Malaysian Airlines MH370 contact lost
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I'm sure the BBC documentary a couple of months ago went into that in some detail, but I can't remember exactly who told who what and when.
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The 4 Corners ABC documentary went into this. Just double checked and it says Inmarsat privately handed over the data to it's distributor on the 11th March, who in turn passed it to Malaysia.
However, Hishamuddin dismissed the possibility that the plane continued to fly on the 13th March. He actually made a point to dismiss it. It was another two days before they abandoned the search in the South China Sea.
My money would be on poor communication and incompetence on the part of Malaysia and Hishamuddin's ever present foot-in-mouth syndrome..
However, Hishamuddin dismissed the possibility that the plane continued to fly on the 13th March. He actually made a point to dismiss it. It was another two days before they abandoned the search in the South China Sea.
My money would be on poor communication and incompetence on the part of Malaysia and Hishamuddin's ever present foot-in-mouth syndrome..
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RR PDA numbers
Have the 9M-MRO RR PDAs surfaced here? Or any difference in fuel in left vs. right tank? I ask because the IG received a 3rd hand report yesterday from someone attended a meeting in Perth on Oct 22, saying that an official member of the search team stated that one engine flamed out ~1 hour before the other. We are very skeptical, but trying to find out if anything like that has ever showed up here.
Thanks Exoixx. That fills in a few blanks. I never saw that story. Will try and find it on line.
The timing still looks very odd.
MH370 goes missing on evening of 7 March UTC, and the world knows its missing by morning of 8 March UTC. The circumstances of disappearance are highly unusual from the outset - e.g. no distress call.
Inmarsat hand the information over on 11 March UTC. 4 days later. After Inmarsat had specifically very recently looked into applying this technology to track a missing plane (as a result of AF447).
I find it difficult to believe Inmarsat took days to discover they actually had this information. Or that it would take 4 days to deduce the plane kept flying for many hours after lost contact.
Did someone at a high level (political rather than Inmarsat) sit on this for a long time? Just one of the many questions surrounding the early response to this incident.
The timing still looks very odd.
MH370 goes missing on evening of 7 March UTC, and the world knows its missing by morning of 8 March UTC. The circumstances of disappearance are highly unusual from the outset - e.g. no distress call.
Inmarsat hand the information over on 11 March UTC. 4 days later. After Inmarsat had specifically very recently looked into applying this technology to track a missing plane (as a result of AF447).
I find it difficult to believe Inmarsat took days to discover they actually had this information. Or that it would take 4 days to deduce the plane kept flying for many hours after lost contact.
Did someone at a high level (political rather than Inmarsat) sit on this for a long time? Just one of the many questions surrounding the early response to this incident.
Last edited by slats11; 29th Oct 2014 at 09:26. Reason: clarification
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Originally Posted by AirLandSeaMan
Have the 9M-MRO RR PDAs surfaced here?
Whatever the fuel imbalance (if any) noted in the last ACARS to RR, there is no way of knowing if that was or wasn't corrected later in the flight.
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Fuel Imbalance and cross feeds
See page 970 here: https://db.tt/4EXSNq5o for info on fuel imbalance and cross feeds.
Can anyone with access to B777 manuals please find out the maximum fuel imbalance?
Balancing, when called for, is performed as ALSM/the FCOM 2 describes.
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2. The BBC documentary said their first thought was that someone was spoofing the system, pretending to be the aircraft. That probably involved pulling in experts from other companies to verify that it wasn't. Again, on a weekend.
So, you're probably already up to the 10th by the time everyone is available who needs to be available.
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Then don't forget getting authorization to release the data and getting the report that was being handed over double checked by lawyers that nothing was going out that would be detrimental to INMARSAT. Calculations and documentation re-checking amendment and reapproval by senior management after all hoops jumped through.
I know some companies where that would take a month.
I know some companies where that would take a month.
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Is this number of transponders correct?
In the following article, regarding redundant systems, Byron Bailey said
"the 777 has 80 computers and three sets of nearly every system on board – including three radios, three radar transponders, three autopilots and three flight management computers – to ensure a "practically fail safe" operation.
A failure of one will result in transfer, usually automatically, to another. "
Here is what I am asking 777 pilots: Is it correct that there are three transponders?
Flight MH370: former Boeing 777 pilot points to sabotage | Flight MH370 News | The Week UK
"the 777 has 80 computers and three sets of nearly every system on board – including three radios, three radar transponders, three autopilots and three flight management computers – to ensure a "practically fail safe" operation.
A failure of one will result in transfer, usually automatically, to another. "
Here is what I am asking 777 pilots: Is it correct that there are three transponders?
Flight MH370: former Boeing 777 pilot points to sabotage | Flight MH370 News | The Week UK
Last edited by TamairTarmac; 9th Dec 2014 at 23:25. Reason: to focus the question
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TamairTarmac
There are actually 2 ATC Transponders; L & R switched by the crew. The general thrust of his statement is however correct in that most flight critical systems are triplicated and have auto switching.
If it's not triplicated; then in most cases it's duplicated. These systems are never on the same power supply.
As a separate example; a non essential system such as ACARS is a software function within the AIMS system. There are 2 AIMS systems and therefore ACARS; The system uses the VHF system it can tune to, one of three (VHF L, C or R), depending on the aircraft option/vintage it will the go for one of two HF systems (L or R) after that; then on to a single SATCOM connection if enabled and optioned. The pilot can select a source if so desired.
