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AF 447 Thread No. 7

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AF 447 Thread No. 7

Old 26th Mar 2012, 17:17
  #981 (permalink)  
 
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Mach.

Perhaps. However, and it may be merely linguistic, but FLAPS are extended, Spoilers are Deployed. The first bit of FLAP is an extension of the chord of the wing, and adds lift, further FLAP extension creates more drag than lift. Anything on top of the wing spoils lift, as you know.

Could be wrong, wouldn't be the first time.....
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Old 26th Mar 2012, 17:22
  #982 (permalink)  
 
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When a pilot types, he is assumed to know the a/c. Is AB different? Yep. In approved and certificated ways? Yep, no room to argue.
Sure, but here we had a "perfect storm" where the pilots were apparently not trained (properly). Then, and only then, did these design characteristics come into play. Surely that's a reasonable argument to have.

In the case of your A320 friend, I think that is exactly WHY there had been prior complacency about high-altitude training. It wasn't considered a likely issue, until now. Now there's a mad scramble to address this, and high time, too. What if he HAD found himself in a similar situation? Would he have survived? That can't be known, and I for one don't choose to gamble when the houses get tiny.

How'm I doin', guys?
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Old 26th Mar 2012, 17:32
  #983 (permalink)  
 
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Organfreak

John is reluctant to discuss 447. He does say the pilots were screwed from the outset, and for many reasons, not the least of which is lack of training, especially re: UAS and high altitude SOPS.

Mach. Who's to say PF did NOT conclude "Hmm.... Spoilers were no help, perhaps FLAP?" The word EXTEND suggests that, at least to me... If, as is possible, all three ended up being worried re: Ospeed, there were discussions re: FLAPS, and prolly GEAR.

In a descent as weird as this one, how is it all are so sure what happened?

Can there be another explanation except that they believed Overspeed?

Never gamble, Organfreak, and try always to keep the houses tiny. Big houses are a problem.
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Old 26th Mar 2012, 17:47
  #984 (permalink)  
 
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Lymanaroonie:
Mach. Who's to say PF did NOT conclude "Hmm.... Spoilers were no help, perhaps FLAP?"
Perhaps due to my lack of advanced technical knowledge, but I have never been able to get my mind around the idea that they thought they were in OS.
Why not? Because of the highly unusual deck angle. How in the world could anyone suspect OS when tipped back like that???????????????????????????? I ask you.

I rest my cases and will now quit while I'm behind.
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Old 26th Mar 2012, 18:16
  #985 (permalink)  
PJ2
 
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Machinbird;

This may help the discussion regarding flap position.

The first photograph is from IR2 (IIRC) but copied/rendered in B&W and rotated for easier comparison with the second image which is from the initial wreckage photographs, also copied, cropped and enhanced for clarity.

I think this is conclusive evidence that the flaps were in the up/retracted position. The rotating flap actuator faces forward (retracted) in the accident photograph but faces rearward (extended) in the IR photograph.

For further clarity, a flap-track schematic showing the rotator in both postions is provided below.

PJ2








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Old 26th Mar 2012, 19:26
  #986 (permalink)  
 
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Where in Heaven's name did you retrieve that accident image? That is one I saw that I believed to be in IR3. If not, it should have been.

Mechanically, I am more comfortable than aerodynamically, so I would ask for clarification, as the wreck image seems to show a fully extended flap actuator, not a retracted one. The dog is fully exposed aftward, whereas if stowed, it would be sheltered forward, and along the the top of the carriage. Also, I believe though the images and schematic are oriented correctly, they show opposite side wing attachment. Aren't the Rotators outboard?

Also, isn't the carriage extended aft first, before the rotator deflects the flap surface downward? So the actuator could be stowed, and the FLAP still extended FLAP1?

Thx, Captain.
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Old 26th Mar 2012, 19:59
  #987 (permalink)  
 
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It is rather obvious to me that the rotating actuator controls the fore and aft position of the carriage and hence the flap angle.

Thanks for the clear images PJ2
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Old 26th Mar 2012, 20:04
  #988 (permalink)  
 
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Got it. I see. Are there two other images of the FLAP rails, one that is captioned "EXTENDED"? (From the wreck situs)?
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Old 26th Mar 2012, 20:38
  #989 (permalink)  
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Cheers, mm43.

