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Malaysian Airlines MH370 contact lost

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Malaysian Airlines MH370 contact lost

Old 19th Mar 2014, 00:01
  #5861 (permalink)  
 
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There is an inference that it is known now that the FMS route was changed. This can only be known by the ACARS transmission at 07.

If this is the case:

Everyone on the flight deck at that time would know the route had been changed.

Whoever made the radio call at 19 was aware the route had been changed.
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Old 19th Mar 2014, 00:06
  #5862 (permalink)  
 
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The last Ping

Please correct me if I am wrong. I make the 40 degree LOP arc a 2622 nm ground length (curved or great circle) radius on the earth’s surface, centred on the INMARSAT IOR satellite ‘pole’ at 0.0N 64.5E. i.e. 40 degrees latitude on an earth axis from earth’s centre to the satellite. I assume the satellite is over the equator because they claim equal coverage, North and South.

Approx 1680nm of the Northern LOP arc, most of it, is inside China.

I don’t want to play ‘Pin the tail on the Donkey’ with the rest of the guessing here. But on statistical (and political?) probability MH370 is in China. By the way, it’s been posted here before, are the Chinese investigating the cell operator logs about reports that pax telephones rang when relatives called them after the A/C was overdue?

Don’t hold your breath waiting for news reports.
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Old 19th Mar 2014, 00:09
  #5863 (permalink)  
 
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Deriving the course from the Inmarsat pings

I have done some simulations of whether the route of the flight could be determined if the arcs from the interim Inmarsat pings were available. So far we only have the final arcs (the north and south 'corridors').

I used the final published arc as the set of possible ‘destinations’ of the flight. One example destination on this arc was chosen, this determines the speed and heading from the last recorded radar position to achieve that final position, and hence where the hourly pings would be emitted over the 7 hours of the flight (and thus the distance from the Inmarsat sub-satellite point, which is what Inmarsat measures). A constant speed and heading was used as a first approximation.

The results of this example can be compared with the same calculation for each point along the published final arc, each of which requires a different heading and speed from the last recorded radar position and generates a different set of predicted ping arcs (distances from the sub-satellite point). An overall error can be calculated for each point along the published final arc.

The result is that there is only one constant heading course from the last recorded radar position that matches the example set of ping arcs, that is the destination is uniquely defined by the interim and final ping arcs (if interim arcs exist). There is a (rough) mirror course in the southern hemisphere which may be hard to distinguish as the last recorded radar position was close to the equator.

I also added a random error (noise) to the ping signals derived from course to the example destination, with the magnitude of the error being 50km on the ground (Gaussian, one sigma). This increases the error in deriving the final course giving an uncertainty of around plus/minus 100km in recovering the final destination – but it does not invalidate the technique.

I haven’t yet tried putting in a course with a change of heading along the route, but the method seems quite sensitive so I suspect such a course change could be recovered from the data. Many headings or speed changes would increase the final error, obviously.

So if the interim pings are available (to someone), and hence their arcs, it is very likely that the destination (or at least one in each hemisphere) could be derived with reasonable errors, at least up to the final ping.

Notes:
1. This is a rough piece of work done quickly to see whether the concept works. I have made a few assumptions that seem reasonable.
2. in this first try I have used simple Cartesian geometry (flat plane) rather than spherical geometry. The differences are relatively small as the area covered is reasonably close to the equator. A full spherical interpretation will not change the conclusion that the set of arcs define a single destination (or rather one in each hemisphere) but obviously would be needed to interpret the actual interim ping arcs.
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Old 19th Mar 2014, 00:13
  #5864 (permalink)  
 
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Deriving the course from the Inmarsat pings

And......?
So what heading/ speed did you use and was was the results?
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Old 19th Mar 2014, 00:17
  #5865 (permalink)  
 
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FE Hoppy

I think the route change had only been set up and selected at the time of the last transmission. Not activated until a short time later.
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Old 19th Mar 2014, 00:21
  #5866 (permalink)  
 
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Heli-Phile

Then how do they know the waypoint was inserted?
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Old 19th Mar 2014, 00:21
  #5867 (permalink)  
 
