Malaysian Airlines MH370 contact lost
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Hello. I have a request for more Inmarsat data.
I want to give my own calculations based on the BTO and BFO datapoints posted by Inmarsat a shot. As we know, some of the individual values make little sense. And the diagrams of how the data is collected contain some black boxes just saying "compensation", which could really mean anything. What kind of "compensation" has been done to the data before making a record? Is that reliable? Is that compensation that is predictable enough to undo to maybe correct errors? I imagine whoever programmed that system didn't have in mind that it would later be used to locate a plane based on less than a dozen datapoints and no other information.
What I would like to have is the same set of data for BTO and BFO as we have for MH370, but for a flight that proceeded normally (and hence we know where it actually was for any given value pair).
Is that available anywhere? Any random flight would do, but obviously it would be nice to have something that proceeded at about the same distance from the recording satellite.
I want to give my own calculations based on the BTO and BFO datapoints posted by Inmarsat a shot. As we know, some of the individual values make little sense. And the diagrams of how the data is collected contain some black boxes just saying "compensation", which could really mean anything. What kind of "compensation" has been done to the data before making a record? Is that reliable? Is that compensation that is predictable enough to undo to maybe correct errors? I imagine whoever programmed that system didn't have in mind that it would later be used to locate a plane based on less than a dozen datapoints and no other information.
What I would like to have is the same set of data for BTO and BFO as we have for MH370, but for a flight that proceeded normally (and hence we know where it actually was for any given value pair).
Is that available anywhere? Any random flight would do, but obviously it would be nice to have something that proceeded at about the same distance from the recording satellite.
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Originally Posted by RetiredF4
An aircraft maneuvering in altitude, speed and track could be anywhere on a position close to the south arc and to the north arc.
Quote:
Originally Posted by RetiredF4
An aircraft maneuvering in altitude, speed and track could be anywhere on a position close to the south arc and to the north arc.
Please explain how a position close to the north arc can be compatible with the logged values of BFO (Burst Frequency Offset or doppler compensation error).
Originally Posted by RetiredF4
An aircraft maneuvering in altitude, speed and track could be anywhere on a position close to the south arc and to the north arc.
Please explain how a position close to the north arc can be compatible with the logged values of BFO (Burst Frequency Offset or doppler compensation error).
As I understood it from discussions, a rapid descent or a rapid climb while over the data point would alter the data more than cruising north or south, as climbs would give closure to the satellite and descents would give opening to the satellite. If the aircraft was turning north and descending at the same time, the turn to south at the relevant data point would no longer be the only option, but to the north it would be possible too. Speed and track changes from one data point to the next would alter the present interpretation as well. There would be millions of pathes possible if all maneuvering options would be considered, as long as those pathes ended somewhere close to the northern or southern arc.
The present "only south it is" path is founded on a lot of assumptions and few facts, as would be a north path too. I'm not saying it was the wrong decision to search south, but it might have been flown to the north as well.
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There are not that many permutations with the aircraft out of fuel when it was. From my understanding the INMARSAT team did do comparison/validation with other aircraft flying in the area and that confirmed their view of what happened. The 'North' story doesn't fit the Doppler changes that were recorded. It is extremely unlikely that the person(s) flying MH370 were aware of the SATCOM tracking that could be done, therefore it is also extremely unlikely that they were spoofing the tracking.
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A good summary of what has been used to choose the southern arc can be found here.
http://www.rin.org.uk/Uploadedpdfs/s...at%20Paper.pdf
Note please, that the following initial basics did not change throughout the whole process. Every refinement and the final conclusion are based on the asumptions of this initial reconstruction attempt. (bolding by me)
The changing BFO data caused by the wobbling of the Sattelite and the above assumptions led to the southern path. The sattelite moves north south with a maximum of 2,412 km per day which results in a comparable low BFO change opposed to a climb, descent or a speed change.
Read also on the Blog of Duncan Steel.
