In dispute: whether the search should focus on the area spotlighted by data error optimisation or constrained autopilot dynamics
Disquieting news in the Wall Street Journal today; the paper reports today that the official inquiry into the disappearance of missing Malaysia Airlines flight 370 is riven with disagreement:
Ongoing differences of opinion between five teams of experts that include Boeing Co. and the Australian military have led to search vessels being deployed in two different priority search areas. These zones overlap in some places but in others are hundreds of miles apart, highlighting how efforts to solve one of modern aviation’s biggest mysteries remain little more than educated guesswork. Searchers may only be able to scour around 80% of the probable crash sites before government funding runs out.
For its part, the Australian Transport Safety Board (ATSB) issued a response that essentially confirmed the gist of the WSJ article:
[ATSB chief commissioner, Martin] Dolan said that earlier there had been consensus amongst the five groups, based on the data available at the time, but once the data had been refined, “the results from the methodologies did not coincide exactly. There is no disagreement, just the deliberate application of differing analysis models,” said Mr Dolan.
One would like to think that, nine months after the plane went missing, that the experts would have ironed out any loose threads in their understanding of the plane’s final trajectory. Especially given the fact that Inmarsat scientist Chris Ashton told the BBC program Horizon that the company had cracked the nut way back in March, saying: “The graphs matched, the data worked, the calculation was solved.”
But if we take a closer look at the history of the accident investigation, it’s not surprising disagreements exist. For all the confident press statements that the authorities have released, behind the scenes investigators have always struggled to make sense of the data in their possession. It’s not a matter, fundametally, of a difference in opinion between experts; it’s a matter of inconsistencies within the data sets themselves.
Allow me to explain. As we all well know by now, everything we know about the final six hours of MH370 comes from seven electronic handshakes, or “pings,” exchanged between the plane and a geostationary Inmarsat satellite. Each of these pings, in turn, provides two data points. The first, called the Burst Timing Offset, or BTO, is a measure of how far the plane was from the satellite at any given time; this data is well-understood, reliable and accurate, with an uncertainty of only about five miles. The second, called the Burst Frequency Offset, or BFO, measures the wavelength of the signals and both harder to understand and much more inaccurate, with an inherent uncertainty of hundreds of miles.
Taken alone, each of these data sets provides only a rough idea of where the plane was at each moment in time. But the hope has always been that, if combined properly, they would be indicate the plane’s trajectory and final resting place, in the same way that a line of latitude and a line of longitude can be combined to specify an exact spot on the Earth’s surface.
Unforunately, this turns out not to work in practice. No matter how much Inmarsat and the ATSB have tweaked their algorithms, they have been unable to find any routes that provide a satisfying match to both the BFO and the BTO data.
In its June report, the agency tried to make the numbers gybe by running them through three different types of analysis, none of which made sense on its own but which overlapped in a way that suggested they might somehow be right collectively. In a subsequent report released in October, the ATSB tried a new approach, this time creating one set of routes that fit the BFO data and another set of routes that make sense in terms of how a plane might actually be flown. These areas lay near each other hundreds of miles from the previous search area, but did not overlap much; the ATSB resolved the dilemma by calling them one big area and hoping to search as much of it as possible. This solution is illustrated in the picture at top; the “data error optimization” area attempts to minimize BFO (and BTO as well) while the “constrained autopilot dynamics” ignores BFO and tries to match BTO observations with aircraft performance and autopilot functioning.
Obviously, there must be some gap in our understanding of the Inmarsat data and how it relates to the aerodynamic constraints of a real aircraft. Someday we’ll figure out where we’ve gone wrong; the plane must have gone somewhere, and when we find it, the nature of the shortcomings should become clear. At the moment, my suspicion is aimed at the BFO values, because the algorithm used to explain them are so complicated, and the inherent uncertainty is so large.
We’d have to think carefully about throwing out the BFO data entirely, however, because after all, it’s the only reason we believe that MH370 wound up in the southern Indian Ocean.
@Nihonmama: Let me start by saying I have no relationship with Inmarsat and I have no reason to protect them. However, I do believe they have made an honest attempt to find the plane. Here are some comments:
1. “Processing of data” does not mean changing the data. It means interpreting the BTO and BFO values in a way to make path predictions. The BFO and BTO values that were released are about as “raw” as you can get.
