MH370 Final Major Turn Timing

Path derived from V13.1 Path Model
Path derived from V13.1 Path Model

Guest Post by Michael Exner, Richard Godfrey, and Sid Bennett (Members of the Independent Group)

Beginning shortly after the release of the redacted Inmarsat data log on May 26th, 2014, independent investigators began analyzing the data using analytic models, with the goal of estimating the most likely end point for the flight path of MH370. A combination of secondary and primary radar data provided information about the path from takeoff at 1641UTCto 1822UTC. In its June 26th, 2014 Report, ATSB assumed that MH370 was headed southby 1941UTC, but left open the question of where MH370 went between 1822UTC and 1941UTC. In its second report on July 17th, 2014, the Independent Group (IG) pointed out that the ATSB analysisappeared not to considerthe available Inmarsat data at 1840UTC, and recommendedthat ATSB consider that the Final Major Turn (FMT) to the south may have occurred much earlier than 1941UTC. In its September 9th, 2014, Search Area Recommendation, the IG noted that recent news reports indicatedthat ATSB was reconsidering the time of the FMT, based on the “phone call data” at 1840UTC. On September 26th, 2014, the IG released a Further Progress report in which the IG concluded MH370 must have been flying in a southerly direction by 1840UTC. On October 8th, 2014, ATSB released an Update wherein they also concluded that the FMT must have occurred before 1840UTC, similar to the published IG analysis. Thus, ATSB and the IG agreed by October 8ththat the FMT must have startedbetween 1822UTC and 1840UTC.However, a more exact time for the FMT has remained uncertain. A closer look at the BFO data after 1825 suggests that the FMT started and ended close to 1840UTC.

Read the full report here.


88 thoughts on “MH370 Final Major Turn Timing”

  1. Dr. Ulich
    The fuel burn rate formula I posted a couple of days ago in the Occam’s Razor thread is an average that includes takeoff, climb, cruise, descent & landing. The Delta manual suggests that the extra fuel lost during the climb is close enough to the reduction during descent so it’s OK to use the average. However, in the case of MH370, you (we) are using the fuel remaining after the climb has been completed so the a/c might have been lower than FL400 and still achieve your 6.13kt/hr burn rate.

  2. Hello Cheryl,

    What Kate saw is consistent with a few other scenarios. However, BTO/BFO residuals are slightly worse, though still within or close to the tolerance limits. I believe that what she saw could be MH370. I do not believe in a fire event, but I think the glare she saw could likely be an effect of open window shields + mist (condensation of vapour around some parts of the wings and fuselage due to rapid expansion of the air), which may together indicate possibility of some sort of an emergency event or landing attempt.

    It is one of the reasons why I question whether FMT did really occur between 18:25-18:40 or around this period. In my opinion it could be one of the sequence of turns, or 18:40 BFO could be affected by the altitude change (note the gap in radar data over the Malacca Strait, which indicates the likelihood of the aircraft flying below the detection altitude).


  3. Oleksandr – On the reboot – The plane had plenty of fuel on board and there was no sign of mechanical issues so I guess there would be an assumption on the part of investigators that it kept flying and possibly reached a destination within that range. And there are groups in some of those countries that could find a use for it and so you would have to take it seriously. Once you nick the thing you really don’t want people swarming everywhere looking for it, unless they are all down the SIO somewhere. I’d say integral to any such plot would be an effective counter measure because the response of the respective spy/intel services would sustained and intense, and a crash might not be the prime assumption with a dead SDU? AT the start the retd General McInerney said the search was a sham and it sounded steep. Since then the US could not have appeared any less interested. They either know precisely what happened and are not interested or they are not interested in the SIO. It’s still a hijack and a classy one so you would think there was plenty to learn. Is the US going to swoop on the boxes if they show up? Doesn’t look that way atm. Just my opinion of course – good day to you.

