MH370 Seabed Search Concentrates on Low-Probability Area — UPDATED

Screen Shot 2015-12-21 at 4.14.52 PM
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As I’ve discussed in earlier posts, by its own calculations the ATSB has already searched most of the high-probability areas of the Indian Ocean seabed in its quest to find the wreckage of MH370. The only remaining area of relatively high probability that has not been searched is a stretch along the inside the 7th arc.

(In the image above, the area that had been searched prior to the release of the ATSB’s December 3 report is outlined in black.)

Yet this is not where the search is currently underway. According to ship-tracking conducted by Mike Chillit, Fugro Discovery has spent the weeks since the ATSB issued its report searching an area 40 nautical miles beyond the 7th arc, in the pale blue “low probability” area of the ATSB’s heat map.

It’s hard to understand why.

UPDATE 12-22-2015: I was delighted to learn that Richard Cole is back on the case, paralleling Mike Chillit’s work by collecting and collating ship-movement data in order to understand what areas have already been searched. Richard has given me permission to reproduce one of his charts, which shows the situation much more clearly than my amateur effort above. I’ve outlined the area already searched in light blue. One thing I notice looking at this is that the unsearched high-probability area near 87.5 N 37.5 S hasn’t even been bathymetrically scanned yet! Click to enlarge:

Richard Cole 2015-12-22


170 thoughts on “MH370 Seabed Search Concentrates on Low-Probability Area — UPDATED”

  1. Trip,

    What was recorded after 18:25 is summarized in the header of Inmarsat logs. The most interesting parameter after BTO and BFO is a signal strength. It could possibly help to eliminate spoofing theory as otherwise the correct alignment of satellite dishes would be inconsistent with BFO. But Inmarsat opted to withdraw this information.

  2. Happy New Year to all posters.


    That is interesting about other paths leading to a terminus further north of the current search zone, I sort of felt that since that particular Inmarsat data set of the MAS call to MH370 that had not been used originally, and was then used after to determine the FMT, then shorten that leg of the flight a bit from the FMT to the current search area perhaps. I question why the FMT took place minutes after the reboot. Do we have that conscious pilot gone down the wackadoodle path making the FMT on a trip to oblivion, or not……..

    Sajid UK,

    Regarding the NOK and the cell cos. and the phantom ringing. That did not surprise me at all, I would say very few folks in general would be that tech savvy to know that the cell cos. choose what you hear when one calls yours phone and have the option of one hearing a ring or the voicemail while it attempts to reach the phone. I would say that initial ringing the NOK heard gave them false hope at the time.

  3. Oleksandr,

    A perfect magnetic track route does not match the BTOs as well as it should. However, if the plane uses just the ADIRUs to navigate in track mode, there will be some error to the actual route. It happened all the time, e.g., for planes flying trans-Atlantic before the days of GPS. Could the errors be large enough to account for the mismatch? Lots of things to fiddle.

  4. DennisW Posted January 4, 2016 at 6:28 PM: “@Gysbreght
    Yes, as you know there are an infinite number of flight paths that can satisfy BFO and BTO. ”

    Well, I’m afraid that my agreement with that statement is somewhat qualified.

    Within the time window of 11.6 minutes between 18:28:15 and 18:39:53 the turn south must have occurred. Does that leave an infinite number of flight paths? For each time in that window there is only one path that satisfies the measured values of BFO and BTO exactly.

    On the other hand (as VictorI has observed yesterday), if you assume, like the autors of the Bayesian Methods paper, a standard deviation of 25 HZ for BFO “bias prior mean” error plus a standard deviation of 7 Hz for BFO measurement error “noise”, then of course almost any path can be claimed to satisfy the measured BFO values.

  5. Happy New Year to all good people! 🙂

    @Jeff, OT here
    excuse me, I dont use twitter, but discussion there about Bellingcat…. ummm, I am not sure if they arent trying to brainwash you, ’cause, you sed:
    “Bellingcat is highly respected; their findings support my analysis assigning blame for MH17” … confirmation bias?
    omit the source of article here (as its RT so, you know…) and fetch details about the Germans who criticize them; I simply dont believe them any single word in relation to eastern conflict – dont remember when, but they published several times things highly biased ONLY against Russia, AND … you know, anybody has already knowledge that its far more difficult than initially shown in media

  6. Sk999,

    RE: “A perfect magnetic track route does not match the BTOs as well as it should”.

    Why do you think so, or what do you refer to? How well should it match in your opinion?

    I recall, for example, my very early calculations of the “magnetic rhumb” trajectory had the maximum BTO distance-equivalent residuals of order 6 km, which is well within the measurement error (, especially when compared to the errors of ~17 km in KL. Magnetic heading was 173.9 deg; groundspeed 456.7 knots. The trajectory was slightly curved.

    But again, it is nearly impossible that 3 ADIRU, SAARU, and 2 independent GPS, all were down as a result of some catastrophic event.

