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Malaysian Airlines MH370 contact lost

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Malaysian Airlines MH370 contact lost

Old 13th Mar 2014, 23:52
  #2981 (permalink)  
 
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I find it very hard to believe that the ACARS system on Malaysia aircraft do not have SAT connectivity.

What is most likely is that MAS does not subscribe (pay) for airframe status monitoring. That requires a lot of bandwidth that they've determined are not worth the extra cost.

OOOI/weather/free text are probably all available to the pilots when the ACARS is using the VHF *and* SAT medium. Additionally, the RR health monitoring is probably paid for by RR and/or MAS as part of the purchase/warranty programme and does transmit via satellite, but only when programmed or demanded.

Snapshots of engine parameters are taken and sent at pre-programmed intervals or whenever something is out of tolerance. What that programming is is known to the engineers.

What the WSJ got wrong was that the Inmarsat network detected "pinging" from the Satcom system itself, not the RR trend monitoring data.
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Old 13th Mar 2014, 23:56
  #2982 (permalink)  
 
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Many posts ago somebody stated that their cell phone had received three texts welcoming them to a country that the aircraft they were in had transited at FL330

If this occurred it would have required a “handshake” signal exchange between the phone and mobile network operator.

I can’t help wondering if those coordinating the SAR effort have considered cross referencing the mobile phone numbers of all on board with every cellular network that flight MH370 could conceivably have over flown?
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Old 13th Mar 2014, 23:57
  #2983 (permalink)  
 
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FIRESYSOK

MAS officials said that since the question was asked during a press conference (don't remember which one), and that info has been quoted here also (maybe 80-100 pages(!!!) ago...) : They only have ACARS access thru VHF, not thru SATCOM.
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Old 13th Mar 2014, 23:58
  #2984 (permalink)  
 
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Fuel capaicity

Has there been any disclosure of the fuel uplift on this flight (Max endurance possible)
Assuming centre tanks were selected first, at what point would centre tanks have to have been deselected (before contact was lost or after?)
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Old 14th Mar 2014, 00:02
  #2985 (permalink)  
 
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How do MAS pilots get weather, etc. enroute when over oceans? Wait for VHF? I find that hard to believe- it's a global airline. If true, it says a lot about the operation in general.
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Old 14th Mar 2014, 00:10
  #2986 (permalink)  
 
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Re: post 2957 Dual AIMS failure

Systems affected are
CMCS(maint computre, faults reporting etc),
ACMS & ACMF(processes all engine, air and adiru data, etc and feeds relevant data to their relevant systems ),
EICAS and EFIS displays (Left with only basic Standy-by) ,
24bit aircraft address,
FMCS (Flight management etc)
TMCF(thrust management)
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Old 14th Mar 2014, 00:11
  #2987 (permalink)  
 
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FIRESYSOK

I find it hard to believe too, but I assure you I remember perfectly that info since I thought it was very surprising for such an airline.

And Radio ears, e-mails and internet connection go thru a different system (such as On Air, or the former Connexion by Boeing).
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Old 14th Mar 2014, 00:13
  #2988 (permalink)  
 
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Seems like a strange way to go about it. Possibly 1000's of plane pining a satellite for no reason & being denied due to lack of contract. Surely it would just be disabled onboard to save wasting resources.
Strange to who? Others have use for that data. It is well documented that cell phones continue to send pings, printers print microscopic dot codes on every page, photos include dot codes on every image so apparently someone involved with the manufacturers has a use for this information. The power required to send a few bytes of ping data an hour is negligible given the power available on aircraft.
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Old 14th Mar 2014, 00:22
  #2989 (permalink)  
 
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Search Organisation

It's easy to sit back & be critical of all the various agencies presently involved with the search for the B777, but to me it does appear, the Malaysian Authorities are well out of their depth. There appears to be a division of action & responsibility between both the Military & Civilian sections. Each agency is giving out conflicting information & both seem to be more interested in saving face, I would suggest. We have some senior Malaysian Military Officer totally adorned with ribbons & various insignia, standing up & saying very little indeed, this may well be just waving the Military flag. Civilian spokesmen, of which there are many, also seem to be there, just in order to make their presence know. At this stage, all of the local authorities appear to be running about , but doing little & achieving less. All this demonstrates, that the local agencies in Malayisia, have absolutely no idea of what happened to the missing 777 & where it is. Why not just come out & say this?
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Old 14th Mar 2014, 00:27
  #2990 (permalink)  
 
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How do MAS pilots get weather, etc. enroute when over oceans? Wait for VHF? I find that hard to believe- it's a global airline. If true, it says a lot about the operation in general.
They would use HF ACARS (link to a list of HF ACARS ground stations is here:

HF ACARS

As posted earlier, the nearest F ground station is at Hat Yai (south Thailand).

