One of the most misunderstood insights into the riddle of MH370 is how the plane’s final path can be derived from Inmarsat BTO data alone.
Recall that the data, which was generated after someone on board caused the Satellite Data Unit (SDU) to re-logon to the Inmarsat Satellite 3F-1 over the Indian Ocean at 18:25, comes in two flavors. The first, the Burst Timing Offset (BTO) data, reveals how far the plane is from the satellite at a given time. This can be mathematically converted into a set of “ping rings” along which the plane must have been at a given time. The BTO data is very well understood and fairly precise, providing an accuracy of within 10 km.
The second, the Burst Frequency Offset (BFO) data, is more more complicated and much fuzzier than the BTO data; its inherent uncertainties are equivalent to a position error of hundreds of miles. It doesn’t have a single physical correlate but is related to how fast a plane is going, what direction it is headed, and where it is located.
For a time after MH370 disappeared, searchers hoped that they could combine these two data sets to identify the area where the plane issued its final ping. After months of work, however, they determined that this would be impossible. The BFO data is just too vague. However, along with the bad news came some good: it turned out that by the clever use of statistics they could figure out where the plane went using the BTO data alone. The methodology developed by Australia’s Defense Science and Technology Group (DSTG) and explained in an ATSB report entitled “MH370 – Definition of Underwater Search Areas” released last December.
Many independent researchers do not understand the technique and believe that it is invalid. For instance, reader DennisW recently opined that “The ISAT data cannot, by itself, be used to determine a flight path. One has to invoke additional constraints to derive a terminus.” But I believe that the DSTG position is correct, and that one does not need to invoke arbitrary additional assumptions in order to calculate the plane’s track. I’ll explain why.
First, some basics. Imagine that you have two ping rings, one created an hour after the other. For the sake of simplicity, let’s say the rings are concentric, with the later ring’s radius 300 nautical miles bigger than the earlier one’s. Let’s further assume that the plane crossed some arbitrary point on the innermost ring. If that’s all we know, then the plane could have taken any of an infinite number of routes from the first to the second. It could have travelled radially directly outward at 300 knots. Or, if traveling straight at 400 knots, it could have turned left or right at an angle. Or, it could have traveled faster than 300 knots on any number of meandering paths. So, the fact of the matter is that this simple understanding of the plane’s situation indicates that it could have traveled by wide number of paths and speeds to a wide range of points on the second arc.
However, there are some pecularities of commercial aviation that narrow the possibilities considerably. The most important is that planes can only travel in straight lines. They can turn, but in between turns they will fly straight. Knowing this vastly reduces the number of paths that MH370 could have taken between 19:41 and 0:11. It could not of simply meandered around the sky; it must have followed a path of one, two, three, four, or more straight segments.
Through the marvels of modern computing, researchers can generate a huge number of random routes and test them to see which fit the observed data. It turns out that if the plane flew straight in a single segment, the only routes that match the data are those that are fast, around the speed that commercial jets normally fly, and end up over the current search area. If you assume that the flight involved two straight segments, it turns out the ones that fit best are those in which the two segments are nearly in a straight line and are also fast and wind up over the current search area.
If you suppose that the flight after 19:41 involved a larger number of segments, your computer’s random generation process will be able to come up with valid routes that are neither straight nor fast, and do not end up in the current search area. But to come up with such routes, the computer will have to generate many, many others that do not fit. So it is extremely unlikely that by random chance the plane would have happened to travel a slow, curving route that just happened to “look like” a straight, fast route.
“Well,” you might object, “presumably whoever was in control didn’t fly randomly, they had a plan, so modeling by random paths isn’t appropriate.” But a plan of unknown characteristics is equivalent for our purposes to a random one. After all, there is no imaginable reason for someone to fly a plane over empty ocean in the dark at a slower-than-usual rate, making slight turns every hour or so. (Before you say that they might have done it to throw searchers off their trail after the fact, bear in mind that whoever took the plane would have had no way to know that Inmarsat had started logging BTO values a few months before, let alone imagine that they would be able to conduct this kind of analysis.)
When DSTG ran the math, they came up with a probability distribution along the arc that looks like the image at top.
Worth noting that the peak of the curve, and the lion’s share of the area under it, lie in the southern half of the search box, but it also has tails that extend past the box in either direction.
When the search of the seabed began, many expected that the plane would be found in short order. When it wasn’t, the burning question then became: how far out from the 7th arc should we search? A one-dimensional question had now become a two-dimensional one. Based on past loss-of-control accidents and flight simulations, the ATSB decided that an out-of-fuel 777 with no pilot would enter a spiral dive and impact the surface within 20 nautical miles. Mapping the two probability distributions (i.e., where the plane crossed the 7th arc, and where/how far it flew after that) yielded the following probability distribution:
I believe that we have to take the image above with a grain of salt, as I don’t think it is really possible for a plane to fly more than 40 km by itself. It’s generally agreed that the only way the plane could have plausbily gone further than that is if the pilot was conscious and actively holding the plane steady in a glide, in which case it might have gone as far as 100 nm.
