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Malaysian Airlines MH370 contact lost

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Malaysian Airlines MH370 contact lost

Old 3rd Apr 2014, 23:48
  #9101 (permalink)  
 
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But certainly the 30-day clock began to wind at the point in time no later than scheduled arrival plus 24 hours.
I think this a bit humorous, who cares about 30 days, 60 days, etc.
Cameroon didn't bother to release any preliminary report when KQ507 crashed and the final report was released like 3 years after the crash.
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Old 3rd Apr 2014, 23:56
  #9102 (permalink)  
 
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Possibility Set

A. Inmarsat got it completely right and MH370 came down in South arc.

A1. Controlled ditching left nothing on surface
A2. Debris not yet found

B. Hole in Inmarsat calculations as noted by Duncan Steel and MH370 came down in North arc.

B1. Landed in North arc and concealed. Passengers???
B2. CFIT in mountainous terrain while flying below radar.

A1 looks most probable at present.

If/when raw Inmarsat data becomes available, Duncan Steel's possibility set will be either validated or dismissed.
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Old 4th Apr 2014, 00:20
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The big difficulty with the Inmarsat analysis is that the equipment in the a/c was in a suspect condition. Possibly it had suffered physical damage from an event or it had been switched off. For equipment that isn't designed to stop cleanly on switch off, very odd things can happen as the supply rails fall so instead of some meaningful 'ping' that everyone has been analysing, they might have been analysing a 'chirp' as the volts die. A huge amount of weight seems to be given to this analysis. I'm with the group who feels that case is not proven. The a/c might be anywhere, even landed softly enough to let some or all souls survive. I hope so.
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Old 4th Apr 2014, 00:27
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ELT changes?

I've seen elt's fail because the antenna lead was ripped off the antenna at time of crash

I would like to see other methods trigger the ELT to transmit.

May I offer this:

Instead of JUST using impact G loads or even salt water emersion, how about: a timer.

During pre flight the timer is set for fuel exhaustion minus 30 minutes ( or anything you like ). It can be reset upon the ground (WOW switch for example) after safe arrival (do your checklists boys!)

But if you fly till fuel exhaustion time, its been sending out a signal for 30 minutes to aid in finding your plane.
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Old 4th Apr 2014, 01:32
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Inmarsat publication: original docs

The most official (and, IMHO,,accurate) info about maths done for looking at MH370 tracks is there:
You searched for mh370 - Inmarsat
It seems all those who have tried to make their own "predictions" from published pings data are coming with too high Doppler values vs the published chart.
With the chart, Inmarsat published this:

and also a worded explaination ( http://www.inmarsat.com/news/malaysi...tails-uk-aaib/ )
The report states that the calculations were made using the automatic ‘pings’ sent to the satellite via the ground station and the aircraft after it vanished.
It explained that if the ground station does not hear from an aircraft for an hour it will transmit a ‘log on/log off’ message – a ‘ping’ – and the aircraft automatically returns a short message indicating that it is still logged on, a process described as a ‘handshake’.
The ground station log recorded six complete handshakes after ACARS, the aircraft’s operational communications system, stopped sending messages.
Refined analysis
Inmarsat was then able to calculate the range of the aircraft from the satellite, and the time it took the signal to be sent and received, to generate two arcs of possible positions – a northern and a southern corridor.
OK, this is for the "arcs".
This follows:
The report goes on to explain that Inmarsat developed a second innovative technique that took into account the velocity of the aircraft relative to the satellite and the resulting change in signal frequency, known as the Doppler Effect.
The Inmarsat technique analysed the difference between the frequency that the ground station expected to receive and the one actually measured, known as the Burst Frequency Offset.
And this is the Doppler from which is the well known chart.

But what is D1 in above picture? Is this the part (?) of the Doppler corrected by the a/c unit (as explained by mm43: http://www.pprune.org/rumours-news/535538-malaysian-airlines-mh370-contact-lost-457.html#post8416026 ) But then, what is D2?

Could be that the frequency (from the a/c) is corrected to zero Doppler (from true frequency received and internal clock), and Inmarsat made the measured from the length of the bits of data (lower "frequency" > lower Doppler)? Perhaps a stupid guess...

Last edited by Shadoko; 4th Apr 2014 at 02:21. Reason: Bad link to worded explaination: corrected (sorry). And another question
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Old 4th Apr 2014, 03:31
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Originally Posted by YYZjim
In most countries, military assets exist to help the country's defence should it go to war. Such wars rarely start with a surprise attack. There are days, even weeks or months, of escalating tensions before armies face each other. The goal of the military is to have its assets ready, to train soldiers in their use, and to use them once hostilities actually start. Not before.