  7. Gysbreght,

    Re: “Within the time window of 11.6 minutes between 18:28:15 and 18:39:53 the turn south must have occurred”.

    In this case I agree with Dennis.

    Even if one turn occurred within this time interval, what is evidence it was final?

    And even if the turn was a single one, there is still infinite number of trajectories, which comply with BTO and BFO data. Only if BTO and BFO are available as the functions of the time, and if altitude is known, then a trajectory could be reconstructed in a unique way. This has nothing to do with errors in the measurements.

  8. Some here will remember that I have been adamant about calling this “unauthorized divert” instead of “hijacking”, not because I wanted to defend Captain Zaharie but just to clarify some things. While the plane is moving it’s Captains responsibility what happens with the plane and he is the one deciding where the plane will go.

    Here is another example of a Captain doing some things on his own.

    In this case it was justifiable so he didn’t face any disciplinary action.

  9. Oleksandr,

    I had lost track of those calculations, so thanks for the reminder. If I plug in a constant magnetic heading with initial conditions at 19:41, I come pretty close to the route that you calculated – e.g., at 00:11 I compute a position of longitude 99.2, latitude -27.8 where you have 99.0 and -27.7. Not perfect, but not too bad either! My fit to the BTO’s is OK, but could be better (I don’t compute arc distances). But details matter. If I increase the altitude to 35,000 feet, the winds are different, and the final latitude changes to -27.5, and progress along the route is different. Any good fit to the BTOs is degraded. Another difference is the epoch of the MagVar tables in the ADIRU and FMC. I used 2014 for the preceding calculation, but almost certainly that is not what was loaded into MH370’s computers. I actually don’t know how the tables work in detail (in spite of much digging), but outdated MagVar tables are something of a chronic problem in the aviation industry. I have a reference if interested.

    A bigger difference is that I am computing the entire route starting at 18:22:12 – the last radar point. My preferred magnetic track route reaches position 93.7 and 0.1 at 19:41, much further South than your starting position, even though I place the FMT as late as possible and use a lower airspeed.

    Anyway, you get a taste for all the fiddling that is going on.

  10. @Oleksandr
    “But again, it is nearly impossible that 3 ADIRU, SAARU, and 2 independent GPS, all were down as a result of some catastrophic event.”

    It does seem nearly impossible, but only something nearly impossible can explain the loss of MH370.

    How about flying through a swarm of bees crippling the ADIRUs… and SAARU at the same time, and somebody on board toying with a GPS jammer…

    Wouldn’t have thought of that one!

  11. @sinux

    it’s quite clear this was result of deliberate action, at least up to FMT point

  12. Sk999,

    Thanks for cross-checking.

    Yes, you are right with regard to all your points.

    Just FYI I have used online calculator of the 2D magnetic declination field for Mar 7 2014 UTC and then applied interpolation. There was also a Fortran script available for downloading to compute declination at any given point of the space and time, but I was too lazy to plug it into my matlab script. I think all the links were posted at Duncan’s Web.

    It is not known when the aircraft entered its final mode. The sequence of numbers suggests this likely happened by 18:40, but the sequence of events – later. That is why my preference is to exclude 18:40 BFO from the residual-minimization procedure and connect 18:22 and 19:41 positions by logic rather than geometric approach.

  13. Sinux,

    In my opinion there are more probable failures, particularly related to the wiring behind the cockpit, than simultaneous individual problems with 3 ADIRU, SAARU, 2 GPS, 3 VHF, HF, and SATCOM.

  14. @StefanG
    Deliberate action of course! What caused this deliberate action is any body’s guess. Could have been nefarious, could have been a response to an emergency.

    There has been multiple pitot failing on B777 before (8 until 2010), cf this article :

    You might also find the ATSB report on 9M-MRG interesting :
    There we have a failure of the ADIRU.
    What would be interesting to know is if the failure of the ADIRU had consequences on the SDU, I doubt we’d be able to get records for that 2005 flight from Inmarsat… 😉

  15. SharkCaver – Just making sure we are on the same page regarding the search, what I was floating back there(been away a few weeks) is that a future search be limited to an expanded bathy survey as opposed to sidescan, and head up the arc at whatever width they chose?……to look for for hard objects 60m long. Results could be followed up later. I have been under the impression that a routine seabed survey is a much simpler undertaking and are occurring all the time? Am I still bonkers?

  16. All, happy new year. Please excuse me if I’ve missed something, but has anybody investigated the possibility that the Inmarsat data was manipulated at the commencement of the investigation to mask the real flight path and final location? I think manipulation at this point is higher probility than an inflight spoof. The death of the Inmarsat employee during the analysis of BTO and BFO was never satisfactorily explained in my recollection.

  17. I just got an update from 2 yrs ago on facebook, they were looking in this area to begin with, that a 79′ piece of debris was seen on the Digital satellite Tomnod site we were all searching. Do we know if they ever found this huge item in the ocean?

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