Guest Post: Why Did MH370 Log Back on with Inmarsat?

[Editor’s note: One of the most intriguing clues in the MH370 mystery is the fact that the airplane’s satcom system logged back on to the Inmarsat network at 18:25. By understanding how such an event could take place, we can significantly narrow the range of possible narratives. In the interest of getting everyone on the same page in understanding this event, I’ve asked Mike Exner for permission to post the content of a detailed comment he recently provided.  One piece of background: a lot of us have been referring to the satellite communications system aboard the aircraft as the “SDU,” but as Mike recently pointed out in another comment, it technically should be called the “AES.” — JW.]

Until we have more evidence to support the theory that the loss of AES communications was due to the loss of primary power to the AES, we must keep an open mind. Loss of power may be the most likely cause (simplest explanation), but the fact is we do not know why the sat link was down between 17:37 and 18:25. My reluctance to jump to the conclusion that it must have been due to the loss of primary AES power is based on decades of experience in the MSS (mobile satellite service) industry. It’s not just another opinion based on convenience to support a theory. Let me elaborate on a few possible alternative explanations.

The potential for loss of the pilot carrier, due to the orientation of the aircraft in relation to the satellite, was increased as soon as the airplane turned WNW. Between the time of this turn (circa 17:50) and the time of the FMT (final major turn circa 18:25-18:40), the aircraft was flying more or less toward the satellite where the antenna pattern was near a null. Don and I have both looked at the antenna pattern in some detail and concluded that the antenna pattern and coincidental direction of flight were unlikely to be so bad that the pilot carrier would be lost due to this geometry. Moreover, according to a MAS Press Conference on March 20, 2014, there should have been an ACARS message transmitted at 17:37, but none was received. ( bit.ly/QFbF6C ) At 17:37, the aircraft was still over Malaysia SW bound, so the HGA pattern would not have been an issue at that point. Taken together, loss of the pilot carrier due to antenna orientation appears to be a possible, but unlikely explanation for the outage.

Ionospheric scintillation has also been suggested as a possible explanation for the loss of service during this period, but there have been no reports of other aircraft in the vicinity suffering a loss of service, so this explanation is also unlikely. (Note: Ionospheric scintillation in the equatorial regions can be a big problem for VHF and UHF communications, but it does not affect communications in the L band as much.)

The MCS6000 AES, located in the back of the airplane, requires a continuous feed of INS data (position, speed, etc.) via an ARINC 429 link from the computers in the front of the plane. If the AES stopped receiving INS data for any reason, then it would not have been able to steer the HGA, or compute the required Doppler corrected transmitter frequency. Thus, it is very likely that the AES would be out of service if there was any loss of this 429 data link, or the information carried over the link. Given that there was no VHF voice communications after 17:19:24 and the Transponder Mode S data was lost after 17:21:13, it is certainly possible that the INS data flowing to the AES was disrupted due to a common failure in some piece of equipment in the E-Bay. This explanation for the loss of service cannot be dismissed as easily as the two previous theories.

However, there is one additional observation that tends to favor the loss of primary power theory over the loss of INS data theory (or the other two theories above). We note that when the AES logged on at 18:25:26, the BFO values for the first few minutes thereafter appear to have been drifting in a way that is more consistent with a restoration of primary power event than a restoration of INS data event. If the AES power had been on during the outage, the oven controlled reference oscillator would have maintained a stable frequency and there should not have been any significant BFO transients following the 18:25:26 logon.

In summary, there are multiple alternative explanations for the AES outage, but loss of primary power is the most likely explanation. Like so many other necessary assumptions, like the mode of navigation after the FMT, we have no choice. We must base the search on the most likely assumptions while maintaining an awareness that few of the assumptions have probabilities of .999.

637 thoughts on “Guest Post: Why Did MH370 Log Back on with Inmarsat?”

  1. @everyone

    While we are at this junction, lets start addressing the input/output flow data approach and the comment made here seems like a solid historical area to begin addressing the history without rehashing the entire “hogwash” as Butler identifies in his verbal attack and offensive statements.

    This person brings forth a list in this forum as described and dated in the note below:
    “airlandseaman Posted February 14, 2015 at 12:29 AM”

    This person brings a strong point that in and of itself of the commentary is “manifestly” insane and lacks support of grounded principles, including the author that they cited for the book they use as reference.

    1) The ADS-B/C data is not actuality Real-Time as the preliminary report along with the January 29, 2015 Pre-leased March 7th report outline. The ADS-B/C service providers addressed this issue and is a matter of record. The service providers themselves informed the Malaysian Government upon the early hours that it is in-fact not real time and the data is updated in period time via input flight data and history.

    2) Radar Data set, including Phuket: It is clear and evident the point of disappearance was actuality Singapore’s Radar Field and monitored by permission to the Malaysian as a frequent fly path, thereby being a dual overlapping radar field on the lines of Viet Nam; Indonesia; Cambodia; and Thailand’s Radar perimeters and overlapping coverage, not lack of coverage that couldn’t be missed, so where is all this radar that was inoperative? The point is clear on this portion of the radar issue.