The United States is the exception. As the world's superpower, it sees a need to keep a proactive defence 24 hours of each day. It even needs to aware of the comings and goings (and communications) of its own residents. If MH370 gone missing in US airspace, it would be a wonder if the military bases within range were unresponsive.

Elsewhere in the world, though, common sense still prevails, and military assets are maintained for a state of war, not for the surveillance of civilian aircraft.
Not quite true - the UK has fighters on QRA that are quite regularly scrambled to assess civil aircraft, from hijack to commuter aircraft failing to flight plan or to navigate as expected; and of course the occasional Russian probing flights. This has been the case for decades. The Contiental US did not have any similar QRA capability until after 9/11 - a case of once bitten twice shy.
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Old 4th Apr 2014, 05:58
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I see they have announced that they have deployed the towed pinger locator".

"The hunt for the missing Malaysia Airlines plane has shifted below the surface, with the "towed pinger locator" deployed on Friday to search for the black box before its batteries expire.
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Old 4th Apr 2014, 07:26
  #9108 (permalink)  
 
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Originally Posted by 500N

I see they have announced that they have deployed the towed pinger locator
A stab in the dark!

However, a chance for the ship's crew to get familiar with towing the TPL25 at depth, including the constraints on speed and manouvering.
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Old 4th Apr 2014, 07:50
  #9109 (permalink)  
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Originally Posted by drwatson
What ATCC KUL and RMAF ( and even ATCC SGN -Ho Chi Minh) did those crucial hours went MH370 was trackable is important. When i lose anything i track back my exact actions to the time i last saw the missing item and the actions prior ..during and proceeding that.
True.

In professional terms an minute by minute detailed incident report from the time contact waa lost is needed. . . Simply assume the plane crashed into South china sea and do nothing?
We don't even know they made that assumption for some time.

No alerts went off to RMAF to scramble rescue..a plane down kn the seas wiyh possible survivors? No maritime or RMAF radar on high alerts? The current view is that they are a third world nation and simply messed up their SOPs does not cut it for me.
As pointed out below, there was no assessed air breathing threat to the CONUS so your military was effectively stood down prior to 911.

MH370 may not have been thought to be a threat or hijacked or been flown rogue but some reaction was taking place..adrenaline was rushing through some ATCC operations and MAS and RMAF and did they did nothing or everything wrong or made all the wrong assumptions is highky unlikely.
I think many people in a similar situation would be covering their six rather than admit out right that - they didn't notice, they didn't think, they weren't looking etc etc. It needs a special culture to say - Boss I goofed and for the Boss not to cover his 6.

Last edited by Pontius Navigator; 4th Apr 2014 at 09:22.
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Old 4th Apr 2014, 08:08
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@Shadoko
Could be that the frequency (from the a/c) is corrected to zero Doppler (from true frequency received and internal clock), and Inmarsat made the measured from the length of the bits of data (lower "frequency" > lower Doppler)? Perhaps a stupid guess...
I don't think it's a stupid guess at all.

A while back in the thread there was an excellent post explaining the nature of the satellite/aircraft handshake (the "ping"). This included a requirement for the aircraft equipment to Doppler correct its transmission to the satellite.

That being so, it's also possible that Inmarsat may have done some of its analysis not based purely on the straightforward Doppler effect between aircraft and satellite, but on the residuals left after that correction took place, whether in terms of uncorrected shift or some other consequent effect.

It's also noteworthy that Inmarsat were at pains to state that they had calibrated their work against other southbound Malaysian B777 flights. The specificity of that statement implies that such a calibration may not have been valid if done against a flight by another carrier, or by another aircraft type. Or, indeed, on another routing. Perhaps the work relies, in part at least, on the specifics of the performance of the particular equipment build installed in MAS B777s??

If so, then attempts to reconstruct what Inmarsat have done based purely on the freshman physics of the Doppler effect and basic orbital mechanics are doomed to failure.



