Slip and turn, none of these links nor the ones I found make as strong a statement as Coagie did, that the submarine search was ineffective because they were simply unaware of the signal being sought.

However that second link is quite interesting. I had not seen it; thank you for including it.

Coagie, there is a big difference between not knowing what signal to look for and adjusting the sensors settings / filtering / noise suppression, whatever, to improve the sensor range. Further, none of the sources I found indicate that the reanalysis of the tapes actually _did_ locate the signal. It appears it gave them a new search possibility that did not pan out, unless it was the basis of the phase 3 search.

Michelson interference? As in the Michelson-Morley experiment on the speed of light that demonstrated the lack of an ether (or that by a coincidence we happen to be stationary relative to the ether... always wondered why they discounted that possibility so readily -- okay only being tongue-in-cheek here :) ). I'm not quite sure what that has to do with underwater acoustics...

Very ex-ba -

The max radius of a cell in the GSM system is 35KM, usually much less. CDMA is about double that in theory (although in practice, about the same).

If the postulation is that the flight had descended to low level, then those ranges hold true. They would have to be within 35KM or so of a suitable cell. Added to the attenuation effect of being inside the aircraft skin, it doesn't seem likely to me. If the aircraft landed on a remote airfield (also seems improbable to me), it would have to be so isolated as to be entirely devoid of communications for it to have not been picked up by now. You can't hide an intact B777 when the world is looking for you. There's always the sat phones of course, but they aren't exactly commonly carried.

On the subject of the those whose phones have been called and they rung, this seems like rubbish to me. For the phone to have appeared to ring, the phone must be registered with the network (i.e. in a group of cells), been paged, and then responded to the page. If that had occurred, the network KNOWS which cell the mobile responded from, and records it. Ergo, the SAR authorities would know where to look. If they knew which cell to look in, I doubt it would take so many days to find it, and I would have expected the authorities to have said they know where the phones are/were.

I've had nothing to add on the aviation aspects, I'm just frequent SLF, so I have kept out of that, but I am a telecom engineer.

"So it is at the bottom of the sea, where the ELT transmissions can't be seen.
But the reality is that it could be anywhere in a radius of well over 1,000 miles."

So even if the Elt beacon is out of range, the emergency locator beacon that is usually with CVR/FDR will have/should deploy and be visible to those scanning the known frequency up to 6000m deep. I gave full details and links yesterday. Or course the signal won't radiate from 10km asl though.

I also caution people to read carefully Official statements with modifiers such as may. One word can give a lot of wriggle room and convey different meanings,

A CCTV video of the Captain and FO going through security before they board the flight. I'm amazed at the clarity of the video. Surely the fake passport holders boarding the flight could be easily identified as well.

http://www.facebook.com/photo.php?v=...type=2&theater

[quote[The max radius of a cell in the GSM system is 35KM, usually much less. CDMA is about double that in theory (although in practice, about the same).

If the postulation is that the flight had descended to low level, then those ranges hold true. They would have to be within 35KM or so of a suitable cell. Added to the attenuation effect of being inside the aircraft skin, it doesn't seem likely to me. If the aircraft landed on a remote airfield (also seems improbable to me), it would have to be so isolated as to be entirely devoid of communications for it to have not been picked up by now. You can't hide an intact B777 when the world is looking for you. There's always the sat phones of course, but they aren't exactly commonly carried.

On the subject of the those whose phones have been called and they rung, this seems like rubbish to me. For the phone to have appeared to ring, the phone must be registered with the network (i.e. in a group of cells), been paged, and then responded to the page. If that had occurred, the network KNOWS which cell the mobile responded from, and records it. Ergo, the SAR authorities would know where to look. If they knew which cell to look in, I doubt it would take so many days to find it, and I would have expected the authorities to have said they know where the phones are/were.

[/quote]

I absolutely agree. I'm not in aviation, but I deal more with the forensic analysis of data, including cell phones. As of today it looks like 19 people have come together to say they've attempted to call and successfully ring onboard cell phones.

19.

Missing Malaysia Airlines Flight MH370: Passengers' Mobile Phones Ring But Not Answered

That seems a little suspect, but at the same time not that unbelievable. These phones could have been roaming and could have registered, profile/prl updates with the nearest network cell. When I travel internationally that's how it works for me if my phone is set for that.

I wonder how much of this information is going up the flagpole to the people who need to know, assuming it's true. At this point in time, I have no reason based on the what the news is reporting that it's NOT true. So in essence, there may be a phone that is registered on a network receiving incoming trx.

Now where those phones are? Who knows, but as you mentioned the authorities CAN backtrack off the signals.

Wild Goose,
There's not much canopy left in southern Vietnam. South of Saigon, it is effectively one giant, heavily-populated rice field, broken up by canals. Someone would have noticed a 777 coming down.

