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AF 447 Search to resume (part2)

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AF 447 Search to resume (part2)

Old 1st May 2011, 07:55
  #401 (permalink)  
 
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Machinbird, that excitation idea is pretty good with a large "if" involved. If the "speaker", the element that imparts the sound in the water, is a resonant element of some sort it should work fine. If not getting energy in through the water to housing discontinuity and then the housing to air discontinuity inside may be difficult. And the resonant element, if there is one, would have to get hard enough to get energy back out.

It might have something as simple as an RC time constant setting the oscillation frequency. With a little more complexity it could be something akin to a watch crystal. (And without driving it so hard it fractures you're not likely to hear it outside of the crystal case.) The next step up might be a tiny higher frequency crystal with a CMOS divider circuit to get it to frequency. I'd vote for the little quartz tuning fork or watch crystal type oscillator.

Stepping backwards a tiny bit if the structure itself plus the transducer has a resonance it might be possible to excite that and notice a distortion in the return signal as you go over the package. The package should have several resonances. Maybe one of them is strong enough to be exploitable.
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Old 1st May 2011, 07:57
  #402 (permalink)  
 
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Loose_rivets, military sonars are well beyond reasonable power for this application. Get too close to them in the water and you'll get homogenized nicely. (With some slight exaggeration. It'd not be at all healthy and likely deadly.)
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Old 1st May 2011, 11:35
  #403 (permalink)  
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Image metadata

ChristiaanJ,

> Does anybody really know the origin of this picture?
> All that's obvious so far is that it was "photographed" from a video monitor, presumably on the "Ile de Sein", since it's in colour."

The information sought is largely present in the image metadata. Personally, I like the way they've tethered the monitor to the desk.
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Old 1st May 2011, 12:29
  #404 (permalink)  
 
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Machinbird

If you could excite this with a pulse of the appropriate frequency, and if it were nearby, you might receive a slight signal back from the oscillating element after the exciting signal cut off. This signal would have a characteristic amplitude decay over time which should be easy to characterize from experiment with similar pingers. You would also receive echos of the original pulse as it bounced off more distant items, but these would not have the characteristic decay signature.
Oh wow! Have you been reading your "Magnetic Resonance Imaging for fun and prophet" Machinbird? That is exactly the basis of MRI and you may have hit on a novel and just possible answer. Nice one.

The return signal will, of course, be tiny and distance will work against you dreadfully, but at the frequencies we are talking about, powerful transmitters are already available and suitably sensitive receivers too. Experimentation would, as you suggest, be necessary to study the characteristics of the received FID (Free Induction Decay) and what proportions of transmit and receive would be necessary.

And you wouldn't need a nice, clear signal ready for image reconstruction, just a return - any return - showing the FID of the pinger.

Very nice lateral thinking sir, if I might say so?
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Old 1st May 2011, 14:10
  #405 (permalink)  
 
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There is a K.I.S.S. way to check

Machinbird,

http://www.pprune.org/tech-log/449639-af-447-search-resume-part2-20.html#post6422330

With the number of EEs looking at this thread, I'm sure the darts will be flying if it won't work. Fire when ready.
BEA should test! Could be done in few hours at lab. (low water pressure)

Considerations:

1) If you transmit high power pulses and listen after a short burst you may be able to detect.

2) I send you a "DART WITH KUDOS" for your feeling!
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Old 1st May 2011, 14:24
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CSMU location

Machinbird,

On AF447, I would be most surprised if the pingers are still attached to the memory modules.
They SHOULD be still attached. They were designed for.

Anyway, there are several improvements that should be made after AF447 crash and the "boxes" are candidates for.

Last edited by Jetdriver; 1st May 2011 at 14:42.
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Old 1st May 2011, 14:41
  #407 (permalink)  
 
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Machinbird

Great suggestion. This is above my pay grade, but not understanding. I would think that those knowledgable in this field could refine your idea thereby improving the possibility of sucess. Implementation should not be all that difficult with proper preparation. Lets hope some consideration will be given by those who know.
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Old 1st May 2011, 15:01
  #408 (permalink)  
 
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Non metalic VS structure as HF antenna

JD_EE

Your second message prompts as reply that I am interested in your observation that a non-conductor can make an antenna. Your message is nonsense because the VS is fiberglass with little or no metal in sight, so far as I know.
Even if AF447 plane had an all plastic (non electrical conductive) VS structure it still had an HF antenna in it. And the antenna was not the high current shunt feeder. It΄s more than that and much taller.