    2a) As for the hanging unknown Thailand Radar specular scan correctly timed initially as 20:25/41 aka 19:25/41. This Thailand Radar time was adjusted early on to reflect the Local UTC time of the Malaysia a/c incident time line to be 18:25/41.

    In Fact, the time of this radar event in and of itself crosses out and cancels itself as being applicable as the Thailand time zone correction would in fact add (+) 1 or 2 hours to being that Thailand is (-) 1 or 2 hours in the Straits of Malacca.

    You do not deduct the hour clock going back to the East, but add hours and the inverse going West. So if the True radar time was 18:25/41 for example then you add (+) 1 or 2 to correct the event at the Local Malaysian Time thereby making the 19:25/41 or 20:25/41.

    In the matter of MH370, the adjusted time was actually from 19:25/41 and / or 20:25/41 thereby correctly adjusting Eastward adding + 1 or 2 hours to that time making the local Thailand Radar specular at Malaysian Time 20:25/41 or 21:25/41. I do not see and correct correlation on this event that applies correctly to what is “presumed” to be the a/c of MH370 than what actually is the aircraft. The Malaysian Government, nor the AUS authorities bare any credit to these reflections, except a “presumption” to a hypothetical unfounded model of events.

    Thank you for allowing this post to be presented and I will continue to address the remaining issues in that post as needed.

    @Chris Butler “zap-zap” is tongue and cheek, a Metaphor if need a little help understand the sarcasm.

    via shark laser

  2. @MuOne,

    >I also recall discussions way back when that these phone calls got to a level where the A/C systems responded (hence logged on the ground), but failed to complete to a level at which the on board phones would have actually rung.

    So there is no hogwash in terms of “the science guys” changing their mind about phone calls reaching MH370. It did reach, but didn’t ring, hence un-answered calls.

    Okay…does someone care to explain just exactly what precluded the phone from actually ringing? What precisely allowed for the A/C systems to respond, yet prevented the actual ringing of the phone?

    Also, it was my recollection that the ‘science guys’ had nothing DEFINITIVE to opine on the matter, only that it appeared likely that the phone did not ring?

    Can anyone here state unequivocally that the phone did not ring?

    Spencer

  3. This was posted from Ben Sandilands (Crickey) today:

    Whoever was trying to make MH370 disappear without trace didn’t seem to understand that even attempted sat phone calls to the cockpit would produce evidence of the general direction of the flight, even though the phone rang and wasn’t answered.

    I suppose he is incorrect in what he says here???

    @Chris Butler

    Lot of spooks in the hood.

  4. @Spencer

    sopcvkrt shark lasers is an idiot.

    Probably sent by non-conforming idiots, for non conforming reasons. Repel borders & the like.

    No worries, just another idiot.

  5. @Brock and ALSM – I’m wondering if the probability models for the completed search area are missing something.

    Let’s pretend for simplicity that the search area is circular, that the probability is normally distributed and highest at the center of the circle, and that the search area covers all points where the probability is greater than 1/1000.

    If we randomly covered 25% of the area, the chance of finding the plane should be approximately 25%. If we randomly cover 50%, we have a 50% chance of finding the plane.

    On the other hand, if we start at the middle and spiral out, after covering 25%, we’ve covered an area with a cumulative probability of 55%. At 50% spiral coverage, the cumulative probability is 87%.

    ALSM’s estimates look closer to the first example while Brock’s are higher and look to be based on a normal curve.

    However, the search coverage is neither random, nor perfectly prioritized around the highest probability. The limiting factor is the ability and efficiency of the ship, so the spiral becomes more of a series of long straight passes. The cumulative probability of this search pattern should be somewhere in between a random one and s perfectly prioritized one.

    Do either of your models account for this, and if so, how?

  6. @JS

    Absolutely–this is what I was trying to get at. It seems rather odd that there has been no attempt by those leading the investigation to find and publicly state alternate explanations to some of the more strange reports we’ve all heard over and over again. If nothing else, it would help quiet some of the people who are adamant that this is a conspiracy of the highest order. A few in addition to the 6 you mentioned:

    1) Cops get reports on low-flying aircraft and loud noise. http://www.thestar.com.my/News/Nation/2014/03/12/Cops-get-reports-on-lowflying-aircraft-and-loud-noise/

    2) Malaysian lady’s sighting of a sinking plane: http://www.thestar.com.my/News/Nation/2014/03/21/Woman-reports-sighting-jet-Raja-Dalelah-Im-convinced-I-saw-aircraft-near-Andaman-islands/

    3) Another eyewitness account by the Indonesian fishermen spotting the plane with smoke possibly crashing into water. http://www.philstar.com/world/2014/03/18/1302295/indonesian-fishermen-saw-plane-crash-mar.-8

  7. @Christopher Butler

    I must note the record per the conversation between myself and the Editor-in-Chief that your continued comments are “manifestly” offensive and subject of paranoia being “insane”.

    Additionally, you have not shown any valid reasoning to curtail facts or denouncing what is presented as factoid to input/output flow data procedure or any relative scenario that will in fact, discredit the statement made.