So what he's saying in a nutshell is that something IS fishy leading to the end of this aircraft.
There are actually 2 ATC Transponders; L & R switched by the crew. The general thrust of his statement is however correct in that most flight critical systems are triplicated and have auto switching.
If it's not triplicated; then in most cases it's duplicated. These systems are never on the same power supply.
As a separate example; a non essential system such as ACARS is a software function within the AIMS system. There are 2 AIMS systems and therefore ACARS; The system uses the VHF system it can tune to, one of three (VHF L, C or R), depending on the aircraft option/vintage it will the go for one of two HF systems (L or R) after that; then on to a single SATCOM connection if enabled and optioned. The pilot can select a source if so desired.
So what he's saying in a nutshell is that something IS fishy leading to the end of this aircraft.
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2 is 2 and 3 is 3
I have just seen him quoted all over the internet referring to three transponders; and I just wonder if it is only 2, that no one has called him on it. Or if there is some kind of third redundancy, want or where it might be. Or might he be referring to the Inmarsat pings as a kind of transponder?
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As somebody who knows nothing about this (or anything of a technical nature like this) i'm curious, how does the auto-switching work? That is, what is the technology that detects the need for a switch and switches it? To my lamen brain, it seems logical than in order for a switch to take place between two systems, they would have to be connected in some sort of way?
Apologies if this is really dumb question.
Apologies if this is really dumb question.
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Exioxx
You are correct that there is a link between systems for automatic switching to occur; this can either be via data bus links between computers or simply by relay connections.
Trying to keep it simple;
Depending on the system; computers on different power supplies will be connected through data buses, each computer comparing and monitoring against the computer in control to detect a failure and then force a transfer to a good computer.
Relays often provide discrete inputs to computers as to status of power and other circuits. A failure of power on a circuit can be the trigger to initiate the system on standby.
You are correct that there is a link between systems for automatic switching to occur; this can either be via data bus links between computers or simply by relay connections.
Trying to keep it simple;
Depending on the system; computers on different power supplies will be connected through data buses, each computer comparing and monitoring against the computer in control to detect a failure and then force a transfer to a good computer.
Relays often provide discrete inputs to computers as to status of power and other circuits. A failure of power on a circuit can be the trigger to initiate the system on standby.
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I have just seen him quoted all over the internet referring to three transponders;
Just a thought about this faux concern vis a vis 3 transponders. Uninformed complaints / criticisms seem to abound in the media these days.
1. The IFF/Transponder system doesn't need to be triple redundant, the way some of the flight safety systems mentioned above might need to.
Why?
The plane flies safely with 0, 1, or 2 operational.
If 0 are working, the crew need to use their radios more often in terms of coordinating with ATC on where they are and what they are doing, since the information isn't passed by the system via the radar and radar returns.
You can argue that if you wish to "for safety's sake" rely on a third layer of capability, that third layer is present in the ability to use two way radio communication:
You tell them where you are and what you are doing, just as we have always done in areas where there is no radar contact.
ATC then associates that with a radar reflection, rather than a transponder paint/code, and can thus track you and sequence you into the air traffic du jour. If you turn off your two transponders, and refuse to talk to them on the radio, it amounts to the same thing as turning off three transponders.
May we put to bed (without any supper!) this "three transponders" thing?
For any journalists reading (Mr Bailey?): please, give it a rest.
1. The IFF/Transponder system doesn't need to be triple redundant, the way some of the flight safety systems mentioned above might need to.
Why?
The plane flies safely with 0, 1, or 2 operational.
If 0 are working, the crew need to use their radios more often in terms of coordinating with ATC on where they are and what they are doing, since the information isn't passed by the system via the radar and radar returns.
You can argue that if you wish to "for safety's sake" rely on a third layer of capability, that third layer is present in the ability to use two way radio communication:
You tell them where you are and what you are doing, just as we have always done in areas where there is no radar contact.
ATC then associates that with a radar reflection, rather than a transponder paint/code, and can thus track you and sequence you into the air traffic du jour. If you turn off your two transponders, and refuse to talk to them on the radio, it amounts to the same thing as turning off three transponders.
May we put to bed (without any supper!) this "three transponders" thing?
For any journalists reading (Mr Bailey?): please, give it a rest.
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Setback announced by OZ
The Deputy Prime Minister/ Minister for Transport announced a setback today:
MH370 setback in search | Assistance to the Aviation Industry
MH370 setback in search | Assistance to the Aviation Industry
New Theory about MH370
Flight Magazine has just published a new theory on the location of the possible crash site of MH370. It looks very plausible, what do others think?
Is this where MH370 is?
Is this where MH370 is?
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R.E. Flight Magazine article
The proposed route is not all that different from routes that others have proposed. Great circle and true track routes at constant air velocity tend to end up at the Southern limit of the search area, around -37 to -40 deg latitude. Once again, however, only BTO data are considered in the detailed solution. Such tracks do not match the BFO data very well - the BFO data favor a lower velocity for the first hour after the final turn South and either an increase in velocity or some sort of curved path thereafter. Unfortunately we do not have as clear an understanding of the BFO error model as we do for the BTOs, so deciding whether a seemingly poor match to the BFOs is significant or not is still unclear.