They would also use HF voice comms for weather reports etc.

A link to a list of HF aeronautical stations is here:

http://www.canairradio.com/hf.html

For the region of interest, there are HF ground stations at KL, Singapore, Bangkok etc.

Last edited by simon43; 14th Mar 2014 at 01:22.
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Old 14th Mar 2014, 00:27
  #2991 (permalink)  
 
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Strange to who?
My understanding on satellite technology is that anything you do is incredibly expensive. You don't do anything unless there is a reason for it.

Pinging a satellite which then logs and downlinks this data (again x1000's planes 100's times a day). A satellite which will not respond under any circumstances has no point. A simple off switch in the software onboard would be the most logical way to perform this rather than a credential check via satellite using up bandwidth from the plane to the ground base to the satellite back to a ground base and then onto IT HQ and back again.

Now maybe this pinging leads to results but that isn't by design.
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Old 14th Mar 2014, 00:33
  #2992 (permalink)  
 
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Simon43,

Thanks. Had no idea HF ACARS would be used by an airline such as this.
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Old 14th Mar 2014, 00:35
  #2993 (permalink)  
 
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Costs of Satellite Data (e.g., the pings)

Your understanding has gone out of date. Smartphone plans over satellite now have costs similar to what we paid for cellphones a decade ago.

I'm told by a friend in the business that the satellite industry has surplus capacity, and companies are out beating the bushes to find new users.
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Old 14th Mar 2014, 00:44
  #2994 (permalink)  
 
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Even more to the already-long tale. The question is: deliberate or not?

"KUALA LUMPUR, Malaysia -- Two communications systems on board the missing Malaysian Airlines plane were shut down separately, CBS News confirmed Thursday, a development that suggests the systems were deliberately turned off.

CBS News correspondent Bob Orr reported the two systems used to track Flight 370 were shut down sequentially, just before the Boeing 777 apparently changed course and turned west.

While that could suggest a deliberate act, CBS News aviation and safety expert Capt. Chesley "Sully" Sullenberger cautioned that it is "conceivable" that the communications systems could shut down sequentially on their own in the event of a catastrophic electrical failure. He said the systems in a plane are so compartmentalized that things could shut down in a cascading, domino fashion instead of all at once."

Full story here
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Old 14th Mar 2014, 00:45
  #2995 (permalink)  
 
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I was just reading a report on CNN that states that MAL 'DOES NOT' subscribe to the ACARS aircraft monitoring so no data was uploaded during the 4 hour period. But it did also say that even if the airline does not subscribe to the ACAR's Satcom service the aircraft will still ping the satellites and establish contact because that is how the 777 system is designed, the fact that MAS doesn't subscribe does not effect that. It is these 'pings' that they have now found to have carried on for 4 hours after last contact and they apparently will only happen whilst the aircraft is powered with engines running. The report also said that the aircraft could be airborne on land or indeed just flying around in circles.
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Old 14th Mar 2014, 00:46
  #2996 (permalink)  
 
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ACARS Access

There seem to be three separate issues in connection with ACARS that MAS senior management has been unclear about:

1. Human Messaging through ACARS

When MAS talks about ACARS, they are probably viewing it from a layperson's perspective: No HUMAN OPERATOR received/sent any messages through ACARS.

2. Automatic Messaging through ACARS

It seems that some system status information was successfully sent to Rolls Royce and to Boeing, presumably through ACARS. These transmissions occur only when triggered by specific conditions (e.g. engine start/take off). It is not clear when the last transmission from MH370 was received.

3. ACARS Link Establishment

Apparently, the ACARS Satcom "pings" a satellite at regular intervals (hourly?) to establish contact and download incoming messages (if any). Unless messages are actually sent or received, this link establishment or "ping" information would only be available to the ACARS system operator, NOT to MAS, Rolls Royce or Boeing.

Ollie Onion's post above indicates that Satcom "pinging" would occur even though MAS may not have subscribed to the Satcom options for ACARS.

It seems that U.S. Government statements were referring to these Satcom pings, NOT to full messages. (Of course, anyone familiar with the detailed workings of the system would have tried to ascertain the ping log on Day 1.)

