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Malaysian Airlines MH370 contact lost

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Malaysian Airlines MH370 contact lost

Old 20th Mar 2014, 00:35
  #6281 (permalink)  
 
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Pinging 101

Tracking flight MH370: ACARS and transponder - ABC News (Australian Broadcasting Corporation)

The head of aviation at the University of News South Wales, Professor Jason Middleton, helps explain just how these systems work and why there is no exact location for the plane.
A rough location can be extrapolated by measuring the time it takes for the ping to be picked up by two satellites.

"[Investigators] are actually using not the signal itself, but the time of reception at different receivers," Professor Middleton said.

"So if you sent out a ping of some sort and it arrives at two receivers and you're exactly halfway between, you can expect that ping will be received – milliseconds later – at the exact same time at both, because it's got the same distance to travel.

"On the other hand, if you're two-thirds closer to one than the other, then that one will receive the signal more quickly than the other."

Professor Middleton says you can use that satellite data to identify a rough line on the surface from where the signal most likely originated.




Any guesses where the second satellite is? The further apart the greater the doppler effect.

If two satellites are used it would be almost impossible to spoof a signal from a fixed point, an idea I raised earlier. You would need to send two pings a split second apart in a way where only one ping was received by each satellite.

For those that want to keep the dream alive that the aircraft has landed;
A drone could have shadowed the flight then turned off and mimicked the ping, but not many drones have speed and endurance to cover the route.

Pingers located on water and land that were activated in sequence.

911 conspirators still claim that ACARS was received after aircraft had crashed.

There was a fast moving ship at the southern search area in the middle of nowhere, a few days ago before the search area was announced..

On the net, so easy to cast doubt on the plausible eh?



Mickjoebill
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Old 20th Mar 2014, 00:43
  #6282 (permalink)  
 
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Flash8

It does not do anything to the AC bus. It is a software selection only which has no effect on the electrical busses.
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Old 20th Mar 2014, 00:46
  #6283 (permalink)  
 
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John Young AMSA briefing
John Young AMSA (Emergency response division) briefing was very interesting.
Acting on information from NTSB He explained that:

Quote:
"Regular messages from the aircraft, at approximately hourly intervals during its flight. Those transmission were detected by a communications satellite over the indian ocean and with the time of those communications and the distance, Then clarified "They can't plot exact distance but sequentially they can be build up into a route the aircraft took."
The wording here is crucial, it implies that all pings were received and from that, a 'join the dots' plot can be derived. This would be the first confirmation that all pings were received, not just the last one!
Unless the Australians are assuming this is what NTSB has done, this would indicate the aircraft has been plotted heading due south or of course due North as the arcs are mirrored!
No, there is really only one arc with a bite taken out of the middle to eliminate the area covered by the adjoining satellite which did not receive a '0011Z ping'.

When John Young says 'sequentially' he is probably indicating the use of earlier 'ping rings' in the calculations. I suggest that if so, these would be a series of running fixes from the last reliable co-location of radar fix and 'ping ring', using max and min ground speeds, which would branch out into some but not all of the final arc.
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Old 20th Mar 2014, 00:49
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Any guesses where the second satellite is? The further apart the greater the doppler effect.
There is no second satellite. There is only one INMARSAT satellite that picked up the pings. They have used the response time delay to determine the distance only and that is relatively imprecise.

See this: TMF Associates MSS blog » 2014 » March

It's extremely well written and right on the money in terms of details.
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Old 20th Mar 2014, 00:50
  #6285 (permalink)  
 
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ARINC data bus

A Q. for 777 avionics techs; could the ARINC data bus be damaged / destroyed in a way that prevented Transponder and ACARS transmissions, but in a way that still provided position information to align the SAT antennae and allow 'pings' ?
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Old 20th Mar 2014, 00:59
  #6286 (permalink)  
 
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@the WAWA ZONE quoting me/ignoing what I wrote

Here, what part of my summary did you miss?

The wording here is crucial, it implies that all pings were received and from that, a 'join the dots' plot can be derived. This would be the first confirmation that all pings were received, not just the last one!
Unless the Australians are assuming this is what NTSB has done, this would indicate the aircraft has been plotted heading due south or of course due North as the arcs are mirrored!
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Old 20th Mar 2014, 01:02
  #6287 (permalink)  
 
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New BBC video report, which includes one of the Australian search and rescue people talking about the hourly pings being used to help with possible locations. This means they do have information from all of the pings, but it isn't being made public, as suspected:

BBC News - New clues in search for Malaysia Airlines MH370
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Old 20th Mar 2014, 01:07
  #6288 (permalink)  
 
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Space Jet

So there saying there is more than six pings?
They're saying there's more than one ping and they have their records.
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Old 20th Mar 2014, 01:13
  #6289 (permalink)  
 
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Those 'Pings" again.