A few months before the ATSB publlshed this analysis, a further set of information about the impact point of MH370 became availalble: the plane’s right-hand flaperon washed up on Réunion Island. Reverse-drift analysis was performed by several independent groups to determine where the flaperon might have started its journey. The German institute GEOMAR came up with the following results:
As you can see, the probability distribution hardly overlaps at all with the probability distribution derived from the BTO data; it only touches at the northeastern corner of the search box. Drift analysis performed by other groups reached a similar conclusion. Using a branch of mathematics called Bayesian analysis, it’s possible to take two probability distributions and merge them into a single one. I’m not a mathematician myself, but intuitively one would surmise that given both the BTO and the drift-model data sets, the new peak probability are should lie somewhere between the northern end of the current search box and Broken Ridge.
The ATSB report disagreed, arguing that the drift analysis
… made no meaningful changes to the ATSB search area due to the relative weighting of the significance of the drift analysis in comparison with the analysis based on the satellite data. While this debris find is consistent with the current search area it does not provide sufficient information to refine it.
What this means is that the ATSB considers the BTO data and its analysis “hard” and the reverse-drift analysis “soft,” because the random motion of ocean currents introduces a large amount of uncertainty. However, the reported also noted that “if additional debris is identified it will be included in the analysis to provide further information on the location of source areas.” Indeed, after the report came out other pieces of debris were found, and drift modeling of these pieces be used to refine the search area. Indeed, after I published last week’s guest post by MPat, reader Ge Rijn pointed out:
Over those 20 years in MPat’s model only 7 out of 177 buoys landed in Australia. Those 7 all passed the search box under 36S… [this] points clearly to the trend the more south you go under ~36S the more likely it becomes buoys (debris) will land on Australia and the more north you go above 36S the less likely it becomes buoys~(debris) will land on Australia. This is also because the more south you go under ~36 the currents tend to go further east and the more north you go around 36S the currents tend to bend stronger to the north avoiding Australia. And this is exacly what the facts about found debris shows us till now.
Note that 36 degrees south is just shy of the northern end of the current search area; as Ge Rijn observes, historical drift data suggests that if the plane had crashed south of this latitude, debris should have been found in Australia, which it obviously hasn’t.
The size and species mix of barnacles growing on ocean debris could provide clues as to which waters it floated through; oxygen isotope analysis can provide information about the temperature of the waters that it floated through. As far as I know, no such analyses have been conducted. For a long while now, the ATSB’s weekly update reports have included the phrase “In the absence of credible new information that leads to the identification of a specific location of the aircraft, Governments have agreed that there will be no further expansion of the search area.” The fact is, though, that further information is available, and it could be used to determine which of the two possible explanations is more likely: that the plane passed over the current search area and was held in a glide, or crossed the seventh arc further (but not too much further) to the northeast.
http://www.channelnewsasia.com/news/asiapacific/possible-mh370-personal/2968200.html
Well at least Blaine kept his end of the bargain. But in keeping with bizarre nature of this missing flight,none of the personal effects surrendered had identification tags. I mean none, nada, nil, zero, zilch.
But then again that’s not surprising given that no Indonesian ( whether in Medan, Sabang or elsewhere) and Australian ( be it CI, Exmouth, JORN) radar saw the plane presumably cos they were all mysteriously “in operational” simultaneously! Further, no pilot flying over that busy airway saw any blazing plane flying by and no pilot was contacted by Malaysian ATC to look out for a “rogue” plane even as Military Radar was supposedly tracking it across the Peninsular and beyond.
And yes sir, now we are requested by some here to accept that ALL sailors on ship convoys were fast asleep when MH 370 supposedly flew over their heads in the SIO at an unearthly hour at that and that their ship’s radar conveniently and “collectively” failed to track the aircraft as it flew overhead.
I can go on with endless mind boggling, brain freezing observations but I guess at the end of the day, if one is obsessively wedded to a delusion, one would inevitably find it difficult to wean oneself away to inhale a fresh breath of reality.
@ROB – Yes, you are correct that the BFO at the 18:40 phone call indicates southern flight. However, Richard Godfrey analysis on duncansteel.com excluded the BFO values. His flight path goes from MEKAR to LAGOG, back to BEDAX and then south. (BTW, BEDAX to OLPUS looks to be due south and Richard’s final point of 34.1049S 94.0118 is within a few nm from this track. Average speed and endurance meet fuel burn rates for a high and fast flight.)
