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-   -   Malaysian Airlines MH370 contact lost (http://www.pprune.org/rumours-news/535538-malaysian-airlines-mh370-contact-lost.html)

Speed of Sound 22nd Mar 2014 13:29

Google Maps
 
PilotsResearch, UnreliableSource, & mm_flynn, thank you for your replies.

I had always assumed that as you toggle between 'Map View' and 'Satellite View' on Google Maps, all images were from a satellite. :*

fg32 22nd Mar 2014 13:38

awblain
Quote:

From their own data, Inmarsat can't say whether it was going North or South: they inferred that North was unlikely, as someone would have seen it go by.
Agreed. The only reasons I have seen against North are
"it would have been seen" - but how about the long transit across Indonesia?
And (more recently) "the pinger batteries will run out, so sea first".
I don't think much of either.

Particularly since, in the south, nothing but dead people.
In the north, tiny chance of survivors on a remote hillside.
I know which I'd prioritise.

The resources aren't interchangeable, though, are they, and the access more problematic. I'd at least throw all at the north that I could, though. The Malaysians have two search aircraft in Khazakstan. Maybe its just the media neglecting the northern efforts.

oldoberon 22nd Mar 2014 13:44

Quote:

Originally Posted by fg32 (Post 8394286)
Sorry oldoberon

Both quotes are cut and paste from the interview reports

IBTimes report of interview: Report 20 Mar
Malaysia Airlines Flight MH370 Would Have Been Found If Communications Box Had $10 Upgrade

There are multiple reports of the Fox news one. I got my quotes from here, well down under "satellite Analysis:
Hunt for Jet Switches to Visual Search as Radar Empty - Bloomberg

Apologies not needed and thanks for reply

Here is what i believe to be one of the source interviews with megan kelly on Fox, she appears to be far more objective than your average talking head, I did not hear in the interview that exact quote.


Satellite Company Inmarsat Says Its Data Could Help Find Malaysia Airliner - Fox Nation

awblain 22nd Mar 2014 13:47

The lack of a beacon signal also indicates something: either a hard impact or a safe landing in the north or a quick sinking in the south. A sinking in the South makes more sense to me.

If it's sitting on the ground somewhere in central Asia, and there were no further Inmarsat calls because the power was turned off, I'm sure a radar difference image between three weeks ago and two weeks ago would have been able to show it up.

How many places with a 777-sized hangar to hide it in are there in central Asia?

There would seem to be no prospect of survivors, so the only issue is whether the causes can be determined.

felix505 22nd Mar 2014 13:47

ATC @ 1700-1730Z on 7 March (+8hrs)
 
WMKK Kuala Lumpur Control radio traffic 1700-1730Z is available as a downloadable archive.
The transcript suggests there are comms from Malaysia 370 (MH370) at 17:01:14 (+8 01:01:14)
The archived radio recording is silent at the time indicated in the transcript. The other times indicated in the transcript also do not bear these communications, through to 01:19:29.

Each downloadable file is 30 minutes long, so that final transmission would be at 19:29 in that 30 min file.
http://archive-server.liveatc.net/wm...2014-1700Z.mp3
LiveATC.Net ATC Audio Archives

One of the transcript links Revealed: the final 54 minutes of communication from MH370 - Telegraph

Maybe I have got the wrong day...

fg32 22nd Mar 2014 13:49

Pontius Navigator
Quote:

If it flew over the equator then it had to fly south.
McClaughlan said it, but he gave no evidence.
Later he has said the reason he said it is that "it would have been seen if it went north".
Firstly, thats an assumption, Secondly, as Inmarsat, such a judgement is not his job.
Look at his resume. He's not technical. PR man.

fg32 22nd Mar 2014 13:54

odoberon
Quote:

Here is what i believe to be one of the source interviews with megan kelly on Fox, she appears to be far more objective than your average talking head, I did not hear in the interview that exact quote.
Maybe I'm confused, and my second interview was with Bloomberg. I had about seven interview windows open at one point.
Anyway, the link is there. Thats my source.

I'm confident he said it…and twice.
And I find it pretty significant.

