEL101 - or anyone else who knows the technology -am I correct in thinking that ACARS transmissions via satellite require a directional antenna; and that, for each transmission, the antenna has to aim a signal at the satellite and receive an acknowledgement before it transmits?

If so, could that mean that for most of the four minutes the aeroplane was in something like a normal flightpath - but that it was pitching and rolling from turbulence or the flightcrew's efforts to re-establish control? So that the antenna had to line up on the satellite several times, each time waiting for the acknowledgement and then sending a burst of messages? But then losing contact and having to start over?

[Interflug]

The "Satellite Streaming CVR/FDR" discussion is ill guided. Improving the devices existing (lighter, stronger beacons with much longer endurance for deep sea detection etc.) is all that is needed.

Regarding technology for continuous broadband satellite connections etc. it is all there already. UAV are used for a long time now.

Wherever this goes, I'm afraid it will be one more step toward fully automated commercial flying, even though at the moment it is still far away.

[Dan Air UK]

RWA - The ACARs messages go via any of one 4 (soon to be 7) operation Inmarsat sateliites (plus backups). The SATCOMs is continously tracking the satellite on which the A/C has logged-on. The Inmarsat Aero air-interface should allow any ACARS messages to be transmitted within a few seonds in normal circumstances and certainly in less than a minute if the Ground Earth Station is operating normally.

[mixture]

I do know something about IT and can confirm that satellite internet connections are available with downlink speeds of 400 Mb/sec.

hmmm.... everyone seems to "know something about IT" these days. :ugh:

Stuff like BGAN only does around 400kb/s. Even modern platforms such as "SPACEWAY" only get up to 30Mbps.

Believe me, it's going to be a looooong time before you see 400Mbps coming from a satellite !

Units .... units...... always verify your units ! :ugh:

[RU4Real]

I have taught emergency procedures training for 15 years. Interesting photographs of a/c debris. Items of interest are liferaft survival kit including slideraft canopy/inflatable centre mast and flare kit. This is usually slung/attached to slide/raft. Wonder which door it comes from?:(

[Lemurian]

RU4Real.
Agree.
There is also the orange/red pharmacy box. One of a number on board, placed close to an F/A position.
In my opinion, the jumpseats are from the aft bulkhead, as will Fraser noticed :
The jumpseats are most likely aft, since the radius of the perimeter of the bulkhead is small, and if that is a passage to the left of #3, that is a pair, possibly even on the aft pres bulkhead.
The jumpseats sem to have been unoccupied, the belts nicely stowed.
One reason could be that, four hours into the flight, half of the F/As would have been resting in the crew bunks.

[zak0r]

The jumpseats sem to have been unoccupied, the belts nicely stowed.
One reason could be that, four hours into the flight, half of the F/As would have been resting in the crew bunks.



Question: Is it a correct assumption that the F/A move from the bunks to the JS to be all hands available "incase" in a forseeable and developing critical situation?

[RWA]

"RWA - The ACARs messages go via any of one 4 (soon to be 7) operation Inmarsat sateliites (plus backups). The SATCOMs is continously tracking the satellite on which the A/C has logged-on."

Thanks, and welcome, Dan Air UK - only meant in fun, but I can't resist quoting a WW2 divisional commander (forget which one) who once said at a briefing, "The next fellow who fires an obscure acronym at me is going to find himself bloody RIP........"

I'm pretty sure that 'SATCOMs' means 'Satellite Communications,' and also that you mean the ones fitted to the aeroplane, not the satellite itself or the ground station. But I can't be sure, given that the only serious radio I've ever used is military Radio Telephony. :)

'.........should allow any ACARS messages to be transmitted within a few seonds in normal circumstances and certainly in less than a minute if the Ground Earth Station is operating normally.'

My question was, could the fact that (as far as I can tell from the transcripts) the ACARS (sorry for the acronym :)) messages appear to have come in batches about one minute apart mean that the aeroplane was bucking about a fair bit and the aircraft antenna kept 'losing its line' and having to line up and' re-connect again?

The reason I ask is that, if that's so, it suggests that, for the four-minute period we're discussing, the aeroplane was flying more or less normally. Maybe bucking about a bit, but certainly not upside down or in a vertical dive, because the satellite antenna would have had 'NFC' (No 'Ejaculative' Chance' :)) of lining up at all if that were so.

The reason that it's important to me is that, as far as any of us know, the signals ended either because the aeroplane had either dived straight down into the sea (at a descent rate of the order of 8,000 feet per minute) in that four-minute period, or had a catastrophic event (like a high-altitude break-up) which cut off all communications?

Hope you don't mind me pulling your leg. Return the compliment any time. But I guess that you can see why I'd like to know for certain......... :)

PS - ex-Dan Air customer, used to fly a lot with them from Newcastle and Teesside.

[eliptic]

A woman who showed up late to the airport and missed the doomed Air France (http://www.nydailynews.com/topics/Air+France-KLM+Group) flight from Brazil (http://www.nydailynews.com/topics/Brazil) died in a car crash a couple of days later, news services reported.

Johanna Ganthaler (http://www.nydailynews.com/topics/Johanna+Ganthaler), an Italian senior citizen, was on vacation with her husband, Kurt, in Brazil and were ticketed to fly on Flight 447 to Paris (http://www.nydailynews.com/topics/Paris).
The couple showed up late at Rio de Janeiro (http://www.nydailynews.com/topics/Rio+de+Janeiro)'s airport and missed the flight on May 31.
All 228 people aboard were killed after the plane crashed into the Atlantic four hours into its flight to Paris.
The couple took another flight to Europe (http://www.nydailynews.com/topics/Europe) the next day and were driving to their home in Italy (http://www.nydailynews.com/topics/Italy)'s Bolzano-Bozen province.
The ANSA news agency (http://www.nydailynews.com/topics/Agenzia+Nazionale+Stampa+Associata) reported that Johanna Ganthaler died when their car veered across a road in Kufstein, Austria (http://www.nydailynews.com/topics/Austria), and swerved into an oncoming truck.
Her husband was seriously injured.

Read more: Johanna Ganthaler escapes Air France crash only to die in car crash days later (http://www.nydailynews.com/news/us_world/2009/06/11/2009-06-11_johanna_ganthaler_escapes_air_france_crash_only_to_die_in _car_crash_days_later.html#ixzz0IJ30gZPY&C)

[Pontius Navigator]

Looking at the photgraphs of the FA seats I don't think you can conclude anything except that there was no one strapped in them.

I don't think you could say they had not been in use during the incident. There are many reasons why they were unoccupied. They may not have had a full complement of FA but more likely, given what appears to have been a sudden emergency, they may have been attending to the passengers first.

[gillesf]

Would it have been removed, or should we assume they were empty? How does the decompression/recompression hypothesis flies if they were not empty?

Thanks- Gilles

[The Chaser]

1. The ACARS messaging (if complete and accurate) up until 02h14 provides only a preamble of circumstances, circumstances that we are all aware could/would place the flight deck crew in an unenviable position for a whole host of reasons.
2. What we do not know with any certainty are the accompanying actual conditions such as Turbulence intensity, airmass movement and possible high level sheer (vertical and or lateral), Airframe Ice, Hail etc both before, and more particularly after 02h14.
3. We have some very good work by Meteorologist experts that ‘might’ indicate what they were faced with, nothing definite though, so apart from the ‘turbulence report’ there is nothing definitive beyond that.
4. We cannot draw any firm conclusions yet regarding the latent/possible connections between 1. 2. and 3. above


It is after 02h14 that the main destructive events occur of which we know very little


1. The Vertical Stab and Rudder became separated from the rest of the aircraft at some point after 02h14 (otherwise prior to 02h14 ACARS would likely have shot off other pertinent WARN and FAIL messages related to that structure, its integral systems and its operation)
2. Those recovered appear (if condition reports are accurate) to have left the aircraft structure sometime after 02h14, and most likely well before the fuselage section/sections met the surface
3. The small amount of debris (and its condition) recovered is suggestive of ejection (likely at high altitude and high speed) without high speed destructive impact with a solid surface such as other aircraft structures and/or the surface/water (NB: disputed, see below)


To glean anything further at this point is going to be difficult unless information such as:-


1. The seating positions of those recovered is known and published
2. The aircraft parts recovered are identified and their positions in the airframe confirmed and published


Even with that information, the dots are only very loosely drawn. It is my opinion that it is critical that retrieval (at any cost) of the FDR, CVR and the QAR (if it is not totally destroyed), as well as the aircraft structures is paramount. There may well be latent failure modes here that could develop without the preamble events as we suspect them to be, the only way those question marks can be eliminated or addressed is to know the actual events and behaviours. There is only one way to obtain the necessary information.

[iakobos]

RWA - The ACARs messages go via any of one 4 (soon to be 7) operation Inmarsat sateliites (plus backups). The SATCOMs is continously tracking the satellite on which the A/C has logged-on.

Inmarsat 3rd generation constellation, four satellites in geostationary orbit.
In that area, two birds cover the place, AOR-E (atlantic east) and AOR-W.
The a/c's antenna is "omnidirectional" (actually hemispheric), there is no tracking.

Transmissions are almost real-time.
In other words, during those four minutes the antenna "saw the sky".

[ttcse]

Chaser: 3. The small amount of debris (and its condition) recovered is suggestive of ejection (likely at high altitude and high speed) without high speed destructive impact with a solid surface such as other aircraft structures and/or the surface/waterIf you researched at least 2 other Airbus into-water crashes and reviewed the floating debris recovered, you would want to retract this.

[Rananim]

As deSitter explained,rudder use(if it was used) may have been instinctive or even last-resort.
There has been no feedback whatsoever re what rudder deflection was available in ALT law:
-Ive heard TEN
-Ive heard FOUR(ie last cruise default)
-Could full deflection have been available if CAS was erroneous?

Naturally,one pilot would be PF during unreliable airspeed whilst the other attempts to read the procedure and recommendations.But lets assume this was unreliable airspeed with severe turbulence.The larger the upset becomes,the more likely the PNF would be tempted to input control.There is no control yoke in the Airbus,just 2 sidesticks.They dont "mirror" each other and in any case because of their position/size you,as PNF,wouldnt get an idea of what the PF was doing,even if they did.Fine in normal operations but what about in a full high alt jet upset?The possible "dangers" of the design are proven in x-wind landings(lufthansa 320 incident).Same applies here.

I read that the computer in this situation(control inputs from both pilots) takes the sum of the two inputs and gives the mean(if contradictory) or additive(if complimentary)value.Is this true in ALT LAW as it is in NORMAL?If so,the question now becomes does this design in any way make it more difficult/confusing for a succesful upset recovery(assuming the forces of nature were in fact recoverable on 447)?
You have two pilots with different experience levels and set of skills.One may recognize the importance of "ATT vs speed only" in an upset,the other may give equal importance to ALTITUDE/COURSE (this is an emergency..theyre irrelevant).
If the two minds thinkalike,can it lead to an over-control situation?I understand that G-LOAD protection is still available in ALT LAW?2.5g to -1g??
What about other protections though?
If the two minds are not in sync,the appropiate inputs may get diluted by the inappropiate ones.
The takeover button is supposed to address this "fight for control".Use of the "I have control" button in a x-wind landing by a training skipper is one thing but in a severe high-alt upset,reluctance and hesitation may creep in.

It is interesting to remember that during Egypt Air's suicide flight,the Captain remarked "Pull with me".He knew(because he could plainly see) what the FO was doing at all times.

[ttcse]

Chaser, review the photo of the Perpignan A320 on page 50 of this thread. Note the lack of large floating debris to be picked from the surface. Review the Armenian Airbus crash off Sochi into the Black Sea from a very low altitude and relatively low speed (much less than cruise) during a go-around in weather. Note the difficulty finding and retrieving floating debris.

RWA as far as any of us know, the signals ended either because the aeroplane had either dived straight down into the sea (at a descent rate of the order of 8,000 feet per minute) in that four-minute period, Few or none of those who know would believe this flight dove straight down (all the way) into the sea.

[RuudA]

The Brazilian Air Force released information on 9 June showing that bodies from flight af447 had been recovered from locations that were more than 50 miles apart.

This two finding locations can be explained by a broke up in flight (see the New York Times 11 June) but can also be explained by the influence of the surface current: the Northern South Equatorial Current (NSEC).

This NSEC current is a westward flowing current that extends from the surface to a nominal depth of 100 m. The westward flowing NSEC is situated between 1°N and the SEUC at 3°S-5°S.... Its velocity rarely exceeds 30 cm s-1. This velocity is also confirmed by the Brazilian Navy on 11 June: "the maritime current has changed from North to a Westerly direction, with a speed of around 1,1 kilometers per hour".
This western current is also influenced by the wind. The wind was on 1 June also from the east ( see the detailed meteorological analysis of Tim Vasquez)
So we can assume that the surface-current was about 25 km per day from east to west

The AF447 tailfin was found at 8 June. So this fin traveled 8 days with the NSEC current about 200 km (= 8 x 25 km).
If you want to find the impact-location of the tailfin then start on the finding location of the fin and follow the NSEC.
So it is reasonable to assume that the impact-location will be about 200km ( = 2 degrees) more to the east then the finding location.

This drift of 200km from the impact-location to the finding-location can also explain why on two locations bodies were found.
On the impact-location the surface-currents are diverging. The south-part is going west-northwest and the north-part drifts more to the north.

http:///img.ruudabeln.nl/af447impact.jpg


You can see this surface-currents at: The North Brazil Current (http://oceancurrents.rsmas.miami.edu/atlantic/north-brazil.html)

So if the plane made debris on two different moments, then small differences in time (or place) at the impact location can give after 8 days bigger differences at the finding locations.

The next scenario gives an explanation of the two separated debris locations:
Assume that the impact started with a tail-break and the first loss of bodies and debris from the tail-section (this explains the finding of the crew container, the laval door and jumpseats).
Then some moments later during the sinking of the plane a second wave of bodies and debris was going to the surface. From this second location there can be a debris-trail from the impact-location to the second finding-location.

The consequence of an impact location 200km eastwards of the finding locations (or Tasil) is that the plane was 200km in the air after the last ACARS messages.

[iakobos]

Stuff like BGAN only does around 400kb/s. Even modern platforms such as "SPACEWAY" only get up to 30Mbps.

Believe me, it's going to be a looooong time before you see 400Mbps coming from a satellite

This is an operator's choice with respect to its business case, not a technical limitation by the satellite.
The bird carries 30-40 transponders (Ku band), each has a bandwidth of about 50MHz.
A 50MHz pipe, with compression, can deliver very high speeds....but there is price to pay.

BGAN tops at 512kbps (IP mode).