NOTE: Similarly, there has been no official recognition of the potential that cell phones left active established contact with ground-based cell towers if/when the plane crossed peninsular Malaysia (and Sumatra). Also, ADS-B messages may have been received by ground-based stations in those areas beyond those evaluated by FR24. All this would be of a piece with the apparent failure to check primary radar recordings at an early stage.

Last edited by Communicator; 14th Mar 2014 at 06:57. Reason: clarification - VHF may work differently and is less relevant given US Govt. statement
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Old 14th Mar 2014, 00:46
  #2997 (permalink)  
 
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No inflight Internet Access for Pax?

If there had been, you might conclude that a well thought out cockpit-driven "total disappearance event" may have given a disabling of that non-essential bus feeding the rear areas a high priority. They'd not want the pax emailing their concerns to anybody (such as a locked cockpit door). But if MAS were too cheap to maintain a satellite ACARS contract, they'd likely also not offer their pax inflight internet access. Organic IFE is much cheaper.

Why would a "total disappearance" be a priority to someone? You have to conclude that the eventual lessons of Silkair and Egyptair's MS990 was that any relocatable wreckage would always give up the facts of the accident. A solution to that would be to place the aircraft beyond the search parameters and in water too deep for recovery of DFDR/CVR. That's the Indian Ocean, not the South China Sea/Gulf of Thailand.

But the additional puzzle might be that there should be no in-cockpit or avionics bay methodology for disabling an Emergency Locator Transmitter (E.L.T.) or stop it transmitting to a SAR satellite on 406MHZ. This jigsaw is missing a few pieces.

Last edited by TheShadow; 14th Mar 2014 at 01:10. Reason: afterthought
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Old 14th Mar 2014, 00:57
  #2998 (permalink)  
 
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"There is probably a significant likelihood" that Malaysia Airlines Flight 370 is on the bottom of the Indian Ocean, a senior U.S. official told CNN's Barbara Starr Thursday, citing information Malaysia has shared with the United States."
And I submit that there is a significant likelihood that US subs or subhunters have picked up the underwater ping from the emergency locator transmitter.

If so, expect a breakthrough in the next 12-24 hours.
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Old 14th Mar 2014, 00:58
  #2999 (permalink)  
 
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Many posts ago somebody stated that their cell phone had received three texts welcoming them to a country that the aircraft they were in had transited at FL330

If this occurred it would have required a “handshake” signal exchange between the phone and mobile network operator.

I can’t help wondering if those coordinating the SAR effort have considered cross referencing the mobile phone numbers of all on board with every cellular network that flight MH370 could conceivably have over flown?
I wil guarantee you this has been checked very early on.

If we find this plane, more than likely it is due to some device that has been detected pinging away. Could be passenger mobile phones. Could be ACARS. Could be engine telemetry. These signals may have been received by various means other than the intended network.

Note that RR aren't saying there was no transmission. Just that they didn't receive any transmission. That seems to tie in with the WSJ clarification.


White House: Hunt for missing airliner may extend to Indian Ocean - The Washington Post

One senior administration official said the data showing the plane engines running hours after contact was lost came from the Aircraft Communications Addressing and Reporting System, or ACARS, a way that planes maintain contact with ground stations through radio or satellite signals. The official said Malaysian authorities shared the flight data with the administration.
Interestingly, this doesn't state in which direction the information was shared. Words can be chosen very carefully and used very specifically at times.
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Old 14th Mar 2014, 00:58
  #3000 (permalink)  
 
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Damage caused by a bomb, missile, un-contained engine failure or mid air collision does not necessarily mean a catastrophic in flight disintegration, with a significant amount of wreckage that would float.

So those who theorise since no wreckage has been found at sea level around the point of loss of contact that none of the above could have happened, should be more equivocal.

Nor do we know that any of the above events could have been reliably picked up by a surveillance satellite tuned to monitor "flashes", especially a brief flash from a small bomb that could be shadowed by the body of the fuselage.

The US say they have monitored some faint electrical/RF activity on the plane which they say was connected with engines running.
We do not know why contact with this signal was lost, the plane may either have crashed, landed and shut down or travelled out of reception range and so it could have continued on its way for a further hour or more.

They say they couldn't derive the heading of the plane from this signal so it may have turned again.

Last edited by mickjoebill; 14th Mar 2014 at 10:26.
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