  4. I better add – The US son’t own the boxes obviously but they have plenty of leverage with Aust/Malaysia and could muscle their way in if they wanted. The search isn’t a total sham, it just might not be the only game going on.

  5. Nihonmama – You get nervous about sticking the neck a long way out but this has never looked right. In the very least it’s a groundbreaking crime but you wouldn’t know it at the moment. Ostensibly treated as an accident?

  6. Matty:

    I concur – it has never looked right. And as you’ve said repeatedly, I’m also (very) happy to be wrong. Seems neither of us are afraid of sticking our necks way out. Somebody has to.

    Just consider that if it’s not an accident, the current level of search activity (and corresponding expenditure) would suggest the magnitude of the crime.


    I just got an excellent question on Twitter from Annette (@aussie500). She asks if maybe the flight crew immediately went to a high altitude (> FL350?) when returning to Malaysia to avoid a midair collision since they had no functional radio or radar transponder? Perhaps this might explain, or be consistent with, the increased air speed seen immediately after diversion.

  8. @Oleksandr – if the SDU had stayed off, the search would have indeed been focused in the Andaman Sea. But with no signs of any wreckage whatsoever, suspicions would have been raised quickly.

    The reason “no debris” is at least partially accepted for an SIO endpoint is that there was nobody there to look for it – nobody flying overhead, no good access, etc.

    So while spoofing may be difficult, undetected it would do far less to arouse suspicion than plane that was headed for the Middle East with no SDU and no wreckage.

    One interesting observation – we’re saying that the delay for the signal is measured only from the time of the next signal block, so a spoof could create a BTO higher or lower than the distance between the spoof hardware and the satellite. But is this really true, and if so, why is it that the extremely high BTOs can’t be normalized to a signal block?

    And if it turns out that the spoof hardware must be within the closest ping ring to work, is there any reason why it could not have been on a boat?

  9. Here is my neck sticking out (just a what if, not a pet-theory):

    If hijacked and spoofed, the hijack is likely still in progress. It will only end with the re-appearance of MH370. In that context, a hijack to steal cargo would probably be one of the more preferable (benign) motives. The other end of the motive spectrum is more McInerny-ish.

    A SIO spoof compared to one that leads to a land based crash-site would be hugely more advantageous for ongoing hijackers, since the time from initial hijack to authorities determining “the plane is definitely NOT here” and start looking for alternative evidence is much longer.

    If still ongoing, I think this extended time span would have been integral to the original plan, hence my “its not over until the fat lady sings”.

    What sort of modifications/fit outs to a B777 take 9+ months to complete?

    Or, if the mods/fit outs are complete, maybe the plan is in the waiting game phase. Waiting until the official search is declared over, the plane declared lost and media and Intel attention subsides.

    Watch out for that “fat lady”!


  10. @Brock,

    I believe the two human-caused events occurring just after 18:25, the restoration of power (to the SDU) and the aircraft final major turn, are likely to be related as components of a single strategy.

    The 18:40 satellite phone call was initiated on the ground. It may not have even chimed in the cockpit. In any case, it was not answered. If a human-caused turn also occurred at 18:40, I would guess that those two events were likely to be just coincidental. In the same vein, in my opinion the power restoration at 18:25 and the loss of radar contact at 18:22 are not related events – just independent events that happened to occur 3 minutes apart. So far, I see no need to invoke hihacking to explain the little information we have in hand. Conspiracists will disagree.

  11. JS:

    Thanks for your post!


    “If hijacked and spoofed, the hijack is likely still in progress.”

    YES. YES.

    Watch out for the fat lady indeed.

  12. And to balance the hijack conspiracy scales a scenario that reflects a completed hijack without spoof (inspired by Anette’s, Bobby’s altitude question):

    Hijack via a software/systems hack, e.g. a malicious program uploaded on the ground prior to the flight to modify flight plan and control AP.