Hydrophones
 

The US (and probably other) Navy operates hydrophone networks to track submarines. There's other listening posts. When the USS Scorpion collapsed underwater, research hydrophones in Newfoundland and the Canaries caught the sound and triangulation helped narrow the search.

A lot of tape had to be analysed to determine which noise was the collapse event.

There would be an acoustic event if an intact hull (or big enough piece) hit at speed. But would the sound propagate in shallow water to wherever a hydrophone would pick it up -- provided that there's any hydrophones that would pick up acoustic events in the area.

Navies are very secretive about where their hydrophone networks are placed.

Jackets left on
Alarm seems to go off, but
Manual search rather non existant

As these details pop up (by whoever for whatever purpose), we will see many more of these breaches.
All passengers searched?
All hand baggage screened?
All belly baggage screened?

Seems you are correct about doctored passport photos as Malaysian authorities have confirmed Italian passport holder was black. Says believes dealing with a passport forgery ring.

Given the press conference and the SAR grid update, are we now able to assume that an 'event' causing it to crash into the sea at IGARI is now not the favoured theory, unless it slipped under the surface at this location without trace, although there is some precedent for this it does seem unlikely.

Therefore it flew for some distance after the last piece of public available data and crashed somewhere else. I'm discounting the theory that this bird is somewhere on the ground intact. Assuming the authorities have more detail than us (very much hope so) the change in SAR grid does seem to indicate the plane flew for at least another 30-60mins before crashing somewhere.

That leaves us with the option of an unlikely catastrophic electrical failure at FL350 causing the transponder to fail along with anything but basic instruments & controls, perhaps a RAT failure so no chance of radio contact. Then an attempted return under VFR at night, got lost, fuel starvation and crash. We then need to factor in the failure/non activation of the ELT.

In other words the last two paragraphs need a lot of holes to line up to occur.

The more realistic option based on this (sad to say) is someone pulled the CBs in an attempted hijack, flew for sometime, passengers/crew attempted to retake and the result was a crash.

In both cases the SAR area is much larger as the plane could have flow in any direction for 4/5 hours. I think it will be found but outside even the current search grid.

Pressurization?
 

Does it seem likely to the 777 guys that the pressurization was not set, mis-set, or malfunctioned? Was MH 370 already at cruise? Possibly a Payne Stewart Lear Jet type of event?


Failing that theory, seems like explosive decompression from whatever cause is most likely.

I would assume this sort of technology requires line of site (or whatever it is called underwater). I am guessing that the previous incident you are talking of happened in the Atlantic? Where it is thought this aircraft went down is almost surrounded by land, I do not know how the sound wave would get around these masses.

The position of that debris field would indicate it stayed on the flight plan route or close to it.

@Roadster280

Unless extended range is enabled which will give a 70km cell range :)

Another quiet, lurking telecom engineer here too.....

Tribute page to the captain with pics of his sim set up at home:

TRIBUTE: Who exactly is Malaysia Airlines Captain Zaharie Shah of MH370? - Sharelor

(sorry if link already posted, I haven't seen it here.)

Hello all. I only have 1 post but I will try to make it a good one.

In regards to someone referencing cabin pressure. A little more info...

On October 25, 1999, a chartered Learjet 35 was scheduled to fly from Orlando, Florida to Dallas, Texas. Early in the flight the aircraft, which was cruising at altitude on autopilot, quickly lost cabin pressure. All on board were incapacitated due to hypoxia — a lack of oxygen. The aircraft failed to make the westward turn toward Dallas over north Florida. It continued flying over the southern and midwestern United States for almost four hours and 1,500 miles (2,400 km). The plane ran out of fuel and crashed into a field near Aberdeen, South Dakota after an uncontrolled descent.
http://i59.tinypic.com/oh1rtc.jpg

Flight Following and South East Asia Authorities
 

in light of today's switch to searching mainland Malaysia, The Malacca Straits and further north to the Andaman Sea.
Can a Airliner traverse the whole of Malaysia without anyone detecting it?
Also should we not have heard from Thailand, Cambodia and Vietnam's Aviation Authorities about any efforts they might be taking to find this missing aircraft?

If ever there is a chance of a 'cover up', this might be the only one that makes sense. In other words, if the aircraft really did cross over to the Malacca Straits and M'sia didn't know about it from the onset, it might reveal a severe and embarrassing gap in the air defense and radar coverage in that part of the country.

Stanley11, link to news in post #1385 under the map

barti01,
 

Yes.
Vung Tau Port Authority already had a passing ship check the area and it reported nothing special. The Port Authority have also sent out a fast boat, but it will not have arrived before darkness.

I suspect this is also the same sighting that has been reported "off Hong Kong", as it originated from the HK aviation authorities after a pilot report.