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AF447

Old 14th Jun 2009, 00:27
  #1421 (permalink)  
 
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pathologists will play a vital part as in British Comet disasters

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.
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Old 14th Jun 2009, 00:33
  #1422 (permalink)  
 
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Spoiler

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?
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Old 14th Jun 2009, 00:38
  #1423 (permalink)  
 
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Seems like something as simple as a cartwheel on impact with the water could explain one wing entering backwards.

Last edited by Chu Chu; 14th Jun 2009 at 00:59.
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Old 14th Jun 2009, 00:56
  #1424 (permalink)  
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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.
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Old 14th Jun 2009, 01:42
  #1425 (permalink)  
 
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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.
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Old 14th Jun 2009, 04:03
  #1426 (permalink)  
 
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Spoiler

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
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Old 14th Jun 2009, 04:04
  #1427 (permalink)  
 
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For info, the spoiler from the wreckage is the left hand inboard spoiler.

Photos: Airbus A330-243 Aircraft Pictures | Airliners.net

Photos: Airbus A330-323X Aircraft Pictures | Airliners.net
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Old 14th Jun 2009, 04:24
  #1428 (permalink)  
 
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Spoiler

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?
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Old 14th Jun 2009, 04:28
  #1429 (permalink)  
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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).
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Old 14th Jun 2009, 04:34
  #1430 (permalink)  
 
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More Dodgy Reporting?

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.
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Old 14th Jun 2009, 04:38
  #1431 (permalink)  
 
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From 'The Times'

Crash jet ‘split in two at high altitude’ - Times Online
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Old 14th Jun 2009, 04:46
  #1432 (permalink)  
 
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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.
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Old 14th Jun 2009, 05:27
  #1433 (permalink)  
 
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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"
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Old 14th Jun 2009, 06:46
  #1434 (permalink)  
 
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To Post or Not to Post



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”.



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Old 14th Jun 2009, 06:46
  #1435 (permalink)  
 
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Originally Posted by FrequentSLF View Post
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.
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Old 14th Jun 2009, 07:21
  #1436 (permalink)  
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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?
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Old 14th Jun 2009, 07:27
  #1437 (permalink)  
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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."
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Old 14th Jun 2009, 07:39
  #1438 (permalink)  
 
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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.

Last edited by The Chaser; 14th Jun 2009 at 10:43. Reason: New ACARS transcription correction to ATA 3422 ISIS code
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Old 14th Jun 2009, 07:59
  #1439 (permalink)  
 
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What has changed?

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.

Last edited by 4PW's; 14th Jun 2009 at 08:10.
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Old 14th Jun 2009, 08:30
  #1440 (permalink)  
 
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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.
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