@ROB
Search status… or whatever that means these days
On this swing Equator has been working inside the arc only. When the weather has prevented tow-fish work it has been bathy-scanning and in the last few days it has been extending the bathy-scanned area 100km northeast (inside the arc). This is the first extension of the active area to the northeast since the original definition of the search area nearly two years ago. Until now the trend has always been to concentrate the search to the southwest.
Discovery has just returned to the search area and is moving slowly in the last unsearched portion of the active area. Not clear if it is tow-fish scanning yet – the weather is marginal but improving.
DHJ101 appears to be ineffective in winter conditions.
https://www.dropbox.com/s/pj9mxsjr5oiz5hg/19-7-16.jpg?dl=0
@Ge Rijn
‘Most probable’ is not a useful statistic, the question is what areas can be EXCLUDED using the data, at some level of significance. The uncertainties of using the drift studies as a predictive aid to actually exclude areas along the arc include:
1. The underlying accuracy of the model itself, particularly against the weather conditions at the date of the accident
2. The completely unknown number of debris fragments from the crash that would survive at sea for years. The number of detected fragments is thus almost irrelevant, only the ratio between different geographical areas is useful as a diagnostic of the source.
3. The small number of detected fragments and hence the effect the statistical errors on those numbers in analysis. For example, detection of no fragments on the Australian coast only limits the mean of the expected number to 2.3, at 90% significance using Poisson statistics. Thus the errors on these ratios is large.
This is aside from any possible differential effects on fragments reaching coasts from Africa to Australia, not included in the models.
I could be convinced, but I see it at very difficult to use drift studies to limit a new search to a manageable length of arc, say 500km.
@Richard Cole
Thank you for the search update
Rob
Richard Cole posted “I could be convinced, but I see it at very difficult to use drift studies to limit a new search to a manageable length of arc, say 500km”
Richard, I very much agree with you on that statement. At best these drift models can give us a good indication of where our haystack is but by no means can they pinpoint a specific area within that haystack as to where the plane is. It would be very difficult for any drift model to do this.wirhin a 500Km range.
Laruen H. said, “Yes, you are correct that the BFO at the 18:40 phone call indicates southern flight.”
If the aircraft was descending at 18:40, it could have been traveling towards the north and be consistent with the BFO value.
@Richard Cole
What I am pointing at is also a method for excluding possible crash areas from the 7th arc to come to a most probable crash area.
I suggest dividing the arc into boxes of 5 degrees starting from 35S till ~20S.
Combine historical forward drifter data analysis for each box and virtual forward drifter models up to 500 pieces for each box and compare them for each box with the whole range of debris finding locations (and the locations nothing is found yet).
If you have done this choose the box who fits the found (and not found) debris locations best.
Then divide this latitude-box in two and do the same.
I think statisticaly you’ll find a priority area.
Offcourse not precise but I think especialy using statistics in this regard could be very helpfull.
From the MPat historical model there are only 177 pieces of debris needed to land 31 of them on Africa and 7 on Australia (which only arrived there under 36S)in 18 months.
With 12 or 15 pieces found so far only in Africa and its islands this indicates IMO a small amount of debris from the start.
As Brock McEwen has pointed out in his study, with an amount of 10.000 pieces of floating debris hundrerds of pieces should have been found on African shores and Australian shores. This did not happen.
So I think the number of debris found till now is significant and usefull enough to conduct a study as I suggest.
Like to hear your comment.
@VictorI
Posted July 19, 2016 at 2:42 PM
Laruen H. said, “Yes, you are correct that the BFO at the 18:40 phone call indicates southern flight.”
If the aircraft was descending at 18:40, it could have been traveling towards the north and be consistent with the BFO value.
Unfortunately you and few others have rightly pointed to that fact again and again, but for most experts here on the blog a flight without a vertical deviation from a specific altitude seems appropriate enough. I always wonder why.
@Lauren, @Victor
Victor, you said “if the aircraft was descending at 18:40, it could have been travelling toward the north and be consistent with the BFO value”. I accept that is technically possible, but to me it looks more like a way of making the data fit a theory, rather than a theory fit the data. Richard’s flight path is high and fast, but it has to invoke a descent at 18:40 to fit the BFO data? Just a thought.
@Richard Cole
all 3 very good points
I’d divide search in two phases, one phase would search the whole 2800km narrowly in case the plane is right on the arc or very near
the other one would follow independent drift models and search south of Sumatra up to 300-400 km a bit wider but I have no idea what width should be searched(maybe glide width?)
@Ken S
You are reffering to reverse drift studies. Those studies work the other way around predicting a wide range of possible starting points of debris.
They are usefull to predict a wide range of possible starting points but not for narrowing a search area.