Do you know why?
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Old 1st May 2011, 15:19
  #409 (permalink)  
 
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Public domain solution (non patenteable)

Machinbird,

Your idea and comment could be used in next generation of CSMU location devices (pingers, etc)

If you could excite this with a pulse of the appropriate frequency, and if it were nearby, you might receive a slight signal back from the oscillating element after the exciting signal cut off. This signal would have a characteristic amplitude decay over time which should be easy to characterize from experiment with similar pingers. You would also receive echos of the original pulse as it bounced off more distant items, but these would not have the characteristic decay signature.
Our discussion, a world wide public one precludes the big companies to patent it and can be used for the aviation safety in the future.

Kudos!

I will comment the technical advantages of your solution for underwater box location. Will use messages area,. Who become interested i can copy.
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Old 1st May 2011, 17:06
  #410 (permalink)  
 
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Oh wow! Have you been reading your "Magnetic Resonance Imaging for fun and prophet" Machinbird? That is exactly the basis of MRI and you may have hit on a novel and just possible answer. Nice one.
Wow, The opposite of zingers! Thank you all!

I did try to stay awake in Physics classes . Magnetic resonance is nothing new. The signal processing developments are what made MRI practical. My "idle speculation" evolved strictly from an understanding of electronics state of the art and basic physcs. Probably not a highly attractive patent anyway because of the highly limited demand.

Before we all get too excited, just remember the saying that there is "Many a slip twixt cup and lip." Yes, a competent person could likely acquire the necessary gear in a week, assemble a working prototype in the second week, and go on to deliver a unit capable of functioning at depth in the third....If they had a broad area of knowledge about EE, signal processing, sonar transducers, and operations at extreme depth. There are just a few such people out there. Get a group involved and it slows down considerably. I would bet that the Ile de Sein crew gets lucky before anyone develops a functional unit but the concept mentioned could influence future recorder design (attaching passive resonant elements) and should be followed up on in case we do need a phase 6.
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Old 1st May 2011, 17:35
  #411 (permalink)  
 
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They got one !!!

Information, 1er mai 2011

Sorry guys : English also !
1st May 2011 briefing
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Old 1st May 2011, 17:37
  #412 (permalink)  
 
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Thanks for the info.
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Old 1st May 2011, 17:41
  #413 (permalink)  
 
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FDR localized and identified

Information, 1er mai 2011

The investigation team localized and identified the memory unit from the Flight Data Recorder (FDR) at 10 h UTC this morning. It was raised and lifted on board the ship Ile de Sein by the Remora 6000 ROV at 16h40 UTC.
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Old 1st May 2011, 17:44
  #414 (permalink)  
 
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Tongue Part Way in Cheek

from: Megalith Electronics
to: Mr. Pat Pendng

Dear Sir/Madam:

Thank you for your suggestion that we should buy your invention for Synchornous Anachronistic Wobbly Widget. However, we at Megalith have the greatest scientific and engineering minds in the industry, and if your idea had any merit, we would hold patents for it already.

Thank you again for your interest. We value you as a potential customer.

Randy Sparks, Vice President Engineering
Megalith Electronics

---
Then there's the reality that China does not enforce foreign patents.
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Old 1st May 2011, 17:58
  #415 (permalink)  
 
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Great News!

Let's hope it is as intact on the inside as it appears on the outside.


GB
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Old 1st May 2011, 17:59
  #416 (permalink)  
 
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They found it!!! Barely penetrated the silt - was worried that it'd require sonar scan to find it.

Let's hope the data is usable...
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Old 1st May 2011, 18:11
  #417 (permalink)  
 
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Well done!

