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I think this map says it all.
http://newsimg.bbc.co.uk/media/image...ather2_466.gif |
I'm on the A320 so not that clued up on A330 system differences, so if you went into EMER ELEC you would expect the RAT to deploy. If the RAT was to fail/damaged in wx/not deploy - How would that leave you power wise ? Would be down to 30 mins BAT only ?
If you were down to BAT only - that would put you in ALTERNATE LAW. How quickly on the A330 would the cabin pressure become an issue ? The A320 leaves you with enough time to descend down. Once the batteries are dead - I presume the ISIS would fail too ? |
Beechnut- Good question. I would say, merely to entertain your question, that the position of the explosion and its strength would be important, and also whether ACARS was in real time, or Int. and 'bunched'. (Compressed)
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A number of pages back I stated that charted depictions of ocean currents in that are would have to rule-out currents placing debris to the right, south-east of route. After further reviewing what these charts are and their omission of necessary detail for that area of the ocean, I'd have to retract the previous. It appears entirely possible currents could be a factor but can't say they were. I would think currents would be a factor in why debris locations are so widely displaced. For what its worth.
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@ Phil Space,
is there any confirmation on the accuracy of the map posted by you? @ everybody I have two questions I wonder about: 1. The debris has been found in some distance away from the last reported location and in different spots; debris will find no trouble making it that way in 30 hours considering the current (4 km/h), although it is said to have been headed northwest at the time. While debris can spur around quite a bit due to winds etc. the oil/fuselage marks would be much more coherent. Is there any indication that there have been different spots of oil/fuselage being spotted, say 50 km apart or so? If that were the case, it would point to different impacts. 2. As far as I followed this thread and the news, last radio was with INTOL. Would it be possible that an event occurred before the flight came into the storm but after INTOL, possibly disabling any human actions (unconsciousness etc.) and that the plane followed via auto pilot its set path and only then later switched off? Or would there be electronic checks or alarms indicating that? Thx for your reply and thanks for this great forum. Regards, Denis |
"I still think people are losing sight of the fact that when transiting the ITCZ, sometimes there is NO ideal way through. You've gotta punch your way somehow and that route depends on what looks better on the radar and outside."
How about the option of turning back and returning to base ? IMO, that is the root cause of this accident, "press-on-itis", along with possible complacency / over confidence re: extremely severe weather. Just a coincidence that another AF flight tried to land during a T.S. at CYYZ ? ASN Aircraft accident Airbus A340-313X F-GLZQ Toronto-Pearson International Airport, ON (YYZ) |
Just continuing with the weather theory, there have been some interesting posts on Flight International's site regarding AF flights and weather avoidance in the past.
Perhaps some of the long haul drivers may know whether on an ETOPS flight crews may be reluctant to go too far off course avoiding weather to stay within required ETOPS diversion times? Just a thought, if this crew did not in fact deviate around what looks like (from the satellite images posted) a pretty extensive belt of Wx. |
Despite the wealth of informed comment on this thread trying to pull it together in to a synopsis is difficult.