As for why Inmarsat haven't released the full details of what they have done, a few potential explanations come immediately to mind:
  1. It's just too complicated for ready public consumption . These are press releases, not technical papers, after all. The Doppler effect and geostationary orbits are pushing at the limits of public understanding as it is. I am sure that those who need to know have been given full briefings.
  2. If their work relies on the specific performance of the equipment build installed on the aircraft, then divulging details could well compromise the commercial confidentiality of the equipment supplier.
  3. If this really is "cutting edge" science (a description that doesn't exactly apply to orbital motions and the Doppler effect, after all!), then they may see commercial opportunities for what they've done and want to protect their interests before making a full, public disclosure.
Just a few thoughts...
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Old 4th Apr 2014, 08:36
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2:40am is the time when Subang ATC notified Malaysian Airways that they had lost radar contact with the plane and decided that MH370 was missing.

They actually lost radar contact at 1:21am but there was nothing strange about that as they thought it was heading off to Vietnam.

It was only after Vietnam could not contact the plane and there was a flurry of attempts at contacting it that it was realised that it was missing and MAS should be contacted.

It is perfectly reasonable that in the initial days these facts were sloppily reported by various people as "Radar contact was reported lost at 2:40am".

By coincidence it was discovered several days later that there may have been military radar recordings of the plane elsewhere until about 2:40am. However, this has now been corrected to 2:19am.

Obviously, conspiracy theories can be built on such a co-incidence by those who like to look for such.
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Old 4th Apr 2014, 10:55
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Inmarsat are not the enemy here - they're the only organization that's provided any useful information whatsoever to the search.

Inmarsat have gone far beyond where they need to go in providing the service they were paid for. They've put considerable time and effort into new work to help the investigators, and located the wreckage to within a million square miles. I don't see why a reasonable court would demand they hand over their private records, even to someone with standing to ask for them.

Their reputation is now at risk from all the doubts flying around. The best way to avoid that would seem to be to publish their 12-16 data points for the arcs and doppler speeds, with a summary of the conclusions that set off the Australian snipe hunt. Duncan Steel can redo his sums, which might focus the snipe hunt, and the more reasonable conspiracists will be satisfied.
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Old 4th Apr 2014, 11:09
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Does anyone remember this earlier report - citing 'radar'? Since it is still not found, maybe worth re-looking at.

March 8th

The Vietnamese navy had earlier confirmed that Kuala Lumpur-Beijing bound Flight MH370 had crashed into the sea off Tho Chu island.
Tuoi Tre quoted Navy Admiral Ngo Van Phat, Commander of Region 5, as saying that military radar reported that the plane crashed into the sea at a location 246km south of Phu Quoc island.
Vietnam confirms MAS flight crashed into sea off Tho Chu island - The Malaysian Insider
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Old 4th Apr 2014, 11:25
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Why has this only been deployed today, just as the black box possibly starts to run out of charge?
Since Tireless was reported to have arrived in the general area on Monday 31st, that press release would seem to have been substantially overtaken by events.

Dangling a single microphone on a rope would seem to be less effective way to hear high-frequency pings than having seasoned and skilled ears using a big computer and a phased array of at least hundreds of them located beneath the thermocline. If I wanted to bet on the most likely to be successful, I'd put my money on the submarine.
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Old 4th Apr 2014, 11:47
  #9115 (permalink)  
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Quick Reaction Alert

Is a 3 minute alert posture by the RMAF possible?

Yes, but consider what they need for 2 aircraft.

This is cockpit readiness. Assume a rotation of 2hrs on and 4hrs off. You need 6 crews per day and 12 for 2 days. That is a crew/aircraft ratio of 1:6. Then you have crews under taking routine training on leave etc.

A more normal peacetime readiness is Crewroom readiness - typically 15 minutes - but you still need 4 crews per day as a second pair would be on one hour. Typically you still need 6 crews in 2 days.

Small air force's would struggle to meet the task.
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Old 4th Apr 2014, 12:29
  #9116 (permalink)  
 
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Originally Posted by awblain
If you don't trust the Inmarsat data, then there's nothing else to go on.
Thank you for interjecting a massive dose of sensibility. I have also read Duncan Steel's blog and it is long on hubris, and a deep self-satisfaction smugly based on exploiting the fact that not all technical details are revealed (I am redundant; I guess that self-satisfaction he oozes can be called "hubris," too). Back-tracking from press releases and simplified graphics is not a way to do science, regardless of how hard he implies it is. It just seems terribly self-aggrandizing and without sufficient details to refute the Inmarsat assertions prior to a comprehensive review.

Again, thank you. Very little is publicly known. Trying to extrapolate much more from press releases is not only futile, it's foolish. It seems we now have more high-profile media fools in this tragedy than we have victims.