The Inmarsat-3F1 Doppler Data Do Not Exclude a Northerly Flight Path for MH370 | Duncan Steel
http://www.rin.org.uk/Uploadedpdfs/s...at%20Paper.pdf
Note please, that the following initial basics did not change throughout the whole process. Every refinement and the final conclusion are based on the asumptions of this initial reconstruction attempt. (bolding by me)
Initial flight path reconstruction attempts were based on the aircraft flying at a steady speed on a relatively constant track consistent with an aircraft operating without human control. It was initially thought that for the fuel to have lasted until 00:19 UTC the aircraft would have needed to be flying at high altitude, where the air is thinner and drag is reduced, which would have resulted in its flying at close to its maximum speed of just over 500 knots (926 kph). This gave two solutions, one in a northerly and the other in a southerly direction, as illustrated in Figure 6, where thered lines indicate the flight paths prior to 00:19 UTC and the green lines indicate the potential additional flight paths between the last signal at 00:19 UTC and the failure to respond to the LOI message sent by the GES at 01:15 UTC.
It is important to remember that these initial flight paths, while consistent with the BTO timing data and the aircraft performance, were based on a number of assumptions: that the aircraft travelled at a steady and high speed and did not make any manoeuvres beyond a turn to the north or south shortly after its last radar detection.
It is important to remember that these initial flight paths, while consistent with the BTO timing data and the aircraft performance, were based on a number of assumptions: that the aircraft travelled at a steady and high speed and did not make any manoeuvres beyond a turn to the north or south shortly after its last radar detection.
The changing BFO data caused by the wobbling of the Sattelite and the above assumptions led to the southern path. The sattelite moves north south with a maximum of 2,412 km per day which results in a comparable low BFO change opposed to a climb, descent or a speed change.
Read also on the Blog of Duncan Steel.
The Bottom Line: A northerly route for MH370 deep into central Asia cannot be excluded on the basis of the publicly-available Inmarsat-3F1 satellite data.
The battery powering the underwater locator beacon on missing Malaysia Airlines flight MH370's data recorder expired in 2012
"]http://www.abc.net.au/news/2015-03-08/mh370-report-says-black-box-locator-beacon-expired/6289462"]
Last edited by sunnySA; 8th Mar 2015 at 11:24. Reason: Link now works
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RetiredF4:
I suppose mr. Duncan Steel doesn't like to be reminded of that blunder he published on 2014 April 02, when he did not understand the interpretation of the logged BFO's. That was explained in the ATSB report "MH370 - Definition of Underwater Search Areas" dated 26 June 2014.
Your first quote doesn't have a date and does not mention BFO.
The BFO's for a northern route would be about 78 Hz greater than the logged BFO's in level flight. To obtain the logged BFO's on the northern route the aircraft would have had to climb at 3360 feet per minute during the 343 minutes of flight remaining after the first 'ping' at 18:25 UTC. That is 1,152,480 feet.
I suppose mr. Duncan Steel doesn't like to be reminded of that blunder he published on 2014 April 02, when he did not understand the interpretation of the logged BFO's. That was explained in the ATSB report "MH370 - Definition of Underwater Search Areas" dated 26 June 2014.
Your first quote doesn't have a date and does not mention BFO.
The BFO's for a northern route would be about 78 Hz greater than the logged BFO's in level flight. To obtain the logged BFO's on the northern route the aircraft would have had to climb at 3360 feet per minute during the 343 minutes of flight remaining after the first 'ping' at 18:25 UTC. That is 1,152,480 feet.
Gysbreght
The BFO's for a northern route would be about 78 Hz greater than the logged BFO's in level flight. To obtain the logged BFO's on the northern route the aircraft would have had to climb at 3360 feet per minute during the 343 minutes of flight remaining after the first 'ping' at 18:25 UTC. That is 1,152,480 feet.
