AF 447 Search to resume (part2)

[Machinbird]

I hope they have a "shopping list" of items to grab for the return to the surface if they don't find the recorders they are searching for on a particular run. With all the travel time going down to the wreck and up to the ship, It would be a shame to waste the opportunity. I would sure like to know the THS position. Recovery of the THS actuator would be key to a lot of questions.
Full nose up trim? Normal cruise range trim? Full nose down trim? The last would be the result of a crew attempt to recover the aircraft-unsuccessfully.

[RR_NDB]

Hi mm43,

The only purpose of my comment was to remember it is possible to locate buried ferrous and also other metals with simple devices.

The "oscillating tuned circuit" being moved to nearby not visible metal objects is a simple solution. There are other approaches.

The rationale is: A metal (ferrous or not) changes the environment of a coil and this can be detected. How? Can be by the voltage at coil terminals. This is used in aviation, the "Eddy current tester" for metal checking.

I must study if at salt water, high pressure and salt sand burying a small aluminum (Dural, Avional, Hiduminium) part; To check if the issue is more complex at this environment.

My intention was not to correct you with the bold red. Was to remember we are able to locate not just ferrous.

On the IC memories (non volatile) i commented just to remember the magnetic fields generated by locators will not affect recorded data.

Stay sure my comment was to ADD and in an assertive way communicate to clarify inform what i am convinced.

Sometimes we can fail and learn from errors. With a good and constructive intention this can be just a small CAT (clear air turbulence) in our "learning route". To further reduce the "error rate".

[ChristiaanJ]

Re the 'altered' image.
Sorry to restir the mud....
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.
Probably already a digital "photograph".
Then it made its way, via various intermediaries, to what we've finally been looking at.
How many more stages of 'processing' by all kinds of weird and wonderful software did it go through, before WE got a look at it? There are already obvious JPEG artefacts.

The picture does show the FDR chassis quite clearly. What else do you want? Maye there were some human remains next to it.... and if so, kudos to the BEA for publishing the photo without those.....


PS Maybe one of our conspiracy experts could re-position the CSMU in that "grey area" and do a "Capricorn Two" ?

[RR_NDB]

ChristiaanJ,

conspiracy experts

Consider we are in early stages of the investigation we could imagine what we will see from them...

I am considering to sometimes "change my software" and exercise thinking like an active conspiracy expert. Likely will be funny.

And eventually opening our minds to the "unthinkable"

[mm43]

Flight Global - new A330 cut-away

Seeing there is continuing discussion on the components located in the area of the THS screw jack, and the apparent ducting, it is timely to note that Flight Global on 2011-04-01 published a new high resolution (4,500px Ũ 2,501px) cut-away of the A330.

The ducting referred to above appears to carry APU services (including fuel) and may also carry the fuel transfer line to the trim tank in the THS.

I suspect that the detail afforded will help in identifying objects as the are presented by the BEA.

EDIT :: Though of the A300 empennage, the cut-away below shows a similar general arrangement to that found on the A330.

[HazelNuts39]

PJ2;
I'm an engineer but not particularly knowledgeable about structures. At first sight, the rear frame appeared to me to be more complex than I felt to be functional. Next, I realized that this picture explains how the THS is assembled to the fuselage. The top and bottom thirds of the frame are one-piece forgings or castings, and are permanently fixed to the fuselage skin and stringers. The connecting parts between them are removable. I suggest these 8 removable elements need to be removed to put the THS in its place, and are then re-installed to attach the THS to the fuselage. Does that make sense?

[SaturnV]

An interesting description of what happened to an Israeli sub when it hit the bottom (2,900 meters) after experiencing an out-of-trim catastrophic hull failure.

The Dakar, imploded and broken up, continues her dive to the depths of the Mediterranean. Within 10-15 minuets she reaches the bottom of the sea and crashes with a huge impact. The crash separates the hull between the engine room and the stern compartment. This causes the broken stern to fly forward and land near the conning tower. Heavy parts fly in all directions,

(Unfortunately, the description is not from an official Israeli document. The sub was ex HMS Totem, commissioned in 1945, so maximum operating depth was apparently about 100 meters.)

