Our CFO had terrible reception in his office but was the only one that could make a call from inside our data center across the hall and two doors down from his office.

With DF equipment, they can find a bearing to the source. Move the receiver, get another bearing, and triangulate.

I was wondering how - suppose the pings last long enough for the approximate location of the recorders to be determined. How then will the recorders be actually found and retrieved? It seems that the ocean in the location of the detected pings is very, very deep. Close to three miles in places.

Well, the AF447 recorder(s) were retrieved from a similar depth, 13,000 feet, in a flat area next to very mountainous terrain. The fourth search mission finally succeeded, 2 years after the plane craished. They used three semi-autonomous "Remus 6000" robot submarines, mapping the ocean floor, and were prepared to search 10,000 sq km at the rate of 100 sq km/day. In the end the fourth mission located the wreckage after a week. Many passengers' bodies were still strapped in the seats, in the partly intact fuselage, preserved by the cold and depth. The robot subs located and retrieved the recorder, and then retrieved 104 bodies. 74 bodies remain missing, 50 were previosly retrieved from the surface.

http://boingboing.net/2011/05/06/air-france-447-how-s.html

I'm supposing something like this will be attempted with MH370. The sub operators will have a big advantage over their AF447 predecessors if the recorders' location can be narrowed down in the remaining battery life of the pingers. They will have a big disadvantage if the wreckage is in an unstable or steep location. I am guessing that, since no floating wreckage has been found, the airplane might be more intact than AF447. I would guess that would be helpful.

Here is something I don't understand. Apparently the Remus subs are semi-autonomous, meaning the sub is programmed for the dive, and then operates autonomously during the dive. The sub operator cannot control or receive information from the sub during the dive, except for some limited positional data. I can see how a semi-autonomous sub can search and map an area of ocean, following a programmed path and using its limited intelligence to react to obstructions. I do not see how a semi-autonomous sub can retrieve a recorder - recognize the object as a recorder, undo fasteners or cut material, extract the object from wreckage. I also do not see how the sub can retrieve a body - recognize the object as a body, cut or unfasten seatbelts, pull the body from the seat and manuever it through a damaged cabin. I didn't think robots are that intelligent yet. But obviously it can be done. Anyone able to explain how?

The Remus subs are not used for recovery, they are used for mapping and discovery. Once the wreckage is located, other types of submersibles that are controlled from the surface (or possibly some that are manned) are deployed to actually get the boxes and other pieces from the ocean floor. If you've seen pictures of the Remus subs, they look very much like over-sized torpedoes with no mechanical arms, claws or lights.

Ossi, thanks. That helps me understand.

The media is hand wringing about the extreme depth of the ocean in the area being searched. But I see AF447 was recovered from a similar depth. So I hope it can be done.

As soon as the get a few Pong backs, we'll be all set...

http://forums.pelicanparts.com/uploa...1397085227.jpg

There is much media focus on recovering the flight data recorder as though it will be the Rosetta Stone for this puzzle but it seems there is a good chance it will pose more questions than it answers since from what I understand it will only report the operating parameters of the engines, control surfaces, air speed, altitude etc but cannot report why the aircraft changed course, the intent of the pilot or even the identity of the person at the controls. According to Wikipedia the typical cockpit voice recorder loops every 2 hours so the crucial time when the aircraft diverted from its original course will likely be written over???

I've been thinking about that. What is it going to show? A turn to the left, climb, level out, a turn to the south, then in the water after running out of fuel. Won't tell us who did it or why.

This is correct^^

Like all evidence in investigations, the information from the recorders will be used to eliminate causes as much as to identify a cause. The recorders can confirm or eliminate mechanical or catastrophic reasons for the flight. If the data recorder shows only normal functions, that would leave only deliberate human intervention as the cause, as is already suspected. It could tell if the plane was hand flown or programmed through the auto pilot. The voice recorder may not have the sounds during the initial course change, but it may have any warnings and alarms that were in the cockpit in the final hours and, of course, any voices. That would aid in knowing if anyone was alive and at the controls, at the end.

In short, a much clearer picture can emerge from the data and it can reinforce a purely human cause, but unless there is a voice hinting at what was happening, the black boxes cannot tell us the motive of the person(s) involved.

Thanks.

It the plane is found semi intact, they could have divers document the positioning of the bodies, how the controls were set, internal damage to the plane (fire, deployment of masks) and probably a million other things. A pilot bent on creating a mystery could tamper with the crime scene before ultimately crashing of course. I'd hate to by an NTSB type and have to dive 3 miles deep to assess the wreckage.

Sounds like something James Cameron would rent the Keldysh and the Mir submersibles to check out. He would then somehow make a movie out of it.

So at one point there were two signals that were several hundred miles apart. I know this sounds like a conspiracy theory, or tinfoil type, but I wonder if the first signals they found were actually from the plane or if some government who didn't want to reveal all their intelligence planted some kind of pinger to help locate the plane.

Or they could just bring it up and piece it back together like TWA flight 800.
Well, supposing there is some way to bring it up from that kind of depth.

The first signals were detected by the Chinese ship. Most likely, they were detecting the first mate's snooze alarm going off.

Not related to the crash...

JR

How deep is it...

The depth of the problem - The Washington Post

Project Azorian Glomar Explorer

every problem has a solution

Much deeper than I thought. I remember reading 4,000ft but I guess that was an earlier area they were searching. Lots of pressure at that depth!