Lyman;

The original image was provided by the BEA just after the discovery of the wreckage. There were seven other images provided at the time. I don't think that there are/were other images of flap tracks from the wreckage site.

(Edit: I took a look at the two photos of the tracks in IR2, one showing the flap rotational actuator in the extended position and the lower image showing it in the retracted position. The track itself is very beefy, (about six feet long in total, IIRC) and hangs down a long way thus the need for the aerodynamic "canoes". The first photo in the above post was actually from the left wing, but in the rotation to conform to the photo of the wreckage, it appears to be "correctly" oriented. It makes no difference as longitudinal orientation is here unaffected by lateral orientation. This is Flap Track 2 from the R.Wing. Flap Track 1 is differently structured and mounted inboard of the gear near the fuselage/wing join).

PJ2




Last edited by PJ2; 26th Mar 2012 at 21:34.
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Old 26th Mar 2012, 21:12
  #990 (permalink)  
 
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It is very kind of you to post that additional image, sir. Now I must locate the image with the "extended" caption.

In IR2, the canoes were used as a proxy to suss position at impact, that is why I had assumed the images I saw were from the IR3, the actual equiment is not likely to have remained floating.

Also from this image, I see no evidence that Gear was extended, There is no deflection evident other than mostly vertical whilst stowed.

Thank you again, Captain.
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Old 26th Mar 2012, 21:15
  #991 (permalink)  
 
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Lyman,

In the BEA IR#2, go to page 20. There you will see a photo of the flap extension #3 in the extended position.

Go to page 21. There you will see a flap extension #3 in the retracted position.

Both photos are from an identical A-330 aircraft, not AF447.

The photo of flap extension from the floor of the sea posted by PJ2 is from a series of photos taken by the BEA from the wreckage, but is not in BEA IR#3. Only 4 photos are shown in the report, an engine, a wing section, a fuselage section and the nose landing gear.

Now, if you go to PJ2's post containing the flap extension drawings, you will see how the mechanism works. As the flap actuator rotates clockwise, the flap is pushed rearward and is pulled downward by the carriage as it travels down the angled track. Conversely, when the actuator is rotated counterclockwise, the flap is pulled forward and is pushed upward as it moves up the angled track to its nesting position. IMO, the photo of AF447's flap is in the retracted position.

Hope this clears up your confusion. But Lyman, I have a question: Why is this flap or spoiler position important at all? This large swept wing jet was descending at a pitch up of 16.3, an AoA of at least 35 or more and a vertical speed equal to the horizontal speed of ~124 miles per hour. So what exactly would flaps extended or spoiler extended do in this situation?

TD

Last edited by Turbine D; 26th Mar 2012 at 21:18. Reason: Correction of flap extension #
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Old 26th Mar 2012, 21:17
  #992 (permalink)  
 
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Time for you to re-read FCOM flight controls again.
Reading the FCOMs when one cannot tell the subtle difference between speedbrakes and flaps is total waste of time.

How in the world could anyone suspect OS when tipped back like that???????????????????????????? I ask you.
How in the world could anyone not abort the takeoff when it's obvious left ASI is not working then after liftoff couple autopilot and autothrottle to the single malfunctioning ASI and stall the airliner on initial climb?

How in the world could anyone hit the ground below airport elevation?

How in the world could anyone turn ninety degrees off required heading during night descent into long, narrow valley?

How in the world could anyone not understand that using the rudder to roll the airliner is reserved strictly for total loss of lateral control and not for wake encounter?

How in the world could anyone pull when faced with stall warning?

How in the world could anyone push the aeroplane into sea during go-around?

Simple.

All it takes to provoke the Grim reaper is to stop thinking and acting as a pilot.
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Old 26th Mar 2012, 21:35
  #993 (permalink)  
 
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Hi TD

From the Captain's re-entry to the flight deck til impact, we are told there were no displays on the panel, for either pilot. That means all the flight data available had to be guesswork. The a/c meandered about a "g"of a fairly consistent "1", so deck angle, A/S, and control actuated excursions were all a matter of guess, and what we are shown to have been very little discussion amongst the three.