The head of aviation at the University of News South Wales, Professor Jason Middleton, helps explain just how these systems work and why there is no exact location for the plane.
A rough location can be extrapolated by measuring the time it takes for the ping to be picked up by two satellites.
To the best of my knowledge the Inmarsat I-3 series satellite at nominal position 0° 64°E had logged the unique ID of this aircraft when the SATCOM was activated prior to departure Lumpur. The Satellite checked hourly that the bird was still in range by 'pinging' it. The return time of the signal originated by the SAT and acknowledged by the aircraft is the means of creating a position line (in this case a curved one) that is being used to determine the radius of a circle on which the aircraft could be. This whole procedure has been explained in many posts to this thread, and the Professor should at least get his facts right.

The basic explanation can be found on -page 297 Post #5935
and an example showing the possible 180°M heading is on - page 299 Post #5971

The BBC seems to be reading PPRuNe, and its a pity the professor hasn't.

Only ONE satellite is involved.
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Old 20th Mar 2014, 01:13
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Wawa: been to NG737 school as an avionics tech. No direct hands on in a 777. In general most boxes have 2 different buss inputs. Not so say it couldn't happen, but sems way out there. And you would get error messages on the EICAS.

In retrospect, it the pings included basic lat/long info, just degrees and min. We wouldn't be so lost at this point. And the satcom needs it to point the Antenna anyway. 10 bytes once an hour...
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Old 20th Mar 2014, 01:14
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Fascinating that the reported flight track appear to follow the FIR boundaries. Would be great to overlay the track on your FIR map. The U turn when a/c touched the Indonesian FIR could be consistent with evasion. This would make sense if pilot thought he might have a tail/intercept/monitored after his crossing of the peninsula. If there was a low altitude over the Peninsula and Straits it would also be consistent with radar evasion. I think we have to give evasion a high probability given the known/likely data points
Try www.skyvector.com -- it has global high altitude charts and a flight planning function that enables you to compute leg distances. Input WMKK-ZBAA into the base flight track, then drag the track line over the asserted waypoints. Bearings and leg distances will be computed and you'll be able to see how they match up with the FIR boundaries.

ETA: Let's see if this works. Link to map here: http://skyvector.com/?ll=5.687414242...VAL:F.VO.IGREX

Tried to post an image, but the link works. Times are based on an assumed 462 knots i.e. M= .80.

Last edited by mseyfang; 20th Mar 2014 at 01:29.
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Old 20th Mar 2014, 01:27
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Map of data

I have put together a map of the known bit of info
MAS370
I have marked up the flight plan, the three named waypoints mentioned by various sources and confirmed by Malaysian authorities, the Inmasat angle ranges and the final 40° line.

I have added the known points of info we have, last radio transmission, last acars, last primary radar return, based on their timing and then joined the dots a bit from the last known point to waypoint GIVAL. Comments by the Malaysians say it tracked towards VAMPI, but not over VAMPI.

Based on the last known radar point 200 nm of Penang gives us a gound speed in the range of 420 knots. If I stretch the last known point to 250 nm of Penang it comes back at about 470 kts which I think is more reasonable. The last GS from Flightaware had it at 468 kts.

The possible flight paths are my own supposition, it had to get from the last known radar point at 0215 (local) to the 40° inmarsat intercept at 0811 (local) so the lines reflect approx positions based on a number of ground speeds.
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Old 20th Mar 2014, 01:28
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Will they release the ping data today?
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Old 20th Mar 2014, 01:28
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The wording here is crucial, it implies that all pings were received and from that, a 'join the dots' plot can be derived
A "join the dots" plot is not possible from one satellite. There would be several full circles, one for each ping, no dots. Parts of each circle could be eliminated but an exact plot would be impossible from the ping data from only one satellite.

This is the unfortuate truth of the matter. If a second satellite was involved two connect the dots plots could be made, one to the north the other to the south in a mirror image.

If a third satellite was in line with the first two it wouldn't help anything but if it was off the line to the north or south it would pinpoint the exact location.

Last edited by lakedude; 20th Mar 2014 at 02:08.
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Old 20th Mar 2014, 01:32
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ReadMyACARS

ReadMyACARS...that is very astute - assuming they took the southern arc.