[The Chaser]

ttcse

Agreed!

1. The XL Fuselage was intact on impact (all inertia contained) Correct???
2. The Armenian Fuselage was intact on impact (all inertia contained) Correct???

Thus my view that:- The small amount of debris (and its condition) recovered is suggestive of ejection (likely at high altitude and high speed) without high speed destructive impact with a solid surface such as other aircraft structures and/or the surface/water

[ttcse]

Chaser Thus my view that:- The small amount of debris (and its condition) recovered is suggestive of ejection (likely at high altitude and high speed) without high speed destructive impact with a solid surface such as other aircraft structures and/or the surface/waterI wouldn't argue FOR a high-speed impact. But you might also consider that this debris could have resulted from airframe subsections breaking upon impact at less than a high speed. Keep in mind we have no clue the condition of debris which sank.

If the aircraft largley disintegrated at altitude I would think many more floating items would be found.

[flyblue]

There is also the orange/red pharmacy box. One of a number on board, placed close to an F/A position.-The orange one is the Doctor's kit, and there's only one on board, stowed in proximity of door 2R. The FAK which are near the CC stations are clear plastic, and none is in the pictures.
-The 2 jumpseat could come either from doors 1 or 4. There are twin jumpseats at each of these locations (my bet would be doors 4 for the ones in the pictures by looking at the wall partition they are attached).

[The Chaser]

ttcse

Again agreed!

There are other examples (beyond the two you cite) where an intact airframe has structurally failed on impact with water at various speeds.

The thing that sticks in my mind (although I would be happy to be challenged as an open mind is critical in such circumstances) is that most all structurally intact fuselage's retain most of the items within during impact save for the odd bit of non-structural cowling doors etc. Sure, some small unsecured items onboard might be ejected intact through fuselage breaches during deceleration and remain largelly undamaged. I would at first glance (and that is all it is at this point) suggest an almost complete unoccupied (seats) partition bulkhead would not fit this description, nor is the reported condition of those found.


I agree that if the fuselage has been breached at altitude (for whatever reason), it would have to breach in a fairly localised fashion for this type of debris footprint, which is possible of course, given the first breach will have to deal with the pressure differential outflow if it occured at high level. The remainder of the fuse may have remained intact, or, later in the sequence (under torsional loads) breached in other locations.

[Captain-Crunch]

Although a different aircraft, the leaked Adam Air loss of control CVR can give us some idea of how fast a Jet upset will take. Do not listen to this tape unless you have a strong stomach. It very sobering. It's authenticity is disputed, however, it matches exactly the accident sequence discussed on the Adam Air thread at pprune. Start it about 2/3 through. The cricket sound on Boeing is the overspeed Mach warning (crowding supersonic.) The key event is the audible "bank angle" heard over the cockpit speakers. This would be an excessive bank over thirty degrees at high altitude. From that warning, and the subsequent overbank and dive, it takes 50 seconds before the airframe fails with a small crackle followed by a loud thump (likely main wing spar failure). Then 20 secs of disintegration. The increased wind noise (louder than barberpole) in the background is something I've never heard before in a jet. And never want to.

YouTube - Takbir Pilot Adam Air (http://www.youtube.com/watch?v=qESY8q99ClE)

The reason for posting the link, is so you can have some kind of idea just how dangerous it is to loose either flight controls or flight instruments at night. Also you can see why a lot of us suspect a dive followed by a break up at mid-altitude before sea level.

CC

[Dan Air UK]

RWA My question was, could the fact that (as far as I can tell from the transcripts) the ACARS (sorry for the acronym http://static.pprune.org/images/smilies/smile.gif) messages appear to have come in batches about one minute apart mean that the aeroplane was bucking about a fair bit and the aircraft antenna kept 'losing its line' and having to line up and' re-connect again?I am sure others may have mentioned this before, but it is probably worth mentioning again, that the timestamps on the ACARS messages relate to the event time and rather than the transmission time over the satellite. The messages may indeed be batched if they have the same transmission priority and the interval between batches will depend of the data rate the A/C is using (600, 1200 or 10,500 bps). From the incomplete data that I have seen, it is clear that SATCOMS transmissions are regular and consistent with an A/C that is tracking the satellite reasonably well up to the last transmission at 02:14

[Chu Chu]

I'm not sure we can assume that water bottles would rupture on depressurization. They handle the pressure drop from sea level to 8000 feet (about 4PSI) without any obvious stress. 8000 to 30,000 feet is about another 7PSI. It's by no means unlikley that the bottles that can handle 4 PSI differential would rupture 11. But it's not self evident either.

In fact, if you've ever made a "rocket" from a 2-liter soda bottle, you'd know you can pump several atmoshperes of air into it with a bicycle pump without rupture.

[RWA]

[quote] "From the incomplete data that I have seen, it is clear that SATCOMS transmissions are regular and consistent with an A/C that is tracking the satellite reasonably well up to the last transmission at 02:14."/QUOTE]

Many thanks, Dan Air UK. Can I take it that your opinion (as someone who genuinely knows a lot about satellite communication) and mine (as no more than a 1960s 'seat of the pants' light aeroplane pilot) largely coincide?

That the aeroplane was under reasonable control (flightpath-wise) for plus or minus four minutes. And then 'blacked out' - among other things, losing all communication with the satellite. Suggesting either a catastrophic systems failure or an 'Extreme Flight Path Irregularity' - like the aeroplane standing on its nose and heading for the deck at Mach. speed?

[Will Fraser]

RWA Everything depends on the provenance of the ACARS copy and the lack of additional similar information. If the transmission terminated at the top of page two, and there is no more, it would tend to support a theory similar to yours. 'Absence' of evidence is not 'Evidence' of absence. The data is proprietary, AF has behaved 'erratically' (my term) in this event.
Who knows?

[ClippedCub]

In fact, if you've ever made a "rocket" from a 2-liter soda bottle, you'd know you can pump several atmoshperes of air into it with a bicycle pump without rupture.

Good point Chu-Chu. Looked it up, the 2-liter soda bottles are good to 50 psi.
Cabin differential pressure at 35k ft is 9 psi. Can't be as confident as before, but those clear water bottles in the photo are more flimsy than the 2-litter ones. Might do a little experiment in the hangar later.

[HarryMann]

The other 'news' is that (since the FDRs of the time recorded pedal movement and rudder movement, but were not able to 'say' whether the pedals moved the rudder or vice versa) AA587 may well not have been pilot error at all.

1) I find that very hard to believe... low frequency flutter on powreed controls?

2) If true, then where are the ADs? A very serious problem indeed with immense ramifications, which surely couldn't be covered up - requiring fundamental control system redesign.

1) & 2) taken together make it sound more of a conspiracy theory - so solid evidence please

[deSitter]

Something that has to be considered now is the simple failure of the aft pressure bulkhead as in JAL123. That could certainly knock the tail section off.

-drl

[Longtimer]

In particular, the vertical stabiliser is missing from the items being displayed. Simply because it has not yet made it to land or was it withheld from the display for some reason?

http://www.pprune.org/4994299-post1367.html

[daikilo]

As far as I am aware, no cabin seats are attached to the aft bulkhead. In my opinion the seats photographed may have come from the front face of the right-side aft galley or from a left-hand partition such as at door 2 or 3. I do not know the precise AFR configuration for cabin attendant seats.

[tubby linton]

General seating chart for an AF 332:
http://www.airfrance.fr/common/image/PlansCabine/fr/A330200_nev_219pax_maxi_fr.gif

[daikilo]

... or door 2 rh but probably not door 3 lh.

[RWA]

1) I find that very hard to believe... low frequency flutter on powreed controls?

2) If true, then where are the ADs? A very serious problem indeed with immense ramifications, which surely couldn't be covered up - requiring fundamental control system redesign.

1) & 2) taken together make it sound more of a conspiracy theory - so solid evidence please

I'm sure that no offence was intended, Harry Mann. Nor was any percepted. But I'm not in the habit of telling lies, or even 'inaccuracies', on the Net or anywhere else. And I'm sure that you feel exactly the same.

The rudder controls on AA587 were conventionally-linked. No Airbus-style FBW..........

Please read this whole NTSB report through. And then get back to me, and we can have a fully-informed discussion. :)

NTSB Abstract AAR-04/04 (http://www.ntsb.gov/publictn/2004/AAR0404.htm)

[Yaw String]

Rob21,
Interesting point. I all my many years of transatlantic crossing it has always been difficult to get 2 particular carriers to talk on 123,45 on 128.95 to discuss anything pertinent, ie, turbulence, or levels they will be requesting for onward planning purposes.
Those carriers are Air France and Lufthansa.
Don't know why...and this is my personal experience only. I always thought it to be because I am a pom!

[justme69]

As previously reported, there were indeed other airplanes nearby, even in the same route.

Closest one was Iberia IB6024 (A340-300) which took off 7 minutes after the AF to a (geographically) similar destination on the same route. They briefly saluted and chatted with the AF crew while getting the flight ready earlier in the airport.

Press reports IB pilot declaring: "We flew about 10 minutes (~80 miles) directly behind the AF, at 35000'... being monitored by TCAS, noticed bad weather ahead and decided to deviate from it an unscheduled 30 miles to the east at about the same time the AF dissapeared from the radar forever..." They never had visual contact. They never picked up any transmissions from the AF around the time the accident is believed to have happened in any of the open frequencies.

He heard the repeated attempts of brasilian traffic controllers to contact the AF after its dissapearance from radars all the way to the entrance to Senegal air space". Iberia flight was totally uneventful otherwise, with nothing unusual about the weather etc (except that there were indeed patches of bad weather around the area at around that time worthit of circunvention).

[CONF iture]

Press reports IB pilot declaring: "We flew about 10 minutes (~80 miles) directly behind the AF, at 35000'... being monitored by TCAS, noticed bad weather ahead and decided to deviate from it an unscheduled 30 miles to the east at about the same time the AF dissapeared from the radar forever..."
Maximum range for the TCAS to display a target is only 40 NM ...

[jcarlosgon]

"Maximum range for the TCAS to display a target is only 40 NM ..."

The airline I fly for has five A330s (sn 800s and 900s) that show TCAS targets up to about eighty miles ahead and about twenty behind.

[rmn_76]

Hi RWA

At the risk of being completely wrong...

I don't think that the rudder would feedback force to the pedals. Even in a non FBW plane this big the controls are moved by hydraulic actuators. The pedal force feel is artificially generated (by the artificial feel box or Q-feel box) which simply converts a pedal position and dynamic pressure into a force.

On another point about composites, when I was at Airbus working on VTP structures we always used hot/wet testing (both heat and moisture degrade composite structural properties). I don't know about the fatigue work as I wasn't involved but I don't think it would have been done differently. Thats not the same as fluid getting into a sandwich structure, as with the rudder failures, which is a more serious problem.

[CONF iture]

Ok, I didn't know that.
But I'm not sure that the IB A-343 are that new ?

[flyblue]

The twin jumpseats are located
-FWD, near L1
-AFT, at the far end of the back galley. You could say they mark the end of the cabin.

[Pontius Navigator]

The Brazilian Air Force released information on 9 June showing that bodies from flight af447 had been recovered from locations that were more than 50 miles apart..

. . can also be explained by the influence of the surface current: the Northern South Equatorial Current (NSEC).

This NSEC current is a westward flowing current that extends from the surface to a nominal depth of 100 m.

As I tried to post before, but it was deleted, the surface current moderated by the wind, will account for a significant distance between the point that debris entered the current and the point at which it was found.

The significant point in RuudA's post is surface. Debris is more likely to be released from the wreckage as the aircraft descends and breaks up at depth. Such debris will be affected by sub-surface currents until such time as it rises to the surface current zone.

There is no guarantee that all sub-surface release will occur at the same time or the same depth. It is as likely that the debris spread is from sub-surface release as from an airborne breakup.

PS, I believe this post-crash surfacing of debris was a feature of a RNlN Atlantic aircraft about 30 years ago.

[pattern_is_full]

It seems to me that where these threads go wrong is when someone fixates on a single fact.

A single fact can disprove a theory, but it can never prove a theory. And a theory is only viable when it accounts for all the facts known.

An example: It was noted previously (multiple times - I'm not specifically responding to the immediately preceding posts) that the dispersal of the remains is not firm evidence of an in-flight breakup, because ocean currents could also play a role in the dispersal, or even account for it completely.

As far it goes that is reasonable. But it ignores other reported evidence - e.g. ocean currents do not account for the reports that some victims had all clothing ripped off, or had ceased to breath by the time they encountered water (no water in lungs).

But those other data points themselves do not "prove" in-flight breakup either. Other explanations are still open.

We have pictures of a VS no longer attached to the rest of the aircraft. A data point. I see no evidence one way or the other as to when the VS ceased to be attached: At 35,000 ft? At 15,000 ft? At 0 feet?

I see a VS in which the failure point appears to be in the aluminum-alloy supports, not the composite structure - but am perfectly prepared to be corrected on that.

As far as I'm concerned, there are only four clearly established facts in this tragedy: The plane departed radar range, the flight was in the vicinity of tropical convective weather, a series of maintenance/failure messages were sent, and remains have been found on the ocean.

What occured amidst and between those knowns is still a very large black hole bespeckled with a few dots of light.

[Will Fraser]

flyblue
I originally thought the two jumpseats were attached to an aft bulkhead (structural or otherwise) because of the seeming reduced radius apparent at the perimeter of the curved joint with Fuselage inner skin. If the structure's termination in a straight line adjacent the 'inner' seat is a 'passageway', it suggests a narrow (overall) width. The Fuselage forward does not reduce its diameter until forward of where the jumps would be.

Also, in observing the belts, it is possible they were 'adjusted' by recovery personnel, although one is doubtful that pros would in any way alter the appearance or the ability of evidence to tell a story when closely examined. I think they were well aft and near the pressure vessel's aft terminus.

[HarryMann]

e.g. ocean currents do not account for the reports that some victims had all clothing ripped off

You haven't been back-reading the posts lately, have you?

[Pontius Navigator]

We have pictures of a VS no longer attached to the rest of the aircraft. A data point. I see no evidence one way or the other as to when the VS ceased to be attached: At 35,000 ft? At 15,000 ft? At 0 feet?

Or sub-surface breakup either.

[pattern_is_full]

Harry: Well I've been trying - sometimes Pprune outruns me... (edit) have double-backread everything now - not sure what your point is?

Pontius: true.

[flyblue]

Will Fraser,
the twin jumpseats FWD have the CIDS located above them. That's why I'd say the ones shown are AFT. There doesn't seem to be a trace of the CIDS on the pictures, although it is impossible to be sure without a close examination, the pictures are not clear enough.