    Program steps:

    – Do nothing/Idle until near IGARI
    – Turn off comms systems, lock out crew from control systems
    – manoeuvre a short steep climb (sorry Annette, Bobby)
    – pop a vent or door to depressurize, knock out crew and PAX
    – execute turn back out of short climb
    – follow the radar track (pre-hacked flight route)
    – monitor radar pulses
    – program uses lack of radar pulses to turn back on/re-enable SDU
    – hijacker/hacker calls someone on the plane (problem: it was MAS who called)
    – program uses satcom call as trigger for commanding AP to turn south
    – hijacker/hacker calls plane again (problem: it was MAS who called)
    – program uses satcom call as trigger for commanding AP to ditch/dive or dis-engage AP to the same effect

    Fits all data
    All INMARSAT data valid (no spoof necessary)
    All radar data valid (including sharp turn, ooops, didn’t mean to say that)
    No hijacker on board necessary

    Why did the Malaysians only call twice? Or, why did they call at all, given that the
    assumption at those times were that MH370 may have crashed as it disappeared from all radar and comms?


  13. Dr. Bobby & Oleksandr,

    Hello and thank you both for responding. Well, two conflicting opinions then on what Kate might have seen but that is good because nothing is written in stone yet on all of this.

    I believe Kate saw something that night or in the wee hours of the morning and it was out of the ordinary. Whether or not it was MH370 that I have no idea. But what she saw haunted her and that image has been engraved in her mind. And she has a keen intuition on it and sometimes intuition can be right on point.

    Oleksandr, to your point then you are saying that perhaps a series of turns south due to an emergency was a landing attempt? I agree to a point but why did they not land near all the various airports in Malaysia or Indonesia then and why decide to turn south to land where, keeping fuel levels in mind? Then again we don’t know too as to what capacity physical or mental whoever was piloting was functioning with. Without comms how does one land anywhere? I still see the reboot as some sort of communication attempt at landing if it was not part of the hijack spoofing scenario.

    At what point of the Igarian/Bitodular turn (did I just coin some new words there) would the pilots be going through that frantic checklist if in an emergency? Would that have started prior to deciding the diversion and continuing across Malaysia, how long does that chceklist take?


    Good point about “singing.” But wouldn’t it be against human nature for someone not to have “sung” all this time to Rand’s point, a ground crew person, an airport worker, even some kind of strife and disagreements between those in the hijacker camp itself if there is one, someone taking care of the plane or revamping it, someone who took care of the passengers alive or otherwise, someone?

  14. Some of the passengers had intellect property useful to Middle East /Russia / Kazahstan. Maybe the mh370 would be a nice model for aircraft cloners. If the pax were still alive they maybe housed in some old soviet style city waiting for all of this to come to some resolution.

  15. MuOne/Will/Nihonmama – The freescale link would make it straightforward technology theft? It was known that other countries were playing catch up and that Israel were at the forefront. Putin is badly hindered by lack of money, he can’t go $ for $ with stealth technology for example so he has to do something. There is a lot hot air about Chinese/Russian stealth planes but in reality they have big hill to climb with not much in the tank. Does he drop off the pack or pull out a card? The Freescale technology was very desirable stuff but once again, by making that link you became a conspiricist. Putin would be happy to acquire that stuff and maybe dispose of the plane? Iran on the other hand want nukes quite specifically to destroy Israel – Shiite eschatology demands it, and Khorosan is a reference to endtime vision that inervates the whole programme. Problem they have is that Israel’s air space is so well defended and anything Iran puts up will be lucky to get through. An airliner with fake transponder code though? Russia also wants Israel gone and always has. Russia and Iran are allies in a number of areas. Conspiracy overdrive? I grew up with mutual assured destruction but it was understood that noone really wanted to pull the trigger. This is very different but everyone is sleepwalking. We can’t deal with North Korea let alone Iran so when a plane went missing I was holding my breath.