    I will continue to address these discrepancies as a matter of proof and if you can not handle a firm peer review of the “hogwash” in and of itself, well maybe you should remove yourself from the kitchen as the heat continues to build and if you don’t mind go swimming in the SIO as the shark will be awaiting fresh bait. w/(sarcasm)

    This is the Ultimate Ping Zone, Less Noise More Signal in the approach via NASA spook proof. (Metaphor)

    Thank you for your kind and offensive insults that appear to reflect a radar speculation of your own continued insanity and paranoia and obvious insecurity of your analysis. (sarcasm)

    Have a Great Day!

    via shark lasers

  8. Hey Shark!

    Thanks for arriving in character , style , and “tude
    But let’s get this peer review done and show the way before you are zapped away like the Megalodon…

  9. @Matty

    Thanks for your concern Matty. This is not about who is right and wrong. This is about what is correct and what is not.

    It may certainly cause a stir. After all, there has been many hours and sleepless nights by numerous individuals and hard work around the globe that no person wants to say was wasted on the issue of MH370.

    It has now been roughly a year, and the only thing that has hung in the balance is speculation until recently when the newly formed elite team was presented with a task of information never before known to be understood on MH370. The fact is that all of it was understand and blinded by non-sense and continued as non-sense unknowingly.

    None of this Mysterious event should have been Mysterious from the outset.

    Anyways, thanks for the warning and heads up.

    @Myron “Off subject” Is Megalodon real in our time, as I am curious about Megalodon and appears to be truly a Mystery and fascinating.”

    via shark lasers

  10. JS,

    Note that yours:

    2. The NE IO, according to Ms. Tee
    3, The middle IO, according to some interpretations of Curtin data
    4. The SIO, according to most interpretations of Inmarsat data

    appear to be consistent with each other under the “free flight” hypothesis.

  11. @Matty

    Yeah…..looks like spooky dudes pet fish “Perch Low-beam” is trying to make his way out of his bowl.

  12. Brock McEwen has posted some interesting analyses of the potential position of MH370 following loss of power close to the 7th arc, using models of circular paths and a distribution of the radii of those paths.

    As a comparison I have looked at paths with rates of turn that increase with time. Mike Exner’s notes on his simulator trip mentions increasing bank angles following loss of the second engine.

    I used an idealised smooth increase in turn-rate, i.e. fixed accelerations in units of degrees/second/second. I also included deceleration in forward speed – three values of 1, 1.5 and 2 km/hour/second. I do not consider vertical speed.

    I started with a course of due South at 870km/hr (470kt) and calculated the position every second using the changing forward speed and turn-rate as above. I stopped each simulation after 400 seconds, four turns or when the speed decayed to 400km/hr, whichever happened first.

    The paths for turn-rate accelerations between 0.01 and 0.3 deg/s/s are given in the note below. These accelerations correspond to times to reach a rate half turn (1.5deg/s) of 150 and 5 seconds respectively; I understand that a rate half turn is the standard maximum for manoeuvring in high-speed flight. I have used turns to the left which are the worse-case for separation from the 7th arc but of course the turn could be to the right. I also plot the distance between the start of the turn and the centre of the final spiral as a function of the turn-rate acceleration.

    https://www.dropbox.com/s/2sduhzvbmoxfxya/spiral_dive_analysis_20-Feb-15.pdf?dl=0

    Some comments/conclusions:
    1. The various options have the same behaviour, a final tight spiral around a characteristic position which is a function of the turn-rate acceleration. These positions are not sensitive to the simulation end criteria listed above.

    2. Generally the rate of change of forward speed (within the limits chosen) does not make much difference to this characteristic position.

    3. The distance of the characteristic position from the start point is obviously a function of the turn-rate acceleration but the curve flattens at the higher values of acceleration, that is, higher accelerations make progressively less difference to that distance.

    4. I don’t have any information on possible distributions of turn-rate acceleration so cannot offer any statistical estimates for the final distance from the 7th arc; in any case this is an idealised model. However, the bias of the final position is away from the 7th arc, at least for turns to the left.

  13. @ sopcvkrt shark lasers

    “In the matter of MH370, the adjusted time was actually from 19:25/41 and / or 20:25/41 thereby correctly adjusting Eastward adding + 1 or 2 hours to that time making the local Thailand Radar specular at Malaysian Time 20:25/41 or 21:25/41.”

    I understand you’re saying the radar scan must be timed either 20:25/41 or 21:25/41 Malaysian time.

    Can this be verified?
    How would either scenario correspond to the ping rings?
    Did you plot flight paths? I would like to see the charts.

    Thank you.

  14. @Richard – wow, those are really nifty charts – not only are they useful indicators of sensitivity to acceleration/timing, but I also like how they help indicate forward bias from the point of fuel exhaustion.

    I’m led to believe that the signal data suggests (2nd-engine) fuel exhaustion at around 00:16, with a spiral dive already well underway by 00:19:30. This may help you both calibrate your model, and add context to your graphs.

    Final thought: I recall Mike cautioning that his simulator results did NOT suggest to him that a constant acceleration in turn rate was a safe assumption. Could your model be adapted to take as input an acceleration rate which was allowed to VARY (albeit [calibrated to]/[constrained by] our collective expertise re: corkscrew dynamics)?