[Airbubba]

Maximum range for the TCAS to display a target is only 40 NM ...

Iberia was probably tracking AF447 on the CDTI on ADS-B which will show aircraft well over 100 miles away.

[justme69]

Maximum range for the TCAS to display a target is only 40 NM ...


Well, the press report is ambigous (for a change), but I also did see the Iberia pilot interviewed in a TV program.

The recap, this time in my own words is:

-They took off 7 minutes later on the A320 to follow "dead on" the tail of the AF 330

-At some point, they had TCAS contact and the captain had an eye on it to monitor, as they were sharing the route and fairly close.

-The Iberia pilot believed the AF was about 80 miles dead straight ahead when he noticed bad patch of weather coming and decided to start a change in the scheduled course and turn east some 30 miles to circunvent it (potentially leaving the AF, around 8 minutes ahead, in a course to go through this rough weather patch). He believes this coincided almost exactly when the moment the AF went "missing".

-The Iberia pilot wasn't really "afraid" for the AF when they weren't answering ATC figuring perhaps they had a transporder/communication problems as, in his opinion, there was nothing unusual at all with the weather or circunstances around the area, in spite of some "normal" rough patches. He was surprised to later find out the AF had likely crashed as he couldn't figure out a situation with such high risk of accident (at all), in spite of occasional bad weather spots. He insists circunstances were well within, and even "below", normal for the route, while not "perfect" or "great", but not unusually bad or even "strong". Just plain old bad-ish. Certainly nothing in his opinion to warrant a high risk of accident. Of course, he wants to make clear that, in the aprox. 8 minutes that separated them, the weather could've changed quite a bit as it's unpredictable, but he just can't believe it could've turned so bad as to endanger the AF to the point of catastrophy, but with the weather, everything is, of course, possible.

FWIW

[Airbubba]

Possibly not probably, and easy enough to find out.

Well, then, go find out for us and report back.:ok:

[Airbubba]

Good point Chu-Chu. Looked it up, the 2-liter soda bottles are good to 50 psi.
Cabin differential pressure at 35k ft is 9 psi. Can't be as confident as before, but those clear water bottles in the photo are more flimsy than the 2-litter ones. Might do a little experiment in the hangar later.

Another aspect of the water bottles is that many flight attendants intentionally don't tighten the caps when they are empty. If you do, you get an uncomfortable crackling sound as the cabin descends and bottles collapse.

Not sure you can tell much either way from the condition of those bottles. They may have been emptied at altitude, had tightened caps, partially collapsed at sea level and popped back when opened after recovery.

[ttcse]

PatriciaG
Just asking. Interesting item. Thinking human factors, I'm also interested in whether people who are in a broken & tumbling aircraft would, for some reason based on primal instinct, unlatch their safety belt. I know people who jump from great heights and start to tumble have a natural overpowering urge to reach out for something to stabilize them. To unlatch their safety belt would position them to be more effected by air and water currents.

Maybe all people, falling over land or sea get stripped by the air pressure or later by the ocean.Harry Mann referred to analysis of the Comet breakups where they concluded wave action was responsible for (at least some)clothing removal. I never would've considered that before but thinking of how my water-saturated-loostened-weighted clothing behaved when I swam with clothes on, it sure clicks with me.

As to whether clothes could be removed by decompression, my personal experience with only 'rapid' decompression in an altitude chamber says no-way. As for explosive decompression and airframe breakup you MUST refer to other accidents (at altitude over dry land) where that would have been the dominate possibility and what the outcome was.

We do have a case of rapid-or-explosive decompression of a B737 near Hawaii where a flight attendent was pulled from the cabin. I saw the photos of passengers after landing and saw NO EVIDENCE or remarks of clothing removal.

[grizzled]

Pattern is full - What Harry is saying is that (prior occurrences and research have shown) there is no correlation to the remains being "clothed / unclothed" and the height (if any) from which they fell. Especially after many days in the ocean. In additon to the comments immediately above this, there are (or were) posts early in this thread discussing this point and citing sources.

All who are wondering about seatbelt positions, bottles being crumpled or not, and other thoughts related to "condition": If (and its a big "if") the people who first came into contact with items from AF447 were properly trained (or at least briefed) then many photos of each item will have been taken prior to any contact by human or machine (if at all possible). Having said that, even if it was done, in some cases it will be of little or no help, but in others it often turns out to be useful.

[Airbubba]

Will be astonished if the searchers touch anything on those debris..as they are evidences ...
They had certainly be briefed for not disturb any pieces of evidence..


I agree they shouldn't do much to the debris but the items displayed in the photo op seem to have been carefully cleaned and dried for display.

[Pontius Navigator]

I agree they shouldn't do much to the debris but the items displayed in the photo op seem to have been carefully cleaned and dried for display.

as in - no salt stains.

[emil011]

Quote from Aviation Herald:

The FAB said on Jun 13th, that a merchant ship "Gammagas" on the route from Uruguay to the United Kingdom discovered and recovered the rugged structure of the aircraft about 415km northwest of St. Peter and Paul.

[Rob21]

Thanks Yaw String, Justme69 & Slotpolice for your inputs.

Wouldn't be "normal" the IB pilot try to call AF447 on open freq to advise that control is trying to reach him? Specially that control began its calls at almost the same moment AF "disapeared" from his TCAS display.

Would be important to know more about this a/c that was ahead of AF447, if he heard control calling AF 447, if he heard Iberia's deviation report...

[ttcse]

cesarncMakes one wonder on the decision discrepancy. One thought he should circunvent, the other didn't... I'm not saying the AF crew did something wrong, though... You must be there to know what's going on....But... it makes you wonder.A set of people, even when exposed to precisely the same conditions would do different things. These crews weren't exposed to precisely the same conditions.

[pattern_is_full]

ttcse and grizzled: Thanks. So we're still left with far too few dots to connect into a picture yet.

[ttcse]

pattern_is_fullttcse and grizzled: Thanks. So we're still left with far too few dots to connect into a picture yet.I see multiple vague possibilities but haven't heard of cookies or free jump-seat tickets or public recognition ceremonies being offered to the person who makes the first correct guess.

[barit1]

The FAB said on Jun 13th, that a merchant ship "Gammagas" on the route from Uruguay to the United Kingdom discovered and recovered the rugged structure of the aircraft about 415km northwest of St. Peter and Paul.

Photo of recovered wreckage (http://jc.uol.com.br/canal/voo-447/noticia/2009/06/13/peca-do-airbus-foi-resgatada-por-navio-de-antigua-e-barbuda-190548.php)

[grizzled]

pattern is full

Exactly! (re connecting dots)

Even after the FDR and CVR are found, recovered and analysed (which I believe will happen) and even if much of the aircraft itself were to be recovered, connecting the dots will still be a very long, tedious and expensive process. And, in the end, some of the lines will likely remain forever dotted (best guess) as opposed to solid (factual).

[HarryMann]

Recovered structure (http://jc.uol.com.br/canal/voo-447/noticia/2009/06/13/peca-do-airbus-foi-resgatada-por-navio-de-antigua-e-barbuda-190548.php)

Is that looking quite like a part of the HS?

[VIE_PAX]

The German newspaper "Der Spiegel" (normally a quite seriouse and trustworthy paper) now reports on the results of the first postmortem examinations. According to pathologists, the findings indicate that the plane broke apart in the air. No traces of fire / explosions could be found. Also no water was found in the lungs of the deceased. The detailed article can be found here:
Air-France-Absturz: Erste Obduktionen geben Hinweis auf Unglücksverlauf - SPIEGEL ONLINE - Nachrichten - Panorama (http://www.spiegel.de/panorama/0,1518,630330,00.html)

Being not a pilot but a frequent (sometimes to frequent for my share) flyer, have there been cases of planes (speak wide-bodies) disintegrating mid-air due to turbulences?

Cheers,
VIE_PAX

[connector]

Strange display, that shows you 2 different ranges in TCAS. must be confusing.

[wilyflier]

Following comments off the cuff and all deletable
Todays report of rugged item picked up by freighter 400 km away
Photo seems to show a crewmans foot to give scale
Item about 1 metre x 3 metre
Cross section is tapered like an aerofoil,
But surfaces look planar with a slight "hard chine bend"
Could be a door , some sort of control surface , flap , or an internal
longitudinal structure.
It looks (by coincidence of dark background of ship structure) as if
the panel is translucent
400 km a long way away
Reports exist of several fatal European CB encounters by paragliders,and hang gliders finishing, up to around 100 miles from where they entered cloud Frozen solid and asphyxiated.Could light broken parts of aircraft expect to be scattered by CB in the same way
I was informed one time of giant hail/ very large lumps of ice falling from a storm in South Africa required a calculated 300mph updraft to support them during build up accretion
Chillyflier

[PJ2]

Harry - not sure where my post went - I may have deleted it when adding the photos, now found below, of the spoiler panel.

I offered my thoughts on what the recovered parts on display were, which is new information - the most interesting parts I think are the two, intact overhead bin covers and the doctor's kit.

We cannot say anything from the photos about the F/A seatbelts. It's not from L1 where the CIDS is as there are no traces of any such displays or equipment on the bulkhead in question. It could be from any section - we just can't say.

"wilyflier";

It's a spoiler panel from one of the wings.

The torn section in the center is where the hydraulic cylinder that extends the spoiler is attached. The attachment points to the rear spar wing structure can be seen at either end.

http://i277.photobucket.com/albums/kk76/batcave777/img_6a.jpg


http://i277.photobucket.com/albums/kk76/batcave777/img_5a.jpg

http://i277.photobucket.com/albums/kk76/batcave777/img_4a.jpg

[wilyflier]

Thanks PJ2

How does that 415km northwest of st peter and st paul relate to fin and rudder recovery position??

[Towhee]

FWIW


...At the Lufthansa flight 507 from Sao Paulo to Frankfurt everything seemed to run as planned. The flight was quiet, the stewardesses served the passengers, all was peaceful. Three hours after the start of this suddenly changed, because the jumbo in the midst of a severe tropical storm was advised.

The relaxed atmosphere on board was easy after the first shock apparently soon to panic. After 15 minutes, fought during the 350-ton jumbo with so great turbulence and air holes that passengers are not restrained to the floor and the ceiling were hurled.

A man had his head pushed so hard that he bled heavily. His wound had to be later by a doctor on board are sewn says "star".

Even beverage carts and luggage herumgeschleudert should have been.

"This is something I have on this route has never experienced. We had to claw regelrecht firmly, "the magazine quoted a passenger. Once the worst was over, that chaos prevailed in the cabin: people crying, leftover food and clothes, "everything just a single mash," said another passenger as "star".

How had it come? The pilot was apparently from the strong storms have been surprising. He was in the dark night, the tropical storm cells do not recognize them. Apparently the weather had no radar warning.

Lufthansa: turmoil not only on this route

"Stern" had spoken with passengers, with the horror of it had come, and the horror of the flight case made public today. Lufthansa again mentioned the incident until today - despite only two days later occurring crash disaster AF447 on the same route.

At Horror flight approached, a spokesman relativised Lufthansa Blick.ch from the incident. It had said the turbulence in flight and given a slightly injured. By "flying drinks trolley 'could, however, no question.

The air eddies were flying "of everyday life," said the spokesman continued. And: "Such turbulence is also not just about this area, but on quite a number of routes around the world."

The fact that the weather radar shows the storm does not have denied the Lufthansa spokesman also. "The radar worked and the storm was very well displayed. But that the turbulence in the storm would be so severe, it can also be a radar does not show. "
(gux)...

from: Das Blick, 6 June 2009 (google translation)

[grizzled]

PJ2 wrote: "the most interesting parts I think are the two, intact overhead bin covers and the doctor's kit."

I agree with PJ2. These are examples (IMO) of items that investigators can look at and, surprisingly quickly, eliminate a couple of scenarios (re aircraft breakup). I would add that eliminating some possibilities DOES NOT infer being (lineally) any closer to "causes". It's simply how investigations proceed.

Grizz

[Will Fraser]

It almost appears as the spoiler had been fully deployed when it was torn away. When stowed, it's a fairly firmly rooted panel, and flush to the airflow across the wing. I'm trying to visualize the type of odd flow that would pull it out of the wing while stowed. Looking at the hinged corner failures, it would appear the spoiler failed forward, away from its mount, with the airflow from the trailing edge of the wing flowing forward.

[PJ2]

It's simply how investigations proceed.
Precisely.

Tell-tale marks, including the texture, color of such traces, and the order in which they occurred, are as important as fracture patterns themselves. There'll be a way for AB to determine which spoiler this was and possibly which wing.

[PJ2]

Will;

Re possible air "flow" over the wing... or what other possibly-mechanical force? The attach points are intact, with some small structure attached to one end - cylinder still likely attached to the spar.

[Will Fraser]

PJ2, yes, but the surface skin is not broken, while the underside has a fracture that would suggest forward failure, and the rollers ripped from the rails/attach points. Deployed in normal fashion, airflow pushes energetically to stow the spoiler, the structure is not designed to prevent the spoiler from 'being pulled or forced' forward. It is only a suggestion, but may explain why the fracture is underneath and the attachments are fairly sound.

[ClippedCub]

It almost appears as the spoiler had been fully deployed when it was torn away. When stowed, it's a fairly firmly rooted panel, and flush to the airflow across the wing. I'm trying to visualize the type of odd flow that would pull it out of the wing while stowed.

For constant flap setting, a wing changes load mostly on the forward part with angle of attack. The load on the aft part of the wing where the spoiler is changes very little with lift/AOA, though q increases with speed.

Can't tell if it separated in flight.

[Will Fraser]

I'll be blunt. It appears that if airborne prior to failure, the wing was traveling through the airstream backward.

[ClippedCub]

Will, can see your point now. If they were deployed, and the airplane broke up in fight, then the air would have been coming from behind during the tumble. That could indicate that in forward flight, q wasn't high enough to fail them aft.

[Mad (Flt) Scientist]

I'll be blunt. It appears that if airborne prior to failure, the wing was traveling through the airstream backward.

I'm not sure evidence supports that as an only conclusion.

Without suggesting that this is in any way validated by the picture, IF an aircraft were to (for whatever reason) exceed its demonstrated dive speed and be subject as a result to aeroelastic instability (flutter) of the wing I can imagine all kinds of unusual and extreme loads being applied to parts of the wings. Only someone who knows exactly what damage that part has and also what it would be subject to under various scenarios can identify the most likely cause.

[Will Fraser]

Mad. Of course. I have no conclusions about anything. I certainly don't speak the language of the events during the a/c demise. It is simply what that unfortunate assembly could be implying. Will catch up later. It is reasonably consistent with a possibility the a/c tumbled. They will do that without much tail. Swap ends.