  16. Hello Bobby.

    Re “> FL350 to avoid a midair collision”.
    I lean to think that the answer is no. The reason for me to think so is that MH370 did not stay at a constant altitude, but it was “unevenly descending” from ~14 to 3 km (?) as described elsewhere. To me this indicates possibility of: (1) mechanical failure (plugoid), or (2) hijacking. If the intent was to avoid a mid-air collision, MH370 would stay at a constant altitude for a while.

    In addition, I trust onboard radar (if functional) would alarm pilots about possible collision.

    Changes in altitude are apparent till 18:22 if one considers radar data reliable. That is why I am asking for a while if anybody aware of altitude data (digital or time series plot), but did not get any answers so far. Wiki says that the altitude at 18:22 was around 9 km, meaning that MH370 was climbing up again. Consequently 18:25 BFO data could be affected.


  17. Hi Cheryl,

    An emergency event, as one of possible scenarios in my opinion, could occur at around 17:22. I am thinking of a mechanical failure of the right wing, which resulted in a short circuit and badly controllable aircraft in terms of turns and vertical movement. Uncontrolled climb to 14 km could have caused further damages and decompression.

    Sometime later the crew instructed passengers to open window shields in a preparation for an emergency landing, which are normally closed during night (I am not familiar with procedures; just a personal observation of their instructions on take off and landing). The crew was working on restoring communication, and they partially succeeded by 18:25. This hypothesis explains why SDU came back.

    An attempt of landing could take place some time between 18:25 and 19:20. However, something went wrong again, so that when Kate saw the aircraft, it was already a “ghost plane”…

    So the answer why they did not attempt to land before 18:25 – they simply could not due to mechanical/electrical failures, and/or incapacitated crew.

    Please keep in mind that all of the above is just one version of what could have happened.


  18. @Oleksandr, I understand that you’ve been away from the discussion for a while — this kind of scenario was discounted months ago due to the fact that we now understand that the plane flew straight, fast, and waypoint-to-waypoint before disappearing from military radar. This rules out large altitude fluctuations and is also not consistent with the plane being barely controllable.

  19. Dr. Ulich: While the 18:25 termination of the radar trace and the 18:28 initialization of the SDU may be coincidental, there are a host of other elements that select for a hijacking over a cascading mechanical failure. We can’t be certain of either, of course, but to favor a mechanical failure simply because the data does not as of yet present clear evidence of a hijacking is no less ‘overly assertive’ than many conspiracy theories. An civilian airliner has ‘disappeared’ under relatively anomalous and unprecedented circumstances, leaving only a sparse trail of data indicating where any debris may be found. The data, then, is but a map that provides information as to the location of the debris; it does not in anyway explain what happened aboard the night of March 8/9. Meanwhile, one would hope that there is an authority in the mix rigorously pursuing an investigation into a hijacking, which is at least just as probable as a mechanical failure at this point. The problem is, I am uncertain whether there is such an investigation being actively pursued at present, as we haven’t heard a peep from anyone, including the burglary squad at the KL RMP, now ten months in.

  20. @Matty, Mu/Will:

    In “Occam’s… (December 9, 2014 at 1:42 PM) I said:


    And here’s where it get’s really interesting. The likely reason that those (Freescale) engineers might be interesting is not the red-herring people have been chasing.”

    At the end of that post is a Twitter link that contains four posts (read in order) that tell the story of the link between Freescale, Certicom, the Canadians and the NSA. Here’s the main point: Freescale sells a technology that works with CERTICOM’s solution, which appears to have a secret ‘back door’ and (per Edward Snowden), the NSA has the key.

    In the software encryption community, this flaw was apparently well-known and many concluded that the flaws were “deliberately inserted to make it easy for at least one spy agency – the National Security Agency – to break the encryption.”

    My first thought when I saw this: anyone (state or solo) who wanted to enter that same ‘back door’ and watch what the NSA was doing — and WHO they were watching — would be very interested in Freescale.