AT1 22nd Mar 2014 13:58

Quote:

I took a look at post 7124. I have to say that I don't buy this. It basically says that the antenna on the aircraft is tied to an extremely fast computer chip that is guaranteed to send a response to the "ping" from the satellite within a few nanoseconds of receipt. I don't have any documentation to back this, but I find this extremely improbable, especially for a 1980's system (classic aero). And, more generally, no one writes networking code like this, not even in perfectly controlled conditions, let alone for a noisy 36000 km long satellite link. The computer in charge of sending the response may have other things to do, it will reply eventually, but realtime response is not guaranteed.
This is exactly NOT what I was attempting to explain. Firstly, as a bit of context, one of the most powerful computers you will ever come close to is in your mobile phone. The digital signal processors in these cheap phones pack astonishing punch, and run "fast". They are pretty well dedicated hardware only good for running phone comms, so not as general purpose as an Intel i7 for example, but by some measures much more powerful. Don't underestimate the power in relatively cheap comms kit. Inmarsat C may not support high data rates, but remember it is serving many many planes and many many ships all at the same time.

The key point here is that I am NOT requiring a response in a nanosecond. The response could be half a second later - 500,000,000 nanoseconds later. The terminal just counts ticks while a far more pedestrian processor prepares the response and sets it up ready to be sent, and it is then sent at the right "tick". The satellite knows the defined protocol and so can eliminate the delay, giving it access to the actual "flight" time of the message.

But I also said these are communication systems, not navigation systems. The overall system is designed to maximise the data they can handle as it is data that makes money. They could at one extreme simply say we have no idea where each user station is, we will provide in the protocol a "window" wide enough to accommodate the user being anywhere over the 1/3 of the globe. That would mean the satellite had wasted potential fee earning capacity waiting for the full potential window for each and every communication exchange, when in fact it can reduce, though not eliminate the window.

My explanation was, as I had said, simplified. In practice there are a whole load of other complications, spreading data bits over many carrier cycles and error handling codes etc etc all of which will introduce more variability, but at the heart the system is operating at 1600 MHz, giving an inherent timing capability irrespective of GPS time stamps etc, with the potential of measuremment to quite high levels of accuracy. In practice the level will not approach this - but talk of "miliseconds" and hundreds of Km is not appropriate. The underlying principles may be designed in the 1980s - as was GPS - but we are not talking valves and clockwork here!

I say again, I can go to my hardware shop and buy for a few £/$/Eu a handheld laser tape measure that can fire and time a pulse of light sufficient to measure distance to a few mm. Give it a more stable clock - which the satellite will have, and using the same principle of counting ticks you can time to great accuracy over very long periods, eliminate the "processing" time at the receiver by specifying how many ticks later the reply is sent, and there you have a system with the potential of astonishing accuracy - just as GPS has.

But one last repeat - Inmarsat is a comms system designed to support comms. It is talked of as a bent pipe, but that is a great simplification. The content of the data being exchanged may appear to pass through a bent pipe, but there is a lot going on over and above passing the data to keep the pipe itself working.

Air33bus 22nd Mar 2014 14:17

Center of gravity theory.
 
if yours and all other theory's about flying further is correct without electrical or any control who will take care about trimming,we also have to know the c.g. of the aircraft, because the c.g. will shift and there will be no trimming so the aircraft will climb or descend during fuel burn.

Methersgate 22nd Mar 2014 14:21

"I am an ATC and the transcript also surprised me.
I guess the problem is that it is a translation from English to Chinese and then to English. However, the lack of read back is not explained by incorrect translation."


I lived in China (next door to the Air China Airbus rep - thereby hung a few tales...) for a few years. Believe you me, a translation into and then out of Chinese, a language very different to English, can very easily explain the lack of read back!

castleford tiger 22nd Mar 2014 14:29

Medan airport ATC did they pick anything up? If it came back there way as suggested they should.
There is also a fair size Base close to there with a fair few fighter jets. Again not heard anything from them?

EPPO 22nd Mar 2014 14:38

Quote:

From their own data, Inmarsat can't say whether it was going North or South: they inferred that North was unlikely, as someone would have seen it go by.
The north path would be very embarrassing for many people.
The south path hypothesis (fire - decompression - zombie a/c), however unlikely, is the only one that allows to save face for all countries (eastern and western) affected in some way by this 'event'. Any other explanation would point to incompetence or worse, misbehaviour by some governments.

