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AF 447 Search to resume (part2)

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AF 447 Search to resume (part2)

Old 16th May 2011, 15:20
  #1481 (permalink)  
 
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Pitot Upgrade

I remember a post very early on here that the mechs at destination had received ACARS report of faulty airspeed on 447, and moved that plane to the front of the queue for getting the new pitot probes.
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Old 16th May 2011, 15:53
  #1482 (permalink)  
 
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Originally Posted by RatherBeFlying View Post
I am worried that the BEA announcement hints that FDR readings will not be released until the next interim report "after analysis".
I don't think it's about the technical difficulty. The BEA isn't a press agency, its missions don't include, AFAIK, to release ASAP all gathered data.
They have (and will) release intermediate & final reports when those are finished/ready/approved.
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Old 16th May 2011, 16:14
  #1483 (permalink)  
 
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Recovered Engine Observations

lomapaseo,

Thanks for the good photo of the engine.

Bear,
Your arrow (fore), are you noting the sheared Fan Blades as evidence of high N1?
IMO, what you are observing is not sheared fan blades. The entire fan blade rotor including the disc is gone. What you see are remnants of either booster vanes or blades, but, I can't tell for sure which from the angle of the engine. There is quite an axial distance between the fan rotor and the fan frame. The space between is taken up by 5 stages of booster vanes with 4 stages of booster blades between each stage of vanes. This package of airfoils is sometimes referred to as an LP compressor. It is really hard to say what the N1 speed might have been from this photo, will have to wait for the FDR information to exactly know. If I would hazard a guess, I would say the engine was running (rotors rotating) at impact.

The depression in the stator ring, does that indicate 12:00? Where the engine was lifted into the pylon? The extensive damage below (6:00), that would be water contact??
The 12 o'clock position is at the rectangular box-like structure just to the right of depression. The rectangular box structure is integrally cast as part of the one piece fan frame hub. To this an engine mount yoke is attached. You will note in the photo below this a flat platform. The platform attaches to a landing area integrally cast as part of the fan frame. This is a complex mounting system which contains a triple redundancy failure system. Vertically loading is transmitted by 4 bolt between the pylon and then to the mount yoke. In the mount yoke the vertical loads are carried down links on both sides to clevises on the fan frame. You can see one of the clevises in the photo, the broken link is visible and perhaps tells a story. It is both bent down and rearward besides being fractured. By the way, the pylon attachment point is to the horizontal platform.

After two years at sea, this engine looks as though it was just removed from a mineral oil bath, very clean. What do you make of the integrity of the IP/LP turbine casing, very stout, yes? So much plumbing left, and reasonably continuous.

The crinkled vanes, there's your forward acceleration, yes? A few milliseconds post water contact?
The rear engine mount has a linkage yoke which contains two short pivoting links on one end that that is joined by pins to accommodate thermal expansion between the mount and frame while the link on the other end directly connects to the turbine frame integrally cast clevis. This then connects to the rear pylon strut bulkhead by means of an upper mount fitting and linkage that accommodates differential thermal expansion of the engine relative to the pylon. In looking at the photo, this detail was all crushed by the vertical impact and appears to be gone, stayed with the pylon?

The "crinkled vanes" should be the stage 5 turbine blade rotor. The turbine rear frame serves as an aerodynamic stator and the LPT module is referred to as a "5 1/2 stage module". The LPT casing is a 360° machined forging made in two sections. The forward section is of a higher temperature capable material welded to the aft section made from the same alloy as the turbine rear frame one piece casting. It is a strong design and should be capable of retaining multiple blade failure from exiting the casing walls. I can't tell what the "crinkling" means as the down (180°) section of the aft end of LPT can't be seen to know if it has been crushed from the vertical forces.

As a matter of interest, these engines are produced (assembled) in the US as well as in France at a SNECMA plant, shared or co-production.

Correction:

Bear, your observation concerning the existance of fan blades is correct. The video in a subsequent posting shows the front of the engine, even the spinner cone on this engine is present. It is the least damaged engine of the two. In the video you will see the second engine pulled up, it has the fan rotor completely missing.

TD

Last edited by Turbine D; 16th May 2011 at 20:46. Reason: Correction of observations
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Old 16th May 2011, 16:18
  #1484 (permalink)  
 
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AZR & others

Let's not overlook the fact that various interested parties, especially Airbus, will be provided with a copy of the FDR data very quickly.

In the past, if Airbus finds an aircraft-related issue needing operator action or warning, it issues a notice to all operators within days.

This is not intended to guess or replace the official BEA conclusions.
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Old 16th May 2011, 16:21
  #1485 (permalink)  
 
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@ Graybeard in re distance and decision points: thanks for the insight on timelines and timeliness.