  15. @IG: can IMPLIED engine PDA’s be reverse-engineered from the ATSB performance limit (e.g. Fig.3, Oct.8 report) and [everything else we (think we) know about the plane]?

    Related: does anyone in the IG have any concrete results to report re: independently computed performance limits?

    Just curious. Thanks.

  16. @Matty – I agree. Usually the ones that fall off the bar stool before they get served tend to be short term.

    @Oleksandr – those three could be reconciled with each other, although I thought the Andaman story had been debunked as impossible, as the passing plane was too high to see a plane in the water.

  17. Brock – for the first time I confess to getting interested in the numbers and Brock, I’m blaming you. The probability stuff is very interesting but I’ll stay on my tangent because geopolitics are apparently anathema to a cruncher and someone has to do it.

    Nihonmama – On that note – Oh, those Russians! From The Australian – and not the reference to cyber capabilities and technology theft. Vlad has no intention of being left behind, it dovetails also with his own wrestle with Jihadism, remembering that Malaysia, and MAS by default have become synonymous with weapons/technology and theft/smuggling.

    RUSSIAN President Vladimir Putin has increased Moscow’s spy operations against Australia, boosting his country’s espionage to levels not seen since the Cold War.

    The move is part of a growing push by Mr Putin to use his overseas foreign intelligence services more aggressively in a bid to steal hi-tech military, scientific and economic secrets from the West.

    Australia has been among those countries recently targeted by Moscow as part of a broader ­intelligence campaign against the West driven by Mr Putin, himself a former KGB agent, security sources have told The Weekend Australian.

    During the Cold War, Russia posted undeclared intelligence officers to Australia under diplomatic cover while others have worked here pretending to be business people or other ­professionals.

    Some have been agents for Russia’s foreign intelligence agency, SVR, and others for the country’s military intelligence agency, GRU.

    As part of its push to glean military, technological and scientific secrets, Russia is also understood to have recently stepped up cyber warfare against Australian government organisations.

    It comes as tensions between Australia and Russia remain high following the shooting down by suspected pro-Russian rebels of Malaysian Airlines flight MH17 over eastern Ukraine last July. A total of 298 people, including 38 Australians, were killed.

    That was followed by a fraught visit to Australia by Mr Putin for the G20 summit in Brisbane in November before which Tony Abbott had threatened to “shirt-front” the Russian President.

    During that same visit, Russia sent a naval task group to waters off Australia’s northeast coast in a display of brinkmanship, prompting Canberra to send two navy frigates and a P3 Orion maritime patrol plane to shadow the Russian flotilla.

    The government does not comment on the espionage ­efforts of specific countries but in ASIO’s most recent annual ­report, the agency warned that espionage activities against Australian interests were now “extensive”.

    “Nations use a range of clandestine or deceptive activities, ­including undertaking espionage and other forms of foreign interference, in order to advantage themselves, to protect or project their national interests or to harm adversaries,” ASIO said in the ­report.

    “Espionage and clandestine foreign interference activity against Australian interests is ­extensive.”

    However, the agency also warned that the extra resources involved in countering Islamic extremism was limiting its ability to tackle the growing problem of foreign espionage. “Resourcing pressures will ­remain in relation to the organisation’s non-counter-terrorism ­focused areas,” ASIO said.

    Professor Paul Dibb, a former director of the Defence Intelligence Organisation, said it wouldM not surprise him if the Russians had recently increased their espionage activity against Australia. “Does it surprise me that Putin may be up to his old tricks in relation to espionage? No it doesn’t,” Professor Dibb told The Weekend Australian.

    “Australia is one of America’s very closest allies in the world and the Russians here at their embassy will be after the usual sort of stuff and that is trying to probe through us American intelligence secrets and military operation secrets.

    “We know that despite the demise of the Soviet Union, Russian intelligence capabilities, including their signals intelligence and their cyber-warfare capabilities, are first class and most likely better than those of China.”

    Despite Mr Putin’s attempts to boost espionage efforts against Australia, China remains the country with the most extensive espionage network targeted against Australia.

    Beijing is believed to increasingly glean its information through state-sanctioned cyber espionage supplemented by agents, as well as sources within the local Chinese community.

    News of the heightened Russian activity in Australia came as three Russians were charged in New York last month for working as covert agents for the SVR in the US.

    The charges followed a four-year investigation which stemmed from the uncovering of a large Russian spy ring in the US in 2010, which saw 10 Russian agents arrested.

    One of these, Anna Chapman, returned to Russia where she became a celebrity and a catwalk model.

    In Moscow, Russian Foreign Ministry spokesman Alexander Lukashevich criticised the recent arrests, accusing the US of “once again resorting to their favourite tactic of building up spy hysteria”.

    “Russian-US relations have been going through quite a complex period due to Washington’s antagonistic stance,” Mr Lukashevich said.

    Meanwhile, in Britain an inquiry is being conducted into the 2006 poisoning of Russian Alexander Litvinenko by suspected Russian intelligence agents.

    Litvinenko, himself a former Russian spy who had become an outspoken critic of Moscow, died after being poisoned in London by a radioactive isotope, polonium-210, contained in a cup of tea.