IMO forward drift studies (starting from the 7th arc) can, if compared with the actual landing points of found debris.
@Ken S
” Insanity is doing the same thing over and over again expecting a different result.”
That is the case with MH370.
Something is so fundamentally wrong…
@Ge Rijn
Yes I was mostly referring to reverse drift models however Brock’s study is based on statistical analysis of hundreds of forward drift models.
@Ken S @Brock Mc Ewen
You are right about Brock Mc Ewen’s
‘s latest drift study being based on a large amount of forward drift data. But it basically was a reverse drift study as he stated here himself some weeks ago.
If I understood him wrong I hope he reads this and corrects me.
@Rob: In the 18 mins between 18:22 and 18:40, there were many things happening, including disappearance from radar, the log-on of the SATCOM, and a possible side-step to the right. A descent that happened in this time frame is also possible, especially since there might have been a climb/descent at the turn after IGARI and also the aircraft might have been flying low near Penang for the brief connect on the cell phone network, both of which indicate the aircraft was not flying at a constant altitude.
@Ge Rijn
I actually think that the methodolgy you are proposing is not a bad idea if your belief is that the plane crashed near the 7th arc. This study of course would have this inherent bias in it but it may be useful in determining where the more likley hotspots could be along the 7th arc providing that there is sufficient historical data on drift buoys to conduct this research.
@VictorI: “… both of which indicate the aircraft was not flying at a constant altitude.”
Both of which are unconfirmed rumours in the early days of the disappearance?
@Ge Rijn
The procedure you describe may find a most probable position (though it still needs a predicted number of fragments to be quantitative, I think). However, it doesn’t give any statistical significance for that location, or which positions can be excluded from a search.
A factor of two in the estimate of the number of fragments would give significant difference in the possible start points. A larger number would indicate less probable start points from the model, or would lead to an over-estimate of the landed items.
@Gysbreght: I said there might have been a climb/descent after IGARI. I base that on the deceleration/acceleration profile of speed as reported in the DSTG report. That speed profile is not based on a rumor.
As for the cell tower connect around Penang, it is true that this claim has only been leaked anonymously. But like the simulator coordinates in the SIO found on the pilot’s computer, I believe this leak from an anonymous US official is true.
US officials have either been quietly trying to get the truth out or are they are deliberately deceiving us. I have no reason to believe they are being deceitful. In fact, I don’t know any leak pertaining to MH370 from a US official that has been wrong.
http://www.cnn.com/2014/04/14/world/asia/malaysia-airlines-plane/
@VictorI:
Below is a graph showing the deceleration/acceleration profile of speed as reported in the DSTG report.
https://www.dropbox.com/s/c0lbayxeys88hw0/BayesianGS.png?dl=0
Do you see an indication of a descent as the airplane passes south of Penang Island?
@Victor
Would you happen to know, off hand, what the timing of that supposed cell tower connection of the F/O cell phone near Penang was?
Thx
@VictorI said:
“If the aircraft was descending at 18:40, it could have been traveling towards the north and be consistent with the BFO value.”
@VictorI: This is in relation to the possible loiter / landing before the 19.25 ping. Maybe this has been discussed before, if so apologies.
Looking at Richard Godfrey’s latest paper, it’s interesting that the altitudes he gives in Table 2 seem to show a continuing descent of around 1100 fpm for the last 7 minutes after VAMPI. At MEKAR it had also slowed from 512 to 485 knots GS.
Could VAMPI have been programmed as top of descent in a new flight plan?
If the aircraft had continued to descend at that rate after MEKAR, and assuming it continued at a similar speed for a while then slowed (to, say, 250 knots?) at some point of its descent (10k feet?) then a (very) rough calc taking an average of its speed at MEKAR (485) + 250 /2 = 367 knots GS suggests it might have been ‘landing’ in about 20 minutes and thus around 122 nm further.
If you take the last heading (visually, I don’t have access to accurate klm files)) and extend it 122nm from MEKAR it seems, coincidentally, pretty close to Campbell Bay (144 nm or so). Problem is, of course, Campbell Bay runway is listed as only around 1000′ long. Although there are reports of plans to extend it to 6,000′ by 2016 the latest Google maps still show a shorter one.
Of course, although seemingly flying via waypoints and air routes since IGARI to blend in, once out of radar range it could have changed course direct to the intended destination, but still flying lower to avoid any radar coverage.
If a new flight plan had been entered after IGARI without a flight ID, that would explain the lack of flight ID on the SDU logon. If the original flight plan had simply been amended, it would likely still have the flight ID.
The reason for the left bus being powered on again could be that it was needed for landing, the original reason for de-powering it (perhaps to prevent the cabin oxygen masks dropping? – does anyone have access to a 777 AMM to check?) having served its purpose.
