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AF 447 Search to resume (part2)

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AF 447 Search to resume (part2)

Old 12th May 2011, 16:01
  #1241 (permalink)  
 
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Sorry to go off topic but I have just looked again at the break up Ethiopian Flight 961 in a shallow lagoon on a flat sea.I wonder if the debris was ever mapped or was there no invesigation completed as the crash was due to a hijacking?It would be interesting to compare the debris field with that of AF447.
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Old 12th May 2011, 16:07
  #1242 (permalink)  
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tubby linton Both Ethiopian and Schiphol have much to say, the water impact for a yawing hit, the Turkish for tail strike and belly hit.
 
Old 12th May 2011, 16:08
  #1243 (permalink)  
 
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takata, assuming the head was attached when retrieved and remained attached when the bodies were brought aboard, they really wouldn't need DNA, just the dental records.

Importance of dental records for victim identifica... [Public Health. 2007] - PubMed result
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Old 12th May 2011, 16:16
  #1244 (permalink)  
 
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IMHO the APU and the two engines give a consistent projection to the bottom of the a/c at impact.

The distribution of the other parts could well be attributed to different exposure to westward setting subsurface currents or tumbling/sliding effects during their way down.

That would give a heading between 80 and 120.
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Old 12th May 2011, 17:36
  #1245 (permalink)  
 
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Fan Casings

Tubby,

I, like you, think the items denoted in red are the ones recovered and the ones in blue are those of interest not recovered at the time this slide was prepared. The fan casings would be of interest as they do contain the engine controls which are mounted on the side of the fan casing just forward of the fan frame, if they are still present.
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Old 12th May 2011, 17:49
  #1246 (permalink)  
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TurbineD

Hiya TD. From their particular deformation, wouldn't these composites divulge with precision, the angle with which they hit the water? Metal 'forgets'.
 
Old 12th May 2011, 19:28
  #1247 (permalink)  
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Chris Scott

"Other than an academic point of view .. what is the importance of the "trajectory" when a/c hit water or a/c heading for the investigation of the accident ?" jcjeant.

Try to keep your players straight. I am the one who is confrontational, opinionated, ramble, and am ambiguous.

jcjeant is none of those. Save your rancor for the one who admits to your charges.


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Old 12th May 2011, 19:43
  #1248 (permalink)  
 
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Hi Bear,

Yes, there is some information to be had in the recovery of the fan casings. Fracture surfaces tell much (direction & path). The 80C & 80E engines went to a "soft" containment construction from earlier engines. The casing portion where the fan blades are located is made of aluminum. On the outside of this is an aluminum honeycomb structure that tapers in thickness, thin at the LE, thick in the center, thin at the TE in respect to the fan blade tip. The honeycomb is then surrounded by a kevlar/epoxy protective cover. Recovery of this, if it is still there, might also provide some interesting data.

Beyond what has been recovered must be a list of prioritized items the BEA would like to raise, fan casings being one of many. Time is growing short as the ITCZ will start becoming active very soon with stormy seas and torrential rain squalls. There is always the possibility the FDR may not yield all that would be liked to be known making the recovery of parts and pieces very important to develop the most accurate complete picture.

I find it interesting the respective resting locations of the 4 weightiest components, the engines, the main landing gears (partial wing section attached?) and the nose landing gear. The MLG's must have been influenced by the wing sections during descent in the water. Just some personal observations.
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Old 12th May 2011, 19:50
  #1249 (permalink)  
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TurbineD

Sincere greetings,

I agree surface conditions may soon preclude further work. The site is impervious to weather, and has remained loyal to its condition upon landing, one thinks?? The parts are instructive, and this zone will reveal data for years to came, as our technologies advance to perceive as yet undreamed of evidence from metallurgy, materials, even Physics itself.. It will wait. It is a place of almost sacramental importance, and I have wept while looking at it......God have mercy on those therein, and those who love them, and those who but for God's grace would be there in their stead.
 
Old 12th May 2011, 20:00
  #1250 (permalink)  

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I, like you, think the items denoted in red are the ones recovered and the ones in blue are those of interest not recovered at the time this slide was prepared.
Red : recovered
Blue : Not recovered ... yet.
Black : Located but not subject to retrieval, unless the recorders won't talk. In this case, will be recovered for investigation analysis.
(From to-day's briefing)
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Old 12th May 2011, 20:09
  #1251 (permalink)  
 
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Turbine D where is the fadec located on the -80E1? On the Trent it is located on the fan case.
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Old 12th May 2011, 20:22
  #1252 (permalink)  
 
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Tubby

The FADEC on the -80E is located on the fan casing at the 2 o'clock position as you would be looking at the fan from the front of the engine.
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Old 12th May 2011, 20:29
  #1253 (permalink)  
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Architecture question. Isn't the TRENT's engine control mounted on the engine itself ?? Not the Fancase ??

