When the French investigators concluded that 447 hit the water intact based on compression evidence from recovered wreckage, does this include or exclude the stabilizer?
Apparently, the tail was recovered >50 miles from much of the rest of the recovered wreckage and the automated electronic messages transmitted to AF indicate a decompression event ocurred earlier?
The BEA has stated that the vertical fin broke away from the fuselage due to impact. Something about how the attach points were distorted and forces were assumed to come from the rear.
Rectification following an article earlier today with regard to KLM suspectingly grounding its A330 fleet. Confirmed sources around the airline have told Worldwide-Aviation.net that all Airbus A330 in service of KLM are still in operation. Replacement of the pitot probes is an ongoing process and it is not expected that this would form a problem maintaining the current flight schedule.
Whilst the pitot issues have concentrated pretty much on Air France, the world fleet of 1000 A330 and A340s - and a host of other Airbuses - extends way beyond that.
What is the picture with the types of pitots in use elsewhere and any need to exchange Thales for Goodrich.
I say this with a very personal interest as I am due to fly as SLF on a Qatar Airways A330 from Doha to Manchester in 2 weeks time and would like to have some insight.
Last edited by Dave Gittins; 12th Aug 2009 at 05:11.
About ten years ago, an Evergreen Intl A/L 747-100 converted to cargo, enroute KJFK-KANC at night over Canada, had A/P roll computer do a slow rollover, and the plane went supersonic in the dive. They landed at nearest airport, and may have replaced a few panels. The plane continued in service for more years. Actual speed was retrieved from the fdr.
Avoiding too fine a point on the topic, it is of note that at least three separately discovered control surfaces were discovered. I haven't followed the drift/current discussions; BEA would conclude that the a/c impacted as a complete airframe. The Vertical Stabilizer, Rudder (attached), a spoiler (left, inner) and a portion of the Elevator were of note prior to the conclusion by BEA that the a/c held together until the last. Since the discussion is drifting in a 'shedding parts' direction, I thought I'd remind us of the evidence, though I'm not implying that is what happened. Since Upset can occur in either of two seperate trends, it appears BEA have selected the Stall rather than the overspeed, shed metal format. BEA's statement is possible, but I question its status as a conclusion.
Since Upset can occur in either of two seperate trends, it appears BEA have selected the Stall rather than the overspeed, shed metal format. BEA's statement is possible, but I question its status as a conclusion.
Hey Will. Can't an overspeed result in a stall ? (hig speed stall/mach buffet). Jeff
Since Upset can occur in either of two seperate trends, it appears BEA have selected the Stall rather than the overspeed, shed metal format. BEA's statement is possible, but I question its status as a conclusion.
Hey Will. Can't a stall originate from an overspeed ? (high speed stall/mach buffet). Jeff
Since Upset can occur in either of two seperate trends, it appears BEA have selected the Stall rather than the overspeed, shed metal format. BEA's statement is possible, but I question its status as a conclusion.
Hey Will. Can't a severe overspeed end up into a stall ? (high speed stall/mach buffet). To me, there is no contradiction between an initial overspeed and a stall (or even two: a stall by exiting the upper limit at high altitude during the overspeed, then, after a nearly successfull recovery/flight point back again within the envelope, exiting the lower limit of the flight envelope due to an overcorrection at low altitude). Jeff PS) Has NTSB scheduled any report of its investigations ?
Last edited by Hyperveloce; 12th Aug 2009 at 16:24.
I think their opinion that the a/c remained whole is meant to include not shedding parts, a Stall and descent to the Ocean. If overspeed, and the potential for elevator failure, spoiler separation, and VS loss, well you see their problem. A kind of Reverse postulation that precludes airframe failure, which would be my goal if I had an opportunity to claim it for a principal in the accident. I think that more is included in the BEA's assessment than is justified in evidence.
Even if the BEA could get some clues about the impact conditions, and will get a more accurate view after the CEAT analysis, the BEA cannot know about pieces of the airframe it hasn't recovered, hence it would be difficult to understand how the BEA could suggest that the structural intergrity of the plane was not compromised at all. In my understanding, the BEA position is only that the plane had not suffered a mid-air break up or a major control surface failure (that would have rendered it uncontrollable) like a VS loss. There had been some speculation about a catastrophic structural failure in altitude. Given this, I don't think that the BEA interim report says that no spoiler was lost for example. But his was a young airframe. Jeff BEA interim report (page 72):
"leur examen visuel montre que l’avion n’a pas été détruit en vol ; il paraît avoir heurté la surface de l’eau en ligne de vol, avec une forte accélération verticale."
"their visual examination (of the debris) shows that the plane did not brake up in mid air ; .../..."
quote/hence it would be difficult to understand how the BEA could suggest that the structural intergrity of the plane was not compromised at all. In my understanding, the BEA position is only that the plane had not suffered a mid-air break up or a major control surface failure (that would have rendered it uncontrollable) like a VS loss. There had been some speculation about a catastrophic structural failure in altitude./endquote
Isn't the theory of the airframe not breaking up at altitude suggested by the absence of flail-type injuries on the recovered bodies?