    Litvinenko’s widow said her husband was the victim of an “assassination by agents of the Russian state”.

  18. JS,

    If under “debunked as impossible” you mean Kate Tee, the only reason for it to be debunked is the incompatibility with the AP hypothesis.

    I am not so sure about Curtin: if they used directional hydrophones at each of the two stations, how accurate these are? If not, they would only be able to detect a line, rather than area. In other words, one would need at least three stations to identify a point, or area if a tolerance error is taken into consideration. But my version of what they recorded is the bed impact sound after ~1 hour of sinking, rather than the surface impact. If the impact point is considered as the intersection of the “Curtin line” with the 7th arc, it fits well into the “constant thrust” model.

  19. @Oleksandr – sorry, I got my stories crossed. The one debunked was the sighting of wreckage by a passenger on a plane flying overhead. I don’t believe Ms. Tee’s story can be debunked or explained yet.

    As for the Curtin boom, everything I saw on it placed it in an area far to the northwest, in the DG vicinity, which is not near the 7th arc. I never read an explanation for why it couldn’t be closer to Australia, but it was never presented as a possibility either. Are you finding any support for the line reaching that far SE? I’m not in a position to say one way or the other myself so I’m curious to hear alternatives.

  20. JS/Oleksandr – The Curtin hydraphones were compared to the ones at Cape Leeuwin that are deployed to monitor nuclear tests. Then other Curtin hydraphones from further north were later pulled for analysis also. Their noise was traced to an area south of India, and area that is active, and said to mimic something seismic as the trace had a distinct “tail.”

    The biggest bit of wreckage on the seabed would be an engine? Sinking in water, hitting the silt, my limited understanding says that it wouldn’t make a huge bang?

  21. To me the Curtin devices are significant in that they apparently did not hear 270 tonnes hitting the water at M1. How many sticks of explosive do you need to match that amount of energy? Someone do the sums – I’m not a cruncher.

  22. @Oleksandr

    If after exhausting fuel @ altitude 35-37K feet as supposed. Certainly there would be two acoustic signatures….no? If only the bed impact, would that tend to support a surface landing?

  23. @JS

    Yes, I mentioned the story about the woman in the plane who claimed to have spotted a plane east of India. However, I do not think this was actually debunked. I’m under the impression that one could certainly see a 777 halfway submerged in water on a clear day from 35k. Any pilots care to verify?

    Also, I’m having trouble finding the connection between these news stories being posted about Russia and MH370..

  24. @All,

    I have been running new route fits to the MH370 satellite data, and I wanted to put out a brief summary of my results to date. I hope that perhaps my results might help answer a few questions and also stimulate discussion and constructive criticisms.

    A table summarizing my results can be downloaded at :

    https://drive.google.com/file/d/0BzOIIFNlx2aUd2lZZVFpZ3BoMEk/view?usp=sharing

    This table summarizes the critical parameters of many of the ~90 fits I did under a variety of assumptions, including the following:

    1. Assume a Final Major Turn between 18:22 and 18:40, and fit the BTO data from 18:22 to 00:11, OR fit only the post-FMT data from 19:41 to 00:11. For the latter case, in order to properly account for fuel consumption, I assume the aircraft flies continually from 18:22 to 19:41 using the selected speed control mode and altitude.

    2. Assume Autopilot LNAV with either a Great Circle or a True Track route.

    3. Assume the speed control is either a constant true air speed, a constant Mach 0.84, or Long Range Cruise (M0.839 – M0.786).

    4. Assume the route passes through the waypoint WITN, or assume no waypoints were used.

    5. I also evaluated specific routes previously published, including Victor Iannello’s and Inmarsat’s (2014.10.01) at 180 degrees, R. Godfrey’s V13.1 (2014.12.11) at 185.6 degrees, and my original 192.4 degree route (2014.09.25).

    Thirty-three fits are included in the table. For each fit, I show the RMS speed error in knots, while keeping all the route points within the ATSB recommended BTO errors. I also show the post-FMT bearing, the 7th arc crossing longitude, and the average engine PDA that matches fuel exhaustion at 00:16. I modeled the fuel consumption from 17:07 to fuel exhaustion using the same method described previously by Victor Iannello. I used the Rolls Royce Trent engine performance data. My results agree with his at 35,000 feet within a mile or two. I also did this fuel analysis at an altitude of 40,000 feet.

    The route fits with the steadiest speeds are highlighted in green in the table. They include both constant TAS and constant Mach 0.84, both with RMS speed residuals of ~ 1-2 knots after wind and temperature compensation. PDAs are typically 2-4%.

    For those people who doubt the accuracy of the satellite data, I would point out that the fuel analysis with reasonable PDAs predicts an endurance with fuel exhaustion within 5 minutes of 00:16, which is inferred from the satellite data, and within a couple of miles range of the 7th arc, which depends on the 00:19 BTO. I find the consistency of the satellite data in this respect quite remarkable, and it supports a convincing argument that 9M-MRO must be close to the 7th arc.

    You will note from this table that it is feasible to fly numerous routes at post-FMT bearings between 180 degrees and 192 degrees and end up on the 7th arc with fuel exhausted 3 minutes beforehand. The PDAs don’t vary much, because the total air miles traveled are nearly constant if the 192 degree route involves an early turn and the 180 degree route involves a late turn.