Perhaps in the future we'll have a new phrase, the "Malaysian Ratio" - the number of self-professed, highly paid experts who talk confidently about something they honestly know nothing about, vs. the real experts working day and night to solve the real crisis. I think the ratio is running 1,000:1 at the moment.

Originally Posted by awblain
If I wanted to bet on the most likely to be successful, I'd put my money on the submarine.
Agreed, but only if the ssn is very,very near the impact point. Nothing from Inmarsat points to a search zone any one or multiple acoustic searches can grid search in a short while. While Tireless may have both sensitivity and specificity for this task, it won't have range. I honestly believe several US SSBN's are tasked likewise, but I do not believe it will help in a significant way, and it would be self-serving to claim it for a PR benefit.

I am going on record as saying this will be found. It may be a year or two. It may be within a month. Like AF447, the CVR and FDR will eventually be in competent air-board hands. It may take a while, but the search to find an answer is not going to be given up. The answer is going to be prosaic - it may be a single human-driven event. Or it may be a massively improbably technical one. But it is not going to be a massive conspiracy on behalf of multiple nation-states as the swell of opinion seems to favor.
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Old 4th Apr 2014, 12:29
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The sudden reappearance of Anwar Ibrahim is quite unsettling. He is a politician hoping to use MH370 to his political advantage, which is dishonourable.

The fact that he has a direct relationship to the captain ought to keep him out of the spotlight, unless of course he is the one politician complicit in the entire thing...
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Old 4th Apr 2014, 13:09
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@SheepGuts

And good old visual sightings don't rate anymore, which is a serious mistake in any investigation.
...
We need to get back to basics and stop betting everything on the tech stuff it does help. But we need to look at all the sightings.
Google the Innocence Project and then tell me you would happily take eyewitness testimony over scientific/technical evidence. In about 75% of convictions overturned by DNA evidence, the main evidence that secured the conviction was eyewitness testimony.

Research shows that the human mind is not like a tape recorder; we neither record events exactly as we see them, nor recall them like a tape that has been rewound. Instead, witness memory is like any other evidence at a crime scene; it must be preserved carefully and retrieved methodically, or it can be contaminated.
This is why two people can witness the same event but their testimony will not be the same. Plus, eyewitnesses will not necessarily see the whole picture and the bit they do see can be biased to a certain conclusion which doesn't reflect the truth.

I would say it would be a serious mistake to discount eyewitness testimony, but a even bigger mistake to put more reliance on it than the technical evidence. I would argue the technical evidence is more likely to give you the truth than eyewitness sightings particularly in a situation where people are panicked or under stress.
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Old 4th Apr 2014, 13:19
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The point is we do not have the data. We 'only' have Inmarsat's interpretation of the data.
"We" don't have much choice in that regard, since it's "their" system that has yielded the results, and "they" know more about how it works than anyone else.

If they say too much about how their system works, then they might be more prone to interference or jamming.

If they were to publish their analysis as a novel technical result or a patent, then the journal or patent office would send it to suitable experts to review.
If they were to submit it to a preprint server, then everyone qualified could have at it, but the best arbiter of the quality of this analysis would remain Inmarsat's own professional pride and responsibility.

The chance of a random blogger finding a crucial flaw in Inmarsat's timing and/or frequency shift analysis is not great.

The Lost Ark would have been investigated by "Top Men", who would include Jones' peers - and rivals - and who would be well known to Jones, if the general had been the boss of a patent office or a journal editor. It would be normal for their identities to be kept from Jones, to avoid the suggestion of any collusion or potential unfair influence.

However, if anti-Inmarsat noise builds further, then the company probably will have to release their arc/speed results. It won't quieten any hard-line conspiracy theorists, but it would allow any reasonable commentator to be absolutely certain that the missing 777 went south.
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Old 4th Apr 2014, 13:46
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@SheepGuts:

DNA was once an untried method that is now an accepted method. Just because something is untried doesn't make it invalid. As I understand it, Inmarsat tested this against flights to confirm their interpretations and that was subsequently referred to AAIB who agreed. I find it hard to believe given the magnitude of this incident that Inmarsat would release this if they were not 100% confident in their calculations.

And it still doesn't change the fact that eyewitness reports are inherently unreliable. I am not saying technical data is infallible because it still is subject to interpretation from the examiner, but generally technical information doesn't change and a consistent interpretation is usually reached repeatedly.
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