The BFO's for a northern route would be about 78 Hz greater than the logged BFO's in level flight. To obtain the logged BFO's on the northern route the aircraft would have had to climb at 3360 feet per minute during the 343 minutes of flight remaining after the first 'ping' at 18:25 UTC. That is 1,152,480 feet.
Only during the short time of those few handshakes about 1 hour apart from each other the BFO data have to be fullfilled, not for the whole time of the flight. The flight could do circles in between, as long as it reaches the corresponding BTO arc at the next handshake and fullfills the respective BFO data. On what heading, speed and altitude that would take place or if the aircraft is climbing or descending at that very moment is not shown by the data.
Your computation assumes again a given track and a given speed and the computed vertical speed not only for the respective time of the handshake, but over the complete flight. It is the assumption that it was flown on autopilot with one fixed final target until end of the flight.
Last edited by RetiredF4; 8th Mar 2015 at 12:09.
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Does everyone else see page 93 (as numbered on the pages) is missing from the Factual information report?
I've just read all the ATC transcripts in the report.
The lack of action and confusion as the events unfolded would be comical if not so serious. All concerned appeared as "rabbits in the headlights" and thus laid down protocols went out of the window.
Why did the Vietnamese wait over 15 minutes before querying the Malaysians as to the location of MH370?
Why did ATC not declare an "uncertainty phase" as per their own laid down procedures?
Why was "aircraft overdue" not declared 30 minutes after the IGARI estimate?
When MAS ops failed to get a response to their ACARS messages what did they hear when they called the aircraft via Satfone? Was it ringing, busy or unavailable?
When they called again a few hours later what did they hear? And, by then, were the SAR team aware MAS ops were able to try to call the aircraft.
More questions than answers I'm afraid...
The lack of action and confusion as the events unfolded would be comical if not so serious. All concerned appeared as "rabbits in the headlights" and thus laid down protocols went out of the window.
Why did the Vietnamese wait over 15 minutes before querying the Malaysians as to the location of MH370?
Why did ATC not declare an "uncertainty phase" as per their own laid down procedures?
Why was "aircraft overdue" not declared 30 minutes after the IGARI estimate?
When MAS ops failed to get a response to their ACARS messages what did they hear when they called the aircraft via Satfone? Was it ringing, busy or unavailable?
When they called again a few hours later what did they hear? And, by then, were the SAR team aware MAS ops were able to try to call the aircraft.
More questions than answers I'm afraid...
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At an early stage in this sad affair, much was made of a statement by a Malaysian official (the PM possibly?) that the SSR and ACARS systems were deliberately switched off from on-board the aircraft. Later on, something similar was said about the inflight entertainment system.
I'm not seeing any of those statements in this report. There's a reference to how the transponder could be switched off, but not that it was, only that the aircraft dropped off SSR.
Similarly I see a reference to the IFE not logging on to the SATCOM system late in the flight whereas it had previously, but not that this was the result of deliberate action.
Am I missing something in the 500+ pages? Is there something buried in the logs that I don't understand?
I'm not seeing any of those statements in this report. There's a reference to how the transponder could be switched off, but not that it was, only that the aircraft dropped off SSR.
Similarly I see a reference to the IFE not logging on to the SATCOM system late in the flight whereas it had previously, but not that this was the result of deliberate action.
Am I missing something in the 500+ pages? Is there something buried in the logs that I don't understand?
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What I would like to have is the same set of data for BTO and BFO as we have for MH370, but for a flight that proceeded normally (and hence we know where it actually was for any given value pair).
Is that available anywhere? Any random flight would do, but obviously it would be nice to have something that proceeded at about the same distance from the recording satellite.
Is that available anywhere? Any random flight would do, but obviously it would be nice to have something that proceeded at about the same distance from the recording satellite.
