Amazing news! Hopefully the plane is not below 4500 meters...so they can get back to the surface the remains of it.

Congrats to the Aussie and Chinese teams, superb job.

Ocean Shield at north end, Chinese ship at south end of high probability area.

He held up a map showing the locations of both ships and the high probability area (of presumed impact).

I wonder if there is a chance the audio signal could propagate quite a distance if deep underwater conditions enabled that?

He's also saying the search grid turn arounds take 3 hours (as we've heard on here, they're difficult)

Of course CNN crawl is saying "US towed pinger locator hears signal..."

Interesting re the towing of the device.

It is at 3000 metres and takes 3 hours to turn the ship around with the length of cable
that is out the back :rolleyes:

Commodore Levy comes across very well indeed. Liked his explanation of how sound travels through water.

At the press conference that just happened Houston said the white squares seen yesterday were checked and are not related to MH370.

I think he said 300k but also the usual provisos about cold water layers, salt layers and acoustics in the sea not being like in air so weird things can happen.
Ah sorry he talks in nautical miles. So 300 nautical miles.

A map:

https://twitter.com/SteveGrzanich/st.../photo/1/large

Water depth reportedly 4,500 m.

https://twitter.com/cctvnews/status/...586752/photo/1

Australian ship detects signals consistent with black boxes - Xinhua | English.news.cn

An earlier post said one ship's cable was 3,000 m, which could still bring it within range of a ULB, but with a much smaller horizontal footprint.

Angus Houston's mention of 2 apparent (but 'distinct') ULB signals (presumably CVR + DFDR) is significant.

Amid much of the 'scenario' speculation (!) on this thread, if the aircraft did end up relatively intact on the sea-bed & still containing the boxes, how might they be retrieved?

[1] Can any of the deep-submersible AUV/ROVs perform any kind of hull cutting activity?

[2] Can hoisting gear be remotely attached to any fuselage structure?

The Australian chief of the MH 370 flight search team just announced that signals sounding like pingers have been heard by an Australian naval vessel. 1st signal held for 2 hrs and 20 minutes. 2nd detection held for 13 minutes but more important two "distinct" signals were heard. The ocean depth in the area is 4500 M. The ship is doing an expanding square search attempting to pin the location down to a 2 mile square. This will take another day or two since they search with a USN towed receiver at (I think) 3000 M and at 3 KT. It takes 3 hours to make a turn and a total of 7 hours a leg. Compared to the speed of aircraft searching, the time to do a deep water search is very long!

The location of the presumed target is within the search area defined by the latest satellite analysis.

They will not claim a find until parts of the 777 are recovered on the surface, or pictures of the remains are taken at the sea bottom. After the location is pinned down sufficiently with the pinger listening device, a remotely controlled vehicle rated at 4500 M will use a side scan sonar to accurately define the location and then take pictures.

It looks like it will take many months to recover and read out the recorders, but eventually we will all know what happened during that final flight of MH 370.

What, (if anything) could go down to +4500m besides the submersible they have.

Glomar Explorer is in Indian Ocean.....
GSF EXPLORER - Drill ship: current position and details | IMO 7233292, MMSI 576830000, Callsign YJQQ3 | Registered in Vanuatu - AIS Marine Traffic

ADV Ocean Shield as per picture here

MH370: black box-type signals picked up twice by Australia's Ocean Shield | World news | theguardian.com

and it's wiki page

ADV Ocean Shield - Wikipedia, the free encyclopedia

These could do it. There are two in the US and one in Germany. The latter was involved in the salvageof AF447and is already being prepared to start the operation.

Alvin Upgrade : Woods Hole Oceanographic Institution

R/e the suggestiion about Exmouth - is topcliffe kid saying this could be an reflection of the VLF sub communication signal, and not the pingers at all?
I hope not...

In answer to how deep:

That is pretty deep.

However in 2012 the Chinese reported

The whole press conference here.
 

http://www.isasi.org/documents/isasi...ix-whoi-a4.pdf

has some ineresting detailsn the search for AF447 and its costs.

surface search June 2009 26 days
€80 million
(estimated for
information)
Phase 1 June/July 2009 30 days
Phase 2 August 2009 22 days 10 M €
Phase 3 April/May 2010 52 days 11.6 M €
Phase 4 March/April
2011
15 days 7 M €
Phase 5 April-May 2011 31 days 6 M €
TOTAL phases 1-5 (on site) 176 days
€ 34.6 million
(estimate)

I have been involved (as an ICAO Annex 13 accredited representative) in the retrieval of a CVR from a commuter category aircraft that sunk in 600 meters of water.

It was a very simple process. The remote underwater vehicle operators are provided with an engineering drawing that shows where the recorder is mounted within the aircraft fuselage. They then navigate the ROV to that location. It is quite easy for the ROV to punch through the aluminum skin of the fuselage. Once that is done, the recorder can be fetched.

In the case of a very large fuselage such as a 777, if the recorder is not mounted proximate to the exterior skin, a hole can be cut in the fuselage by tools affixed to the ROV, and then one arm of the ROV can be inserted into the hole to fetch the recorder.

I was quite surprised to see the ROV operator on this particular mission simply grab onto the bulkhead that the recorder was attached to, and pull on it until a good size chunk of the bulkhead (including the recorder, attached to its mounting bracket) came free. The ROV operator then brought the chunk of bulkhead with the recorder mounted to it to a basket under the ROV, and then the whole ROV was brought to the surface.

I suppose the ROV operator could have just grabbed onto the cylindrical case of the recorder and ripped it off the bulkhead, but that would have run the risk of damaging the case.

As for bringing a portion of the aircraft to the surface, that is certainly possible. The bigger the portion, the more difficult the task, but in the case of the investigation I was part of, we brought the empennage and the flight compartment of the aircraft to the surface for inspection. Special tools on the ROV were used to detach these sections of the aircraft from the rest of the fuselage.

Chronus . . .
 

Presumedly because it's the only credible theory that would fit such a bizarre flight profile; deducting all conceivable combinations of mechanical scenarios as improbable. :ooh:

Required viewing
 

mmurray,

Thank you. I've just viewed the whole video. That should be required viewing for anyone considering posting on this thread.

500km is 270nms which is 311st

Take your pick.