2. Inmarsat has been very clear that all the raw data was released to Malaysia and Malaysia removed columns (some values are not included for all the communication exchanges) and rows (some entire exchanges are not included, in particular those close to 16:00 UTC). The responsibility for the redaction lies clearly on the shoulders of Malaysia. We believe we know exactly what columns were redacted because the full listing of the column headings was released in the data dump and only some of these columns were included in this data dump. The CNN interview by Richard Quest with Inmarsat shows Mr. Quest holding up data logs that have all the columns, as Paul Sladen has reported.
3. The early comments from Dickinson about others not being able to recreate Inmarsat’s work was true at that point. The definition of the BTO and BFO values had not been released, as well as a description of other anomalies such as the bug in the pilot receiver software at Perth and temperature drift due to the satellite eclipse. After the June ATSB report, all this was laid out in detail, and many of us have recreated Inmarsat’s results.
If the plane is not in the current search area, we have to revisit our models. But I don’t think that is a call to abandon the science. Rather, it is a call to understand which of our scientific assumptions are incorrect.
If we totally dismiss the satellite data, then we really have no idea where the plane is as I have yet to see any reliable evidence after 18:22 UTC. Satellite images in the public domain are inconclusive (I have been waiting for months for a satellite imagery experts to render an opinion) and witness sightings have been inexact and inconsistent. I would say the sighting in the Maldives has the most credibility because multiple people have corroborated the evidence, although it is not clear that the sighting was related to MH370, and if it was related to the disappearance of MH370, it is not clear that it was 9M-MRO that was seen. (I have offered a scenario that does indeed relate this sighting to the MH370 incident, but with the twist that it was not 9M-MRO that was seen.)
I continue to suspect that the US, UK, and Australia know more about MH370 than has been reported, but under the guise of regional stability and Western cooperation, they have chosen to remain silent about Malaysia’s “less-than-honest” actions.
I may have “cracked the code” as to what was meant by the cryptic phrase: “passed close to a NW point at 1912” (ATSB June 26 report). The key insight required merely “turning the Inmarsat arc dial” COUNTER-clockwise from 1840 (see my posts last week on this site for the implications of turning it clockwise).
My thought experiment went as follows:
a) rotate NE edge of CURRENT (Oct.8) performance limit COUNTER-clockwise (roughly 11°) until it aligns with its April/May counterpart,
b) convert altitudes into speeds (I did so by inspection of Fig.3 coordinates, e.g. FL250 = 390 knots; similar results should be obtainable by looking up speed for each altitude/weight in performance tables), and
c) fly all generating paths in REVERSE (start at 7th arc, and fly NNW through the arcs) – BUT after intersecting the 1941 arc, instead of heading directly for the 1822 primary radar endpoint (if you tried this, you’d reach it much too soon (late?), as illustrated by the IG in its “52 minutes” publication), MAINTAIN HEADING UNTIL 1912, whereupon you THEN turn & fly SE to the 1822 start-point.
If you try this, you should find that
1) This method has all flight paths converging back at 1822 roughly on time,
2) Each path is indeed marked by a (path-specific) “NW point at 1912”, and
3) Paths ending in the Apr/May search zone have speeds which optimize signal data fit(400KGS+/-).
In other words: the JIT seems to have tried to fill the missing 52 minutes with an arbitrary jaunt out to the NW.
In clearer words: the JIT seems to have tortured the Inmarsat data until it confessed to s21.
(It is worth noting that, relative to s40, s21 is 4x closer to port, warmer, calmer, and of a depth at which bathy surveying is far more likely to yield fringe benefits.)
Taking the above result together with the “acoustic ping” fiasco, I would be surprised to find a serious independent investigator who DIDN’T harbour at least private doubts about the authenticity of the JIT’s directing of the search AWAY from the roaring forties from April 1 until September. At BEST, this was politics as usual: painting a heroic veneer over a cowardly inability to admit to the families they decided not to deploy assets to s40 for the winter.
At worst: the s21 adventure may be a sign that they KNOW MH370 is not (ready?) to be found where the signal data puts it, and have been trying to look busy, whilst running out the clock. The stock on THIS scenario has risen considerably of late, after JIT minions got caught trying to
– send surface debris up-current, and
– shed endurance by turning south sooner (setting up [7th arc e84-88] as a stone they can spend several extra months turning over in 2015)
While maintaining a deep respect for the IG’s members, and their signal data acumen, I fear we are NOT optimizing our collective efforts by inventing clever new refinements or interpretations of signal data which increasingly appears to have been used (if not INVENTED) to send us (and the searchers) on a wild goose chase. We need to pressure the JIT to come clean, and FULLY disclose all data and assumptions – on the fuel analysis in particular.