Will

[The Chaser]

Will I would tend to agree. Had the actuator pushed the spoiler up into the airflow (travelling in the designed direction) but above the designed deployment structural speed, there would likely be convex deformation on the upper surface above the actuator attach point, and failure signatures on the hinge attach points.

There are not too many circumstances that would have a wing facing aft into airflow strong enough to do that. That is not to discount the possibility of this having happened as a result of the wing impacting the water trailing edge first.

[dicksorchard]

I never knew just how valuable pathology reports really where in relation to air accident investigations . amazing to think that even when wreckage is very sparse and in some caese never found .

The Contribution a Pathologist could make was dramatically demonstrated during the investigation of British Comet disasters over Mediterranean in 1954. As the wreckage of aircraft was not available, investigating doctors inferred from the autopsies and other simulating experiments, that occupants suffered a violent upward and forward motion and deduced that injuries could be due to explosive decompression. They also showed experimentally the mechanism of injuries due to impact on sea.

[fun123]

Is it a possibility that the spoiler come off through hydraulic water pressure underneath it when the wing or part of it hit the water?

[Chu Chu]

Seems like something as simple as a cartwheel on impact with the water could explain one wing entering backwards.

[Barkly1992]

I have been looking at the last few posts about the spoiler.

I have never commented on any of the crash threads over the years until now although like many I read daily.

The lesson for me in examining all of the hypotheses put up by very well meaning and knowledgeable contributors is that there will always been a host of reasonable explanations until detailed (and microscopic even) tests are conducted in a laboratory.
:O

[fun123]

Most of what is in this thread at this stage is a guess apart from a few factual posts, those that keep complaining about the speculation should give up reading the thread because it looks like it is not going to change.
If you actually read back through a lot of this thread is also made up of people complaining about speculation ??? not sure which is more annoying.

[fun123]

If the spoiler has beed blown forward as sugested then surely it would have a lined mark on the lower fron edge where it hit the wing skin because the hinge point is lower down in the wing. The other confusing thing is that there is also part of the rib or spa attached to it without any of the wing skin attached to them

[SMOC]

For info, the spoiler from the wreckage is the left hand inboard spoiler.

Photos: Airbus A330-243 Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/Emirates/Airbus-A330-243/0437762/L/)

Photos: Airbus A330-323X Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/Northwest-Airlines/Airbus-A330-323X/0600082/L/)

[md80fanatic]

If flaps were extended in an attempted ditching, the bottom side of the spoiler(s) would be exposed to water (if I understand correctly). Could a forceful splash remove the panel and cause damage like we see in the photo?

[pattern_is_full]

fun123 - take a look at the first photograph someone linked to in the post right below yours:

The hinge geometry is such that the spoiler lifts up over the wing surface slightly, so more likely the spoiler would crease (cut into) the wing skin than the other way around if it were forced up by airflow or water impact.

Also note that there is no wing skin under the spoilers - they lie above the flaps when everything is retracted, and over an open hole when everything is deployed. So the structure right there is rather skeletal - a framework for a lot of moving surfaces (albeit strong to carry the aerodynamic forces those surfaces create when they hang out in the breeze).

[D.Lamination]

Here is an article from today's Fairfax papers in Australia:

Plane plunged into water, not exploded: expertsJune 14, 2009 - 7:14AM
Debris recovered so far from Air France flight 447 seems to indicate the jet plunged suddenly into the Atlantic Ocean and did not explode in the sky, Brazilian experts say.

Almost two weeks after the Rio-Paris flight disappeared at sea, former pilot Ari Germano told O Globo newspaper on Saturday that he was "struck" by at least one of the photographs released on Friday by the Brazilian Air Force.

According to Germano, who has written a book about air crashes, the images suggested that the Airbus A330 passengers were caught by surprise and the tragedy unfolded so rapidly that the crew did not have the time to react.

In the photographs, the seats in the crew area were folded with the seatbelts hanging down, which "suggests that the crew was moving about the passenger cabin. If there had been an alert or a warning about a pending risk, the crew would have been seated," he said.

"They did not have the time to do anything," added the former pilot, who also recognised an orange first aid kit that was left intact.

Dozens of pieces of debris recovered by the Brazilian Navy have been brought to an airport hangar in the northeastern city of Recife.

A French navy ship on Friday recovered six more bodies, bringing to 50 the number of bodies found in the wake of the crash of the plane, which went down over the ocean on the night from May 31 to June 1 with 228 people on board.

Captain Ronaldo Jenkins, a security consultant with the National Union of Air Carriers (SNEA), told Globo that he had identified a safety vest and part of the plane's internal covering, which showed no trace of fire or smoke, suggesting no explosion.

"On the photographs published in recent days, where we can see debris from the plane floating in the water and a restroom door, there were also no signs of fire," he added.

AFP



The questionable part is:
In the photographs, the seats in the crew area were folded with the seatbelts hanging down, which "suggests that the crew was moving about the passenger cabin. If there had been an alert or a warning about a pending risk, the crew would have been seated," he said.

"They did not have the time to do anything," added the former pilot, who also recognised an orange first aid kit that was left intact.

I do not think it is unusual for some of the crew seats to have been unoccupied (see wreckage photos a few pages back) since it was four hours into the flight, at night time, 1/2 the cabin crew would have been in the LDMCR crew rest and in the 4 mins (0210-0214) indicated by the ACARS messages they would have probably stayed there. esp if the s/belt signs were on in turbulence.

[Carjockey]

From 'The Times'

Crash jet ‘split in two at high altitude’ - Times Online (http://www.timesonline.co.uk/tol/news/world/europe/article6493728.ece)

[Me Myself]

I'd like to hear what the actual pilots feel about this situation. They have some experience in turbulence. Would turbulence that would toss passengers, food, and food carts around the cabin leave the pilots "steady enough" to assume manual flight control? Should the pilots try to maintain manual control under those conditions?



It would be very difficult to keep control of the aircraft. Lufthansa was very lucky and could have ended in the same situation as AF did.
Keeping control of the aircraft would be a challenge..........if you can still read the instruments that is.
This is why, you are much better off keeping clear of any kind of weather, regardless of time and fuel.
Our american colleagues may be annoying reporting the slightest baby burp over the atlantic.................but it is them who are right. Turbulence and weather are dangerous and a lot or some of us seem to have forgotten that.
I remember a captain years ago when I was F/O who told me about a flight he'd be on over the Andes. They hit one hell of a wave sending their 747 freighter up at 5000 ft / min.............throttles retarded until they hit the same wave on the down way..................5000 ft/ min with throttles burried in the dashboard. The jet system was over the Andes and the captain he was flying with didn't want to take the alternate route ( south ) because he didn't want to " waste " the 15/20 minutes extra flying time. The beauty is that nobody asked him not to !!
As brillantly demonstrated by Tim Vasquez, MSC systems are to be reckonned with.

[The Chaser]

Jo

The problem is at what point do you ensure A/P OFF Automatically if the data it is using is sus?! It would be far more dangerous to allow an A/P system to stay connected if there is any doubt about its abilities as far as correct response.


In this regard, although there are some differences between the big two, the theory is the same, if there is 'probability' of erroneous input and therefore erronious A/P output, disconnect and let the intuitive humans troubleshoot

The old maxim (as far as synthetic flight systems go) "If it looks and smells like a stiff rat, it probably is"

[grizzled]

Mr. Ali Germano is quoted as saying the “aircraft plunged suddenly into the ocean“.

In the photographs, the seats in the crew area were folded with the seatbelts hanging down, which "suggests that the crew was moving about the passenger cabin. If there had been an alert or a warning about a pending risk, the crew would have been seated," he said.”

So . . . Mr. Germano (who has apparently written a book about air crashes) says the fact that the recovered crew seats were apparently unoccupied means there was no warning of an impending risk, i.e. if there was turbulence, or an emergent situation, they would have been in their seats.

Before I decided to post I took some deep breaths; then had a glass of pinot grigio; then waited awhile.

Mr. Germano’s statement, and his logic, are perfect examples of an important point some have been trying to make on this thread -– and on earlier threads related to other accidents. Investigators (be they aircraft accident investigators, homicide cops, pathologists, insurance investigators, or whatever) look at evidence and say “what is this and what does it tell me?”

In this case, if and when it is confirmed, after extensive examination, that the seats were unoccupied at the time of that structure’s failure, then an investigator will note that those seats were unoccupied. He/she will NOT then make any another conclusion as to why the seats were unoccupied (which is what Mr. Germano and others have done). What he will do is ask himself, “What else (if anything) does this tell me?”

In this example it certainly does not tell him that there was “no warning” or “impending risk”. If one did a brainstorming exercise as to the reasons that cc seats might not be occupied, one would of course come up with some benign reasons (as Mr. Germano is thinking). Those could be things like, “beverage or meal service”, “routine duties”, “chatting with pax in the galley”, “resting in crew rest area”, and the like. But, one would also come up with reasons such as, “attending to injured pax”, “answering many button calls from pax for sick bags”, or even “assisting pax with oxygen masks”.

In essence, all we know at this point (re those particular seats) is: the pix appear to show the seats in the stowed position and the seatbelts hanging loose. That, in the eyes and mind of an investigator, does not lead to statements about “plunging suddenly into the ocean”.

[MG23]

You are inside your software box and you do not understand that without proper sensors inputs any software will not work correctly (or at all)...

True, but that doesn't mean that dumping the problem in the human's lap is going to be any safer... a pilot who doesn't know how fast the aircraft is flying may not do any better than an autopilot which doesn't know how fast the aircraft is flying (but could probably estimate it for a while based on altitude, thrust levels, attitude, last known velocity, etc)

I've worked on avionics software myself, and deciding when and how the software should give up and start screaming for a human to fix the problem is not that easy.

[PJ2]

grizz - Glad you posted, Grigio and all - (had the same this eve', nice summer's night here.)

Among the many highly-experienced contributors are a few here who do flight safety work in it's many iterations.

The people who do flight safety work instantly recognize special interests, the stench of political statements and interference from those who pronounce from their title and their office but who know nothing about aviation or flight safety, and the earnest but inexperienced notions about what happened in this or that accident, all harmless enough, but one never learns while talking or thinking of something to say when someone else is talking.

There are a precious but tiny group here who, while not specialists in aviation, are serious in learning about this industry and what makes it tick from the people who do the work. They ask questions here, read widely, listen to others, ponder and mostly remain silent because they know what they don't know.

You are precisely correct in saying, "Investigators (be they aircraft accident investigators, homicide cops, pathologists, insurance investigators, or whatever) look at evidence and say “what is this and what does it tell me?” "

Lotta wisdom in that statement. How was the Pino?

[RWA]

Thanks for that link to the Times story, Carjockey.

This bit looks downright ominous:-

"It has emerged that the same sequence of events occurred in six cockpit emergencies reported by Airbus pilots over a year beginning in February 2008. According to internal Air France documents leaked to the press, the incidents involved “a rather incoherent cocktail of alarms” and “severe breakdowns”. These appear to have originated with malfunctioning pitot tubes in stormy weather.

"In one incident, an Air France pilot issued a mayday call between Paris and Tokyo in turbulent weather after the loss of speed indication resulted in the disengagement of the automatic pilot and set off other alarms. In all six incidents, however, the pilots regained control of the aircraft.

"Air France advised pilots on November 6 last year about the “significant number of incidents” in which false speed readings had confused the automated flight system."

[The Chaser]

grizzled Well said.

JD-EE You ask the most important question above – "does the pilot have any better information?" = That is the question that remains unclear.

We know there is a procedure for the PF to fly pitch and N1, logically for this to happen successfully the PF needs Attitude and Engine data.

Prior to 02h14, there is no indication that engine data/function was irregular, that’s half of the picture, the other is still uncertain. ISIS did raise a fault, however systems experts have suggested that speed rather than attitude may have been affected. It has since been reported that the original ACARS transcript of ATA 3412 ISIS was in error. ACARS ATA 3422 ISIS is considered to be correct - which would indicate an L-gyro problem/indication), so it is possible that the PF did not have any Attitude reference, only N1 until 02h14. Obviously it remains to be seen whether (all things being equal and accurate) that procedure on that particular flight was a reasonable ask, both before and more importantly after 02h14.

What we also know (if the information provided thus far is accurate) is that the Automation decided that the information it was receiving was not (automated decision) sufficiently accurate to continue automated flight.

Hypothetical work through of what I read you to be asking - In the implied (ACARS) flight modes known before 02h14, were the A/P set up so that the PF was required to demand control from the A/P (otherwise the A/P would continue to fly) then the A/P will continue to react based on the data it ‘thinks’ is correct. What would be the A/P driven outcome if (as suggested) some of the speed indication scenarios discussed here were even party true? Would the automation react to chasing speeds, attitude, auto throttle etc in a reasonable and safe fashion? consider that the ‘protections’ would be (in that circumstance) operating on false information as well, in other words no protection at all.

An interesting technical discussion would be one exploring how well A/P and automatics would keep up if it had a ‘fallback’ [ISIS Attitude and N1 cruise] mode available in these sorts of rare circumstances, which is what I am reading your question to be alluding to.

Whether it is a pilot or the automatics, if either/both have no reliable attitude (primary or standby), nor accurate speed data etc, in IMC, the result is likely to be the same.

Good discussion. :)

[4PW's]

There are five official, damning reports on A330 and A340 aircraft operated by major airlines suffering complete failure of all flight instruments in flight. Pitot probes iced up in meteorological conditions at night, by day, in cloud and in clear air.

Each reported incident occured recently, to a point, and all are of great import. On each occassion, the pilots recovered the airplane. You can do that in clear air, with a visible horizon. The AF447 pilots had neither.

What irks me almost beyond words is the guff masquerading as insightful comment about what happened, and why. The authorities love it. Fluff hides the truth, yet the traveling public and readers on this site seem to demand it. All the better to ignore the horror of the reality of getting onboard an Airbus, perhaps.

Few are willing to tackle the real issues, being twofold: The extraordinary failure of the A330/A340 pitot protection system, and how any civil aviation authority continues to allow the types to fly.

Five genuine, reportable, damning, official and utterly honest incident reports written by experienced, major airline crews - pilots who are at the coal face on these types, show beyond doubt crucial failings in the pitot static heating systems of the A330/A340 type.

Yet this airplane continues to ply the airways.

Yes, turbulence exists. Yes, thunderstorms are wonders of nature. Yes, they should at all times be avoided. No, the AF447 pilots were not incapable of knowing these absolutes of flight. No, most of the subjects being discussed here are not useful, not at all. But yes, they are a knee-jerk reaction to the horror of falling out of the sky from 35,000 feet, and are understandable.