All the oceanographic 'experts' badly missed the final position as well.

Search and Discovery of the Israeli Submarine Dakar

INS Dakar - Wikipedia, the free encyclopedia

[ChristiaanJ]

mm43,
Thanks for the link, and the picture you posted.
I would expect that the people on the "Ile de Sein" have those pictures at hand somewhere, but also the SRM (structural repair manual) of the A330, which is usually a lot more useful to identify 'bits and pieces'.
But for us 'at the outside trying to look in', those pictures should be some help.

RR_NDB,
I "like" 'conspiracy stories', especially to try and understand where they come from.....
Like UFOs, chemtrails, the Habsheim and Concorde crashes, the Kennedy assassination, 9/11, the 'fake' moon landings, etc.
Always worth "keeping an open mind", but usually the 'conspiracy stories' have the 'moonbat' signatures written all over them.

[bearfoil]

mm43

Most excellent diagram. On this A300 one sees three towers, keel to spine, of four faces, with extensive bridgework, that support each saddle which in turn receives the three pins that mate the VS to the Fuselage. They are extensive,and impressive. Take note also of the "lateral rods" detail.

Though the 330 has the rods, the superstructure that fixes each saddle through the fuse and to the keel are not present. What do you make of that??

[ChristiaanJ]

Originally Posted by bearfoil

[B]Though the 330 has the rods, the superstructure that fixes each saddle through the fuse and to the keel are not present. What do you make of that??

I thought we'd been there before....
'Redesign' may be the simple answer...... I think you're on to a red herring, bear.

[Chris Scott]

Purely from memory, I think the A300 has conventional (dural?) structures for the fin and tailplane. The A310 (1982/3) was, I think, the first Airbus to employ major composite structure; the fin is composite (made in Spain?). A similar fin may be used on the A300-600, which was contemporary with the A310. The A320 may take it one step further, as I think it has composite fin and tailplane. The A330/340 certainly have composite fins; not sure about the tailplane, err.. THS.

All the above is off the top of my head, and needs verification and/or amplification.


PS
Also purely from memory, the A300-600R was the first to use a tailplane fuel-tank, followed by the A310-300. But I suspect their tailplanes were made of conventional materials.

[RR_NDB]

Better HF

JD-EE

Inefficient and ineffective are two different ballgames.

Iīll use this to say you:

IMO a/c HF antennas could be more effective. Signals from ground stations would "better trigger" a/c receivers SELCAL; Signals from a/c would "better jump" over squelch thresholds of ground station receivers and crew could better communicate when VHF is out of range.

The efficiency of a C47, L1049, C130 (old versions) antennas were better than the "jet age" solutions.

Who compare? Old crews are retired and younger crews didnīt use older solutions.

I had the privilege to hear BOTH types and the difference is clear to me!

The antenna matching elements are not that bad.

We are talking about antennas and NOT ATUīs!

And efficiency of an antenna can be itīs capability to deliver a good signal to the back of your a/c. Itīs not related to "thermal effects".

On transmit it matters a little

Negative! This can be very important in certain situations!

Remember the "Threshold effect" in FM. We can think in an analogy when the ground station is under local QRN, etc. May be the difference in receive or lost the a/c call.

And every pilot know how difficult is HF in many situations. And always you can blame MUF, "propagation condition", noise, etc.

With better antennas at a/c and ground stations this could be completely different.

IMO the jet age, the SAT availability and other factors will not mention now reduced the "effectiveness" of a very good and reliable way of comm, the HF.

I believe the HF antenna is in the leading edge of the "plastic" vertical stabilizer.

FYI, this is not the antenna. Is just the element to "feed RF" to the VS. The other way (the DUAL) would be to "lift electrically)" the VS (through a china insulator) and feed the base of the VS with an ATU (L and C).

Very good engineers (mentioned by Graybeard 26th Apr 2011, 10:18) worked and invented adequate solutions.

Matching might get "dicey" at frequencies near 14 MHz

Voltage feed like in Zepp is "out of question" IMO in a modern airliner.

To be continued by editing.

