Re: [SystemSafety] MH370

From: John Downer < >
Date: Sun, 16 Mar 2014 17:18:20 +0000


I may be wrong, but I think the 'arcs' are straight lines that just look curved when plotted on a Mercator Projection.

John

On Mar 16, 2014, at 4:53 PM, Ken Hoyme <ken.hoyme_at_xxxxxx

> And from the description I saw in one report, they are working from data from a single satellite.  They just have a measure of distance from a single satellite which describes a particular circle on the ground that makes up the two arcs.  Combine that with the time of the signal and the possible speeds of the plane, they can identify a subset of that circle where the B777 could possibly have been.  
> 
> The claim was that they were trying to determine if any other satellite had tracking information at which point they could get two points, one on each arc that would define the likely location.  But having not seen maps with more precision, I presume such data has not been put forth (if it exists, it could be from classified satellites where the owning country may be less willing to reveal what the satellite is capable of).  
> 
> I don’t think it is “international politics” that has resulted in the two arcs, but simple physics.  
> 
> Ken Hoyme
> ken.hoyme_at_xxxxxx
> 
> On Mar 16, 2014, at 6:45 AM, John Downer <johndowner2_at_xxxxxx
> 
>> Regarding the divergent flight paths. It occurs to me that if you were doing triangulation with just two sources of distance data (ie: two satellites) then you would always get two potential locations. (Think of two intersecting compass-circles.) 
>> 
>> John
>> 
>> On Mar 16, 2014, at 10:37 AM, Chris Hills <safetyyork_at_xxxxxx
>> 

>>> Hi
>>>
>>> Yes there is a possibility it has landed safely somewhere. Depending in if you want to take off again as to how short the runway needed and the facilities required. There is still also a possibility they were abducted by aliens….
>>>
>>> Until a more coherent picture is formed it is all speculation. Despite Peter’s assertion that a clear or at least coherent picture is emerging I don’t think we have enough information to judge
>>>
>>> It *IS* possible that electrical faults killed the ACAS and the other systems in such a way the flight crew did not know, hence no radio calls, and this is still a bizarre accident. However given the information slowly (and somewhat disjointed) coming out of various military and intelligence groups (all with vested interests) mixed with the political shenanigans it may be that we never find out what happened even if the aircraft is eventually found.
>>>
>>> It is interesting that the two possible flight paths are almost in opposite directions… North west and south west (according to the BBC) I would have thought they could do triangulation a bit better than that. This would suggest there is as much international politics as air safety involved here.
>>>
>>> As PBL said this could be a game of not letting the hijackers know how much the authorities know. IF this was a hijacking you would normally expect some group of terrorists/freedom fighters to make some capital out of it. Unless the hijacking is phase one of a plan hence the cat and mouse with information releases from all sides.
>>>
>>> Chris
>>>
>>> From: systemsafety-bounces_at_xxxxxx >>> Sent: 15 March 2014 10:07
>>> To: systemsafety_at_xxxxxx >>> Subject: Re: [SystemSafety] MH370
>>>
>>> For many people this is more than just an interesting story (they have a personal connection).
>>>
>>> Is there any possibility that this plane land safely somewhere?
>>>
>>> Michael.
>>> _______________________________________________
>>> The System Safety Mailing List
>>> systemsafety_at_xxxxxx
>> 
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systemsafety_at_xxxxxx Received on Sun Mar 16 2014 - 18:18:33 CET

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