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Originally Posted by oldoberon View Post
But if 3rd hourly ping is at the same reduced spacing to the 2nd one , as the 2nd one is to the 1st one that constant spacing tells you it is on a constant heading/trk but nothing about that heading or track.. Do you agree that?
Well no, actually. If the spacing between arcs 1 and 2 is less than the distance that the aircraft is likely to have flown in the hour, that tells us that the average track angle was somewhere between radial and tangential. If the spacing is the same between arcs 2 and 3 then there are at least two average track angles that would result in the same flight distance (more if we allow for possible differences in groundspeed, but let's discount that).

Now you may think that is unimportant or of no use others will disagree a) it is an extra known and B) in IMHO it indicates a flight south, constant track north is eventually going to be spotted by the ground or another aircraft visually.
Why north or south in particular, rather than any other possible direction?
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Old 19th Mar 2014, 00:22
  #5868 (permalink)  
 
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Geostationary orbit - Wikipedia, the free encyclopedia

I assume the satellite is over the equator because they claim equal coverage, North and South.
The satellites are over the equator because they are Geostationary. They are stationary relative to the surface of the earth.

EDIT: This is significent because it determines the arc(s). If there were multiple pings and if the satellites were moving relative to the surface of earth we might know exactly where the plane is.

Last edited by lakedude; 19th Mar 2014 at 00:34.
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Old 19th Mar 2014, 00:26
  #5869 (permalink)  
 
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Originally Posted by RichardC10 View Post
I have done some simulations of whether the route of the flight could be determined if the arcs from the interim Inmarsat pings were available. So far we only have the final arcs (the north and south 'corridors').

I used the final published arc as the set of possible ‘destinations’ of the flight. One example destination on this arc was chosen, this determines the speed and heading from the last recorded radar position to achieve that final position, and hence where the hourly pings would be emitted over the 7 hours of the flight (and thus the distance from the Inmarsat sub-satellite point, which is what Inmarsat measures). A constant speed and heading was used as a first approximation.

The results of this example can be compared with the same calculation for each point along the published final arc, each of which requires a different heading and speed from the last recorded radar position and generates a different set of predicted ping arcs (distances from the sub-satellite point). An overall error can be calculated for each point along the published final arc.

The result is that there is only one constant heading course from the last recorded radar position that matches the example set of ping arcs, that is the destination is uniquely defined by the interim and final ping arcs (if interim arcs exist). There is a (rough) mirror course in the southern hemisphere which may be hard to distinguish as the last recorded radar position was close to the equator.

I also added a random error (noise) to the ping signals derived from course to the example destination, with the magnitude of the error being 50km on the ground (Gaussian, one sigma). This increases the error in deriving the final course giving an uncertainty of around plus/minus 100km in recovering the final destination – but it does not invalidate the technique.

I haven’t yet tried putting in a course with a change of heading along the route, but the method seems quite sensitive so I suspect such a course change could be recovered from the data. Many headings or speed changes would increase the final error, obviously.

So if the interim pings are available (to someone), and hence their arcs, it is very likely that the destination (or at least one in each hemisphere) could be derived with reasonable errors, at least up to the final ping.

Notes:
1. This is a rough piece of work done quickly to see whether the concept works. I have made a few assumptions that seem reasonable.
2. in this first try I have used simple Cartesian geometry (flat plane) rather than spherical geometry. The differences are relatively small as the area covered is reasonably close to the equator. A full spherical interpretation will not change the conclusion that the set of arcs define a single destination (or rather one in each hemisphere) but obviously would be needed to interpret the actual interim ping arcs.
Richard great work my maths ability now where near yours but I have argued for days the full set would reveal data, all i could do was a set of results that would confirm a constant hdg/trk but not data o where on the circle or what heading

There was a post earlier today where someone was referring to rhumb lines and loxodromes, he reckoned with all pings you could use them to calculate various heading data, me no idea what they are, just wondering if you did and is the idea useful

Last edited by oldoberon; 19th Mar 2014 at 00:34. Reason: add loxodrome
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Old 19th Mar 2014, 00:30
  #5870 (permalink)  
 
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papershuffler said

The Malaysians' trust in the US may be ebbing as many of the recent stories come from 'US sources', i.e. leaks, and are critical of the Malaysians.
If there is sensitive data you really need to know it's not going to go any further.