Further north is Port Blair (379 nm from MEKAR) – runway is long enough for wide bodies (10,800ft) and it has lights and a glide slope/ILS. Closed to scheduled traffic at night at the time, it seems. Could Port Blair fit with the next ping and other general timings/data, allowing for a landing, unload, taxi, and take off? Or maybe at Car Nicobar?
Further north still is Coco Island, long runway, nice and remote, part of Myanmar but reportedly operated by the Chinese (?).
If the people who do the math/modelling could rule in (or rule out) the possibility of a landing in the Andaman area, it could perhaps help narrow things down in relation to the ‘FMT’.
Just some thoughts.
@Gysbreght: Knowing only the ground speed profile as the aircraft passed Penang, it would be hard to know whether or not the plane was descending. A rapid descent would increase the speed, although the speed increase could be made less severe by using air brakes or by creating slip. A more gradual descent at constant IAS would decrease the speed. So I think the speed profile does not preclude a descent, especially if it occurred between FL350 and FL250, for instance. This is in contrast to the deep dip in speed around IGARI which would be much harder to explain other than a climb.
Also note that according to the FI, as the aircraft passed south of Penang, the radar captures stopped at 17:52, which would be consistent with a descent.
@Ken S: Based in the drop from radar at 17:52, I would estimate that would be the time for the cell tower connect.
I have repeatedly read here more recently that the lack of radar data from JORN may point to whatever theory (plane shot down at an early stage/never flew south).
JORN operators, however, don’t seem to agree:
“JORN was not operational at the time of the aircraft’s disappearance.”
https://www.airforce.gov.au/docs/JORN_FAQS.pdf
@Middleton: If the FMT occurred after 18:40, there are many possibilities. I would advise to not get too attached to any single scenario unless we get more data.
@Ge Rijn said:
“If Malaysia will not release their conclusions I don’t expect the ATSB will assist in covering up for them.
I assume they allready have a lot of information, also on the bio-forensics.
They are only not going to reveil it to the public as long the investigation is ongoing.
Just like the French will not do (on different grounds).
But they won’t let Malaysia dictate them what to release or not in the end.”
If (?) Malaysia has enforced a (confidential) non-disclosure agreement with the other parties in the MH370 search similar to the agreement in relation to the MH17 investigation (nothing to be released by any party unless all other parties agree) signed by Australia, The Netherlands, Belgium and Ukraine – but not on that occasion, apparently, by the MYG since it is not a party to that investigation – then the MYG will have a veto on what is released.
Which might be what we’re seeing (or not seeing) happening already – very little information is being made public, and the MYG is, perhaps, controlling that.
Details of the MH17 agreement were reported by a Dutch news channel RTL Nieuws:
http://www.liveleak.com/view?i=9e0_1426336032
The MYG has also, reportedly, revoked the licences (ie. closed down) several Malaysian news agencies/websites that were critical (or revealing) of the MYG, especially in relation to the 1MDB scandal.
So not exactly a model of openness and transparency when it comes to releasing information it considers not beneficial.
@Brock @Ge Rijn – regarding debris drift and whether there are more items that could inform studies.
I am puzzling over the last part of the most recent Godfrey report’s Introduction. This makes me wonder if all the plane debris pieces specified here have been publicly identified and included in drift studies. The last sentence totally throws me, alluding to more than 50 items of a personal nature being identified, and that they are suspected of being from MH370. If these are only the Blaine Gibson items (Angry Birds bag etc), and what is presently known about these items, then their importance is well overstated here. Blaine himself warned that there may be no link.
Have any other personal items been found that have been tied to the flight?
I appreciate Godfrey’s excellent work, just confused by that Introduction. Salute to all, IG and JW, keep wrestling with it.
@Ken S.
In Victor’s linked CNN article it is stated:
“…detected the first officer’s phone searching for service roughly 30 minutes after authorities believe the plane made a sharp turn westward.”
The turn West occurred at ~17:25. So that places the call at around ~17:55 or as Victor stated at about the time the plane dropped off radar.
@DennisW
Thanks Dennis, just saw the link now.
Well isn’t a cellphone range about 40miles and radar is no more than 200miles. So wouldn’t the cell loose connection long before dropping off radar.
Here is what the DTSG has to say about the speed and track angle diagrams in Figure 4.2 of its report:
“The speed estimates vary dramatically during the first turn, which is not an accurate representation of the aircraft speed at this time. It is likely due to the mismatch between the assumed linear Kalman filter model and the high acceleration manoeuvre performed by the aircraft. Since these artefacts are localised to the time of the turn the influence on the state at the end of the sequence is negligible.” One guesses that what this means is that the acceleration of the aircraft changed significantly enough over the 10 seconds of each sample point that the linearized Kalman filter could not keep up.