    Now would that be the Russians? Would make perfect sense. But they wouldn’t be the only ones. Moreover, did any of the 20 Freescale engineers on MH370 even have relevant knowledge regarding Certicom and that back door to make them worth snatching a commercial airliner over?

    IF those engineers were the reason for the take, then consider that someone inside of Freescale may have been in with the perps — because what those engineers were working on would not have been in the public domain.

    A la the SONY hack.

  21. Hello Jeff,

    Yes, it’s true I was away from discussions in September-October… There was an update in Wiki by the end of October with regard to altitudes. Particularly this image was added:
    The first disappearance of MH370 from the radar screen and re-appearance could be caused by the change in altitude. The first disappearance would correspond to the altitude of around 3 km (based on the approximate distance to the radar – I was lazy to digitize this plot). This is consistent with the explanatory notes in the Wiki. Even though horizontal projection of the trajectory fits waypoints, it looks like the altitude changed a lot. Why was it concluded that the altitude did not change much? What did I miss?

    What I am thinking is that the autopilot could be switched again over the Malacca, while the crew was busy with recovering electronics. Other version: the captain and co-pilot were incapacitated, so that other survivors of the initial accident did not find anything better but to switch autopilot.

    The changes in the altitude and “uneven descent” could indicate a possible plugoid – a sign of mechanical failure.


  22. Dr Ulich – “So far, I see no need to invoke hihacking to explain the little information we have in hand. Conspiracists will disagree.”

    I always had the impression that the crunchers were scared of the possibility of a hijack, or anything that might compromise their numbers. So much so they ignore it? We haven’t heard from the investigation for a long time but I believe the Malaysian PM actually used the word “hijack.” Crunchers want a nice dry mathematical exercise, conspiricists can see that quite clearly.

  23. Matty, Rand (and Neils):

    I was looking for something else, and came upon this forgotten gem:

    ““Malaysian officials admitted that Malaysia has no access to Inmarsat’s raw data and algorithm in terms of how Inmarsat gained the southern corridor conclusion”

    That quote is from “The Circumlocution Office is Alive and Well” (Duncan Steel) – but because DS permalinks are now jumbled up, I can’t (don;t have time to) find the source now. But if someone can, please post the link. It would be most appreciated.

  24. @Oleksandr. Don hopefully will correct me, but I think the radar coverage gap in the Lido Hotel probjection you linked is attributable to a shadow caused by mountainous terrain, not a change in altitude. (The radar is thought to be Thai, not Malaysian.) The altitude changes are thought to be unlikely because any significant drop would prevent MH370 from arriving at the indicated location at 18:22.

  25. Whoops I meant word “truth” instead of the word “clue” at the end of my above sentence in my prev post…

  26. Hi Bruce,

    Thanks for your comment. Yes, this image was initially shown in the Lido Hotel. But it was included along with the respective text into Wiki only in the late October, so I was thinking that there is a growing confidence that a large change in the altitude did really occur. In particular, the text added in October indicates the altitude of 7 km at Penang, and 9 km at the last known location.

    Additional questions:
    -So you think this image a compilation of Butterworth data with Thai radar data, despite its legend, do you?
    -Was it confirmed that the gap is caused by mountainous terrain, or is it an assumption? Publicly available DEM could be used to provide an answer if the exact location of the radar is publicly available.
    -How does a significant drop “prevent MH370 from arriving at the indicated location at 18:22”?

    Perhaps these questions were already discussed – link would be appreciated.


  27. Oleksandr, I’ve linked below a thread which maybe has as much discussion of the Lido Hotel projection as there is in on one page.

    To my understanding, flying low enough to avoid primary radar detection would because of air density make it impossible for MH370 to make it to 18:22. I don’t have a link at hand, but I think that’s relatively uncontroversial. I believe both Houston and Dolan have publicly stated that there’s no evidence of altitude fluctuation, not to say that means much.

