The Mysterious Reboot, Part 3

Two weeks ago, I wrote a couple of posts about the strange reboot of MH370’s satcom system that occurred shortly after the plane disappeared from primary radar, and asked if anyone could come up with a reasonable explanation. I drew attention in particular to the left AC bus, which the satcom equipment is connected to. This bus can be electrically isolated using controls located in the cockpit, and this appears to be the only way to recycle the satcom without leaving the flight deck. I suggested that there might be some other piece of equipment that the perpetrator wanted to turn off and on again by using the left AC bus, thereby causing the satcom to be recycled as an unintended side effect.

The readers rose to the occasion. Gysbreght pointed out that paragraph 1.11.2 of Factual Information states that “The SSCVR [Solid State Cockpit Voice Recorder] operates any time power is available on the Left AC transfer bus. This bus is not powered from batteries or the Ram Air Turbine (RAT).”

This is an incredibly interesting observation. Reader Oz fleshed out Gysbreght’s insight, writing to me via email:

We could isolate the Left Main AC by selecting the generator control switch to OFF and the Bus Tie switches to OFF; SATCOM is now dead.  What else happens……….the Backup generator kicks in automatically to supply the Left Transfer bus. Here’s what’s so spine chilling; if you now simply reach up and select the Backup Generator switch to OFF………..you now lose Left transfer as well.  The CVR is gone!  I couldn’t believe how easy the CVR was to isolate!
To recap;
Left Gen Control to OFF
Bus Ties to OFF (Isolate)
Left Backup Gen to OFF.
I now firmly believe your mystery reboot was Left AC power being switched back ON……….. after something that had occurred that the perp or perps didn’t want any possible evidence of on the CVR……whatever was being hidden was done by around 1822; AC back to normal.

Gysbreght notes that the Factual Information also identifies the location of the CVR as Electronic Equipment Rack, E7, in the aft cabin above the ceiling, and suggests: “Later [the perp] could have opened Electronic Equipment Rack E7, physically pulled the SSCVR power supply plug from its socket, and then gone back to the MEC to restore power to the Left AC bus.”

Oz has his own theory: “If you are thinking why the hell you would turn Left AC/Left transfer back on? Flight deck temperature control comes from these…”

There’s a precedent for a suicidal airline pilot depowering the black boxes before flying a plane into the ocean: the pilot of Silkair Flight 185 appears to have done just that before pointing the nose down and crashing in December, 1997. It’s easy to imagine Zaharie reading the accident reports and realizing he should also figure out a way to disable the CVR before implementing his suicide plan. When the moment came, near IGARI, one can imagine the veteran 777 pilot suddenly flipping various switches while the baffled newbie, Fariq, looked on.

It’s certainly an intriguing scenario, but it is not without its flaws. As Gysbreght notes, “I would expect the Captain to know that the CVR only retains the last two hours and overwrites older recordings.” So if Zaharie planned to commit suicide by flying the plane for hours into the remotest reaches of the southern ocean, he wouldn’t have needed to turn the CVR off: the portion between 17:07 and 18:25 would have been erased anyway. This is not in insurmountable problem, however. Maybe he orginally intended to crash right away, a la Silkair, but then lost his nerve.

I’m not quite ready to declare, as Gysbreght has, “Case closed,” but I have to admit that the CVR idea is fascinating. Great work, Gysbreght and Oz!

720 thoughts on “The Mysterious Reboot, Part 3”

  1. @Dennis, yes, that they didn’t drop trackable floats is a serious oversight. That would’ve been much better than any drift models. Maybe they thought that the predictions of where the plane might’ve cone down were not precise enough.

  2. @Spencer, now you’re the crackpot
    The methods of manipulation you list are much too complicated. You wouldn’t make a good investigator – or perp for that matter 😉

  3. Jeff,

    The B767 inboard ailerons are similar but they are hinged at the rear spar. The B777 has hinge arms also there have the distinctive slots at the ends of B777 flaperons.

    OZ

  4. Something seems strange about this aileron, I see what @matty noticed about the damage pattern. It must have hit a shallow reef with rocks to give that damage pattern. So hold on. This still could be a part from the b767 which crashed at the Comoros offshore reef.

  5. Myron – The way I see it aerodynamic force would have torn the flaperon off cleanly at the actuator/mounting. We wait….

  6. Apparently there is a reference BB670 on the piece. This is more than likely a zonal reference, if it is, the first digit 6 indicates right wing. If it were a 5 it would be left wing. If it is a zonal then it shouldn’t be long before they confirm what it is.