You claim a NU of 16.3? How luxurious! As I have said many times, that is from the DFDR, and the pilots were "out the LOOP". My picture of this flight Path from the outset of Manual Control is that the crew were outside looking in, they were victims of circumstances that prevented their recovery, having caused the Upset in the first place.

The captain had to have noticed the Deck angle, he was walking, not sitting. Whilst seated, at one g, and nothing visible outside, the a/c could have been inverted, for all the pilots could suss. One G is one G. The popular image of goofy pilots at war one with the others is a painstakingly created construct. Deployed Spoilers, (they were) Extended FLAP (we don't KNOW), and Throttle settings seem outrageous. We were not there.

Just as the G traces for PERPIGNAN have not been released, damning evidence of a/c behaviour wil not be seen, as BEA have morphed their mission statement into releasing "ONLY DATA THAT MAY SERVE TO PREVENT FUTURE ACCIDENT".

That's nice, but consider how much unilateral maneuvering that allows re: evidence and its disclosure. Uncommanded Climb? Let's say we knew PF, and he seemed a competent sort of pilot.

Instead of keeping an open mind, the masses have claimed he screwed the poodle from the git, pulling like a maniac, instead of doing what WE all knew was the "RIGHT" thing. His inability to understand (seemingly) what the PNF was saying was construed as incompetence, rather than a genuine take on a misbehaving a/c. He did not know he was climbing? More like he did not know WHY? Again, with the ergo, lack of proper belting, and the shaking deck, how was he to suss what his stick was doing, w/o a speed tape, a FD, etc? Now this too is damning, but also Human.

I don't know this, but neither do you. When I see all the data, to include all the discussion, (what else is there, that all three had?) I'll give it up.
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Old 26th Mar 2012, 21:38
  #994 (permalink)  
 
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Clandestino. FLAPS are extended and then retracted. Also SLATS. Spoilers are DEPLOYED, then STOWED. Words have meaning.
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Old 26th Mar 2012, 22:03
  #995 (permalink)  
 
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"Facts are meaningless. You could use facts to prove anything that's even remotely true" seems to be the philosophy.

Word games or feigned ignorance does not alter the fact that no flaps were extended. Neither were slats.
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Old 26th Mar 2012, 22:11
  #996 (permalink)  
 
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Originally Posted by Lyman
Words have meaning
Non surtout ne ne (les) sors pas
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Old 26th Mar 2012, 22:16
  #997 (permalink)  
 
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Hamburt Spinkleman

"Word games or feigned ignorance does not alter the fact that no flaps were extended. Neither were slats."


Hmm......At Impact? You don't even know that for certain. Is that from chicken guts? Ouija? Not extended then retracted between LOC and Impact?

Who's making bold statements?

If such selections were made, it meant the pilots were desperate, and it is very important to paint them not as desperate, but stupid. Desperate draws attention to their lack of instrumentation, or displays, and that might be construed as a platform problem? Only stupid pilots get wet? Nothing re: Flaps slats or spoilers can be demonstrated conclusively, probably ever. That means certainly that not disclosing these things brings no harm. Only to the pilots, and once they are demonstrated to be fools, to the majority, we can move on?
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Old 26th Mar 2012, 22:31
  #998 (permalink)  
 
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Neither were slats.
"Aye, there's the rub."
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Old 26th Mar 2012, 22:37
  #999 (permalink)  
 
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Slats retracted, sir. Well, that is... the servos are shut. One's missing, but who will know?
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Old 26th Mar 2012, 22:39
  #1000 (permalink)  
 
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I have come to realize that is it pointless to use facts as they will just be ignored, twisted or otherwise mangled to suit whatever agenda it is you are pursuing.

Nevertheless, flaps were retracted at time of impact. That is know from impact marks on flap track fairing debris. That is a fact. Slats were retracted at time of impact. That is known from DFDR recorded data, as is the flap position. That is a fact.

Had flaps or slats been extended and then retracted in flight it would have been recorded on the DFDR and caused the RTLU to return to low-speed position. That did not happen. That is a fact.
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