    Long Range Cruise fits tend to have larger residual speed errors and lower PDAs (~+1%). In my opinion this makes them less likely, although they cannot be ruled out completely.

    The longest range is achieved at Mach 0.84 with a step climb from ~FL350 to FL400/FL410. This adds about 120 NM to the range available at FL350 in LRC.

    My findings are as follows:

    1. Extremely steady air speeds (< 2 knots RMS) are possible with either a constant true air speed mode or a constant Mach 0.84 (and compensating for temperature variations along the route).

    2. Using Long Range Cruise, the air speed is more variable, although in some cases only marginally so.

    3. In Long Range Cruise the calculated engine PDAs are all a bit low (only +1%), no matter the route.

    4. For the constant TAS and constant M0.84 the PDAs are 2-4%, which seems quite reasonable.

    5. The range to my original end-point prediction (~83.6E) is achievable with a single FMT and with an average PDA of ~2-4% (depending on exact altitude and speed mode). On this point I disagree with the ATSB’s chart of so-called “performance Limit.” The ATSB has not provided any details regarding the assumptions that went into those curves, so it is impossible for me to evaluate their potential errors.

    6. Without a precise definition of the final turn(s) between 18:22 and 19:41, it appears possible to reach points on the 7th arc between 93.7E (Inmarsat, & Iannello) and 88.5E (ATSB) with fairly steady speeds and reasonable PDAs.

    7. With a single FMT assumption, points farther west fit better, and end points cluster near 83.7-84.6E.

    8. My best guess at the moment is that the most likely zone is from 83.7E to 88.5E, with the western end being slightly more likely in my opinion.

    It MAY be possible to narrow down the 7th arc location by hypothesizing a multiple turn scenario or a climb and turn scenario that is consistent with ALL the BTO and BFO data from 18:25 to 19:41. However, route uniqueness is not guaranteed. It is difficult or perhaps even impossible to disentangle the limited BTO & BFO data between 18:25 and 18:40 and separate the contributions of Rate of Climb from the bearing changes during turn(s). It seems clear to me that either altitude changes or additional turn(s) are necessary to be consistent with the BFO data then. A single turn at a constant altitude cannot be matched to all the BFO data within the expected errors. If multiple turns in fact occurred, then a more easterly end point is implied. If a single turn plus altitude changes actually occurred, then a more westerly end point is implied.

  25. Richard Cole, Brock McEwan,

    Very interesting results by Richard and observation by Brock re timing of initiation and progress of spiral dive.

    Both of those combined would/could indicate a north ward bias of impact from 6th arc onto 7th arc.

    Maybe the distance between these arcs can help calibrate the dive model’s input parameters? Or, in reverse, independent derivation of these parameters could yield constraints on the possibilities of 7th arc segment.

    interesting avenue of further research. I look forward to further results.

    Cheers
    Will

  26. Jay – how good is your naked eye from 10.5 kms? Half submerged an approx 70m long object in the midst of waves and sea haze? I know I’m past it.

    FYI – there are a few line of theory out there implicating Russia in the the disappearance, Jeff’s being one. Call it the Putin factor. But this episode continues to illustrate how different minds work. There is only one event it seems that would pull the crunchers away from that data, and that is MH370 showing up somewhere else entirely. It’s absence from the search area won’t be enough.

  27. @Matty – I’m seeing quotes of terminal velocity in water of about 25km/hr for LEAD. That’s presumably at the surface. I would imagine there’d be deceleration at depths. Which is consistent with most shipwrecks – if the Titanic hit the bottom at 50km it would not be in the condition it’s in.

    So you’re probably right – even an engine would barely make a noise, unless someone has a different understanding of sinking objects and terminal velocity.

  28. @Dr. Bobby Ulich: I can only imagine the amount and depth of work that lies behind that single sheet – congratulations, and well done.

    And great layout – tremendous information density, without overloading the eyes.

    Initial thoughts:

    – If they keep searching, but DON’T extend the zone west out to E83 ASAP, I will be VERY vocal in protest.

    – Bobby, you allow an FMT as early as 18:22; my last info has ATSB declaring an earliest possible FMT of 18:28 – any comment?

    – one request: presumably, the actual TIME of the FMT is recorded as part of each scenario – can these be included in the summary?

    Huge thanks for your efforts.

  29. @Jay – no go on seeing it from 35,000. Maybe much lower but not 35k. I’ve flown over recognizable airports (notably CLT) at 35k. Runways are unquestionnably visible. Despite the airport being one of the US’s busiest, it is very difficult to spot a plane even when you are looking and you know there are 40 of them down below. Not impossible but very difficult. The other thing is you can’t detect either motion or depth so it’s hard to distinguish one flying from one parked.

  30. @Bobby

    Yet another set of SIO calculations that avoids the questions of causation/motive and the lack of debris.

    Who input the various AP modes you modeled? Why did they do so? Where is the debris? Without a rational answer for these very simple questions your analytics are empty.

    Just another ATSB/IG like solution. These SIO solutions are like a turd. No matter how much you polish a turd, it is still a turd.