    OZ

  7. @Matty – we wait, but why? Could they not obtain a single part or serial number and run it within a few minutes? I don’t understand the delay in confirming te identity of this part. It took much less time to discount debris that was sitting in the water. Not saying it’s not our plane, but with each passing hour it looks more and more like a 767 or an A310.

    Speaking of other planes, everybody is quick to point out, in effect, that there are no missing 777 parts. Was all/any of the MH17 debris recovered? I’m not suggesting that this is a part of MH17, but to flat out say there is no other plane it could be, when debris from the EXACT SAME MODEL is unaccounted for is a bit irresponsible. It would not be unbelievable for evidence to be dumped at sea.

    It’s also odd that those who said their drift models put the debris at Indonesia suddenly say Reunion is consistent.

  8. @Matty,

    Whatever the force was; it did tear off the hinge arms….the hinge arms are where the actuator attaches; so you are right in what you are saying. Having seen a few more images I reckon it’s the right flaperon.

    OZ

  9. OZ – Roger that. What I envisage is aerodynamic force tearing it off cleanly without shredding the trailing back half of it?

    That bit looks like more blunt force of water?

  10. @Matty,

    Something has torn the trailing edge section out before the hinges let go. I tend to agree with your thinking.

    OZ

  11. @Softmachine, excellent point. I can’t imagine what process would take two days to carry out. There are numbers stamped on the debris, it should take a matter of minutes to determine their significance.

  12. Jeff,

    I don’t think any competent investigation would confirm officially the provenance of a piece of debris until some kind of expert has actually looked at the item.

    On another bulletin board an aircraft parts supplier comments that the labels with serial numbers on such items are not very well attached and are sometimes lost in normal operations.

  13. “I can’t imagine what process would take two days to carry out. There are numbers stamped on the debris, it should take a matter of minutes to determine their significance.” – Jeff Wise

    The assembly ID plate is missing. So there are no simple and immediate leads as to the individual A/C this component came from. Any serial number will have to come from the item being disassembled to find that level of detail. Being as it’s a suspected piece of an aircrash investigation, they are not going to just let the local plod run riot with a cordless drill to deconstruct it. Hence why BEA have taken charge to have the part forensically examined in a lab in France. Have patience young man. All will be revealed.

    On another note, breaking news is a potentially shredded suitcase has been found in the same proximity today. But with all the false leads over the last 500 days, I would hold back on the faith of this being related.

  14. @JS and Jeff, yes I expected to wake up and see a positive or negative result posted here.
    Maybe this needs to be done according to a proper protocol, I guess. I have no idea where the serial number stamp is located on a wing flap. But if something needs to be opened up, they need experts, witnesses, make the chain of custody transparent and so on. This is too important for a screw up.
    JS, it’s true of course that may be many spare parts of B777s are knocking about our planet. But unless this is a tasteless hoax or a forgery, a B777’s wing flap emerging from the IO at a spot within the IO gyre can only come from mh370, because no other B777 fell into the ocean.

  15. Before people get carried away with speculation on how a flaperon might be damaged . . . Please recognise that this is not a flap. It is not deployed, as the flaps are, to increase lift to enable slower flight. In fact it acts as an onboard aileron, and is controlled in a similar fashion to the normal outboard ailerons.

    It is, on the other hand, directly behind the engine. Hence if an engine sheared off, on impact say, it is very possible that it would take the flaperon with it.

  16. @Littlefoot and @Sharkcaver — the need to open up the debris to look for a serial number inside would be a good reason for a delay, thanks for that.
    @OZ — Do you know where the serial number/s on a 777 flaperon assembly would be? Also, do you have comparative visual references for a 777 and 767 flaperons? They would be a big help in allowing us to visualize the parts that you’re talking about.

  17. Jeff,

    The data plates would normally be attached at the rib ends but its hard to make out how much has been gouged out. The hinge arms may have taken the data plates out when they were displaced. It definitely isn’t 767.

    There is no confirmation on BB670; this is an interesting point because if it is a zonal reference it is a bit scue. Should be 670BB. I have seen some references on the net referring to 657BB being found.

    The codes follow zones: Major/Sub/Sub-sub = 6 = wing; 7= fairing ; next =particular location. B= second panel in the zone; second B= on the bottom.

    670BB is a flap fairing; not it but on the correct side.

    If 657BB is actually on the unit then that’s it. Warren Truss has only mentioned BB670. Something does not sound right.

