infrequentflyer789

"If it helps, this is my attempt at a not-actually-Photoshop overlay:"

Yes, thanks for identifying the cylindrical part.

It looks somewhat like an oil filter for an ICE engine.

At 16m or even to 50m...you can dive supplied air however long you want....
We have ROV's that can map an area, with video, sidescan, mag, and sub-bottom profilers...mowing the lawn for weeks...
Most have a recovery arm....

turbidus

"Mag"? As in magnetic field detection?

In P#606 I asked "does submersible technology exist that is capable of locating a stainless steel component (which may be made of an SS with properties that are not strongly responsive to magnetic field detection) at some depth below the surface of the sea bed amidst a debris field made up of aluminum and other metallic objects?"

The magnetic properties of stainless steel alloys vary significantly according to elements added to the alloy family. The SS pots in my cupboard are NOT responsive to a magnet, the trim on my vintage car IS responsive.

Also of course there will be a million small pieces of wreckage in the mud :(

At extended times (think hours) this become saturation dives which need much more support and safety equipment compared to normal open water equipment, since you can not decompress to surfaces pressure in short times. You will need chambers and pressurised living compartments. Problem is the nitrogen saturation of your blood and it will take days for decompression after you are fully saturated.
The homo sapiens physiology is not good adapted for long stays below 10m ( 2000mbar absolute pressure) under water level.

The twisted pieces of orange-coloured sheet metal on the tank holding the FDR are most of what was stripped from the top of the CVR enclosure displayed a few posts up the thread. Attachment points for where the CSMU was positioned on the CVR enclosure are visible.

The seemingly intact ULB cylinders on top of the tank - one of which was suspended in brackets protruding from the side of the missing CSMU - look incongruous beside those twisted pieces of sheet metal and the mangled sheet metal CVR housing the pieces were torn from.

https://cimg9.ibsrv.net/gimg/pprune....728d2827c4.png

With so much of the CVR in hand, it is tantalizing to think that the CSMU was nearby, but somehow overlooked.

As lomapaseo intimates, the CSMU might be embedded with other debris. While a thorough search through the artifacts already brought to shore has probably been done once, a second pass with fresh eyes couldn't hurt.

The primary challenge here is the nature of the seafloor rather than anything else. The bottom is not distinct, but consists of a deep layer of fine silt carried to the sea by rivers from the surrounding tropical islands (it is not open ocean, but an enclosed shallow inland sea) which is intermingled with both live and decaying micro-organisms that feed on the nutrients in this silt. The mud thickens as one goes deeper, but the top layer is practically of liquid consistency, any denser object will sink into it. Firm ground is several metres below the top of the mud, and any dense compact object will sink to the bottom. Probably all wreckage that was light enough or large enough to stick out of the mud has already been recovered, now the only way forward is to suck away the mud and search by feel, as visibility is next to zero during this process (and when suction stops, nearby mud flows in to fill the void). If done in a systematic way, this will eventually lead to the recovery of all wreckage, but it is a really tedious slow process.

Who pays for this effort and who manages it?

Who do you think should and why?

It seems nobody agrees since there is no law

Think the best candidate would be IATA, because they live and die by the air transport industry. Plus they presumably have a serious interest in minimizing disastrous aviation accidents.
That does not address issues of expertise or funding, which are separate, but there does need to be some entity that handles international crashes effectively.
Perhaps the BEA or the NTSB need to become UN sponsored entities to allow them to take on this role>

There's an idea, etudiant.

Here's another. The UN could name the entity the International Civil Aviation Organization, ICAO for short.

andrasz

If these are the conditions on the bottom (sea bed) are as described above, divers searching and finding an item such as the CVR component are pretty remote.
As a certificated advanced enriched air diver just disturbing a muddy,silty bottom with a hand or fin renders visibility to zero.
At 16 metres Nitrox 40 is a little OTT, Nitrox 32 is more than enough to give more bottom time and a quicker safety stop (decompression) on ascent.
Divers aiding suction dredging and filtering would be far more productive than literally groping around in zero visibility feeling for the CVR component.

EddyCurr

Well if it's money you want why don't you just go directly to the pot that funds ICAO., maybe that has a slush fund not yet allocated

I believe that is exactly what is happening, but the divers still need to search by hand for remaining heavier components that are not dislodged by suction.

Which one of the several international aviation agencies actually picks up the tab?
Is it a 'case by case' situation or are there agreed rules?

The SAR agency in whose SRR the aircraft is located is responsible for the cost. However if the SEARCH is concluded and there is no RESCUE likely then other factors come in to play. MH 370 for example.

Ref post 711 - Who pays?

Indonesia has been down this road before. See the salvage section of this.

https://en.wikipedia.org/wiki/Adam_Air_Flight_574

I don't believe it's accurate to speak of "several international aviation agencies." There's ICAO. And it's the only game in town.
IATA is a trade association; IFALPA an organized labor entity; ACI an airports industry group, etc.

Annex 13, under which investigations are conducted, itself isn't exactly "law." The Chicago Convention of 1944 is an instrument within international law, but the extent to which any Annex is "law" gets into pedantic territory (and even more so regarding SARPs....).

Regarding the questions referring to the responsibility of the SAR costs, if my rusty memory is correct it was all set out in the original 1944 Chicago Convention (the one that established ICAO) or perhaps some later amendment. Adhering States provide Air Traffic and SAR services to all flights falling under the Convention, and in return they may collect an Air Navigation Charge proportional to the overflown distance modulated by an aircraft weight formula to recover these costs. While purely domestic flights do not fall under the Chicago Convention, most adhering States apply the same rules to domestic traffic too. Same Convention sets out responsibilities for accident investigation, and any related search and recovery costs are bourn by the investigating authority (in principle also funded from the Air Navigation Charge). The picture becomes complicated when a small country (with proportionately small ANC income) needs to fund a major investigation (usually involving a foreign airline), but in this case they have the option to delegate the investigation to another interested party (State of operator or manufacturer).

Of course in real life in most countries the collected charges just get swallowed up by the larger state budget, and there is some moaning involved when the bill is presented for an expensive recovery operation (usually carried out by specialised salvage firms).