The accepted, official reports of job specific inequities in the ice protection pitot system on the A330/A340 series is the real issue. It is what Airbus are desperately trying to buy time to correct. It is what the CAAs around the world need to address. It is what this site should finally, openly acknowledge using previous reports from real pilots who fly these airframes, not what frightened, horrified passengers who have stumbled upon PPRuNe ask of how the poor souls on AF447 died, of whether the airplane broke up, of why the pilots failed to avoid a Cb, of the possible terrorist connection with two known named people onboard, of whether an empty crew seat indicates the flight attendants did not know what hit them; red herrings all, some of them farcical, some innocent, but all of them as red as the anger in my face.

In aviation, as in life, failure to identify the root cause of a problem is to see it repeated. I don't, for the life of me, know how anyone can buy an air ticket without first asking if the flight will be on an A330. Oh, yes, that's how. We keep the information hidden. We damn those who try to raise the failing of the type by not just ridiculing the messenger, but the pilots of the doomed flight.

But what would I know? I'm only a pilot. And these are only official reports. :ugh:

[Mercenary Pilot]

Why don't we wait to find out what actually caused the crash before following a knee jerk reaction and calling for the grounding of the world wide fleet.

The pitot probes changes have been stated as precautionary and until evidence proves otherwise that's what it is, a sensible measure.

While I am very surprised (shocked) that a modern airliner could have icing problems with the pitot system I am still not ready to accept this as the cause just yet, especially as the investigators are infering that the aircraft broke up in flight.

[Dysag]

According to Boeing's figures the 747 Classic has the second-highest hull loss rate of all wide-bodies, behind the DC-10/MD-11.

I presume you wouldn't dare to get on one of those, then.

[norodnik]

for God's sake, get a life. (in reply to 4PW)

The Bus has been flying for years with very few incidents that have resulted in loss of life and/or the aircraft itself.

Everything man made has faults and the idea is we examine the faults to try and make sure they get fixed and don't happen again.

If you want to frighten yourself reading every AD that has ever been issued/is outstanding or everything that has gone wrong without explanation then you'd never get out of bed.

Quite frankly, with comments like yours, I'm amazed you're a pilot (or maybe you just fly the sims ?)

[cirrus32]

On another point about composites, when I was at Airbus working on VTP structures we always used hot/wet testing (both heat and moisture degrade composite structural properties). I don't know about the fatigue work as I wasn't involved but I don't think it would have been done differently. Thats not the same as fluid getting into a sandwich structure, as with the rudder failures, which is a more serious problem.

Fatigue testing is usually done at room temperature ambient conditions with a LEF (Load Enhancement Factor) to account for hot/wet / cold conditions. LEF is usually around 15% for most composite structure.

[Nightrider]

We have a lot of theories, a lot of speculations, some evidence. I am not going to speculate in any direction at all.
What is a little puzzling, at least in my view, there appears to be an "accumulation" of incidents with unreliable airspeed, instrument loss etc.

Did someone establish already the timeframe when these occurrences started to happen in more closer, time-related, manner?

Once this date is known (a rough approximate will do) the next question will be, what was changed in the AB system, and here I mean the electronic bits and pieces, the computers, the software, wiring etc; I also ask for the air system, the pitots, the static ports, the tubes, trapped water releases, all this sort of things.

Our flying offices are constantly "upgraded" to enhance safety; sometimes this implies even removing of items as they are not seen necessary anymore.

The reason I am asking all this, and some colleagues may have experienced the same over years, there are airplanes around which during design state had a certain recommended configuration for individual flight phases; after several "incidents" the once recommended procedure / setting / part was altered / prohibited or even removed.

[teropa]

Sorry for soundling like a broken record:

Does anybody know, if the AF A330s are equipped with the Backup Speed Scale (BUSS) package?

rgds,
Tero

[PPRuNe Towers]

Here's a thoughtful piece from Prof.Peter Ladkin:



A list of the 24 ACARS messages listed by Air France that were sent from AF 447 between 0210Z and 0214Z on 1 June, 2009, the last information received from the aircraft, was shown on the France 2 TV channel on Thursday June 4. This list, in which incomplete information was shown, was typed up and distributed on the Internet (one must beware of typographic errors in the various versions which I have seen). Thus people started to interpret the messages and inquire about their significance.

I take it that people know what “reading tea leaves” means? Fortune tellers would look at the pattern of leaves left in the cup after the tea had been drunk, and wondering what they say about the future. Similarly, people (including myself, here) have been looking at the (partial) ACARS messages shown on the TV, and have been wondering what they say about the past. I adduce the comparison to propose a healthy dose of scepticism about what one can validly conclude from the currently publicly-available information.

The messages were listed in the following order (omitting messages which consist of maintenance warnings). The four-digit numbers are the Joint Aircraft System/Component (JASC) code, which I interpret from the FAA JASC Table and Definitions Document from February 11, 2002, which is on-line.

* at 3.5 hours before the main events, a 3831 event. Something concerning waste disposal (38 is water and waste, and 3830 is the waste disposal system)

* at 0210, a 2210 event: AP off (22 is Auto Flight and 2210 is the Autopilot system)

* at 0210, a 2262 event (22 is Auto Flight; I have no code 2260)

* at 0210, a 2791 event, flight control switch to alternate law (27 is flight controls; I have no code 2790 or 2791)

* at 0210, two 2283 events, flags raised on CAP and FO Primary Flight Displays (PFD) (22 is Auto Flight, I have no code 2283)

* at 0210, a 2230 event, autothrust off (2230 is the auto throttle system)

* at 0210, a 3443 event, a TCAS problem (34 is navigation; 3443 is the Doppler system. The Doppler system here is used to measure relative motion of another body, in this case another aircraft, for TCAS).

* at 0210, two more 2283 PFD flags

* at 0210, a 2723 rudder travel limiter fault (27 is flight controls, 2720 is the rudder control system). At higher airspeeds, the rudder travel is limited by the Rudder Travel Limiter; far less movement is allowed than at lower airspeeds.

* at 0210, a 3411 event with EFCS 2, reported by EFCS1 (3411 is the pitot/static system. I understand that on these airplanes, the system is divided into the pitot subsystem and the static subsystem).

* at 0210, a 2793 event involving EFCS 1. (27 is flight controls. I understand from colleagues that, on the A330, 2793 is the Flight Control Primary Computer, FCPC, also designated PRIM)

* at 0211, a couple more 2283 PFD flags

* at 0212, a 3410 event. A disagreement between the air data units, the AD part of the ADIRU (34 is navigation; 3410 is flight environment data). An “ADR disagree” can only occur when one of the three ADIRUs has already been designated as faulty by the FCPC, and the two remaining ADIRUs yield discrepant readings (this information from the Aircraft Operating Manual of the A330)

* at 0212, a 3422 event in the standby flight instruments (ISIS) (34 is navigation, 3422 is directional gyro and indicators)

* at 0212, a 3412 event involving IR2, the inertial reference part of ADIRU2 (34 is navigation; 3412 is the outside air temperature sensor and indicator). Reported by IR1 and IR3 and EFCS1.

* at 0213, two 2790 (EFCS) events, FCPC 1 and Secondary FCC (FCSC) 1 faults (27 is flight control; I don’t have the 2790 designator)

* at 0213, a 2283 event, reported by FMGKC1 (22 is autoflight, I understand from colleagues that 2283 is the Flight Management and Guidance Computer, FMGC)

* at 0214 a 2131 event (21 is the air conditioning, 2131 is the cabin pressure controller).

What about the ordering of these messages? First of all, they are time-stamped by the minute, so that orders them into five groups (the 0210 messages, respectively 0211, 0212, 0213, 0214). What about a finer ordering? That is going to be much harder. We don’t know whether this listed order is the order in which the messages were received (but Air France can probably tell us that). We don’t know whether the order in which the messages were received were the order in which they were transmitted (but maybe there is something in the code that can tell us that). We don’t know whether the order in which they were transmitted is the order in which they were generated (maybe Airbus can say something about that, but there might also be some indeterminacy). And, finally, we don’t know whether the order in which they were generated is the order in which the events occurred (that may be hard even for the manufacturer to say, because the rates at which values are sampled are very different, depending on the system).

For the purposes of a speculative interpretation, let me assume here that the events occurred in the order listed above. I do caution that this is quite a significant, and not necessarily correct, assumption. Let me further assume that the messages are veridical. For example, that the “ADR disagree” message really does indicate that the FCPC has ignored air data input from one ADIRU and is judging that the air data input from the other two are not consistent with each other. How significant this assumption is depends on whether one is a sceptic or an optimist about the reliability of these highly complex programmable-electronic systems and one’s trust in their design.

So here goes. The AP went off and flight control went to alternate law. Flags pop up. Autothrust disconnects, something with TCAS and then two more flags. Rudder travel limiter has a problem and then something with the pitot-static system that the EFCS’s have problems with. Sometime over a minute later we are told that the air data from one ADIRU has been designated unreliable by the FCPC and the air data from the other two disagree. Then the laser ring gyro in the ISIS complains, as do the primary and secondary flight computers (these systems are duplicated: it is the number 1 units of each that are complaining), something happens with the FMGC, and then there is a cabin pressure warning.

Why might AP go off and flight control go to alternate law? One possibility is (1) you’re being severely shaken around, or (2) for some reason the AP couldn’t maintain altitude. Another possibility is that (3) there was a system problem. Then the autothrust (AT) goes off. That would happen if, for example, that auto flight systems cannot maintain stable air speed (AS) and altitude. I don’t know what the TCAS notification would signify. Then there is a rudder travel limiter fault. That device has AS as input, so maybe there is an issue with AS sensing. Then EFCS1 thinks EFCS2 has problems with pitot-static sensing. The pitot system colludes with the static system to measure AS, and the static system is also used to measure altitude. Then EFCS 1 complains about FCPC (I take it that would be FCPC 1, also known as PRIM 1). Then two of the three remaining air data units disagree and can’t reconcile (we don’t know when the first was voted out by the FCPC 1). At a similar time, the DG in the stand-by flight instrument system complains. At a similar time, the inertial reference part of ADIRU 2 is faulted by the other two. Then unspecified faults with FCPC1 and FCSC 1, but it’s not clear which system component is reporting those faults. Then another flight control issue, and finally the cabin pressure controller squeaks.

There are some patterns here. One pattern is there is a lot of stuff involved with AS and altitude, and at least one with the outside-air-temperature sensors. The commonality here is the pitot and static systems and their interaction. Then later comes the DG in ISIS, followed by IR2 being voted out and then FCPC and FCSC faults and cabin pressure.

What could be up with the P-S systems? One possibility is that they are getting all iced up. That would be why AP and AT think they can’t maintain altitude. That might also explain the outside-air-temperature probe complaint, if it were being iced also. But manufacturers and regulators know about ice; it must have been extraordinarily severe to overwhelm the sensor heating systems.

Another possibility that some have mooted on the internet is that the aircraft was being blown around a lot in severe to extreme turbulence, but I don’t see how thereby one would get discrepant readings: rather, all probes would vary wildly, but coordinated, as individual gusts hit all three at more or less the same time. So I really don’t see that as a plausible reason for the P-S system issues.

The IR units are self-contained: they are calibrated sometime way back when and that’s it for the remainder of the flight. So when they start complaining, it is either a system fault or you are already out of control and moving them around more than they judge appropriate.

Severe icing alone overwhelming the sensor systems, though, does not by itself lead to an accident. The AC could be controlled with pitch and power, and the Aircraft Operating Manual explains exactly what pitch and what power setting in some detail, if one has an “ADR disagree” warning.

Severe turbulence, though, could cause a control problem if there are shears of more than 50-60 kts differential, because that is approximately the width of the speed band for that flight at its cleared flight level - this has been verified, using a conservative estimate of the aircraft’s weight at the time, by experienced A330 pilots (by “speed band”, I mean the difference between “maximum Mach operating” speed and stall speed). However, turbulence of that sort, while supposedly possible, is very, very unusual.

How do you get that severe icing overwhelming the PS systems? Temperature at that altitude is well below the freezing point for water, so clouds are generally formed from ice crystals. The properties of these are well known and the air data systems and their certification is aimed to cope with them, unless there is an entirely new phenomenon manifesting itself here. Ice crystals don’t show up on weather radar, so even with careful use of weather radar one might not fathom the presence of a storm whose water content is crystalline ice, no matter how violent that storm is.

The behavior of supercooled water droplets doesn’t seem to be as well understood. Water can become supercooled, even as low as -40°C (which would be a typical temperature for the flight level at which AF 447 was flying), especially in strong convective atmospheric currents. Water requires a certain amount of energy to crystallise, and if the air is cooling fast, adiabatically, that energy just might not be there. And if there is enough water, at -40°C, colliding with your sensors and freezing on impact, it may overwhelm the sensor heating and cause air data problems. However, supercooled drops are water and would show up on weather radar. One would expect a crew to avoid such an area being “painted” on their radar, especially in the Intertropical Convergence Zone (ITCZ) in which such storms are frequent, indeed expected. It is common for pilots to deviate many tens of miles from the planned track to avoid such storms, for avoiding the storm is the main priority, and use of the oceanic tracks is designed to accomodate such deviations.

So the severe-icing root-cause hypothesis is not puzzle-free.

What about some sudden, catastrophic structural-failure event such as the sudden in-flight break-up of TWA 800 in 1996? Any such hypothesis must accomodate the fact that parts of the electronics were muttering to themselves in a fairly orderly fashion, and transmitting those mutterings over a SATCOM link, for some four minutes. I don’t see how. (It is obvious that structural-failure occurred – the aircraft’s vertical stabiliser has been found separated – but, one would conclude, later in the accident sequence.)

That is enough tea-leaf reading for one note. We might hope that the BEA will explain the exact meaning of the ACARS messages, and its conclusions about their true ordering, in the interim report which, by ICAO rules, must appear within 30 days of the accident (so, by 1 July 2009).

If anyone has more detail on the exact JASC codes used by the airline and (very important!) can demonstrate to me that that information is reliable, I would be very glad to hear from you.

PBL

.............................................

You'll find more over at The Abnormal Distribution (http://www.abnormaldistribution.org/) including a demonstration of how a simple transcription error in a post on PPRuNe ended up propagating around the world.

[auraflyer]

For info, the spoiler from the wreckage is the left hand inboard spoiler.

