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AF 447 Search to resume

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AF 447 Search to resume

Old 30th May 2010, 09:13
  #1281 (permalink)  
 
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Thanks, CONF_iture and mm43, for the schematics.

Yes, they both confirm that Spoilers 1 perform as Speedbrakes as well as Ground Spoilers − clearly disproving my contrary suggestion. Sorry if I put the cat among the pigeons, but we now have some useful extra material to refer to. (In the cockpit, if selected, the F/CTL page of ECAM would clearly show this during Speedbrake operation.) It seems the air-braking capability of this A330/340 wing is quite powerful.

Chris
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Old 30th May 2010, 10:25
  #1282 (permalink)  
 
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Bearfoil,

the flipping over of the Spoiler is an interesting theory.
However, in that case I would expect upward bending / buckling of the trailing edge.
You would neet a fixed point around which the spoiler would create a lever to tear off the actuator. That would have to be the trailing edge.
Hiowever in the pictures, the trailing edge looks pristine compared to the rest of the device.
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Old 30th May 2010, 12:04
  #1283 (permalink)  
 
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Hello,
Originally Posted by ARFOR
bearfoil
Yep, put the trailing edge front on to high speed air flow. Barn doors are not designed to withstand airflow from behind [swept wing roll without VS, flick, yaw, all over red rover]. The only way that could happen is loss of the VS following assem upset at alt.
What precipitated the loss of the lateral control [the VS] is any ones guess [Takata will chime in i'll guess].
What precipitated the loss of the lateral control [the VS] seems to be impact with water.
At least, there is no clue that it happened between 02.10 and 02.14. Such a loss would trigger critical Hydraulics faults and all the relevant ACARS are missing. As none were received, it may be reasonably pointed that VS was not separated or badly damaged until ACARS stopped.
What happened later is still unknown but in flight separation would have certainly caused another kind of impact that what the investigation described. Now, one may want to be convinced that the BEA is bullying everybody but it would have to be done in collusion with NTSB and other bureaus working with it.
S~
Olivier
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Old 30th May 2010, 14:01
  #1284 (permalink)  
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henra

The trailing edges are in no way pristine.
They (corners) have failed down, the entire trailing edge has folded backward (from overloading), and the leading edge has failed from the middle (as a result of the hinges popping loose. At this point, all the airstream needs is a "peek" underneath, and the game is over The airflow is directed under the popped leading eedge, and fills the unprotected bottom surface with extremely energetic air. Meanwhile, the spill from the trailing edge has gotten mixed with other symmetrical spill and creates a local tornado of randomly blended vortices.

It is this folding of the panel back that precipitates failure, as it puts an enormous load on the center hinges, those in front of the actuator. The next stage is a rocking back and forth of the panel alternately loading either trailing corner. It is this undesigned for load that attacks the unengineered for weaknesses of the a/c that push the otherwise capable airframe into uncharted regions. Using an additional actuator might be one approach; bear in mind, this a/c is capable for all use as intended, it is not some exotic fighter that carries a single occupant. Aviation has categories and the 330 is a well made machine.

I think it is clear that the spoilers were deployed, and that some air loads were beyond design. As for the Flaps, they are inordinately robust as designed, but they were not meant to be a stand-in Hull for a water landing.I do think they separated, however, and if the Spoilers did not shear off in flight, they may well have been taken off with the Trailing edge of the wings.

takata

bonjour. I think no one is bullying anyone. A different point of view is not aggression. ACARS had one message left to send, as we know, there is that delay in transmission. You speak of loss of Lateral control, but all that has been shown is Lateral failure of the VS mounts. When the mounts broke and when or if the VS was lost in flight has not been established. Just as the spoilers were deployed as a result of some effort to gain stable flight, (an opinion), the VS may have stayed on.

It also may have separated. I have a theory as to what occurred, and it is based on what is publicly known.