    OZ

  18. @ Richard Cole,

    Interesting photo; how things are changing…. a glued data plate ):

    Supposed to be fastened…..bloody out-sourcing!

    OZ

  19. @OZ, can you enlighten me? I was under the impression that ID plates are somewhat more permanently attached to the parts. Kind of forgery proof. Icm not even suggsting a forgery here. But a few weeks ago the subject came up in connection with a flourishing black market for B777 spare parts.

  20. Jeff – “the need to open up the debris to look for a serial number inside would be a good reason for a delay.”

    Why wouldn’t the French authorities be qualified? With some technical input from Boeing?

  21. @Matty, as far as I know the French authorities ARE conducting this investigation and took either the piece to a special lab in France or flew in some experts. I think it might be both. The experts make sure that the piece gets expertly transported 😉

  22. Bit on flaperons, for info:

    Only flap position and speedbrake lever position determine flaperon droop. Speed has nothing to do with it.

    From the 777 SDS(Systems Description Section of the AMM)
    The flaperons droop to 10 deg TED(Trailing Edge Down) when the flaps are at the 5 position. They droop to 20 deg TED when the flaps are at the 15 or 20 position. They droop to 31 deg TED when the flaps are at the landing position (25 or 30).

    On the ground, the PFCs (Primary Flight Computers) remove the flaperon droop command in proportion to the speedbrake lever movement from 17 to 55 deg. When the speedbrake lever goes back to the down position, the flaperons gradually droop to the position commanded by the flaps.

  23. @dennisw

    drift models

    Since there is no other explanation, when debris turns up at Reunion, and no debris at all turns up at Australian west coast, the crash must have been in the northern portions of the southern arc according to wind drift maps of the Indian Ocean. That points to e.g. Christmas Island. … and maybe a saucy sailoress comes into play again?

  24. @Brian Anderson,

    What you have said does not make sense. A flaperon is by definition, a flap and an aileron. When the flaps are retracted its an aileron; when the flaps are deployed it is both. And with this one it’s a flap (eron) with a slot (creates more lift at lower speed).

    OZ

  25. @Matty – Perth: To be clear, flaperons both “droop” and “pivot (down)”. The droop is associated with the flap position and the pivoting is associated with roll control. At high speeds, the ailerons are locked in the neutral position and the flaperons (and spoilers) are used to control roll.

  26. @cosmic

    I tend to look at it from a “preponderance of evidence” perspective. An incorrect theory will eventually sink as more and more information is accumulated. Only the correct theory will continue to “float”.

    My best fit flight path is some 70km West of Kate’s position. The plane would have been visible, but not in the detail of her reported sighting.

  27. @Richard Cole –
    Thank you for providing that much needed information. If that ID plate is the only proof of origin and VIN type assignment that is pretty outdated as I would assume Boeing would Laser Etch a serial or use a DPM Datamatrix barcode as almost all auto manufacturers / Heavy Industry use this currently for parts which eliminates head scratching scenarios such as these- Maybe we will see.

  28. @Softmachine, let me get this straight: the ID plaque is the only way to tell for sure that this part is from mh370? And just this important piece of evidence is missing? What a mess! There surely must be smaller pieces inside which could clear that up. Let me guess, we’re in for a long wait and many more rounds of speculation…

  29. Here’s a thought on the flaperon damage:

    Plane runs out of fuel. Plane enters, high altitude, high speed spiral plunge towards SIO. The flaperon buffets back and forth so violently that it aerodynamically tears up the trailing edge followed by eventual fail of hinges. Flaperon comes off wing and falls remaining height to ocean surface, floats, and found. Main fuselage plunges into SIO at high speed spiral.

  30. @Brock

    begin quote//

    Here’s the template we can all use in future whenever new info emerges:

    “[new info] PROVES [my pet theory] because [same old argument] and [new logical twist required to accommodate new info].”

    end quote//

    Probably some truth there. I was fond of telling my engineering/science staff that falling in love was an expensive mistake across a broad range of the human experience. One should try to remain clinically detached. I strive to do this, but we all carry some baggage, and selection bias is difficult to eliminate entirely.

    Lets hope the SSWG uses this new information with clinical detachment.

  31. Littlefoot,

    At the moment the internal 657-BB serial is the only number that can be viewed (from the outside) without dissasembling the part which clearly the people on La Reunion are not going to do.

    Sorry the external data plates did not survive a catastrophic accident (and 15 months in the sea) and that you will have to wait a few more days for the results of the BEA teardown inspection in Toulouse.