All I need to do to dust off my #DAY200AUDIT request is to update the DAY…to 269…
Victor: If the plane is not in the current search area, we have to revisit our models. But I don’t think that is a call to abandon the science. Rather, it is a call to understand which of our scientific assumptions are incorrect.
As an outside observer of the evolution of the modelling, I am quite confident, that the BTO and BFO path models are a close fit to the underlying physics.
I base that confidence on two facts:
1. Several relatively independent modellers (ISAT, ATSB, IG, Ulich, et.al.) are coming up with essentially the same qualitative path solutions, give or take a few hundred nautical miles between predicted end points.
2. The early IG modelling was already so good, that it could make a prediction, later confirmed, of “Anti-Perth”.
In my view, what should be revisited, if the box remains empty, are the initial conditions, pumped into the models, namely the 18:22 last “known” radar position. My confidence level in that are an order of magnitude smaller, than that for the ISAT data.
After all, the end point predictions are massively sensitive to these initial conditions. E.g. “give or take a few hundred miles” are mainly due to different assumptions (in a way an introduced initial condition) for the southward legs of different model predictions.
All we, and as I have been told the ATSB, have is the track image and a statement, both supplied by Malaysia, that this is MH370 and the last point was at 18:22. There is no available independently verifiable raw data.
For accuracy of the used initial conditions, the modelling entirely relies on the competence and honesty of the Malaysian authorities…
Cheers
Will
Victor – I’d say an excellent job has been done with the numbers by a lot of people and that there is almost no chance they have all stuffed it at once. And you don’t need to abandon science, instead just embrace it and acknowledge that it could be the numbers themselves. Mike bristled at being taken for a “naive idiot” but the crunchers pretty much accuse the hijackers of the same. If one of these dudes didn’t flick a switch at 30,000 feet we wouldn’t even have any numbers. The dog-leg south at the flick of that switch looks like total shit. But the numbers…..
And not meant to sound adversarial either – you’re an IG member(Iggy?) who was happy to get outside the box and engage. You’ve contributed a lot more than modeling.
Victor:
We’ve moved on to a new (very interesting) thread, so I’ll make it quick:
1. Not at all saying that the science should be discarded, but am saying (as I have been since March), that people need to take Inmarsat’s data with a massive grain of salt. The possibility of a spoof, and/or redactions to hide the location of the plane (BECAUSE it landed), are why I’ve always been skeptical.
2. Re imagery analysis: the rub in pursuing that angle (at least with respect to the company MJ has been in contact with), is that the original (non-manipulated) image is required for an analysis. MJ doesn’t have the original. So either Tomnod is going to cooperate and provide a copy of the original, or we’re going to use an alternative strategy. Watch that space.
3. If you haven’t yet, watch the Oct 7 video I linked to in the previous post. Martin Dickinson’s response to (and demeanor) with Paul Sladen is telling a story. Inmarsat may be making an honest attempt. And they may also be taking direction.
As to “US, UK, and Australia know more about MH370 than has been reported”, I (obviously) agree.
At this point (and IMO), anyone who still thinks this is all about Malaysia is in some form of serious denial. Three of the ‘FIVE EYES’ countries have their hands in the MH370 investigation. The US and AUS surveillance capabilities in that part of the world are, shall we say, profound. The head of IADS has always been, and was, on the night MH370 vanished, an Australian officer. And as we speak, the doo doo is hitting the fan in Australia re the ATSB’s (and Martin Dolan’s) possible role in the Pel-Air cover-up. Look no further than pprune, where someone named ‘Kharon’ is commenting (and/or leaking) profusely, and now there’s a Senate inquiry into what appears to be a possible leaker (about what, we don’t know yet) inside of Air Service Australia (ASA). And who’s the Chairman of the ASA board? Chief Air Marshall Angus Houston.
Now, is any of that connected to (or indicative of) what’s going down with the search for MH370? I’m hearing ‘yes’, but what do I know? I’m just a wild-haired conspiracist in a lounge. Perhaps, if we’re lucky, some intrepid soul will connect those dots for us in the not-too-distant future.
In the meantime, the Maldives has too many witnesses saying the exact same thing for it to be lightly dismissed. Did they see MH370? I don’t know.
But here’s what I know for sure: the fish always rots from the head.
Brock:
“I may have “cracked the code” as to what was meant by the cryptic phrase:
‘passed close to a NW point at 1912 (ATSB June 26 report).”
Would you have coordinates for that point?
Thanks.
@Nihonmama: thanks for alerting me to this question – yes, I’d missed it.