The Malaysians may be thinking, 'You're going to blame either our pilots, procedures, or maintenance instead of your US-made aircraft, why should we work with you?'

Would you want to work with someone who may not be able to help, and could just stab you in the back, repeatedly? Then insist that you are to blame as their investigative bodies may conclude (e.g. Egyptair)?

(During one of the investigations I worked on several years ago, a copy of a request for information to a US state containing many sensitive details was uploaded to the state's public online library and made available for all to view. The state refused to remove it . It made relationships rather frosty.)
This is honestly a flat out freakin disgusting post

First, those "leaks" are pretty much the only reason 14 countries aren't still wasting time looking in the Gulf today - remember, the official Malaysian position pretty much never changed from it going down there until US Officials "leaked" the plane flying for 5+ more hours... (only after which time did India and Australia really get involved searching places the plane could actually be)

Second, the Malaysian Governments biggest concern should be trying to find 200+ lives that may be able to be saved for all anyone knows

Third, the Malaysian Government can clearly not even begin to do this themselves, and has more than a little issue with transparency, consistency and even coming to grips with basic common sense (how long were they going to keep us looking in a gulf they knew on day 1 they had evidence it wasn't in, anyway? And how long was it going to take before they took seriously the possibility the pilot could ever be involved? And on and on...)

Forth, it is hardly JUST the US that is telling them to be more transparent; we have seen similar from just about every country involved in this search (especially Vietnam and China, the two countries Malaysia jerked around the most at the beginning of all this) Shoot, there are even endless reports that most of their own people and a few scattered officials are furious and distrustful of the way Malaysia is handling this!

Lastly, you seem to be under the impression it can not under any circumstances ever possibly be the "pilots, procedures, or maintenance" that is at fault here and absolutely MUST be because it was a "US-made aircraft" - being you have a god-like ability to be so all knowing, I suggest you tell the Malaysian Government exactly what happened and where the plane is then (just don't feel too bummed when they dismiss you outright; you have to understand they have actual evidence saying whatever your theory is, it is already basically impossible)

As I said before, just a flat out disgusting post consistent with a useless tin-foil hat wearing conspiracy nut, not a person with even basic level of critical thinking that should actually be taken seriously by anyone

It's offensive really even having to read the drivel when we have people possibly laying somewhere dying because of the Malaysian 'maybe we'll help, maybe we won't - we'll tell ya later' games with all involved; games you apparently full-heatedly support them playing
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Old 19th Mar 2014, 00:31
  #5871 (permalink)  
 
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As opposed to earth orbiting which is what the GPS satellites are. Hence the ability to get a 3D fix using the latter
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Old 19th Mar 2014, 00:33
  #5872 (permalink)  
 
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Tomnod FWIW has released image maps of what seems to be the Australian Search sector - Indian Ocean

Example:

Tomnod

lat, lon 4.213168, 90.440788
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Old 19th Mar 2014, 00:34
  #5873 (permalink)  
 
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Final ACARS report detailed it. I will try to find the posts that reported this.
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Old 19th Mar 2014, 00:34
  #5874 (permalink)  
 
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Originally Posted by GarageYears View Post
I keep seeing questions related to why the SATCOM system was sent pings, etc, and discussion related to ACARS use, MAS subscription to the ACARS reporting service to Boeing (or not), but isn't it also the case that the SATCOM transceivers at ALSO available for voice comms?
Yes, 777 cockpit SAT comms out of the tin, and optionally, in-seat passenger satellite linked phone service.
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Old 19th Mar 2014, 00:35
  #5875 (permalink)  
 
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Originally Posted by RichardC10 View Post
.