    My theory du jour is that Malaysia has no primary radar tracking of MH370 from Butterworth or anywhere else. The Lido Hotel projection was on March 21, which was 3 days after Thailand responded affirmatively to Malaysia’s plea for radar tracking information from its neighbors.

    I think Malaysia’s military radar was not functioning that night and the Malaysian government is too afraid of domestic political fallout to admit it. Especially in view of all the money Malaysia spent recently to upgrade its primary radar, such a disclosure could doom Hishammuddin’s aspirations to succeed his cousin as prime minister.

  28. Hi Bruce,

    Thanks, I found some interesting numbers with regard to timing in the link you provided.

    Perhaps ‘impossibility’ was referred to the whole section of the path from 17:25 to 18:22 being at a low altitude (?). I hardly believe that a short-period dive (or a couple of dives) could notably affect the ability of the aircraft to reach its known location by 18:22.

    I know that initially there were a lot of talks with regard to altitude change. In fact there was a lot of confusing contradictory information. A recent addition of the radar snapshot into a formal Wikipedia page made me thinking that changes in the altitude did occur. Besides radar avoidance (a path to Afghanistan was one of my first thought back in March), the changes in the altitude could indicate a plugoid. That is why I am interested in the time series of the altitude.


  29. Just one more interesting observation. Not sure whether it was noted elsewhere, so please forgive me if it is a repetition.

    I was curios for a quite long while why approaches based on the minimization of BTO/BFO residuals result in the initial heading being of around 180 deg. In some of my scenarios I even got heading of 180.00x deg at 19:41. Coincidence? Recently I noticed that quite many Waypoints in the area NW of Aceh are located at the same longitude. Examples of such ‘chains’:

    2). AGEDA->BULVA;
    3). DOTEP->MEMAK;

    Could these two things be somehow related? A bridge between waypoints-based and minimization-based approaches?


  30. Near IGOGU, at about 500kts TAS, the best-fit heading to match BFOs is about 200-205 degrees, exactly as the author states…

    and ALSO the mirror-image of that, BFOs derive mostly from the anomalous position of the satellite, which is slightly due north of the equator, so that aircraft tracks either 20-25 degrees West-of-South, and also tracks 20-25 degrees East-of-South, all produce the same Cosines & dot-products & BFOs.

    And, if choose the “inside” heading, of 20-25 degrees E of S, i.e. true heading of 155-160 degrees, then that flight path would extend from IGOGU, almost directly over Banda Aceh airport…

    at almost exactly the right angle to align with its main runway

  31. i find, that at 450 kts, the a/c must be flying due south (heading 180) to match BFOs. And, for every +10 kts, the acceptable tracks swing outwards, from due south, by +/- 5 degrees. So that by the time you reach 500 kts, the tracks are at +/- 25 degrees, i.e. 205 / 155 true heading.

    However, a heading of 205 out of IGOGU carries you to 45S 65E at an average speed off nearly 700 kts. So, you want to “squeeze” the tracks inwards, closer to due south… which requires reducing the speed up front at the FMT…

    the numbers equalize on heading very near due south, 180 +/- 5, with speeds between 450-470 kts, or so.

    This is consistent with the OP, more than less, and implies that the FMT, as a major maneuver “off course” (N2157 on N571 ??), slowed the TAS by 10%, from up to 500 kts down to 450-460 kts or so.

  32. Please consider the possibility, that MH370 somehow lost all capacity to communicate via radio…

    and so tried to communicate with the ground by their maneuvers on radar, e.g.

    overflying Kota Bharu = copilot Hamid’s hometown
    overflying Penang = pilot Shah’s hometown
    flying along route N571 in lieu of transponder code A2157
    turning hard to port at IGOGU by about 115 degrees (from 295 to 180) mimicking the similar turn at IGARI

    Such is consistent with a major electrical issue, and/or possibly a hijacking as well (N571 -> 7500 from A2157 ???) or some such ??

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