As I say, the NW point varies as one varies the speed of each performance limit-generating path, but the turn-point for the key paths are all within a short distance of the southernmost of the Andaman & Nicobar Islands, at [n10.7, e92.5].
I wouldn’t try reading anything geopolitical into that coordinate, Nihonmama – my point is precisely the opposite: that this extra distance is ARBITRARY, and thus likely thrown in after the fact as a cover story for having moved the search further NE than a direct path could possibly justify.
Thanks much Brock.
No geopolitical read intent in the question and appreciate the information.
Hi Gysbreght, Dennis W,
Regarding “No one seems to be terribly troubled by the autopilot assumption”.
Well, I’m troubled too. So far for myself I formulated two working assumptions, which involve some speculations to make things more or less rational.
Version #1. Conspiracy or hijacking. Supportive reasons:
– The aircraft “disappeared” exactly when Malaysia was transferring control to Vietnam.
– All communications went down nearly simultaneously.
– The aircraft was flown exactly over the zig-zag border between Malaysia and Thailand.
– The aircraft turned NW immediately after crossing Malay Peninsula.
– Satellite link was restored virtually immediately after the aircraft disappeared from the military radar (indicating that someone knew the range of the radar… but what could be a reason?).
-The aircraft was not tracked by Indonesian military, which presumably indicates either someone knew gaps in their air defense system, or Indonesian military were involved.
After 18:25 something went wrong. Or perhaps landing really took place, and then someone just wanted to get rid of the aircraft’s body, and simply sent it to the ocean at nearly 180 deg heading…
However, there is yet another option, discussed too little in my opinion.
Version #2. Technical failure.
The same aircraft was pretty badly damaged in Shanghai. It was said “only wing tip”, but online photos suggest the right wing was substantially damaged. I can imagine that some mechanical failure related to the wing could take place just after IGARI. This resulted in a sudden drop of the lift force and increased friction. The pilots performed some rapid actions to stabilize the aircraft. Instead, it went up to 14 km altitude, causing more damages, possibly lost of cabin pressure and consequent suffocation of passengers and cabin crew. Since then the aircraft flew in a “auto-throttle mode”. Perhaps somebody still alive onboard tried to gain control over the aircraft when it was over the Malacca Strait, but eventually failed to do so.
Well, now forget everything what I said above, because it is just my speculation. There are only data and assumptions. The problem is that different assumptions result in different trajectories. I have recently elaborated “pure mechanical” model in terms of forcing(engine thrust + wind + coriolis), which gives surprisingly good agreement with Inmarsat’s BTO/BFO data, considering only samples after 19:40. Surprisingly – because in part this good agreement is achieved because of varying wind. But now I am more concerned about possible plugoid mode of the flight (since ~17:25), which makes things an order more complicated.
Regards,
Oleksandr.
The announcement that MH370 is not anywhere along the seabed on the Southern Arc seems imminent and several hugely over-inflated egos, having squandered a hundred million dollars need to burst.
As I have said for many months with nobody listening, the alleged radar image of MH370 flying though the Straits of Malacca are nothing but a photo-shopped hoax. The image comes from an SSR radar, not the Thales Raytheon GM400 based at Butterworth.
The BFO path calculations have all been based on false assumptions and BTO signal delay figures were “smoothed” to make them conform to the false claim that MH370 reached MEKAR at 18:22 UTC.
Everybody bar none have ignored the fact MH370 was showing Doppler shift at the gate before take off equivalent to a speed of 80-90 knots. Not one person has bothered to consider why?
Electrical overheating in the Avionics bay is a likely suspect. ACARS has a temperature sensitive oscillator in the Automatic Frequency Control (AFC). If overheating changed the frequency by just 1 Hertz we are talking about a 300km error.
If overheating affected the signal delay then the BTO rings are all wrong too, including the Southern Arc.
If that electrical overheating developed into a full blown cockpit fire and melted a hole in the fuselage to depressurise the plane, then the temperature inside the cabin would have plummeted to -53 degC
… so what effect do you suppose prolonged cold soak wold have on the AFC oscillator?
It invert the previous signal error.
Thanks guys for squandering a hundred million dollars on wasted searches to prove your egos.
The correct place to start was not your stupid calculations. It was to reverse calculate the drift of a 24 metre long floating object sighted by satellite back to a likely impact point.
By the time this point occurs to JACC there will be no money left because we have wasted all our time and resources listening to you guys squabble over satellite calculations. Bravo.