The result is that there is only one constant heading course from the last recorded radar position that matches the example set of ping arcs, that is the destination is uniquely defined by the interim and final ping arcs (if interim arcs exist). There is a (rough) mirror course in the southern hemisphere which may be hard to distinguish as the last recorded radar position was close to the equator.
Nice work. Many here would be interested in where you concluded the aircraft may have ended up.
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Old 19th Mar 2014, 00:36
  #5876 (permalink)  
 
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Originally Posted by papershuffler View Post

The Malaysians may be thinking, 'You're going to blame either our pilots, procedures, or maintenance instead of your US-made aircraft, why should we work with you?'
And all that blame may well be completely unfair, but the Malaysians WILL be fairly blamed for their initial in-flight emergency response.
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Old 19th Mar 2014, 00:38
  #5877 (permalink)  
 
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Deriving the course from the Inmarsat pings

Originally Posted by Heli-phile
And......?
So what heading/ speed did you use and was was the results?
What I have done is a demonstration that the course can be derived, if the interim pings are available. Without the actual ping data no further progress is possible.
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Old 19th Mar 2014, 00:39
  #5878 (permalink)  
 
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"Be transparent" could mean anything up to "we know exactly what happened to the airplane and we know that you know. And we are giving you a chance to announce it first." Just saying.
Yep, but with the amount of verbal 'misunderstandings' there have been so far, are you sure they'll understand what the US are saying?

That is a valid position to take, as it is their airline, and the flight originated in their capital. A number of nations will doubtless be happy to assist. The UK and US are obliged to since Engines and Aircraft were built in those two nations.

Therefore, UK and US will be none too interested in a cover up. What they'll want is an actual investigation. My experience with morals and ethics in the third world advises me that this requires some effort to elicit, and pressure at time not to fall into the same old same old corruption that a certain airline captain was vocally against.
Very much an understatement; IME, I would have said nigh-on impossible. Records are 'lost' and witnesses disappear. Legal proceedings take years. Letters go amiss. No one returns your calls. People virtually laugh in your face. Sometimes it doesn't even take a third world country for this to happen.
Without considerable international pressure, I don't have faith in important evidence (e.g. maintenance records) making it to the investigative team, whoever and wherever they may be.

We've seen it all before; as time goes by, the shock will abate and career- and face-saving will take precedence, if it hasn't already.

It will be interesting when/if the fate of MH370 is finally discovered, how much involvement the Malaysians wish to take in the proceedings.

(Personal opinion/suspicion: if it hadn't been (more-or-less) confirmed that the FO Fariq Abdul Hamid was the last voice heard and therefore still alive, I suspect the negative stories discrediting Capt Zaharie would have gathered more pace...)

Last edited by papershuffler; 19th Mar 2014 at 03:58. Reason: extra word deleted/moved to make sense
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Old 19th Mar 2014, 00:40
  #5879 (permalink)  
 
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rigbyrigz,

Thanks for more confirmation of the WP being changed pre-ACARS report. Think I will still leave it as "apparently" though, as some data seems to be "confirmed" then debunked later when Malaysia decides to actually share the data instead of whatever they decided their theory of it was at whatever moment.

As far as your note - any system failure would have sent out an emergency ACARS. If the Transponder did drop because of a catastrophic event it would have. If merely turned off, I am not 100% sure. (but I think it would have) Hopefully someone else can clarify that last bit
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Old 19th Mar 2014, 00:56
  #5880 (permalink)  
 
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Originally Posted by GarageYears
I keep seeing questions related to why the SATCOM system was sent pings, etc, and discussion related to ACARS use, MAS subscription to the ACARS reporting service to Boeing (or not), but isn't it also the case that the SATCOM transceivers at ALSO available for voice comms?

Yes, 777 cockpit SAT comms out of the tin, and optionally, in-seat passenger satellite linked phone service.
Ah, thanks for the confirmation.

Right, so that puts to bed the occasional "well-if-they-aren't subscribed to Boeing's data monitoring... why does the satellite ping them" comment I've seen. The pings are there just as much for the cockpit voice comms link, as any data that may or may not be sent over the same link.
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