If the radar is manipulable by the aircrew, and there are two pilots in a cockpit, and aircrew is familiar with the equipment and its function, I am not sure that the automated version is a requirment. I realize this is a partly philosophical argument, and partly fiscal, since you note that companies are loath to upgrade (cost!) without a compelling reason.

To expand my thought into CRM, if the crew is aware of weather forecast before takeoff, and conditions en route, and get occasional to frequent updates on weather as flights progress, then where there is the sort of weather that Wx radar is built for analyzing, the crew prioritizes that function (figuring out how nasty that Wx up ahead really is) in its tasks en route. One pilot flying/monitoring performance compared to planned and expected, the other "I am on radar" monkeying with the radar to coax the best performance out of it that he can.

Seems to me well within the remit of multi place aircraft crew task loading.

What am I missing? Is the auto feature more useful in terminal area evolutions (departure/arrival) or is it intended for more robust capability en route?
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Old 16th May 2011, 16:31
  #1486 (permalink)  
 
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would they be expected to communicate with other planes flying the same route re weather up ahead?
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Old 16th May 2011, 17:10
  #1487 (permalink)  
 
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Recorders

I for one would like to congratulate Honeywell for manufacturing such strong recorders. This certainly will be a boost to the company's name and reputation.
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Old 16th May 2011, 17:20
  #1488 (permalink)  
PJ2
 
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Lonewolf50;

Re "automated" radar...let me dream off-topic a moment. I am thinking about the usual moisture-driven images but married with real-time satellite returns which provide pilot-selectable three-dimensional images and which place one's aircraft in-situ, in-scale, real-time, with the weather one is navigating a path through/around. Such radar would find shear conditions and provide sufficient filtering for crew awareness without overloading them with possibly-available data but which somewhat-to-largely irrelevant to safe flight around the kind of weather seen here. The quality of the data must be extremely high [reliable] but presented graphically and simply so quick decision making about pathways that are, say, ten miles ahead, (just over one minute of flight) and within the turn-rate capability of between 1 & 2 deg/sec. Such capability avoids the threats-to-flight of signal attenuation, (blocking of returns by closer build-ups).

As with RVSM and lower RNP capabilities and such technology's effects upon altitude availablity in increasingly density-challenged airspace, such technologies might tempt tighter fine-tuning of clearances when negotiating giant squall lines, but all this is dreamland stuff. But is "To Filter or Not to Filter", automation's question? I much prefer manual control so I am more aware of the basis upon which the radar returns I am viewing are created. As many others who do this work here have attested, switching between manual and auto gain, tilting the antenna to "survey" heights of returns and simply being aware of the nature of returns, provides more than adequate information to see, anticipate and where necesssary, navigate such weather.

At night, just looking out the window, hand on the heading knob, with permission to deviate, (using CPDLC!..brilliant technology), and watching the radar while observing/memorizing the "pattern of buildups" during (distant) lightning flashes or by moonlight, can be as effective a deviation technique.

In my experience, far too many crews did not know how to use radar and did not even understand what the returns really meant. Rather than spending money on automating the radar-return process, a better bang-for-buck is teaching crews how to use radar correctly but that's tactical approach and doesn't add to business's bottom line or share price.

Last edited by PJ2; 16th May 2011 at 17:36.
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Old 16th May 2011, 17:22
  #1489 (permalink)  
 
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Unless something really unusual / extraordinary happened I would say that the investigators would have a broad picture of what happened with hours of retrieving the content of the FDR / CVR. I would be very surprised if they manage to avoid any leak within the next 2 months...
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Old 16th May 2011, 17:34
  #1490 (permalink)  
 
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@ oldchina (#1484)
Yes of course. My point was to say that the "impatience" of the general public (and the "public" within the industry) has never better been addressed by the BEA. Therefore, let's be patient. They will know before the vast majority of PPruNers. And when they say when they're to release data, it's a careful saying : IMO better say "you'll not hear from us before summer", and disclose data sooner than anticipated, than the contrary.
As you point it, Airbus will know before us, too. And that's good for safety, as well shown in your post.
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Old 16th May 2011, 17:45
  #1491 (permalink)  
 
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Earlier press reports said that there have been a few cases where info in the FDR was not able to be read after it was recovered.

Would anyone like to speculate on how these boxes survived in 10,000 feet of water for so long? I would have thought the pressure alone at that depth would have made this unlikely.
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Old 16th May 2011, 18:29
  #1492 (permalink)  
 
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They're rated for an even greater depth so not suprising at all that they survived. Finding them 2 years later without the pingers on the other hand.....
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Old 16th May 2011, 18:39
  #1493 (permalink)  
 
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PJ, thanks.