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Old 20th Mar 2014, 01:39
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The very sobering incident of Egyptair Flt MS667

Egypt Air ground accident via Airmike767
http://www.civilaviation.gov.eg/acci...9-09-2012a.pdf
On July 29 2011 an Egyptair 777-200 Flight MS667 Reg SU-GBP was preparing for departure at Cairo Apt and had just finished boarding when the cockpit crew oxygen system malfunctioned and started an intense fire on the RHS of the cockpit.
Everybody evacuated safely through the still-connected passenger bridge through doors 1L and 2L, and the fire was brought under control by the airport fire dept but not after melting huge holes in the exterior acft skin and causing severe damage to the entire fwd section of the plane.
The accident report in the link above is a very sobering read if you imagine the incident happening 60 mins later as the 777 has departed and at altitude.
There would be no time to talk to the ground, and very little time for the crew to effect a descent before smoke/heat/depressurization took everybody out
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Old 20th Mar 2014, 01:39
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@intel101 ...or it could mean that there are unidentified radar echoes (from drone overflights and whatnot) frequently enough for them to ignore those that don't seem to pose a threat...

There is a Global Hawk base not far away, afterall.
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Old 20th Mar 2014, 01:46
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@Readmy ACARS.

A lot neater than my google earth version which is not suitable for public viewing.
You might want to look at the due south assumption which appears to come from the NTSB. That along with the 08:11 range and assumed ground speed might confirm start points for the plot.
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Old 20th Mar 2014, 01:50
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It is apparent that the INMARSAT data is believed by the Australian, New Zealand and US maritime reconnaissance who are flying out into the middle of nowhere and also by the Chinese who are searching again in potentially reachable areas. I rather doubt that these new searches would be happening due to a PR statement.
More compelling reasons in my view are that OZ public prefer its government does something i.e. "have a go" to find its six Aussies and the rest of the passengers, rather than appear to wait for more conclusive information.

Also there was a Chinese registered vessel ALREADY in the area at the time the search was announced and the SAR could monitor it.


ABC noon news interviewed Aussie Jeff Askew ex Group General Manager Security and Emergency Management at Qantas for 15 years, and formerly with police and defence and Australian Airlines, he now runs a consultancy company, with a "top secret" clearance.

Summary;
He says they probably will find the plane, it may take time.
He couldn't answer questions about Pine Gap but says they wouldn't hold back info.

Last two weeks public have learnt it is more difficult to find a plane than previously thought, the capability is not there.
Says this incident will have ramifications to airlines and manufacturers. Will be driven by what is found to be facts.
Changes could be to airspace management and broad security of it including passports.
Live tracking of flights, passenger screening, change to looking for bad people not just bad things.
Airlines will need to manage threats from inside (pilots) and greater cargo security.

Industry has understood these issues, but were not at forefront of thinking.
Pilots should not be able to close down transponders, so fire issues will need to be addressed.

Says Malaysians Airlines did the best they could then other agencies took over.
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Old 20th Mar 2014, 02:10
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@ ReadMyACARS / Map of Data

Great map. Just had one query. Bearing in mind the Indonesian denial that MH370 crossed their airspace:

But according to the Wall Street Journal yesterday, Indonesia said its two radar stations in the Aceh province, nearest to where Malaysia lost sight of the Boeing 777-200ER carrying 239 people in the Straits of Malacca, found no indication of the aircraft.
“Malaysia said their radar detected [an object] near Pulau Perak, and then it disappeared.
“Had the plane entered Indonesian territory, the two radars must have detected it,” First Marshal Hadi Tjahjanto of the Indonesian air force told the WSJ.
Defense Minister Purnomo Yusgiantoro has asserted that the military radar placed in Sabang, Nanggroe Aceh Darussalam -- Indonesia's westernmost point -- did not detect missing flight MH370 or any other foreign aircraft crossing Indonesian airspace.“I have received a report about it. The air defense radar system in Sabang is very sophisticated and it did not detect any aircraft,” he said in Jakarta on Wednesday, as quoted by Antara news agency.
The minister said the military radar owned by the Defense Ministry was more sensitive than civilian radars so that there was no reason to doubt its accuracy.
MH370 not detected by Indonesian military radar: Defense minister | The Jakarta Post

Does that infer that more turns were made before hitting 'open water'? Or do you think that the current path is far enough away from Indonesian primary radar capabilities (whatever they are)?
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