  31. @Matty:

    “Oh, those Russians!”

    Well, there are things in the world that are (clearly) Putin’s handiwork, but is MH370 one of them?

    Take two facts from my last (long) post:

    MH17 is shot-down with the step-grandmother of Malaysia’s PM Rajib Nazak and Defense Minister Hishammuddin Hussein on board.

    And

    Two weeks before Air Asia 8501 crashes, ‘Landlord’ warns (specifically) of an AirAsia disaster in a Chinese online forum.

    BOTH of these things HAPPENED. What are the statistical odds of either happening?

    Also note that ‘Landlord’ made specific mention of a “black hand” targeting MALAYSIAN airlines. What are the statistical odds that THREE MALAYSIAN-OWNED airplanes suffer disaster in one year?

    Further, given Landlord’s spot-on call re 8501, I’d submit that this — “Black hand has hijacked and shot down MH370 and MH17” — may not be a fiction.

    The STATE of Malaysia is the common denominator here. And someone (with capabilities beyond Malaysia) appears to be sending it (airlines and top politicians) a message.

    So, if you want to implicate Putin, we need a compelling answer the next question: why would Russia want to target Malaysia?

  32. DennisW – Having just followed a few twitter threads it seems clear that some pretty esteemed crunchers are getting totally pissed off at having to fend away critiques like yours, and I suppose mine if they cared enough about what I say. But their delusion is on display, and I don’t use that word by mistake. Why don’t the IG bashers come up with their own coherent logical findings and put them up says one. So, what’s so logical and coherent about twisting your life around 7 patchy handshakes?

    This may require another season of deep-sea towing says another? Who’s paying I say? As an Australian taxpayer who actually has skin in the game I confess that if we could elongate the current search it may be attractive to PM Abbott as he could feel it owes him something. But to roll up the sleeves and do it all again next year I don’t think so. It’s only my judgement, but as a nerdy watcher of domestic politics here, with a broken budget entering an election year it will be down the list and he could claim to have met all obligations.

    The Jeff Wise comments have descended into comedy they prattle. So what is comedy? Maybe pompous remarks that miss the mark? Like – this should be over pretty soon. Or – will be over sooner rather than later. Or – we’ll find the plane, grade the conspiracy theories later. Or – we’ll wait till we get the boxes. And there are many others.

    I have no doubt that some good people have done some very good and altruistic work on this case, but there has also been so monstrous conceit. A while ago I said that if it comes up empty there might be some shattered crunchers lying around and it’s already showing. On my part it wasn’t meant to be antagonistic. I’ve just casually opined for the last year because I had nothing invested in any analysis and I’d be happily wrong. Not everyone can say the same.

  33. @Nihonmama,

    Forget about Russia for a minute – if there was really s black hand behind three disasters, the last people to talk about it would be those in the Malaysian government.

    Back to Russia – my guess, if they’re involved, it’s in a mercenary role. Too much talent and not enough economy so they “export” their skills.

  34. @JS:

    “if there was really s black hand behind three disasters, the last people to talk about it would be those in the Malaysian government.”

    1. That’s right. But just because Malaysia would be the last to talk about it (there could be many reasons why they wouldn’t) doesn’t mean that a ‘black hand’ scenario hasn’t occurred.

    “Back to Russia – my guess, if they’re involved, it’s in a mercenary role. Too much talent and not enough economy so they ‘export’ their skills.”

    2. If Russia is behind this as mercenary, you still haven’t dealt with MOTIVE. WHO would have hired Russia?

  35. @Matty:

    “it seems clear that some pretty esteemed crunchers are getting totally pissed off at having to fend away critiques…

    … monstrous conceit”

    You are the truth-teller.

  36. @Brock,

    The 18:22 limit obviously refers to the last radar contact. I don’t think a significant turn occurred before the 1st handshake at 18:25:27. There is simply too much distance to cover in between. The western end point has a turn time starting near 18:28. The eastern end points have turns ending at ~18:39. It is possible a slight additional turn occurred even after 18:40. However, the amazing constancy of the many BFOs from 18:39:55 to 18:40:56 strongly argues for no climb or turn in progress during that one-minute period.

    @DennisW,

    You completely miss the obvious. In situations like this, one must find the “what” before the question of “why” can be answered. That’s how all accident investigations work. You use all the data you have to locate and recover the aircraft and data recorders (to know the “what”), and then determine the cause of the crash (to know the “why”).

    To answer your questions, I believe the final turn(s) were initiated either by the flight crew or possibly by a flight attendant. Both had access to sufficient oxygen to remain alive and functioning for at least an hour after the diversion. As for not finding surface debris, the SIO air search did not extend to the location I have predicted on the 7th arc.

    If you can make a case for why the search should be extended to a different location, please do so. If not, nothing you can say will ever make the slightest bit of difference in finding the aircraft or in determining why the crash occurred.

  37. @Nihonmama – I completely agree – it is entirely possible that there’s a “black hand” at work. I can’t answer the second question – who would have paid the Russians – because I don’t follow the politics east of the Urals. But, it’s either a massive coincidence, or Mother Russia is all over it.