PS: Inmarsat's own statement - http://www.inmarsat.com/news/malaysi...tails-uk-aaib/
Last edited by Ulric; 8th Mar 2015 at 11:42. Reason: link added
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Originally Posted by RetiredF4
Only during the short time of those few handshakes about 1 hour apart from each other the BFO data have to be fullfilled, not for the whole time of the flight. The flight could do circles in between, as long as it reaches the corresponding BTO arc at the next handshake and fullfills the respective BFO data.
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No Flight ID was present
On the page numbered 53, point #4 says...
Is this normal after a logon, or perhaps a power interruption? I would have thought that the flight id was available from AIMS?
When the SATCOM link was re-established at the above times, no Flight ID was present.
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Pay to fly
The report seems, in my view, critical of the FO.
Page 80...
and...
On page 14 we are given the FO's experience...
Pay to fly?
Page 80...
The airline embarked into sponsoring fresh cadets for pilot training since it first started but
had slowed down this programme with the abundance supply of self-sponsored pilots
since the last 5 years.
had slowed down this programme with the abundance supply of self-sponsored pilots
since the last 5 years.
By the time a captain is ready for the B777, he would have at least flown
F50, B737 or A330 or combination of all the 3 aircraft with at least a total of 6000 hours,
part of which has to be a minimum of 2000 command hours on the smaller jets.
F50, B737 or A330 or combination of all the 3 aircraft with at least a total of 6000 hours,
part of which has to be a minimum of 2000 command hours on the smaller jets.
Date of joining MAS 23 July 2007
...
Aeronautical experience 2813:42 hours
Experience on type 39:11hours
...
Aeronautical experience 2813:42 hours
Experience on type 39:11hours
sooty655
True, but the time of the handshakes was reset by external events a couple of times. Expecting any spoofing attempt (manual or pre-programmed) to take account of that pushes the limits of plausibility.
True, but the time of the handshakes was reset by external events a couple of times. Expecting any spoofing attempt (manual or pre-programmed) to take account of that pushes the limits of plausibility.
All I'am saying is, that the southern arc is one interpretation of the data, even a highly probable one, but it is not an exclusive one as others have stated. The conclusion for the southern arc as the most probable track relies heavily on the assumption of near constant track, near constant altitude and near constant speed, simplified on a flight to a preset target in the south flown by autopilot.
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Originally Posted by RetiredF4
The conclusion for the southern arc as the most probable track relies heavily on the assumption of near constant track, near constant altitude and near constant speed, simplified on a flight to a preset target in the south flown by autopilot.
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You may have missed the point, I'm not talking about spoofing the data nor assuming that the datas have been spoofed. Whoever was part of the disappearance of Mh370 knew nothing about those data as the rest of the world didn't know either.
All I'am saying is, that the southern arc is one interpretation of the data, even a highly probable one, but it is not an exclusive one as others have stated. The conclusion for the southern arc as the most probable track relies heavily on the assumption of near constant track, near constant altitude and near constant speed, simplified on a flight to a preset target in the south flown by autopilot.
All I'am saying is, that the southern arc is one interpretation of the data, even a highly probable one, but it is not an exclusive one as others have stated. The conclusion for the southern arc as the most probable track relies heavily on the assumption of near constant track, near constant altitude and near constant speed, simplified on a flight to a preset target in the south flown by autopilot.
The alternatives, orbits crossing the distance ring (which you did not know about) at precisely the right time at precisely the right velocity (ground speed/track/climb corrected for winds) to look like an aircraft that was on a consistent southerly heading. Yes - it is possible. I challenge anyone to do it.
The problem I see is not overtly modeling all the other 'ideas' and showing where they fall down. If instead of repeatedly reassessing the one path, someone had set up a relatively straight forward computer model to vary the assumptions made within their possible limits and falsify (disprove) these alternate ideas. There might be a small family of possible tracks that would work. However, looking at the 'search area' which is very imprecise, I think that it may have been defined by an approach of varying the assumptions within their feasible limits, plus uncertainty due to error.
I have a feeling we will eventually find out.