However the UK Daily Telegraph has this: Details have emerged of the moments leading up to the disappearance of flight AF 447 with 228 people on-board, with error messages reportedly suggesting the plane was flying too slowly and that two key computers malfunctioned. Flight data messages provided by an Air France source show the precise chronology of events of flight AF 447 before it plummeted into the sea 400 miles off Brazil on Monday. These indicate that the pilot reported hitting tropical turbulence at 3am (BST), shortly before reaching Senegalese airspace. It said the plane had passed through tall, dense cumulonimbus thunderclouds. At this stage, according to a source close to the investigation cited by Le Monde, the Airbus A330-200's speed was "erroneous" - either too fast or too slow. Each plane has an optimal speed when passing through difficult weather conditions, which for unknown reasons, had not been reached by flight AF 447. Airbus is expected to issue recommendations today to all operators of the A330 model to maintain appropriate thrust levels to steady the plane's flight path in storms. At 3.10am, the messages show the pilot was presented with a series of major failures over a four-minute period before catastrophe struck, according to automatic data signals cited by the Sao Paulo newspaper, le Jornal da Tarde. At this time, the automatic pilot was disconnected – either by the pilot or by the plane's inbuilt security system, which flips to manual after detecting a serious error. It is unclear whether the pilot wanted to manually change course to avoid a dangerous cloud zone – an extremely difficult manoeuvre at such high altitude. At the same moment, another message indicates that the "fly-by-wire" electronic flight system which controls the wing and tail flaps shifted to "alternative law" – an emergency backup system engaged after multiple electricity failures. This system enables the plane to continue functioning on minimum energy but reduces flight stability. An alarm would have sounded to alert the cabin crew to this. Two minutes later, another message indicates that two essential computers providing vital information on altitude, speed and flight direction ceased functioning correctly. Two new messages at 3.13am report electricity breakdowns in the principal and auxiliary flight computers. At 3.14am, a final message reads "cabin in vertical speed", suggesting a sudden loss of cabin pressure, either the cause or the consequence of the plane breaking up in mid-air. Despite the precise details, sources close to the investigation contested the chronology and denied that the two computers providing altitude, speed and directional data malfunctioned. The suggestion that the pilot gradually lost control of the plane appears to counter reports that the plane exploded in mid-air. These were lent more weight today after a Spanish pilot in the vicinity at the time reported seeing an "intense white flash". "Suddenly we saw in the distance a strong and intense flash of white light, followed by a downward, vertical trajectory which broke up into six segments," the chief pilot of an Air Comet plane from Lima to Madrid told the Spanish newspaper, El Mundo. He has reported his observations to investigators. Some experts have supported the theory that the plane exploded, given the wide area where debris has been found. However, Brazil's defence minister, Nelson Jobim, said an explosion was "improbable" given the 13-mile trail of kerosine spotted on the sea. "If we have fuel slicks, it's because it didn't burn," he said. Paul-Louis Arslanian, the head of the French air accident bureau in charge of the investigation, also said there were other possible reasons for wide debris area, such as high winds and choppy seas. Yesterday he warned against hasty "speculation" and said that the search would take time. Four naval vessels and a tanker are in the area around 400 miles off Brazil's northeastern coast. Some 11 spotter planes are searching for more debris, after finding a seat and a 23-foot metal object thought to be part of the fuselage. A French mini-submarine will arrive in the zone next week. |
Will Fraser: Even if bunched / compressed messages are used, you would send you the already waiting message about cabin pressure with the other messages. So, the order of messages should be considered as relevant factual information.
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From a post by "nyt":
For what it's worth, "Le Monde" claims through a unnamed source We have "stories" being quoted about speed control, stalling an Airbus, going 'too fast', going 'too slow', getting bombed ad nauseum, with absolutely no basis in fact, "no attribution" as one poster honestly states and no documentation. All we have are "layman's terms" everywhere, which are not only disrespectful to a general audience but which do great violence to real understanding and comprehension of the airplane, the environment it was operating in and what the crew did and did not do. We've seen this all before. Decades ago, Randy Sohn on AVSIG very pointedly used to ask the question all the time: "Does anybody actually read the thread?", or are they just interested in hearing the noise of their own voice? In the eight pages growth while I slept, there is precisely nothing new or even interesting; what I read is manufactured, regurgitated (because someone was too lazy to read the thread - the Vazquez presentation is cited at least five times) or picked out of thin air. The thread is bulging with explanations to the newly-curious about why in many cases their wild notions about what happened are wrong. I'm not saying "wait for the report". I'm not that naive and I think informed speculation is a good learning exercise. But for the newbies and others who talk and never listen/read, please - respect what has happened and think before you write. This thread is a deep embarrassment. |
If one is to lend credence to the reports of the wx experts in lightning using NASA lightning strike data, the storms in the area were not emitting much lightning activity. In fact the closest strike at the time the airplane was in CB area was located some 70 miles away. This being the case, then a strike can all but be discounted, and if true then, it begs the question – what caused the electrical failure alerts?