    @Dr. Ulich – your math, models, and presentation are impeccable. But I have to point out that it is based on an underlying assumption that the Inmarsat data is what we’re told it is. At least as far as I can tell, the criticism is coming from a camp that believes we’ve been lied to, upstream of your work. It’s not a criticism of your methods.

  38. @Bobby

    You are hopelessly lost. I have nothing to say to you or ALSM or of any of the IG team at this moment.

    Your forensic experience is zero, and yet you talk like an expert. You should stick to what you know best, which is spinning numbers.

  39. @Bobby

    BTW, I have already made my best prediction which satisfies motive, lack of debris, and is consistent with the BFO/BTO data. The aircraft entered the sea South and East of Christmas Island.

  40. Bobby – “As for not finding surface debris, the SIO air search did not extend to the location I have predicted on the 7th arc”

    The satellite search did though. It was not done as a grid as I understand. Instead it was effectively scanned for debris, and they turned up patches from far and wide.

    JS/Nihonmama – Foreign politics is guided by pragmatism half the time. Plenty of the muslims in Iraq atm are from the Stan’s, and they have taken up pivotal roles there, and Vlad would be aware how interconnected the various Jihadi movements are. He would also be aware that a lot of their hardware and know how is smuggled out of the west through Malaysia, and MAS. He is keen to keep it away from their hands and in some instances would want it for himself maybe?

    I just read Jeff’s updated Kazakhstan angle via kindle and it rests on the same data as the SIO angle, but discards the less reliable BFO numbers. If the Inmarsat data is still unverifiable then they are both still theories, right? In the same basket right? So why the veiled condescension?

  41. LGHamiltonUSA – I can’t get that interview to roll, but it was recorded in May last year. The debris is an issue to me because we only need one single piece to close the matter. I’ve heard of Sebille and I wouldn’t doubt his quals but a year on, nothing. In this day and age, not one piece. It all got sucked away to nowhere? What were the odds of that, and who would have predicted it.

  42. @matty – you said it first – so I was going to say likewise that the satellites scanned for debris in the SIO but found nothing of significance nor did any ships in the area at the supposed crash site area. as we heard a great deal of debris drift so these ships should have come across debris by now.

  43. Myron – Indeed, and at the time they were pretty much investigating each new patch of litter that was passed onto them by the Chinese/French and others. They jerked this way and that in accordance with the latest detection. Maybe we lack a specialist here, but the only way the radar on the sub trackers could miss it would be if they totally buggered the drift analysis, yet they had many markers in the water from the outset. The very latest gear was used.

  44. @Matty & N-mama

    “Black Luck” vs Black Hand” vs “Life”

    Lost my brother, six years my senior, on the 11th of Oct 2014, it was a Saturday. My Mother took a slip, hit her head on the 11th of January & passed the 17th of 2015, it was a Saturday.

    The reasons are obvious why I bring this up. While Putin & the Russians are very capable of such a deed, why do so? Especially with so many Chinese pax on board? Why risk that relationship? Just a horrible set of circumstances, hard to digest, MAS especially.

  45. @All

    Sorry to be so pesky, but no one has addressed the two impact acoustical data scenarios, unless I was running late for class again.

    1. If plunging from altitude & exploding into the SIO. Would that not set off a signal?

    2. When reaching the bottom of SIO, would we not have to distinct acoustical signatures.

    3. IF there was a surface landing/ditch, would the acoustical equipment detect it??

  46. @Brock
    There is the single BFO measurement at 00:19:29 that can be interpreted as a indicating a rapid descent, assuming the whole transmitter frequency correction chain works correctly in a double engine failure/APU start scenario – no doubt the investigation has looked carefully at this and run appropriate tests on real hardware.

    The corrected BTO measurement at 00:19:29 is consistent with progress South at the same modelled speed prior to that point. A spiral descent clearly loses time/distance South with respect to an aircraft continuing South undisturbed. For some of the turn-rate accelerations in my note the ‘lost distance’ after one turn of the spiral (and the time to the end of that turn) is as follows:

    Accel. Lost Distance S. Time to end of first turn
    0.05deg/s/s 20km 120secs
    0.09deg/s/s 15km 90secs
    0.15deg/s/s 12km 70secs
    0.2deg/s/s 10km 50secs

    These distances are becoming significant with respect to the stated 99% probability error (10km on the ground) in the BTO measurements as discussed in http://www.atsb.gov.au/publications/2014/mh370-burst-timing-offset.aspx

    The point is that an extended period of turning flight (more than around 60secs) prior 00:19:29 starts to affect the average speed between 00:11:00 and 00:19:29, and thus the predicted BTO value at the later time, to the point it is not consistent with the measurement.

    On non-linear turn-rate acceleration, I just tried putting in a limit on the turn-rate (so accelerations as before, but to a limit in angular velocity). Using a limit of rate 2 (6deg/sec) did not make any material difference to the final distance from the start point for the cases I considered before, but a limit of rate 1 (3deg/sec) did affect the higher acceleration cases, pulling the centre of the final spiral closer to the start point.

  47. Wupe…meant to ask

    2. When reaching the bottom of SIO, would we not have TWO distinct acoustical signatures.

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