I think you're right. The following photos show it perhaps a bit better. The first is from an identical model also in Air France service, F-GZCG (and you can see the same 3 - 1 - 3 distribution of rivets in the centre, which I presume will be the same on the crash a/c):

Photos: Airbus A330-203 Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/Air-France/Airbus-A330-203/1365991/L/)

This one, in TAM service, shows the narrowing & curvature at the rear corner:

Photos: Airbus A330-223 Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/TAM/Airbus-A330-223/1369105/L/)

Contrast it with this from F-GZCC on the right side:

Photos: Airbus A330-203 Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/Air-France/Airbus-A330-203/1516944/L/)

And for an overhead shot:

Photos: Airbus A330-203 Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/Qatar-Airways/Airbus-A330-203/1420356/L/)

[BOAC]

Useful stuff, PPT. I am very puzzled by the LRGyro in the ISIS throwing a wobbly 'at the same time'. I can only surmise either exceedance of attitude limits (if any), power suply issues or a software glitch. Sadly my old git's instinct points ME to number 3. Surely the odds of a cotemporal failure there are remote? PJ2? Is there any (unlikely?) cross-tell between ADIRUs and ISIS?

EDIT: I do query PBL's diagnosis of the ISIS fault, however "At a similar time, the DG in the stand-by flight instrument system complains." - what is a 'DG'?

[RetiredF4]

The FA-Seats come imho from the front. There the fuselage sleeks down already to the cockpit. The anunciator Panel got separated, if you draw lines from the brown spots (holes from screws broken out) you get the panel-size. The headrests are gone as well as the plastic cover. However the metal fixings of the plastic panel are visible.
Note also the opening to the lower right of the panel besides the seats. In the picture below there is an access panel visible.

I only found a picture (hope the link works) of those seats from a Ethinad-Airways A330, but you can see the point.

Photos: Airbus A330-243 Aircraft Pictures | Airliners.net (http://www.airliners.net/photo/Etihad-Airways/Airbus-A330-243/1271101/L/&tbl=CABIN&photo_nr=6&sok=WHERE__%28airline_LIKE_%27Etihad_Airways%25%27_OR_airlin e_LIKE_%27Etihad_Crystal_Cargo%25%27%29_&sort=_order_by_photo_id_DESC_&prev_id=1280494&next_id=1225925)

If my asumpttion is correct, i dont know. It might be speculative.

My thanks by the way to the mods, i´m longtime out of flying, however such a tragedy keeps coming back t my thoughts again and again.
regards

[dougydog]

Me Myself,

Your post at 5.46 today...Spot on IMO.

1. Go round the weather if you can ( you normally can)

2. There`s normally no excuse for going into v bad weather. As I`ve said before in 22 years of LH flying I can count on one hand how many times I`ve been in a storm- Most of them at low level too...Where theres more margin..Ie on decent or climb out of somewhere.

3. Go round the weather....AF 447 is probably going to be a sobering lesson to all of us, I think/hope.

[A33Zab]

A330 FCOM Bulletin No. 810/1 (Jun 2004)
< but still present in recent FCOM revision >

Subject: ERRONEOUS AIRSPEED/ALTITUDE INDICATIONS

Background:
Two recent fatal accidents on non-Airbus aircraft and several reported incidents attributed to unreliable speed and/or altitude indications have prompted the need to improve flight crew awarness to identify and tackle the failures described in this bulletin.
Most failure modes of the airspeed/altitude system are detected by the ADIRS and lead to the loss of the corresponding cockpit indications and the triggering of the associated ECAM drills.
However, there may be some cases where the airspeed or altitude output is erroneous without being recognized as such by the ADIRS. in this cases, the cockpit indications appear normal, but are false, and pilots must rely on their basic flying skills to identify the faulty source and take the required corrective actions. When only one source provides erroneous data, the straightforward crosscheck of the parameters provided by the 3 ADRs allows the faulty system to be identified. This identification becomes more difficult in extreme situations when two, or even all three, sources provide erroneous information.

This FCOM Bulletin provides the following information:

1. Recall of pitot/static system layout;
2. Situations which may lead to erroneous, airspeed/altitude indications;
3. Consequences of various failure cases;
4. Recall of recommended operational procedures.

DISPLAY ARCHITECTURE:
- The CAPT side pitot and static probes supply the ADIRU 1 which is normally used for display on the CAPT PFD.
- The F/O side pitot and static probes supply the ADIRU 2 which is normally used for display on the F/O PFD.
- The STBY pitot and static probes supply the ADIRU 3 which can be used for display on either PFD in case of failure. They also directly supply the standby instruments.
<read: "ISIS">

MAIN REASONS FOR ERRONEOUS AIRSPEED-ALTITUDE DATA:
The most proberly reason for erroneous airspeed and altitude information is obstructed pitot tubes or static sources. Depending on the level of obstruction, the symptoms visible to the flight crew will be different. However, in all cases, the data provided by the obstructed probe will be false. Since it is highly unlikely that the aircraft probes be obstructed at the same time, bt the same amount, and in the same way, the first indication of arroneous airspeed-altitude data available to flight crews, will most proberly be a discepancy between various sources.

CONSEQUENCES OF OBSTRUCTED PITOT TUBES OR STATIC PORTS:
All aircraft systems using anemometric data have fault accomodation logics. The fault accomodation logics are not the same for the various systems; but rely on voting priciples whereby when one source diverges from the average value, it is automatically rejected and the system continues to operate normally with the remaining two sources. This principle applies to flight controls and flight guidance systems.

NORMAL SITUATION:
Each PRIM receives the speed information from all ADIRUs.
It compares the 3 values
Pressure altitude information is not used by the PRIM.
Each FE (Flight Envelope Computer) <FMGEC> receives the speed and pressure information from all ADIRUs.
For each of these two parameters, it compares the 3 values.

IF ONE ADR OUTPUT IS ERRONEOUS AND THE TWO REMAING ADRs ARE CORRECT
The PRIM and the FE <FMGEC> eliminate it without any cockpit effect (no caution, normal operation is continued), except that one display is wrong and CAT III dual can no longer be available on the FMA.

IF TWO ADR OUTPUTS ARE ERRONEOUS, BUT DIFFERENT, AND THE REMAING ADR IS CORRECT, OR IF ALL THREE ARE ERRONEOUS BUT DIFFERENT.

The autopilot and the autothrust are disconnected by the FE<FMGEC> (whichever autopilot is engaged).
If the disagree lasts for more than 10 seconds, the PRIM triggers the ADR DISAGREE ECAM caution.
It reverts to Alternate 2 law (without high and low speed protection)
On both PFD, "SPD LIM" flag is shown, no Vls and no Vsw is displayed.

This situation is latched, untill a PRIM reset is performed on the ground without any hydraulic pressure.
However, if the anomaly was only transient, the autopilot and the autothrust can be re-engaged when the disagree has disapeared.

IF ONE ADR IS CORRECT BUT THE OTHER TWO ADRs PROVIDE THE SAME ERRONEOUS OUTPUT OR IF ALL THREE ADRs PROVIDE CONSISTENT AND ERRONEOUS DATA:

The System will reject the 'good' ADR and will continue to operate using the two 'bad' ADRs. This situation can be met when. for example, two or three pitot tubes are obstructed at the same time, by the same amount, and in the same way. (Flight through cloud of volcanic ash, takeoff with two pitots obstructed by foreign matter (mud, insects)).
Human beings (the pilot) tend to use the same type of 'fault accommodation' principles to detect an erroneous IAS/altitude indication. Flight crews will tend to reject the outlier information, if the other two outputs are consistent. This choice is, in the majority of cases, correct; but, all flight crews should be aware of very extreme and unlikely situations where two (or even three) speed/altitude indications can be consistent and wrong.

BEWARE OF INSTINCTIVELY REJECTING AN OUTLIER ADR

The following chart provides a non-exhaustive list of the various consequences of various cases of partially or totally obstructed pitot tubes and static ports on airspeed and altitude indications. It should be noted that the cases descibed below cover extreme situations (e.g. totally obstructed or unobstructed drain holes) and that there could be multiple intermediate configurations with similar, but not identical, consequences.

FAILURE CASE:
Water accumulated due to heavy rain, Drain holes unobstructed.
CONSEQUENCES:
-Transient speed drop until water drains
-IAS fluctuations.
-IAS step drop and gradual return to normal.

FAILURE CASE:
Water accumulated due to heavy rain, Drain holes obstructed.
CONSEQUENCES:
Permanent speed drop.

FAILURE CASE:
Ice accretion due to pitot heat failure or transient blocked due to severe icing, unobstructed drain holes.
CONSEQUENCES:
-Total pressure leaks towards static pressure.
-IAS drop until obstruction cleared/fluctuation if transient erratic ATHR if transient.

FAILURE CASE:
Ice accretion due to pitot heat failure or transient blocked due to severe icing, obstructed drain holes.
CONSEQUENCES:
-Total pressure blocked
-Constant IAS in level flight until obstruction cleared.
in climb IAS increases.
in descent IAS decreases.
-Abnormal AP/FD/ATHR behaviour:
a) AP/FD pitch up in OPN CLB to hold target IAS.
b) AP/FD/ pitch down in OPN DES to hold target IAS.

FAILURE CASE:
Total obstruction of static ports on ground.
CONSEQUENCES:
- Static pressure blocked at airfield level
- normal indications during T/O Roll
- After lift off altitude remains constant
- IAS decreases after lift off
- IAS decreases when aircraft climbs
- IAS increases when aircraft descends.

Based on the information given in the preceding chart, it is clear that no single rule can be given to conclusively identify all possible cases of erroneous airspeed/altitude indications. However, any case of erroneous speed/altitude indications will always be associated to one (or more) of the following cues:
a) fluctuations of airspeed indications;
b) Abnormal correlation of the basic flight parameters (IAS, pitch, attitude, thrust, climb rate):
- IAS increasing with large nose-up pitch attitude;
- IAS decreasing with large nose down pitch attitude;
- IAS decreasing with node down pitch attitude and aircraft descending;
c) Abnormal AP/FD/ATHR behaviour;
d) Undue staal warning or overspeed warnings;
e) reduction of aerodynamic noise with increasing IAS;
f) Increase of aerodynamic noise with decreasing IAS.

RECOMMENDED POCEDURES:

GENERAL REMARKS
The procedures descriped below are intended to provide flight crews with general guidelines to be applied in case of suspected erroneous airspeed/altitude indications.

FOLLOW ECAM ACTIONS
IF FAILURE UNDETECTED:
CROSSCHECK ALL IAS/ALTITUDE SOURCES:
ADR 1, ADR 2, ADR 3 and STANDBY INSTRUMENTS

if it is obvious that the outlier is wrong, select the corresponding ADR OFF and reconfigure the PFD indications accordingly, by appling the ECAM drill which will be automatically displayed.
Flight crews should, however, be aware that in extreme circumstances, it may happen that two, or even all three ADRs may provide identical and erroneous data. Therefore, the suspect ADR should only be switched OFF, if it is positively confirmed that the two other ADRs are correct. if in doubt:

DISCONNECT AP/FD AND ATHR
FLY TARGET PITCH ATTITUDE AND THRUSTSETTING

The initial pitch attitude and thrust values given in the QRH should be considered as 'Memory Items', since they allow 'safe flight conditions' to be rapidly established in all flight phases (takeoff, climb, cruise) and aircraft configurations (weight and slat/flaps). Once the target pitch attitude and thrust values has been stabilized. the expanded data of the QRH(Flight with unreliable speed indication) should be followed to determine the precise pitch attitude and power setting required, as a function of the aircraft's weight, configuration and desired speed.
After applying the QRH procedure, and when aircraft is stable, the flight crew should try to identify the faulty ADR(one or more). Once the dicrepant ADR has (or have) been positively identified, it (they) should be switced OFF. This will trigger the corresponding ECAM warnings and the associated drills which should be followed to adress all the consequences on the various aircraft systems.

<End of Bulletin >

A330 Tech

[deSitter]

Unlike the VS, the spoiler panel is coated with oil/fuel/hydro fluid residue. Taken with the central disruption caused when the actuator was torn away, it's pretty safe to conclude that this panel detached when the wing was destroyed on impact with the water.

-drl

[dougydog]

Biz,

There is no way I`m blaming your colleagues in AF.

I am saying we ALL (All pilots and the industry in general- me included) have a lot to learn from this tragic accident....Speaking the bleeding obvious

[Mercenary Pilot]

I am surprised this is a issue as the rudder is obviously not used in the cruise.The rudder is in constant use in the cruise (at least while the auto-flight system is engaged and operating correctly).

1. How far from the wreckage field was it?Already answered.

2. Did it detach in the same place and in the same manner as the American Airlines fin failure. Has anyone got pictures of both fins to compare?Unknown at this time although there is yet to be any evidence given by the investigators to say when or how the fin detached. The photos of both have been posted numerous times and prove absolutely nothing.

3. Can it be determined whether the fin detached before impact with the water?Yes it can. By qualified investigators, their engineering teams and by advanced computer simulations. Not by armchair experts and conspiracy theorists.

-------------------------------------------------------------------------------

Is there any amplification of early report of body(s) with ox mask (pax or full face?), and recent report "masks found"?Not that I have seen, read and heard so far. I think the only official description is that the bodies were unclothed. Masks have been found and photographs have been released of these but no indication or statements so far to say they were found on the bodies.

http://i86.photobucket.com/albums/k99/flyingphoto/af447o2.jpg

[Mr Optimistic]

'The IR units are self-contained: they are calibrated sometime way back when and that’s it for the remainder of the flight. So when they start complaining, it is either a system fault or you are already out of control and moving them around more than they judge appropriate.'

These are strapdown systems which integrate up rates and accelerations. If the dynamics exceed certain limits the attitude reference will diverge as the integration errors mount up and effectively cause cross channel coupling as the sensor inputs are incorrectly resolved. However do you know that air data isn't used in some damping mode via clever kalman filtering or integrity/sanity cross-checking ?

Any significant to apparent lack of faulting from other systems eg engines ?

[Rananim]

at 0212, a 3422 event in the standby flight instruments (ISIS) (34 is navigation, 3422 is directional gyro and indicators)

Then the laser ring gyro in the ISIS complains,
Ladkin

IF there was no attitude reference,it was mission impossible.Why no mechanical gyro?You must leave the pilot something(SAI/compass)when the primary technology fails.Mechanical gyro has moving parts and can topple but is ROBUST.KISS.

4PWS,
I'm afraid you wont be very popular here.You have my sympathies.

[OPENDOOR]

Given the demonstrated ability of VS/rudder assemblies to float would it be technically possible to locate the FDR and CVR inside the VS?

[curvedsky]

I know little about IT, but as you say, there MUST be a way that modern aircraft can transmit "burst" transmissions on a regular basis (say every 20min) to home base including ALL the info that would normally be stored on the FDR/CVR?