Since the DTSG has the actual radar data (and indicated speeds) for the turn, it would seem prudent to heed the DTSG advice and not attempt to interpret the speed and track values during the turn as being meaningful (although the integral over the interval is meaningful).
As a reminder, I wrote a short report a while ago where I integrated the speed and track angle values from Fig. 4.2 (starting at the last ACARS point) and overplotted on the reported radar track, which has been reproduced in several ATSB and one MOT reports. I believe Gysbreght did something similar. It can be found at the following link – scroll down to Feb 13, 2016 RADAR:
https://docs.google.com/document/d/14hleZyx1pUPL44yaeHKt6jnSQ3DbgRq2zibbKkFLq2c/edit?pref=2&pli=1
The reconstructed path (there are 2 figures – scroll down for the one that shows the entire path) follows the radar track rather amazingly well, and is limited by my ability to digitized Figure 4.2. In the report, I provide a link to a .csv file with the complete reconstructed track (including the turn at Penang) with timing, longitude, latitude, speed, and track. If anyone wants to hazard a guess at the altitude as well, that would be interesting, although values during the 1st turn will be regarded as “not an accurate representation”.
@MH
There were “holes” in the radar track prior to the 200nm radial claimed for the final loss of radar contact at 18:22 or so. The 200nm radar final return occurred about 30 minutes later than 17:55. 200nm is not an unreasonable range for an aircraft to cover in 30 minutes. At 17:55 the aircraft was East of Pulau Perak. Not an unreasonable line of sight distance to Penang for phone “registration” to occur. Maybe a bit too far to initiate a call.
What is interesting about the “claimed” phone network registration (hey, I have no dog in this fight, and refuse to even look seriously at shit before 19:40) is that the numbers – call timing, radar loss, plane posiition… “hang together” better than most of the data we have regarding this incident. It would be hard to make up a story with this degree of coherence, especially for the Malays.
@MH
…more.
One could even argue that near the cell tower “horizon” is about the only place A phone in a plane could be “seen” by the cell tower. Cell sites are designed with antenna “panels” that radiate in the tangent plane of the cell site. If an aircraft were directly over the cell site there would be no chance that the antenna pattern could “see’ the phone.
The horizon is the only option really.
@Ken S, @Ge Rijn
My comment of of a ‘disconnect’ between the ISAT (BFO/BTO) and the debris drift analysis was a bit strongly worded. Jeff Wise has better expressed this in a subsequent post as saying the data don’t actually ‘contradict’ each other but rather don’t overlap, except at the northern end of the ISAT data which contains the low probability search zone.
However the reverse/forward drift analysis which has been well presented in this blog suggests a more northerly entry point of 9M-MRO into the Indian Ocean, as does a lack of debris on the Australian coastline (allowing for a false negative). The west Tasmanian coastline I believe was searched 12 months after 8th March 2014 and nothing was found.
The barnacle species found on the flaperon suggests growth in warmer waters but this doesn’t exclude entry into the SIO as the flaperon could have travelled north before it landed on Reunion Island (presented in this blog).
However there is not truly convergence of the ISAT and drift data (@Ken S)
More worryingly we are coming to the end of the ATSB guided search dictated by the ISAT data and a hypoxic flight scenario. Whilst there is a risk of a false negative I believe the search has been conducted in good faith, comprehensively and with re-scanning of questionable areas with sophisticated side scanning equipment. The risk of a false negative is thus very low. We have not found 9M-MRO in the SIO yet and it appears increasingly likely we won’t.
The French are in possession of the flaperon and the disappearance of 9M-MRO is in the hands of the French Prosecutor’s Office as a terrorism investigation. They are unfortunately not party to the upcoming tripartite meeting between Malaysia/China/Australia re: 9M-MRO.
This brings into question the integrity of the ISAT data and whether it has been subjected to, scientifically speaking, ‘intentional bias’. I agree with you on this point @Ken S (though I don’t agree with your theory that 9M-MRO is in the Maldives).
@SteveBarrett
Thanks for that reply, just to clarify my theory I don’t believe 9M-MRO is in the Maldives either, I just beiieved it did a quick pit stop there to unload cargo and then it was ditched off the coast of Sumatra.
@sk999: The details of the turn at IGARI have little bearing on the final radar capture at 18:22, and so the DSTG glossed over the anomalies of the turn. However, the details of the turn can possibly provide important clues, including the cause of the detour and who was flying.
The caption to Figure 4.2 says “Smoothed estimates of speed and heading derived from radar data”. (They refer to heading when they really mean track.) To me, that implies the unfiltered data is even more extreme than the filtered data that is presented. That’s why the reconstructed path you created from the digitized path has a smoother turn than the turn shown in Figure 4.1.