Tubby

That "oil slick" or "pollution spot" had the makings of being the fuel from THS tanks. The tail section, if it hit first, wouldn't it have been at the beginning of the debris field? Otherwise, if the chevron shaped HS held together, it may have "flown" off in some unrelated direction??

Last edited by bearfoil; 12th May 2011 at 20:42.
 
Old 12th May 2011, 20:39
  #1254 (permalink)  
 
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The FADEC on the -80E is located on the fan casing at the 2 o'clock position as you would be looking at the fan from the front of the engine

So this is why the fan casings would be of interest if they cannot recover any information off the fdr?
Nobody else has picked up on my comment about where the THS is..For a mission such as this the minimum fuel in the tail would have been at least 2500kg at TO with the trim adding up to another 2000 kg for the cruise.If 4500 kg of fuel was trapped inside ther trim tank it would have made the THS relatively buoyant but if it leaked out I would have thought it would have made a visible slick on the surface...but what do I know!!!
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Old 12th May 2011, 20:40
  #1255 (permalink)  
 
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Bearfoil -fcom 1.70 .20 p1 the Trent fadec is mounted on the fancase.
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Old 12th May 2011, 21:01
  #1256 (permalink)  
 
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80e1 ecu

Tubby,

80E1 ECU (= 'EEC' in GE FADEC architecture) is mounted on the LH Fan Case @ +/- 8 hr. position.


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Old 12th May 2011, 21:15
  #1257 (permalink)  
 
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Press conference


sorry in French

This gentleman is speaking of the card and says that about one day is needed to dry the "cards" from the recorder(s)in a special oven (étuve) then they will start to "discharge "the data from the card to a bank that will be able to read the data. He said that discharge means to copy the data not to transfer these data. Count 3 days if everything is going fine. At the end of this video he says that he proposes to meet again next Monday to give the results of these operations
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Old 12th May 2011, 21:16
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Fan Casings Recovery

Tubby,

That would be my thought, The FADEC would have some interesting information.

Bear

I think the location of the FADEC on the fan casing is for two good reasons:
1. It is a relatively cool (as in temperature) location, any location aft becomes warmer.
2. Servicing convenience, just pop open the cowling and the FADEC is right there, easy to get at.
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Old 12th May 2011, 21:42
  #1259 (permalink)  
 
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Trajectory at impact

I have watched the waxing and waning of the various contributors on what still seems to be a contentious issue, i.e. "the in line of flight, with low bank, tail yawing to port and a high vertical velocity". I have also seen mention of Ethiopian 961 and can see little similarity with what happened there and the effective "slam dunk" that appears to have terminated AF447's flight.

The BEA reported the facts as they had deduced them from wreckage previously recovered, and in doing so gave ample examples (complete with photographs) of the damage and how it was caused. I don't believe that anything has changed in what they reported, as the bottom debris field is made up of many separate pieces of debris, each with differing mass, terminal velocities and hydrodynamic characteristics (including drag). Those items with high mass/volume made it (in my opinion) to the bottom effectively directly under the position from whence they separated from their normal place of attachment.

The detached FDR CSMU fits that category even better than the #1 and #2 engines, as its drag coefficient would be less.

My interpretation of previously published data leads me to believe the low bank angle was to port and the #1 engine "dug in" a fraction of a second before the #2 engine. The tail, yawing to port, will have "dug in" at the same time as the #1 engine. All other items found on the bottom have taken longer to get there, and some have (due to their shape) glided/spun/spiraled down.

In general, the overall effect of the subsurface current appears to have been from 075°T to 255°T and the objects with the least mass/volume have taken the longest to travel the nearly 4km to the bottom and are distributed further to the west.

The aircraft had a trajectory at the time of impact, and I am inclined to say that its horizontal component was North of East and the aircraft's heading at impact was close to East. However, as the Rate of Descent was high, this was no "skipping stone" accident and all horizontal momentum was arrested in just a few meters - say <10m.

The usual rider; - this is just speculation and the FDR could well tell a different story.
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Old 12th May 2011, 21:53
  #1260 (permalink)  
 
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A33Zab

Thanks,

Think I stand corrected, I was looking at an engine photo that might not be a -80E engine but an -80C?
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