So I guess we'll have to buy that one.

Sheep Guts 22nd Mar 2014 14:42

Quote:

castleford tiger Medan airport ATC did they pick anything up? If it came back there way as suggested they should.
There is also a fair size Base close to there with a fair few fighter jets. Again not heard anything from them?
Castleford Tiger,
Still a lot of unanswered questions. They must have something that area of airspace very busy. The investigators and search coordinators in Malaysia who are running this SAR op may need to keep checking all reports and sightings they have be given. Of course we don't know what they have been given, only snippets and releases from the so called Us officials and Chinese news conferences etc have been leaked to the media.
Maybe something they were given days ago and discounted previously may be more relevant now, and needs further investigation. I just hope the foreign investigators who have volunteered their services from different bureaus are being utilized to their fullest. The search window is so large now. No stone should be left unturned.

Durou 22nd Mar 2014 15:25

I noticed the wording at the time of interview and wondered about the "steadily away from the satellite". At last military radar fix the plane was two ping hours north of the equator so would need one hour (maybe two) coming towards the satellite to cross the equator on the journey south. Was he referring to the last few pings or the continuous set?

DX Wombat 22nd Mar 2014 15:32

Nigel Osborne
Quote:

a Transponder that someone just can't turn off with a flick of a switch. Needs to be fitted so it cannot be tampered with from the cockpit, if that is indeed the actual reason of its lost signal.
From personal experience signal from a transponder may not necessarily be turned off deliberately. I am well aware that the vintage transponder in the C152 which I was flying was likely to be far less refined than that on MH370, however, in my particular case was asked by D&D to squawk 7700 and promptly complied - or so I thought. The transponder was certainly set correctly and should have been squawking but in fact was not. The request to squawk 7700 was the last transmission from D&D which I was able to hear for quite some time. D&D could hear me, but I couldn't hear D&D (or at least all transmissions from D&D were almost inaudible and muffled with no identifiable words). Communication was eventually restored via an Emirates Airbus and following a request to turn up the volume on the radio (it was already at maximum) I was asked to squawk 7700. My reply was that I was already doing that but would recycle, did so, and the problem was resolved. It is entirely possible that the crew of MH370 did squawk 7700 but was completely unaware that the transponder was not functioning.

overthewing 22nd Mar 2014 15:44

@felix505

Quote:

The archived radio recording is silent at the time indicated in the transcript. The other times indicated in the transcript also do not bear these communications, through to 01:19:29.

Several posters have stated that ATC is only available for sectors west and north of KL.

Edited to add: I meant listening in to ATC, not actual control. obviously!

Capt Pit Bull 22nd Mar 2014 15:54

Nigel Osborne

Quote:

Also they need to come up with a Transponder that someone just can't turn off with a flick of a switch. Needs to be fitted so it cannot be tampered with from the cockpit, if that is indeed the actual reason of its lost signal.
Perhaps you should have a think about the reasons why we need to be able to turn it off.

arearadar 22nd Mar 2014 15:54

facts
 
Have I got this right?
The secondary response disappeared, then primary return disappeared. R/T shut down.....

Did somebody continuously track the a/c after that..who...verified?

So, the a/ may have disintegrated, it may have dropped below radar cover.
Maybe Blind Velocity Speed (unlikely at cruising speed and altitude) or Tangential Fading. (Radar Type in use ?)

So who continuously tracked the primary return?

If it was not continuously tracked it becomes unidentified. Who then re-identified it and how ? A primary return way off the flight planned track ??

I don`t think so.

awblain 22nd Mar 2014 16:01

McLaughlin might not have meant that all (eight?) distances (0111-0811) to the satellite were monotonically increasing - perhaps just the final few.

If he did mean that all eight distances were steadily increasing, then to accord with the timings, the number of possible routes likely isn't very large.

Savas 22nd Mar 2014 16:07

I just find it difficult to comprehend, that after 2 weeks, still no sure on where it is.
Surely if they can spot the plate numbers on cars from satellites, then surely they can figure out 370 and it's location, if intact.
Also, once it disappeared, I would like to really know, what and whom the Malaysian ATC, contact immediately.
I think, there is a lot that we are not been told, for some odd conspiracy.


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