[RR_NDB]

New materials VS and itīs RF current handling capability

Graybeard,

Airbus adopted shunt antennas in the fin from the beginning. I don't know how well they understand the dynamics, but feeding hundreds of amps into a carbon fiber fin makes me wary. That said, I have no direct experience with A/B HF antennae. AA587 and prior events it highlighted really had me wondering.

I have a high respect to EMI/EMC and i am addicted to safety.

In this case i indeed donīt see problems:

1) The shunt feed "excites" the VS metal structure with the high current (at feed point) going to large section aluminum parts.

2) As far i know the "new materials" is not to (or cannot) "receive" RF current. The RF current will "prefer" to be circulating in metal sections. In an all plastic VS you can integrate a wire to "carry" the current.

3) I did not see a relation to the "hard input" to AA587 rudder to our discussion. RF could damage the new materials VS? They tested, for sure.

4) One dangerous issue is, like i commented before, EMI/EMC to yaw damper system like ChristiaanJ commented on Concord.

Obs. B787 was hit by a lightning bolt during a flight test. And survived.

The currents in this situations are much higher than the ones delivered by an HF transmitter even if the operator keeps it at maximum power with high noise in the microphone.

I will investigate this issue asap.

[bearfoil]

ChristiaanJ

I think the 330 may be in a late, though not final, stage of completion ?? It could be a re-design, as you say.

[Machaca]

Neofit's linked images (post #222) are excellent, but of an A320.

The section 19 and tailcone structure of the A330 is significantly larger and more robust:

[JD-EE]

Green-dot,

Get a bucket, fill it with water. Get a spoon full each of sand, potting soil, metal filings from drilling or a lathe. Drop the sand in 3 cm from the center. Drop the metal filings in the center. Drop the potting soil in 3 cm the other side of center.

Now imagine the results of dropping those items into a 4000 meter column of water.

I think you can imagine your way to an answer for your question. (They are neatly sorted by the rate at which they fall more than anything else by the various currents they fell through. Note that the debris field is WAY larger than the plane's size.

[JD-EE]

RR_NDB, read mm43's message again. He cited the ferrite and brass tests for coil tuning. Ferrite or iron will tend to lower the tuned circuit frequency. Brass brought near a coil will reduce it's inductance (acting like a shorted turn) and raise the frequency. So he got the idea that you can detect anything either magnetic or conductive. (Under salt water this may face some interesting effects when looking for aluminum rather than steel.)

[JD-EE]

RR_NDB,

We are addressing this within the AF447 frame work. The planes are normally heard adequately loud at DAKAR, judging from what I can hear from planes going out over the Pacific with a poor antenna on my receiver. If DAKAR experiences high noise levels THEN the transmit antenna efficiency makes a difference.

On receive if you can disconnect the antenna, replace it with a dummy load, and then observe a decrease in noise as heard in the speakers or on the signal strength meter, there is no improvement to the antenna that you can make that is meaningful. I know there is ham lore that says you gotta have a preamp on the receiver to get best results even at 160 meters. 'Tain't so, McGee. I've carefully tested it. And actually listening is easier with attenuation cranked in enough to lower the noise out of the speakers if the AGC is tuned right. (I doctored my R-390A to prove this. It has a VERY nice gain distribution in this regard.)

At frequencies above 14 MHz the antenna input impedance may become fairly high. But, come to think on it, the coupler elements should have little difficulty matching the higher impedance at a higher frequency. The circuit element value range needed is well within range of a tuner that can tune down to 3MHz.

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.

Please do slow down and think first. (I know, I have the same problem.)

[Machinbird]

Here is a bit of idle speculation.
It regards the pingers. Yes, the batteries are deader than dead by now.
The actual oscillating element on the pingers must have a characteristic frequency (by oscillating element, I mean the item that transmits the vibration to the water.)
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.
You might also be able to transmit an odd harmonic and receive back some primary signal, but my math is a bit stale in this regard.
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.

If something like this would work, it might help find pingers lightly buried in silt or beneath other objects. On AF447, I would be most surprised if the pingers are still attached to the memory modules.

[Loose rivets]

I'd pondered the same idea in the search for landmines. I felt however the power of the ping would have to be beyond substantial.