Once again, I believe the ACARS, which if can be trusted to be fact, are the only few bits of information that have surfaced, and provide a brief insight into what may have occured. Can the dots be connected? They indicate the initial problems which immediately faced the crew. |
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Up to my best knowledge this part of Atlantic is well within ETOPS120, I presume AF and their 330 are ETOPS180 approved? ETOPS180 leaves basically no black spots in Atlantic so whatever en-route deviation is very unlikely to put aircraft outside ETOPS restrictions.
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Take everything you see in the media regarding aviation in general and this accident in particular with several grains of salt. After all, the media was very quick to make a lot of noise about icing in regard to Colgan 3407...
As a long haul pilot myself, what I want to know is this: Did this flight somehow get itself into WX so extreme that it caused in flight loss of control and/or structural failure? If so, how? And how can the rest of us avoid this happening to ourselves? And, if not WX, what did happen, and how might it be prevented in the future? 50 odd pages of speculation (so far) is not providing an answer to these questions. That will come (hopefully) with time, as this investigation will undoubtedly be difficult and time consuming. IMHO, these tidbits about QANTAS, Air Comet, Bomb threats to flights from Buenos Aires, etc. are red herrings and useless distractions. What I've heard about the ACARS messages isn't much more helpful and won't be until the actual messages themselves are made public. Let's all step back a bit and respect the memory of those aboard by refraining from posting "information" that is unverified, or irrelevent, or misleading, etc. Q. ps: Those of you are posting relevant, verifiable, germane facts: I thank you. |
For obvious reasons, and regrettably, principals in the accident are demonstrating a predictable bent. From the instant "Lightning" (AF) to "incorrect penetration AS", (neither of which are remotely demonstrable at this time) it seems that there is an effort to drop the responsibility anywhere but with the a/c, or the line. Nothing is more apparent than the "massaging" of the public's "opinion". It is disgusting.
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ETOPS
No Captain is going to go through thunderstorms to stay within a theory based planning stage paperwork excercise calculation.
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Will Fraser: I know well, that it is essential to examine multiple theories, but in this case we not only have an "order of messages", but we also have information about when the messages were received.
And while investigating many possibilities are important the key is, if one theory can't explain some facts, the theory should be adjusted, and if it cannot be adjusted to match the known facts, the theory can be droped. This is why I think incing, software problems, etc. can be discussed but bombs are unlikely. Not only because lack of threat, lack of organizations taking responsibility, but also because all the security present at airports, etc. |
Well said PJ2, I have never read so much endlessly repeated utter drivel.
Anyone would think that the ITCZ, large and active Cbs and the ability to fly an aeroplane safely were all new! We don't know what happened and no amount of endless fantasising here will hasten the eventual discovery of what caused the tragedy. M.Mouse. (Current widebody longhaul captain) |
Just a point about these sequential "ACARS" reports - if the aircraft
was in fact terminally damaged or breaking up, would'nt the computer systems automatically "report" all sorts of breakdowns, simultaneously, and yet, these immediate transmission could have been received over a longer time period by the Paris base due to conditions at the time and the fact that atmospheric conditions can and do interfere with such radio transmissions ? |
The 00:00 UTC rawinsonde report from Fernando de Noronha, Brazil (below) indicated that the tropical tropopause level was probably located near the 100 hPa pressure level (at a height of 16,649 meters, or 54,623 feet), where the minimum temperature was -77.7º C. The presence of cloud top IR brightness temperatures colder than -80º C on the METEOSAT-9 imagery suggests that many of the strongest thunderstorm updrafts were penetrating the tropopause — and such overshooting thunderstorm updrafts have been known to initiate strong gravity waves aloft that have generated moderate to severe turbulence. CIMSS Satellite Blog Blog Archive Air France Flight #447: did weather play a role in the accident? |
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