The spoiler you referred to was I think the port outer which was picked up by a merchant ship north of TASIL on 13 July. If it had detached on account of an overspeed event, then that would help to explain its recovered position not falling within the range of expectation provided by the surface current/wind data. This would also fit in with the high Gs roll/bank to port and the high speed descent toward the suspected crash site as postulated by you in a recent post.
I have extracted the Quikscat mean surface (+10m) winds from the NOAA site and determined that the mean surface wind at 3°N 30°W for the period 1 - 7 June was from 069.3°T x 11.06 knots (5.69m/sec). The vertical stabilizer has a very low profile to windage, in fact the only significant airfoil was the small piece of empennage skin rolled up and inward on the forward end. The leeway for the v/s shown on the graphic below was 221°T x 11.1NM with reference to the general position of the 5 bodies recovered on 7 June. Without knowing the precise timings for either position (which could have been any time between sunrise and sunset) there is some room for positional error.
The effective windage factor calculated from the graphic is 0.74% which doesn't seem unreasonable. Applying the same factor to the Quikscat data provides a leeway of 249.3°T x 12.8NM over 6.5 days. Sun shadow on a photo taken at the time of the v/s recovery indicates that the sun was near or on the meridian, i.e. 1400z. However, when comparing the Quikscat data with the MSL analysis during the period in question, the wind vector should be more northerly. Putting that aside, the calculated result puts the v/s where it should be +/- a couple of miles.
mm43
Last edited by mm43; 13th Mar 2010 at 23:59.
Reason: changed stbd outer to port outer
While I'm neither supporting or rejecting an in-flight break up, those searching for baggage should consider that an in-flight break up can mean a rather wide variety of things. Peraps the empennage came off and the rest remained intact until impact. Perhaps a wing partially failed, but the remainder remained intact. Perhaps the horizontal tail surfaces failed downwards and the rest remained intact. In-flight break up does not necessarily translate to hundreds or even tens of tiny pieces. It just means some type of structural failure prior to impact of the whole, which precluded the ability to recover from an in-flight upset.
You all need to be as creative in your thinking about structural failure as you are about drift patterns, ocean currents, ice crystals in pitot tubes and 180 deg turns. At this point all that we have is a mystery, therefore anything is possible.
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Will asked a fair question, "What gives you the confidence to quote "60-120 mph" ??"
That is pure conjecture considering the terminal velocity of a human (about 120MPH) and the wings. I doubt it'd hit flat at 200 MPH with both wings present. (With only one wing it would not hit flat at all.) It might have hit faster if the pilot had been in a poorly controlled dive and managed to try to pull up as he saw the ocean. That would account for the flat or almost flat attitude, the tail breaking off as it did, and would likely give a faster velocity vector when contacting the ocean.
If I understand the construction of the pressure vessel and the interior the pressure vessel does not support much weight at all. That is all handled by an interior cabin construction. That way the pressure vessel would not be punctured by a lot of small holes supporting heavy weights. Thus it would be sort of like dropping a cigar tube on its side with the cigar in it. You'd get crumpling on the bottom that hits the ground. But the top would not crunch down. That's an extreme example. But it gives the idea behind my thinking. Mass as well as deceleration is needed to crunch the cabin.
Some evidence indicates a break near the front of the wing. That is how the galley and other parts "escaped". And it explains the crew rest facility pieces. If that happened before the rest of the fuselage crunched with its circular integrity removed you can explain the distribution for the recovered passenger bodies.
The chief arguments regarding a break-up in mid air involve getting the debris to where it was found given the ocean currents and the missing items you'd expect to see from a breakup. This would be items of luggage from the hold rather than the sparse couple things found that are generally overhead bin items.
The breakup scenario also requires the plane to remain in a relatively stable attitude until after the last message. It also requires the plane to remain enough in one piece to hit the ocean more or less flat. And you have to break off the VS in the mode seen. (Remember my demo concept of pulling pages out of a three ring binder. You can figure out how you pulled the paper out by the tear patterns. And the VS is very much like that piece of paper right down to the "three ring binder" mounting.)
I'd believe breakup in the air if you can prove God or weather could swat at a plane mashing its tail forward and up without leaving marks on its rear edges.
IF the a/c broke up at a decent height, the main bits would then have dropped to the surface at a high speed.
Would they ? The engines would, a centre section section wouldn't tumble 'that*' fast, with main wing panels attached.
*What is 'high speed'?
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The surface impact would probably have been extreme and the a/c would have been reduced to smallish pieces.
Would it? More likely if striking as a whole unit ?
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Although a lot of these would have sunk, many would have floated. More than the bits that have been found..
Not so in the case of the Comets, which 'definitely' broke up at altitude...
The only real difference, is that here we'd have a few more pieces floating, due to composite construction... seems they stayed attached?
============================ We seem to be not only wantonly urinating, but to windward with a lot blowing back in our faces here...
Someone's going to be right, but probably more by chance than genuinely educated deductive reasoning
So I think BBF's conclusion is probably right, it agrees with BEAs and currently is the more likely occurrence, but some of the conjecture on kinematic and aerodynamic behaviour requires more rigorous justification.
Something may well have bent or broke at high altitude, but just as likely in thicker air at low altitude if control was compromised (which obviously it was, one way or another)....