I do know what happens to control surfaces when their mounts are broken. After mount failure, there is a lack of direct response, and depending on circumstances, control is compromised in vibration, loss of rigidity, and ever increasing play. It is this play that needs to be handled with great care. Just as more control is desired, there is degraded performance, and the temptation is to regain the control provided by increasing input. It is a cycle that has befallen uncounted aircraft

au demain,

bear

Last edited by bearfoil; 30th May 2010 at 14:35. Reason: to address takata
 
Old 30th May 2010, 14:58
  #1285 (permalink)  
 
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Impact Load on spoiler

If the aircraft impacted the sea more or less wings level with significant downward speed, is it that clear how the wing structure would respond dynamically (flexing) and the consequential loads that would have been imparted to the spoiler, actuator and supporting structures ? Add in a bit of roll with one wing impacting first and the analysis gets even more complex. Think I'd want an FE model before I tried to assess the remains.
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Old 30th May 2010, 15:07
  #1286 (permalink)  
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Greetings
What about the Engines, dont you think they will touch the water first and subsequently take the maximum load
 
Old 30th May 2010, 21:04
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Program on BBC 2 now in the UK if anyone is interested

"Lost : The mystery of Flight 447"
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Old 30th May 2010, 21:11
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First thing they're doing on the BBC programme is eliminating the possibility of in-flight break-up.

Did the production team read the interim reports? Would have saved them the effort.
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Old 30th May 2010, 21:36
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For the "creative" team doing the "production", facts are irrelevant. It's audience and sponsor appeal that supports their lifestyle.
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Old 30th May 2010, 22:04
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So...nothing new, then.

Just a recap of the same theories. I like the way the in-house investigation 'discovered' things which the BEA publicly listed months ago.
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Old 30th May 2010, 22:06
  #1291 (permalink)  
 
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"Our independent team believes . . . ."
May as well believe most of you lot
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Old 30th May 2010, 22:14
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Bearfoil;

I found another image showing the topside of the spoiler. It clearly shows that the damage caused was puncture pressure from the underside. Note the neat rows of holes where the actuator attachment pad bolts have been dragged through. The other damage is self explanatory.



However, when referring to the BEA Interim Report, the caption associated with their published image - see Post #1253 doesn't make sense. It says, "Lower surface of left-hand spoiler No.1, with a piece of the fitting attaching spoiler No.5 to the wing aft spar: failures due to the bottom upward loads on the spoiler".

From my perspective, if it was the right-hand spoiler No.6, then "with a piece of fitting attaching spoiler No.5 to the wing aft spar" would make sense. Any comments?

Starboard Nos.2 and 3 in ground mode, showing fittings.



mm43
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Old 30th May 2010, 22:15
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I'd like to congratulate the bbc for a very good program. The media rightly comes in for a lot of stick on this forum for sensationalist rubbish it normally produces but this was well researched, accurate and non sensationalist. As some say maybe not ground breaking news but the general public probably haven't read the bea's report.

Yet again, it seems that basic flying skills were not sufficient to mitigate an accident on a highly automated aircraft after a series of failures - failure to avoid the storm and failure of the pitot static heat to keep the probes de-iced.
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Old 30th May 2010, 22:15
  #1294 (permalink)  
 
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BBC2 prog. wasn't as bad as it could have been....

Yes much has been said before and by the expert reports. However, their mention of previous Pitot failure incident reports and how some other A330/340 crews took up to 60 secs to apply the 5 deg pitch and greater manual thrust (point and power) technique is still quite astonishing.
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Old 30th May 2010, 22:37
  #1295 (permalink)  
 
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I agree - the documentary was unremarkable, but welcomely unsensationalist.

One thing I find truly remarkable was the chief pilot's statement that transport pilots nowadays don't undergo stall training. Can anyone confirm this?

I find it quite incredible. As a student glider pilot, I have to do stall and spin recovery training, learning to recognize the symptoms and recovery procedures for both. To me it seems like a very important component of core flying skills, and I'd be really surprised if transport pilots don't do this.
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Old 30th May 2010, 22:37
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The Beeb experts seemed to say Speed would have been reduced from M0.82 to M0.76 and then be only 10knots above stall speed?