In my experience, far too many crews did not know how to use radar and did not even understand what the returns really meant. Rather than spending money on automating the radar-return process, a better bang-for-buck is teaching crews how to use radar correctly but that's tactical approach and doesn't add to business's bottom line or share price.
1. Isn't it cheaper to do than buy more expensive new kit?
2. Isn't there a motivation, a cultural norm within the pilot community, to know what the kit does? I guess something you are touching on is how to formalize the passing on of lore, rather than the informal "learn on the job" that many pilots are familiar with.

Can't there be a mix of both? Does this all have to be "either or" in terms of getting to know one's machine?
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Old 16th May 2011, 18:42
  #1494 (permalink)  
 
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WXR-2100

Rather than try to explain it, this is from Collins:

The Rockwell Collins MultiScanTM Hazard Detection System is the first and only radar that analyzes and determines actual weather hazards, not simply atmospheric moisture content to provide flight crews more accurate weather returns. The MultiScan system is derived from extensive operational experience to create a fully automatic, hands-free airborne radar system that reduces pilot workload and enhances safety and passenger comfort by minimizing unexpected turbulence encounters, and provides optimal clutter-free weather displays.
Learn more about MultiScan at Rockwell Collins’ Web site: http://www.rockwellcollins.com/products/cs/at/avionics-systems/weather-hazard/science/index.html

Key Features & Benefits
  • Fully automatic operation
  • Advanced ground clutter suppression at all ranges
  • Enhanced geographic and seasonal weather correlation for maximum worldwide performance
  • Optimized weather detection from 0 to 320 NM and all altitudes
  • OverFlight™ Protection (prevents inadvertent thunderstorm top penetration)
  • SmartScan™ real time weather in turns
  • TrueZero™ antenna compensation
  • Predictive windshear detection with magnitude, velocity and duration data recording and retrieval
  • Variable temperature based gain
  • Certified turbulence detection
  • Redesigned RF section for improved performance and enhanced reliability
  • Demonstrated industry-leading pedestal reliability
  • Simultaneous display updates in all range/mode combinations
  • Split Function Control on some platforms
  • Optional manual mode can be used by crews at any time
You can buy the automated radar with 20 years of improvements one time, or forever train and re-train pilots. Do you have any idea how much the airlines should be spending on training for a 30 year old system?
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Old 16th May 2011, 18:43
  #1495 (permalink)  
 
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Survival of FDR data unit

Simply by adequate engineering. Desighn depth is close to 20 000 ft. Exposed was the unit to about 13 000 ft. So a lot less than desighn + saftey margin. The hydraulic environment produces a steady load. So if that piece is watertight at the beginning of the period under water it will be watertight even after 2 years or more.
I remember a post in this thread that showed the exact data for that type of FDR, beside the 6000 m depth resistance I thought to remember an impact resistance up to 750 km/h. It´s apparently a very massive piece made of steel.
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Old 16th May 2011, 19:02
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Radar manual scan at many tilt angles

Graybeard,

the tilt should have been pointed down into the wet part of the storm, moving the tilt up and down to see maximum return
I commented on this simple and effective procedure in a post some weeks ago.

In most of cases doing that you will be able to fully "characterize" the WX pattern ahead for an adequate "decision making/risk taking" by scanning from sea level to your FL.

And this possibility certainly they had in advance.
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Old 16th May 2011, 19:05
  #1497 (permalink)  
 
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Annex14

Simply by adequate engineering.

Simply by engineering to the specifications. Unfortunately 228 souls had to lose their lives to prove, in a real accident, that the company produces what it promises.
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Old 16th May 2011, 19:15
  #1498 (permalink)  
 
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I commented on this simple and effective procedure in a post some weeks ago. In most of cases doing that you will be able to fully "characterize" the WX pattern ahead for an adequate "decision making/risk taking" by scanning from sea level to your FL. And this possibility certainly they had in advance.
I don't understand. Is that a criticism of the flight crew?
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Old 16th May 2011, 19:24
  #1499 (permalink)  
 
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Wow, where are you guys getting all the news tidbits on AF447? Some "great" pictures in this thread too...where's it all coming from?

Any word on FDR / CVR data recovery yet?

Does France / "Europe" allow the release of such information to the public?
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Old 16th May 2011, 19:27
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Readable after ~2years at ~4,000m depth

It´s apparently a very massive piece made of steel
The one showed in mfr website for 4700 is not the cylindrical shape. (see my post #417)

They are using the same case now for CVR/FDR memory. And proved successful.

We need ASAP better ULB´s. Being addressed presently.

And "last but not least" better AS sensors. The 38 cases with machines so dependent on it´s data is a proof of a "slow motion" kind of bureaucracy.

Still for some time giving chances to "Murphy Law".

Last edited by Jetdriver; 16th May 2011 at 20:40.
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