I commented above that the sharp dip in speed after IGARI suggests a climb/descent sequence. If the unfiltered data has an even sharper dip in speed, the climb/descent would be even more extreme.
I have asked both Malaysia and the ATSB for the radar data so we don’t have to guess. So far, no joy.
@SteveBarrett
I regard the ISAT data as a gift. There was no reason at the time of the diversion to alter it, since I do not believe it was a vital component of any conceivable scenario. I truly believe its existence is an “accident”, and that no one could have reasonably anticipated that it would be used in the manner it has been used, much less altered it in a systematic way to deceive.
@DennisW – you said ” the numbers – call timing, radar loss, plane posiition… “hang together” better than most of the data we have regarding this incident.”
It sure sounds bad for solving this mh370 incident if only those numbers “hang together”. I really need them to fit clearly at IGARI & BITOD.
Yes cellphones work line of sight if signal not blocked by some structure in the way.
@Middleton, @Ge Rijn and all
Middleton wrote: “very little information is being made public, and the MYG is, perhaps, controlling that.”
Yes, it is pretty clear that the ATSB will not release any technical reports on debris etc. unless MYG agrees. Whether any fully detailed reports will be made available after the current search is complete is doubtful IMO. Darren Chester, Australian Minister for Infrastructure and Transport, will be attending a tripartite meeting in Malaysia this week (21st & 22nd). There was a swearing in ceremony in Canberra yesterday (19th) for PM Malcolm Turnbull and his ministerial team after our recent election, so that would be the reason the meeting was put back a few days.
IMO, assuming ISAT data currently publicly available is full and accurate, while drift studies can be indicative of broad areas where the plane may have crashed or not, they can’t provide enough detail to inform a new search area of manageable proportions. To define a new search area we surely need radar data confirmed and supplemented; even then, flight assumptions need to be made and despite best efforts to calculate flight paths we would still be in danger of GIGO.
@all
I cannot recall who was “in” on the moon illusion. As anyone who is paying attention would know, tonight is a full moon. I looked at the rising moon between my legs while tipped over, and it looked just as abnormally large as it does while standing erect.
As far as I am concerned the moon illusion is an unresolved illusion, right up there with the “two envelop problem” (which I have solved, BTW), and Bertrand’s Paradox which I have not solved.
@DennisW
I would dearly love to think the ISAT data was a gift too. However if, and a big IF, the French are right and this is terrorism then we need to question the integrity of the ISAT data. I have a lot of respect for the French on these things- they’ve been through a lot over the ages.
Even in a purely scientific forum, one would routinely question the validity of the data. This would include detailed questions regarding the equipment, service history, calibration, relevant software updates/patches and QA benchmarks. Here for obvious reasons, we cannot.
@All: drift studies such as depicted above – which are based exclusively on the flaperon – are obsolete: we have new confirmed debris, which should be used to the extent possible. As it turns out, the new debris is even more damning than the flaperon.
For instance: while Adrift’s online tool cannot seasonally adjust its reverse drifts like it can for its forward counterparts, its “Startmon=Jan” default reverse setting happens to be perfect for debris found in late December / early January.
This is ideal for, e.g., the first of the two Klein Brak claims (end December, 2015).
If we set Adrift to “end” at the mouth of the Klein Brak, and run the drift backwards for 1 year and 10 months (to early March, 2014), we find that the resulting probability distribution of impact zones does not even intersect with the wide search area.
http://adrift.org.au/backward?lat=-34.5&lng=22.3¢er=39.3&startmon=Jan
If these two regions don’t intersect at all, then either…
1. the Adrift model does a terrible job of reverse-drifting “Roy”
2. “Roy” did not arrive there naturally,
3. the signal data has an error in it, or
4. the signal data is a smokescreen to conceal MH370’s true fate
The behaviour of key players in the MH370 saga draw me toward 4. But I will listen patiently to differing views.
As long as they don’t dredge up arguments already thoroughly debunked. Notably:
“Reverse drift studies are all bunk”: no, they’re not. Those which end at Réunion were indeed particularly vulnerable to wide distributions, and were thus less helpful in pinpointing impact location. But not only is this less of an issue for Klein Brak, but the entire argument misses the point: if drift and ISAT distributions don’t intersect, then the inordinate wideness of the former makes the gap even MORE concerning.
“Things drift much faster in reality than in the models”: this may be true for some models, but not for Adrift. Erik’s model is calibrated to the travels of both tethered and UNtethered drifters – with the express goal of simulating a wide array of buoyancy profiles.
@Brock
The signal data, or ISAT data, does not predict a terminus by itself. I have beat this notion to death here. It is the assumptions that need to be wrapped around it to produce a terminus that may be flawed. Your options 3> and 4> are total misconceptions.