OK a lot can happen in the 20min between transmissions, but surely a pattern may emerge leading up to a serious incident?


Dating from the early 1960s Lockheed Skunk Works used 'BirdWatcher' on the U-2 and later on the A-12 and derivatives to keep an eye on these aircraft in flight . It effectively tracked disasters - aerodynamic, mechanical or combat related. Aircraft parameters such as altitude, overspeed, canopy off, electrical faults, high tgt, flameout and many more were compressed and then event transmitted by a short burst of HF to homeplate. When things were going well, the pilot would use the cockpit BW transmit key to signal/authenticate a task done - complete with the flight parameters relevant to that time period. The many Area 51 websites give some insight into this remarkable precursor to ACARS and the satellite monitoring technology of today.

Like so many Kelly Johnson schemes, it worked well in real life. Thus BirdWatcher was able to provide plausible likely scenarios and reasons for the many disasters encountered in the early 1960s.

See A-12, YF-12, SR-71 Blackbird crashes (http://area51specialprojects.com/crashes.html)

[Captain-Crunch]

Yeah BOAC,

Good point. I recall other bus guys earlier in the thread complaining about repeated failures of that unit (ISIS.) But in this case, I think Professor Ladkin's use of the term "DG" is wrong. Also Ladkin's use of only four digit codes for the ACAR's faults does not seem very accurate to me. Faults are six digit. Warnings only four. For example the 3411 he references is not as descriptive as the actual 341115 which denotes more than just a problem in the Pilot static system; it denotes more specifically that either the heater or the computer that monitors the Airspeed Probe pressure data has faulted.

Also, there is something important that you all need to know. After considerable digging for 24 hrs, I have a fairly good opinion that the France2 TV shots are a SITA reformat of the AOW2 satellite data. That means, as a few sharp minds on pprune have mentioned, that it is just a "leg report" and as such, is TRUNCATED for brevity. My college degree is in computer studies. Still, for some reason, it did not occur to me that the ellipses (...) mean there's more information available than is being displayed. Recall, if you will, that one poster was objecting, a thousand posts or so ago, that the message was incomplete and it did not include pitot 1,2,3 failure language. I feel certain now, because of the ACARs standard conventions which SITA follows, which sends a second set of transmissions to check for errors, that the 0210z to 0214z list is complete with all the message events that were sent for that time period. We can't see specific language to Pitot probe failures, because SITA ommitted them (...) in order to get the warning or fault listed on one line. Greenspinner and others, IIRC, were complaining that we needed the full Aircraft Maintenace Report for AF447, which for whatever reason, was not leaked to FranceTV2, or they decided not to air the final flight maintenance report, or it never made it before breakup.

To Recap:

The screen shots are authentic and complete as far as France2 knows.
They are missing key mention of Pitot triple failure because (...) the program SITA truncates the Sat message for one-line brevity on the leg report only.
The 341115 code is confirmed by our techs here at pprune to be the pitot.

Captain "Ironside" Crunch - out


The above, as all my post are, are just my opinions only.


.

[Safety Concerns]

quite a few holes in that piece from an apparent professor. However lets assume its genuine.

For the 6,000,000,000,000 million billion time, there could be a weeks delay in sending the acars messages they will still show aircraft system time taken from the aircraft reference clock as indicated at the time of the event. I don't know how to make that any clearer.:ugh::ugh::ugh:

ISIS is not just a laser ring gyro. It also has pitot/static inputs from the systems being logged as faultly. Maybe thats why it logged a fault message

The one message that remains puzzling is the ir fault. Perhaps yes because the aircraft had already exceeded some limits but that is pure speculation.

[Brosa]

IF ONE ADR IS CORRECT BUT THE OTHER TWO ADRs PROVIDE THE SAME ERRONEOUS OUTPUT OR IF ALL THREE ADRs PROVIDE CONSISTENT AND ERRONEOUS DATA:

The System will reject the 'good' ADR and will continue to operate using the two 'bad' ADRs. This situation can be met when. for example, two or three pitot tubes are obstructed at the same time, by the same amount, and in the same way. (Flight through cloud of volcanic ash, takeoff with two pitots obstructed by foreign matter (mud, insects)).
Human beings (the pilot) tend to use the same type of 'fault accommodation' principles to detect an erroneous IAS/altitude indication. Flight crews will tend to reject the outlier information, if the other two outputs are consistent. This choice is, in the majority of cases, correct; but, all flight crews should be aware of very extreme and unlikely situations where two (or even three) speed/altitude indications can be consistent and wrong.
A lightening strike at the right side of the cockpit could damage both FO and standby pitots as they are mounted close to each other.

Then we could easily have a situation as described above where the system is rejecting the 'good' ADR.

[Captain-Crunch]

ISIS is not just a laser ring gyro. It also has pitot/static inputs from the systems being logged as faultly. Maybe thats why it logged a fault message


You are fast Safety Concerns. I'm going to have to stop editing on line! :} I was trying to rebut the "DG" misunderstanding by the professor, before I realized the ISIS is probably the entire suite of standby equipments. If we lost both Cpt's and F/O's pitot to ice, AND the standby pitot as well we might expect a 342200 FR (fault report).

For the 6,000,000,000,000 million billion time, there could be a weeks delay in sending the acars messages they will still show aircraft system time taken from the aircraft reference clock as indicated at the time of the event. I don't know how to make that any clearer.

Yes, you are right!!!!!! But when this all comes out, I trust you will be willing to accept that the average transmission time all the way to the user in france is only a few seconds. That's the average according to SITA data that I have already posted here. It's not going to take "weeks" for the data to get there. Right :O


Good work everybody. You guys have resolved a lot in my opinion. I just tried to summarize what ppruners have deduced collectively.

CC

[Dan Air UK]

For the 6,000,000,000,000 million billion time, there could be a weeks delay in sending the acars messages they will still show aircraft system time taken from the aircraft reference clock as indicated at the time of the event. I don't know how to make that any clearerSafety Concerns (http://www.pprune.org/members/265772-safety-concerns), you are correct in that there is no guarantee on the delivery time for an individual ACARS message, however I understand the Satellite Ground Earth Stations have an Service Level Agreement with SITA which requires the message delivery time is less than 60 seconds in 99.? % of the time (can't recall the number of 9's). I understand there was no significant delay in transmission in this case.

[Safety Concerns]

Yes, you are right!!!!!! But when this all comes out, I trust you will be willing to accept that the average transmission time all the way to the user in france is only a few seconds. That's the average according to SITA data that I have already posted here. It's not going to take "weeks" for the data to get there. Right http://static.pprune.org/images/smilies/embarass.gifWRONG. As with any messaging system there are issues. The servers and software involved in receiving and processing these messages do hang up.
Messages can be lost in the system for some considerable time but guess what?

They still come out of the tunnel days even weeks later and still show the actual time of the event and not the time they eventually re-appeared.

[Good memories]

The GPS ,IRS or INS speed is difficult to use at high altitude. However it has been done by a B 747 400 crew who flew into a volcanic ash cloud over Alaska many years ago. Apart from multiple flame outs and opaque windows they managed to land safely at Anchorage using their IRS/GPS ground speed for reference during the remainder of the flight and approach.

Good Flying!

John

[CONF iture]

A330 FCOM Bulletin No. 810/1 (Jun 2004)
Actually that FCOM Bulletin was initially published as the No 09 from DEC 99 following the loss of two 757 for similar reasons.

[Captain-Crunch]

Safety Concerns,

I shouldn't have said "a few seconds all the way to france." I should have said a few seconds to the First Downlink Ground Station.

Indulge me for a moment, will you? My point is not what happens after the ground station gets the message. I don't care. You're right. Anything could slow down then. My point is that from my readings, the satellite will not even send the message AT ALL, NOT ANYWHERE until it gets a C31A confirmation transmission from the aircraft. This means TWO transmissions have to come from the aircraft ON EVERY ACARS REPORT before the satellite will decide it's error-free, and then put that stamp of approval (C31A) on the SITA message and THEN (AND ONLY THEN) beam it down the first ground station and THEN is could get delayed. The fact that it exists testifies it passed the ACARs programing protocol.

Wouldn't you say? :8

7.3 Response Time [1973 - CC]

The average response time for Type A messages, i.e. the time lapse between the Instant an operator presses the transmit key of his terminal to send his query and the instant the first character of the reply appears on the screen (see Figure 6) ranges from 1.4 seconds to 3 seconds, depending on the number of links involved in route. A typical response time distribution is shown in figure 9.

7.4 Satellite Processors

The downtime of SPs is around 16 hours per month including scheduled and unscheduled stops (e.g. preventive maintenance, configuration changes, etc.)

Presently, certain SPs switch up to 6 message blocks per second during peak conditions of traffic.

Switching times are in the order of 5 ms per block for both systems.

[lomapaseo]

Unlike the VS, the spoiler panel is coated with oil/fuel/hydro fluid residue. Taken with the central disruption caused when the actuator was torn away, it's pretty safe to conclude that this panel detached when the wing was destroyed on impact with the water.


I'm not sure that this is conclusive.

Both the underside and visible edges appear damaged/scraped/worn. Some thoughts about possible inflight damage if it was shaking hard might still be open.

Not conclusive to me by itself so I tend to move on to the next piece of evidence.

as one poster suggested, you collect the positives and the negatives against the various speculations and then decide which ones are still viable (this is liable to take more than a few weeks for us)

[4krew]

However 1500 replies long, this thread has the only available means for partial understanding of what happened until they find the box, if ever, thanks to You all.

Great brainstorm, despite the "sparks" jumping from time to time at somebody's reply.

I guess the Ps of PPRUNE meant professional pilots and some of us are not even pilots.

I would politely "bag" those of You not pilots to refrain from curiosities as our atempt here is trying to prevent this from happening again.

It may in the interest of other more powerfull force the FDR, if found,
not be disclosed to us ever and this thread eventualy saving real pax.

Thanks ALL for ALL the help.

from an A330 Capt 15000 hours, 7000 on this very same airway.

[Safety Concerns]

sorry cc I was a bit hasty in replying and knew what you meant.

It just gets so frustrating that even after a 1000+ posts into a thread, there are still questions and comments over the time stamps.

Pprune can be a wonderful source of info if only posters would read before posting. I think closing down threads after x amount of posts may not be a bad idea after all. The jump from nonsense to a half decent read was very noticeable after the original thread was locked. It seems direction of this thread is now also slowly being lost.

[Baron rouge]

From brazilian journos recovered bodies were found naked and with numerous skull and limbs fractures .
That scheme recalls exactly G-ALYP accident back in 1954. Flight BOAC 781, a de havilland comet broke up in mid air due to explosive decompression.

Here is a link to that accident. : http://en.wikipedia.org/wiki/BOAC_Fligh ... disaster-1
In order to find more evidence concerning the cause of the crash, the bodies were brought to the coroner for autopsy. During the examination, the pathologist Antoni Fornari discovered a distinct pattern of injuries, which were also identified as the cause of death, in most of the victims. Fornari found broken limbs and damaged limbs, which occurred after death. These injuries consisted of fractured skulls and ruptured and otherwise damaged lungs. Fornari found no evidence of an explosion, and he felt confused by the pattern of injuries.
The ruptured lungs were a sure indicator that the air cabin depressurised because the sudden decrease in pressure would cause the lungs to expand until they rupture. In order to support the theory and also to confirm the cause of the skull fractures, the crash was simulated at the Royal Aircraft Establishment in Farnborough, using the same conditions of the actual plane prior to crash. To do this experiment, a model fuselage was constructed similar to that of the Comet.
Dummies were also seated within the fuselage to simulate possible movements of passengers during the crash. To simulate the crash, the investigators deliberately ruptured the model by increasing the air pressure within it until it exploded. The movement of the dummies within the air cabin at the moment of explosion was conclusive of skull fracture as they were thrown out of their seats and slammed head-first into the ceiling.
Wreckage of the aircraft was eventually found on the sea floor and subsequently raised and transported to the Royal Aircraft Establishment for investigation. Upon examination of the wreckage it became obvious that the aircraft had broken up in mid-air, and initially it was thought that the aircraft might have been brought down by a bomb. Suspicion then shifted to the possibility of an engine turbine explosion and modifications were put in hand to encase the turbine ring in other Comets with armour plate, to contain a possible disintegrating turbine disk.

[Swedish Steve]

I shouldn't have said "a few seconds all the way to france." I should have said a few seconds to the First Downlink Ground Station.

I receive ACARS messages on my SITA printer at work. One message is sent when the aircraft is airbourne. It is sent by VHF to the local receiving station, then transmitted 800 miles to our home base. The Ops computor then sends out the auto departure message that comes back 800 miles and clacks out on my printer. As I hear this message four times a day, I know what it sounds like. Yes the clackety clack of the printer tells me it is a dep message. I look out of my window and see the aircraft retracting irs gear as it flies past. These are very small data packets, and they move fast.

[Graybeard]

Without the FDR to bring in a surprise, the majority of a civil jury (US law) would conclude that Thales, Airbus and Air France share in the negligence that allowed this fleet to contine after five serious incidents caused by icing of obsolescent pitot tubes. I don't see why anyone would try to thwart recovery of the FDR. The evidence from it could hardly be more damning.

GB

[A33Zab]

I would politely "bag" those of You not pilots to refrain from curiosities as our atempt here is trying to prevent this from happening again.


If it is in your opinion that air safety - and preventing re-occurrence of this disaster - is solely a professional pilots issue then this 'opinion' might be a part of the problem.

However if it is just because this is the 'Flight Deck' section I will refrain from 'curiosities'

"Rumours & News Reporting Points that may affect our jobs or lives as professional pilots. Also, items that may be of interest to professional pilots."

A330 Tech.

[jmig29]

Quoting BROSA

A lightening strike at the right side of the cockpit could damage both FO and standby pitots as they are mounted close to each other.

You mean Ledft side for Capt. + Stby positions and right side for F/O...

[Finn47]

insurance companies might have to foot a bill of up to 750 million USD. And they have to recuperate the money themselves from somewhereInsurance companies are not stupid. They have mathematicians who calculate accident probabilities from data from, say, the last 30 years and adjust the premiums accordingly. I´m sure the premiums collected from insuring the thousands of aircraft which have not crashed cover this expected payout and then some.

[DC-ATE]

Let's just list the "Probably Cause" now and save all this bandwidth of speculation.

The Probable Cause of the loss of AF447 was due to the aircraft having problems with the pitot static systems in an area of storms that caused the pilots to lose control of the aircraft because of erroneous airspeed and altitude indications, resulting in an upset from which they were unable to recover.