Here’s the alternative that you people refuse to consider:
Were there serious overheating in the avionics bay prior to take off then this might indicate a diode in the generator bus relays and when they fail the result is usually electric arcing and fire. Prior to failure there may have been surges that took offline ACARS and the transponder.
We know Ho Chi Minh reported losing MH370 off their Ca Mau(SSR) radar at BITOD therefore it is likely MH370 turned back on autopilot as it neared Vietnam.
We know they spoke with JAL750 and MH88 by VHF after 17:30 UTC. Something not possible if they dived east from IGARI because curvature of the earth would have blocked line of sight VHF contact with JAL750 flying north over Vietnam.
What few people understand is that a further transponder contact was detected from MH370 at 17:50 UTC (6.9298N, 103.5901E) and this corresponds with a loud terrifying noise heard by fishermen on Marang beach (17:45-50 UTC) and a non seismic disturbance on the seabed near IGARI about 17:50 UTC.
This reconciles the problem that MH370 had to be turned back on autopilot deliberately by pilots. It is reasonable to assume that if they had a technical problem that seemed non urgent at first then they would have elected to fly back to their maintenance base at Kuala Lumpur and could have done so simply by selecting WMKK on the autopilot.
If catastrophe struck after this turnback the autopilot would have reached Kuala Lumpur and with no further instructions just kept flying the last magnetic heading it was following.
That you should consider would have taken MH370 towards the inner BTO rings but then as MH370 flew south the Agonic magnetic field variation would have curved their true track east like a giant banana.
A giant patch of 300+ floating object were sighted by satellites of four nations from 16-25 March. All of these 300 objects were larger than 2m across and one object at 24m x 13m was as big as the wing from a Boeing 777.
From analysis of the drift pattern and wind/wave patterns on 08 March I am confident MH370 can be found near 44S, 85E. It’s not rocket science.
@VictorI – I don’t have any suggestions regarding the various models that have been proposed but I’ll offer the following “outside of the box” revisions to these basic assumptions:
The “Lido Hotel” photo shows the last radar at 200NM from Butterworth at 295deg. What happens if you use that location (about 6 deg 42.65’N 97 deg 14.11”E) at 18:22 instead of the ATSB’s 6.5deg N 96.3deg E “last radar?” (One thing is, even at 500kts, the a/c would only be half-way to the 18:28 Ring but, other than that, could it work?)
What happens if the BFO Bias were proportional to some of the other variables instead of being fixed?
What happens if instead of constant TAS and altitude a “stepped cruise” were used? For example, say altitude was increased 1000ft every hour along with a 2KTAS increase.
I saw this a bit late, but I totally support Simon Gunson in the suspicions about the oscillator stability. This is what I tried to send to the Inmarsat investigators on March 28, 2014, via a UK journalist, who apparently instead leaked it to another blogger (ConspiracyAtheist) who retweeted it:
“1. The ping time (which gives the line-of-sight distance) includes the response time of the electronics in the aircraft. Every 1 ms of response/reaction/activation time corresponds to 300 km line-of-sight deviation, or roughly 500 km towards West along the surface of the earth, considering the geometries involved in this case. Was the response time of the electronics (a) known, and (b) included in your calculations for those very theoretical thin-line arcs, which were presented as if there would have been no tolerances?
2. The doppler effect you have considered is based on very small frequency shifts between pings with one hour intervals, not observations of a continuous signal, according to what has ben publicized. The oscillator for this type of health check apparatus (in the plane) has no need to be especially frequency stable, since in normal use that would have no significance. Therefore, the oscillator may have easily drifted between the hourly pings, due for example to temperature changes (if the plane changed altitude, which we do not know), or if the onboard power supply voltage changed due to other reasons. Therefore it is a rather inexact and daring assumption to ascribe the hourly frequency differences to a “doppler effect due to the plane’s movement”. That is a big leap of faith.”
In short, I believe the Inmarsat findings are highly questionable.
how about mh370 being highjacked by the two irainians on the plane and the flight engineer, then they went south with it to go around the tip of India and Sri Lanka to get to the gulf of Oman and land at Konarack airport, then use it as a bomb to fly into Israel ?
I also tried to communicate with them, to no avail. The oscillator stability in a piece of equipment of that nature is unlikely to be even stable to 10hz. And the response time of the equipment must depend on some sort of electronics, probably a microprocessor, which can vary so much as to make any conclusions worthless. I assumed that the people concerned have taken these factors into consideration, but now I really do wonder. The only thing we “know” about MH370 is that it is lost. Somewhere.