They also blamed super-cooled liquid for pitot freezing.

Back on thread they also reckoned stall from high level, near recovery, then low altitude stall - which would suggest the search has been too far North?

Last edited by sensor_validation; 30th May 2010 at 23:35.
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Old 30th May 2010, 23:03
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... they also reckoned stall from high level, near recovery, then low altitude stall - which would suggest the search has been too far North?
But then we have recent news reports in which the BEA have been attributed with saying, "AF447 never went south".

Someone must be wrong!

mm43
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Old 30th May 2010, 23:28
  #1298 (permalink)  
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mm43

This looks definitely like a different spoiler than the one in the sea (your image post #1253). I agree wholly that the caption must be in error relative to the outer. It matches number one with number five, (?).

I must say this spoiler exhibits a failure consonant with a great load from underneath, but it also shows that the TL and LE have failed upwards. This is not what is seen with the other spoiler. It may be that the panel is so trashed that its edges articulate in both directions; note it is not leaning against the ship's cabin here.

Thank you for your reply, I think this may lead into a more prolonged assessment, I hope you will stay with us, your work is exemplary, and much appreciated. The landing photos are supreme, they give an excellent view of the strength and the vulnerability of the spoilers . I agree the fasteners remained with the mounting bed, pulled through as the panel left under great duress. A large fracture is seen on the outer edge of the mount, the energy was most profound. This discussion is most instructive on the strengths/weaknesses of materials.

be well

bear

Last edited by bearfoil; 31st May 2010 at 00:12.
 
Old 31st May 2010, 00:24
  #1299 (permalink)  
 
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BBC Investigative Documentary

The theory the producers chose to go for was roughly as follows.

A US meteorology specialist suggests that the main line of Cbs might have been behind, and in the wx-radar shadow of a relatively moderate shower... Thus, having successfully avoided/penetrated the first shower, the crew is unprepared for the severe line of wx just beyond it.

Here a UK-based Airbus training pilot (Capt Martin Alder), and an American ex-Airbus captain/safety analyst take up the story. Belatedly realising the problem, the crew select turbulence-penetration Mach (stated to be M0.76 − that's good for an A320 but I don't have a figure for the A330). The current speed being M0.82, the A/THR reduces the N1 (thrust) considerably for the deceleration. Entering the wx, the A/C encounters super-cooled rain at 40C. Pitots freeze, leading A/THR to disengage at a very low thrust setting, as A/C still slowing down. Pilots slow to take throttles out of CLB gate, so thrust does not increase in time to stop the A/C stalling. Their presumed failure to establish a Thrust/Attitude technique is partly due to non-driven throttle levers (lack of tactile cues).
Situation allegedly exacerbated by: (1) too much reliance by today's airline pilots on AP and other automation; (2) absence of stall-training (meaning as part of type-rating?); (3) plethora of warnings causing excessive work load. A/C may have recovered from first stall with wing-drop, but − if so − probably stalled again.

Little acknowledgement by the producers of the fact that nearly all the aircraft data and photos used must have originated from the BEA and Air France. Knowing Martin, I doubt he would have gone firm on one theory, to the exclusion of others. But, as these shows go, it was a pleasant surprise. The sim. footage was clear, relevant, and fairly well in context with the theory (which has some merit).

In haste (prior to travel),
Chris
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Old 31st May 2010, 03:06
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AF 447 nearly intact wreckages

Nearly a year later,more questions than answers.Just saw again the section of the aft galley(correct me if wrong) and sorry could not paste the link but i`m sure many of you had already seen it ,which seems very intact and also the vertical stabilizer + rudder.Still leaves me baffled if the plane really disintegrated in the air or not.What are the chances of such two parts of an airplane remaining nearly intact after such a massive G load impact.....would it be a airborne disintegration or a particular angle of impact on the water,that would lead parts of an aircraft no to be severely distorted ,let alone mainly intact in composition.Remember that the initial impacting on water at such high speeds is like impacting on solid rock,no difference.Would love to hear your views.
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