[Brosa]

You mean Ledft side for Capt. + Stby positions and right side for F/OYes, of course.

[s2944]

Finn

While insurance companies do seem a bit vulture-like and you would think look on a catastrophe as a chance to zing the policy-holders, they have what in the States is called "re-insurance", which is a policy the insurance company takes out against a major catastrophe. For example, after 9-11, our re-insurance industry was hit hard, far more than the insurance industry, as no one expected to actually collect on replacing the WTC.

Also, don't forget the insurance companies dont have the luxury of gaining additional fees beyond their contracts as the catastrophe value increases - its the lawyers that get the percentage cut that incentivies the increase in the total settlement.

Keep up the good work, y'all, I really miss working in comm av. My ACARS experience is now twenty years out of date, but if anyone has questions about the ACARS I protocol I can help. :)

[RWA]

"Without the FDR to bring in a surprise, the majority of a civil jury (US law) would conclude that Thales, Airbus and Air France share in the negligence that allowed this fleet to continue after five serious incidents caused by icing of obsolescent pitot tubes."

On present evidence, Graybeard -couldn't agree more.........'open and shut''

Buy you a drink in five or six years, when all the hearings and appeals and 'reviews' are done with............. :)

[ChrisVJ]

Just as passing interest. Local papers here are reporting a new Zealand Orion on exercise from Comox was hit by lightening. Blew a hole in the nose and another in the tail and took out the Radar. Unlikely in the AF case but one should not rule out anything at this stage.

[BOAC]

DG?

Has the good prof 'BL' misread the ATA codes? Could an AB man take a moment to explain simply the ISIS system. 'A'G I could understand, 'D'G I cannot. Thanks.

[thesandbox]

After trying to read through the many pages here I have a couple of points/questions that I would like to bring up....

1. If this situation came about due to one of the factors belonging to the pitot tubes and it was indeed similar to previous documented cases then...can and will they not retrieve the ACAR's fault reports, or even the status/ecam faults to see if there is a similar sequence of events being triggered and recorded at the start of this sequence?

2. If as the situation progressed and they eventually found themselves in direct law trying to control the a/c with the joystick....how much of an effect can moderate to severe turbulance along with the possibility of unusual attitude have on controlling a joystick? Is there not the extreme possibility of the joystick being bumped constantly with the hand while trying to use the thumb and finger to control this situation. Being on Boeings for 12 years (727 and 757/767) and never flown a Bus I would find it seeming difficult to maintain a steady hand in this situation whereas with a control column you have much better chance of dampening the turbulent effects with your body and thus lessoning the chance of overcorrecting and let alone misguided imputs at every bump. Is this a plausible and sensible thought?

As a side note I am also currently studing to take my JAR exams to convert my FAA ATP and I must say this is all so very fitting in application...in a serious and sobering way.

[swish266]

In 2006 I was discussing the Toronto accident with an Airbus employee. He suggested that a major change resulting from it might be making the use of AT compulsory unless inop or recommended by ECAM/paper procedure. Obviously Airbus has thought better – introducing this kind of major change to the way the Buses are operated could be very costly!
Today there are already rumors that insurance companies might have to foot a bill of up to 750 million USD. And they have to recuperate the money themselves from somewhere… Correct me if I am wrong, but I have a certain gut feeling that this nuclear sub is roaming the depths not to find the FDR and/or CVR but to MAKE SURE they are not found by the right people, that need them so badly.
IN a world where MONEY MATTERS you and me are only pawns on a huge board.
No government/regulatory agency will stipulate that an a/c must be 100% safe. Because it will never get off the ground and make money. So most a/c are 99.99999999999999999999% safe. Or this is what we are told. And in order for everybody to make MORE money, we got rid of the flight engineers, we accept ab-initio CPL holders to fly FBW a/c with less than 500h career time, we accept maintenance outsourcing, etc. etc.
I don’t intent staring the blame game. But we, professionals should help the general public become more and more aware of the issues facing our industry, like THE GUY who spoke up after he landed successfully on the Hudson….

[aguadalte]

DC-ATE:
Let's just list the "Probably Cause" now and save all this bandwidth of speculation.

The Probable Cause of the loss of AF447 was due to the aircraft having problems with the pitot static systems in an area of storms that caused the pilots to lose control of the aircraft because of erroneous airspeed and altitude indications, resulting in an upset from which they were unable to recover.

I would humbly rephrase it:

The Probable Cause of the loss of AF447 was due to the aircraft having problems with the pitot static systems, the complete failure of all IR's and (maybe the partial) failure of the ISIS in an area of storms that caused the pilots to lose control of the aircraft because of erroneous (or no) attitude, airspeed and altitude indications, resulting in an upset from which they were unable to recover.

(agree with you Safety Concerns, what disturbs me more is the failure of all IR's...)

V.

[JW411]

ChrisVJ:

That was the normal sequence of events during a lightning strike in the old turboprop days. Strike on the radome, takes out the radar and exits through the back somewhere.

It has happened to me in the past more times than you have had a moose steak.

I doubt it has anything even remotely to do with AF447.

[Mercenary Pilot]

2 weeks in to the investigation and some of you are already talking about "Probable Cause".

Unbelievable.

Thankfully BEA will be more open minded as to the events surrounding this accident.

[BOAC]

BOAC

Perhaps DG stands for Directional Gyro?

I'm very familiar with a 'DG' - 44 years or more! That's the one that spins 'up and away' from you so that if it comes off its bearings it won't smack you in the ...............:)

It is the DG in an inertial display I am stuck on. Do we assume:

a) The prof is wrong
b) the ATA is wrong
c) you and I are wrong?

I think the ISIS message is because it lost valid inputs from its Air Data sources. These come from the Standby system ADMs (Air Data Modules that convert pitot and static to digital close to the probes/ports) - absolutely, but why the ATA 'gyro' reference? Are there pitch/bank limits to the system?

[Swedish Steve]

I think the ATA is just plain out of date. When ATA100 was introduced there were only gyros, and now its IRUs it uses the same ref for both.

[deSitter]

Of course one expects some grime underneath, depending on how anal the maintenance people are, but there is a lot of grime on the top panel as well, and distributed in a matter consistent with it washing up on the panel while in a debris field.

-drl

[h3dxb]

@STEVE
The ISIS is one display that takes the place of the Standby Instruments on older aircraft. It doesn't have a DG, it has a Ring Laser Gyro.
I think the ISIS message is because it lost valid inputs from its Air Data sources. These come from the Standby system ADMs (Air Data Modules that convert pitot and static to digital close to the probes/ports)

maybe in Stockholm they feed an STANDBY SYSTEM with values from ADM's.

DESCRIPTION
The back of ISIS is fitted with two pressure connectors:
- One is connected to the standby pitot probe for total pressure
acquisition.
- The other one is connected to the left and right standby static probes
for static pressure acquisition.
ISIS is fitted with:
- One pressure module,
- one inertial module,
- one computation module,
- one display module,
- and one interface module.
The pressure module is connected to the total and static pressure
connectors.
Each pressure line is connected to a pressure sensor in the pressure
module.
The inertial module is composed of three single-axis rate gyros and
two acceleration sensors.
The computation module performs the computing and graphics
generation functions.
The display module is fitted on the front face of ISIS. It is of the
Liquid Crystal Display (LCD) type.
The front face is also fitted with
several knobs for operation purposes.
The interface module is composed of:
- a filtering board linked to an electrical connector at the back of ISIS,
- the 28VDC power supply unit,
- the interface board which links the pressure, inertial, computation

Thats why it is called STANDBY, apart from normal ADIRU SYSTEM :ugh:

[Earl]

Really trying to understand this Alternate law on the flight controls here.
These SLF questions are really useless at this point and provide no positive influence or information to this thread.
Can you guys tone it down a bit so some real crew can read through this and maybe try to have a understanding to what has happened without having to read useless information?
I think I seen a thread on jet blast that may be more in line.
Not saying that what you have to say is not news worthy, but please leave this thread to the front end crews.
Some of us have been around for a long time and are more interested in facts, procedure, known issues, not in what if this situations.

[Lost in Saigon]

Excuse me if my question is stupid or trivial or disruptive in your discussion. I´m not a pilot, not even a couch pilot and I will accept if my post is deleted.


I´m puzzled by the different lat/lon positions of "Last ACARS 0214Z" used in different maps, charts and data from Brazilian Air Force and others. I think this is important, because Força Aérea is referring to that position measuring distances, e.g. of debris found. Here at pprune and in other discussions there are conclusions drawn from this distances - e.g. if the Airbus could have been broken in high altitude or not and in what weather conditions AF 447 really was at 0214Z.

I found different data concerning last ACARS:

1/ Wikipedia, pprune:
Last ACARS 0214Z
3°34'40"N, 30°22'28"W

2/ Last Report ref. to Brazilian Air Force
"Ultimo Reporte"
3°16'28"N 30°22'28"W

Wikipedia does not provide a reference for this particular information. I also could not figure out a reliable source in many days of research. Not even where this "information" first occurred. It has been assumed that lat/lon position is data coming with the ACARS by satellite transmission, but I cannot find a reliable source for this assumption either.
Brazilian Air Force uses different positions for "Ultimo Reporte" in different plotting they provide, one of them suggesting "Ultimo Reporte" being in about 167km distance from TASIL: http://www.pprune.org/rumours-news/376433-af447-49.html#post4986435 (http://www.pprune.org/rumours-news/376433-af447-49.html#post4986435) (see lower picture).

Thus I have the following 2 questions:

Do/could ACARS messages technically include information about lon/lat position?
Are the ACARS messages that have been published truncated in a way that would suggest Air France to have additional information about exact position transmitted by satellite?


Thank you for the opportunity to learn!
Skiperica/self loading freight (-;


You ask very good questions. All these "positions" appear to be only estimates based on where AF447 should have been had they continued on their track from INTOL to TASIL on the UN873 airway.


I don't think anyone has any actual information on the actual position of AF447 when the ACARS messages were sent, or where they actually entered the sea.

Someone please prove me wrong.

[A33Zab]

BOAC:

Are there pitch/bank limits to the system?


Roll / Pitch -180 to +180...as stated in the AMM.

A330Tech.

[h3dxb]

Do ACARS messages technically include information about lon/lat position?

No

Could ACARS messages technically include information about lon/lat position?


Assuming, that no VHF coverage is avail. ACARS is communicating via SATCOM. To contact the satellite, the A/C has to know his position in regard to the satellite to adjsut the dish.
ACARS is linked with most of the computers , so it should be easy to track it by sending LAT/LON datas.

Are the ACARS messages that have been published truncated in a way that would suggest Air France to have additional information about exact position transmitted by satellite?



Maybe, but till now all flight trackings are based on OOOI messages and calculated flightplan. I think there are also some legal issues.

[wheelie my boeing]

Thesandbox - In response to your second question;
No quite simply. The joystick has no feedback. Even if the plane was all over the place, the joystick would not move at all. There is no feedback. Of course, I haven't flown a 'bus in severe turbulence in direct law, but as you were asking about the fact that you can't use your "body strength" etc then it makes no difference as there still isn't feedback.

[Graybeard]

A330 tech: please translate the following ACARS report from you AMM or fault isolation manual:

Quote:
34 43/06 WRN WN0906010210 344300506 NAV TCAS FAULT 09-06-01 AF 447

Thanks,

GB

[captainflame]

BOAC:

Quote : "Is there any (unlikely?) cross-tell between ADIRUs and ISIS?

EDIT: I do query PBL's diagnosis of the ISIS fault, however "At a similar time, the DG in the stand-by flight instrument system complains." - what is a 'DG'?"

The ISIS is a self containted intrument, no one knows what exactely is inside because stuff is still military classified:8 (when there's a glitch with it, maintenance sends it straight to Airbus. There's NO opening the case !:=

contains Gyro and accelerometers (says the FCOM)

It gets direct pitot and static inputs from the stby probe and port. There's no air data computer inbetween.

IT ALSO GET'S INFO from ADIRUs 1 and 3 !!:cool:

[meekmok]

Who, in their right mind therefore, decided it was a good idea to fit three identical tubes, all from the same manufacturer...

Ah, probably the same people who decided to put two identical engines from the same manufacturer on the airplane....

[barrymung]

The aircraft needs two identical-ish engines for stable flight. The pitot tubes, however are somewhat different.

I fail to see the logic in using three identical tubes, purportedly for safety reasons, when three dissimilar ones would reduce the chances of all three failing due to a design flaw/stock fault.

Little additional cost but reduced likelihood of complete failure. It's a no-brainer as far as I can see.

[h3dxb]

@graybard

MAINTENANCE WARNING REPORT
---------------------------
A/C ID DATE FLTN
XXXXX 090614 XXXXX
ECAM WARNING MESSAGE
+--------------+
GMT PH ATA SEQ DESCRIPTION
195X 06 27 90 400 F/CTL SENSOR FAULT

this is the normal format we get. To translate yr format

34 43/06 ATA chapter 34-43 flightphase 6 WRN WN0906010210 Warning Date 09.06.01 0210UTC 344300506 NAV TCAS FAULT Failure code 344300 SEQUENCE 506 NAV TCAS FAULT 09-06-01 AF 447 IDENT

Normally no big deal .

[Mad (Flt) Scientist]

As I understand it, the plane was fitted with three identical pitot tubes. Presumably, the reason 3 are fitted is in case one or more fails.

Who, in their right mind therefore, decided it was a good idea to fit three identical tubes, all from the same manufacturer, all of the same type and presumably the same date of manufacture??

If one tube had a stock fault, all three would have it. :rolleyes:

Surely it'd be far more sensible to use three different tubes from three different manufacturers?

That way, if one failed, chances are the remaining two would be unaffected.

Well, there are various practical problems with dissimilar designs, especially for systems that need to have data in agreement from multiple sources in order to assure safe operation. With three different probe designs you'd get far more ADR DISAGREE type situations with the increased hazard that represents.

You also need to spec the dissimilar designs, and the performance specs would presumably be identical. Since the state of the art for pitot probe design is mature, chances are you'd get very similar designs even from dissimilar vendors.

You'd also end up with the same environmental spec, so the same conditions which would overwhelm one probe's heater capability (if that happens) might very well overwhelm all the dissimilar probes.

And, finally, they didn't put all their eggs in one basket. The ISIS/standby is using a different means in that the standard probes have ADMs at/near the probe, while the ISIS is (I understand) plumbed traditionally with the sensing as part of the ISIS unit. So if you were to have some kind of catastrophic design flaw that took out every ADM the ISIS should still be running.

I don't think the air data system designers are as clueless as you seem to think.