@SteveBarrett
I agree that the ISAT data should be questioned and rigorously tested, more so now that the drift studies are producing conflicting conclusions. To think that it is “beyond reproach”, is unwise. It is possible, that it could have been spoofed, at the time, or “tampered with” after the event.
As an Australian, with a deep mistrust of the efficacy of many recent ATSB Investigations, I must say, that I find the notion, (expressed by some here), that the Australian ATSB, (presumably, in the interests of investigative probity and / or transparency), should, could, or might, “step up to the plate” as it were, and publish anything, that is, or might be, in contavention of Malaysia’s wishes, (as the United States NTSB has on occasions in the past), as being sadly misguided, perhaps even deluded.
The Australian ATSB, will not take similar action, ever, even if warrented, end of, period.
Q. Why is that the case ?
A. If you were familiar with the ATSB’s “track record”, and inparticular, their “Investigations” of the PelAir ditching at Norfolk Island, or the near double B-737 fog disaster at Mildura, or a host of other sub-standard investigations and reports of recent years, you would not need to ask.
Perhaps you should go to the ATSB web site, and download just those two reports yourselves, and get youselves “an education” on the “performance” of the ATSB.
Both investigations are – shall we say – still not finalised – fully – ie, they are still extant – um – ongoing.
Returning to MH370.
Up until now (20th July 2014) Australia’s official position on MH370, has been repetitively, and clearly stated, by the then Minister Warrren Truss, and the then Chief Commissioner Martin Dolan, as :-
(a) MH370 is a Malaysian “Accident” under the Chicago Convention.
(b) MH370 is a Malaysian “Investigation”.
(c) Australia is “represented” on the Malaysian “investigation” as an “accredited representative” ONLY.
(d) Australia is “co-ordinating” the “Malaysian [search]” in the SIO, at the REQUEST of the Malaysian Investigation.
(e) Australia is “providing” other technical “assistance” (eg debris analysis) to the “Malaysian Investigation”, at the REQUEST of the Malaysian Investigation.
In short:
(a) Australia is acting ONLY as “hired help”, ie, as an ENTIRELY SUBORDINATE SUBCONTRACTOR to Malaysia.
(b) Australia has no legal right to publish anything without Malaysian Authority.
(c) Australia WILL NOT publish anything without Malaysian Authority.
Now, we have just had an election.
As a result, we have a new Minister (Darren Chester) and, co-incidentally, a new Chief Commisioner of the ATSB – to replace the now retired Martin Dolan.
Nothing has changed from the legal or policy standpoints, nor will they change.
The next Ministerial Tri-Partite meeting is tomorrow (Thursday 21st July 2016) and Friday 22nd July 2016.
I am not anticipating anything of substance being released, by Malaysia or Australia.
@Victor: in Jeff’s “what we know” post ages ago (summer, 2014?), he documented Dr. Ulich’s conclusion that the distance from IGARI (~17:21) to the last radar fix (18:22) was sufficient to REQUIRE cruising speed throughout, lest it take more than the available 61 minutes. Which, we all seemed to agree at the time, on its face ruled out wild altitude swings.
This belief seemed to be vindicated by the JACC’s concurrent admission that it had abandoned all consideration of large altitude swings, and the associated* heavy fuel burn rates. Angus Houston strongly implied the search was moving to a place only accessible if large altitude swings were ruled out.
(* the “increased fuel burn” argument was advanced by citing increased speed, yet retracted by citing increased altitude. Bizarre in and of itself – but I digress.)
Have you changed your mind, or were you always skeptical of what was once a pretty strong consensus view?
@Brock McEwen
Fabulous! Keep it up, because something isn’t right. Traditionally thinking has led us to dead ends. We need to know all the data the authority has not shared with us. Therein lies the truth of why we can’t piece the puzzle together.
Again – if captain Zaharie was alone in the cockpit, carrying out a pre-meditated plan, why “the high acceleration manoeuvre performed by the aircraft”, why the erratic variations in speed and track after the turn-back until well past Penang?
@Middleton 19 Jul 8.03 pm
Regarding the possible landings at Port Blair and Car Nicobar: Port Blair indeed has a runway of 10,800 ft. It is an Indian Navy air base which has a civil enclave, and is in a fairly populated area which is mainly civilian. Anything out of the normal would have been highlighted in the Indian media. It hasn’t, and censorship is fairly ineffective in this country.
Car Nicobar has a runway of 8900 ft and is known to handle A320s, 7373s and Il-76s. It is an Indian Air Force base with some civilian flights. It is in a rather unpopulated area.
However, any activity involving MH 370 at these places would involve connivance of the Indian armed forces as well as the Indian federal government. Is there any scenario which would involve the Indian government?