It appears that of the CSMU's four attachment bolts, at least one is not there anymore but the remains of two or three bolts are still affixed.

Also, I see no sign of the ULB (underwater locator beacon). From a flight safety improvement viewpoint, this is in my opinion a cause of concern.
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Old 1st May 2011, 18:12
  #418 (permalink)  
 
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Now only one missing CSMU from Boxes of AF447

According to the information supplied by Air France, the airplane was equipped
with two flight recorders, in accordance with the regulations in force:
Flight Data Recorder (FDR)
 Manufacturer: Honeywell
 Model: 4700
 Type number: 980-4700-042
 Serial number: 11469
This Solid State Flight Data Recorder (SSFDR) has a recording capacity of at
least twenty-five hours. The decoding document, supplied with this airplane,
has around 1,300 parameters.
Cockpit Voice Recorder (CVR)
 Manufacturer: Honeywell
 Model: 6022
 Type number: 980-6022-001
 Serial number: 12768
Info on AF447 FDR:

980-4700-042
AC/DC supply
Option Long
ULB Yes
Des 4X
37 Mega Bytes non volatile memory
17.4 pounds Interface unit plus CSMU

SOLID STATE FLIGHT DATA RECORDER
4X SPECIFICATIONS
Honeywell Part Number 980-4700-04X
Packaging ARINC 404, 1/2 ATR Short & Long
Weight 16 or 18 Pounds, Nominal
Power 115 VAC, 400 Hz, 15 W; 28 VDC, 8 W
Data Capacity 25 Hours @ 256 Words/Sec (3,072 bits / Sec)
50 Hours @ 128 Words/Sec (1,536 bits / Sec)
100 Hours @ 64 Words/Sec (768 bits / Sec)
Data Storage Medium 36 Mbyte, Flash EEPROM

The SSFDR's crash survivable memory unit (CSMU) provides for complete data recovery when subjected
to the crash conditions stipulated in ED-55 and ED-56a:
• Impact Shock 3400G, 6.5 milliseconds
• Penetration Resistance 500 lb. weight from 10 feet
• Static Crush 5000 lbs., 5 minutes
• High Temperature Fire 1100°C, 30 minutes
• Low Temperature Fire 260°C, 10 hours (per ED-56a)
• Deep Sea Pressure and 20,000 feet, 30 days
• Sea Water/Fluids Immersion Per ED-55
The CSMU design has been fully qualified to these requirements and, in fact, exceeds them by
considerable margin in key survival areas:
• Impact shock has been successfully demonstrated at 4800 G's
• High temperature fire exposure has been tested to 60 minutes
• Low temperature fire was tested immediately after exposure to 1100°C fire



Info on AF447 CVR:

980-6022-001 120 minute model

Weight: 16 lbs. max
Temperature: Operating: -55 to +70C
Short Term Operating: +70C
Non-Operating: -55 to +85C
Altitude: +50,000 ft MSL Humidity: Severe Environment
Shock: Operational 6 g 11 ms duration
400 Hz single phase or +28VDC
Power Consumption: 8 watts typical, 35 watts max
Input Impedance: 10K ohms Output Impedance: Less than 600 ohms
Bandwidth:150 - 3500 Hz on voice channels 1-2-3
150 - 6500 Hz on area channel 4 Harmonic Distortion: <3% total at 1.0 KHz
Recording Duration: Up to 120 mins
System Deactivation: Cockpit installed circuit breaker

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Old 1st May 2011, 18:15
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All the conspiracy theorists must be fuming by now......

But then perhaps they can now concentrate on how the french can insert faulty data in the recovered SSFDR
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Old 1st May 2011, 18:23
  #420 (permalink)  
 
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vanHorck

How do you know that these pictures have been really taken on the crash site ?
Are you sure that this is THE DFDR aboard AF447 ?
And of course, as you mentioned, data will surely be edited by the BEA/Airbus/AF conspiracy !

I am pretty sure that our beloved conspiracy theorists are going to have a field day on those pictures !!!!
At least 20 pages on the thread if they are in a good day !

Last edited by llagonne66; 1st May 2011 at 18:23. Reason: Typo
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