  32. @Littlefoot
    I was only going off of the info that Richard Cole provided-
    I would seriously hope there is more indentifying information inside the constituent parts of that section but one simply wonders- We are not talking about a moist towelette or a arm rest here. 😉 If it is the case that the metal nameplate is the only identifier then that is pretty bad as one would hope that serial# or part info that would be used in a modern aircraft such as this would have laser etch or DPM barcodes which cannot be destroyed unless the metal itself is.

  33. @OZ… Then you need to read the Boeing manual.

    It does not operate as a flap, i.e. It is not “commanded” or “deployed” downward as a flap might be.

    In fact it is free to float. Yes, it will float downward as the flaps are deployed, but only because it is designed to float and essentially follow the curvature of the wing. It cannot be commanded to do anything unless the aircraft speed is above about 100 knots, with normal control systems running.

    Also there is no slot, in the conventional sense, like a Fowler flap. The flaperon is hinged. It’s prime purpose is roll control, and in fact it is the primary roll control device at hire speeds because the normal ailerons are locked.

  34. @Benaiahu

    “Flaperon comes off wing and falls remaining height to ocean surface, floats, and found. Main fuselage plunges into SIO at high speed spiral.”

    It is very unlikely that the plane plunged into the SIO (as we are currently defining the SIO).

  35. so ok, we need to wait for investigators to officially confirm what it is; in fact, any kind of closure will be good; but its interesting that first thing we found is perfectly indentifiable part of plane

  36. I just read at BBC’s newspage that France has sent experts to La Reunion in order to make sure that the piece gets transported expertly to an expert’s site for crash investigations in Toulouse. And that it could take a while until the experts will come up with an expertise.
    Unfortunately it doesn’t look like this will get resolved speedily. But since all those experts seem to agree – at least unofficially – that this is a piece from a B777,then, if this isn’t a hoax or a forgery – how could it not be a piece from mh370? We all and the nok will have to settle with a few days of insecurity. But they better do this right.It’s too important.

  37. Just a thought from a curious observer regarding the barnacles found on the flaperon: Is any way they could trace the specific species of barnacle found on the flaperon to a specific area in the south pacific? I know it’s a long shot, but there are 1,220 known species of barnacles and maybe this would offer a clue as to what part of the pacific the flaperon first entered the ocean, depending on when the barnacles attached themselves. What species of barnacles are common to the areas around Reunion island, and is that species the same as the barnacles found on the flaperon?

  38. If there is no serial number or ‘vin style’ marker on this flaperon, I wonder if they might be able to do a metallurgical analysis to see if the composition of the metals in the part matches that of a flaperon from another Boeing 777 that would have come off of the same assembly line near the same time as MH370? In other words, try to match the ‘DNA’ of this part with that of another plane that comes from the same ‘family’ as MH370.

    No doubt the experts have all ready thought of this, but I just thought I would throw this out here for the purpose of discussion.

  39. Dennis, Myron

    If anyone with a brain was involved in this investigation, tracking buoys would have been dropped at the prime suspect locations in the SIO long ago, and we would know the likely locations of debris drift from those areas. But no, that did not happen.

    When responsible for the search AMSA did drop self locating datum marker buoys. 33 of them prior to calling off the air search. 21 dropped north of S32º after 27th March 2014.

    The other 12, I presume dropped between 17th & 27th March at lower latitudes. At most, these SLDMBs had 120 day battery life but possibly only 30.

    :Don

  40. @Longtime reader, I’m sure the barnacles, shells and microorganisms in the cavities and other components will be able to tell an interesting story about the flap’s journeys. And even without ID plaques they will clear up the identity of the piece.

  41. All, … Please do not use the word “closure”, as in the NOK finding some closure with the identification of debris.

    Closure is an often used word by the media, and others, as if some event suddenly finalises some aspect of NOK grieving over the death of a loved one. Like finishing the chapter of a book.

    In fact there is no such thing as closure. Ask anyone who has lost a loved one, particularly a child, and they will confirm that new information is welcome, indeed actively sought by many, but none of it alters the fact that nothing is ever closed.

    The loss remains forever. The best the NOK can do is to learn to live with the loss, and this takes time.

    How do I know. Well our son was killed in a light aircraft crash when he was 13 years old. 15 years later and little has changed, other than the fact that we have a heightened sensitivity to others who found themselves in the same situation. In talking with many other parents so afflicted we find exactly the same story. There is NO closure.

    I can only assume that the word is used, especially in the media, by people who have never had the misfortune to experience first hand such a life changing event.

  42. @dennisW
    >It is very unlikely that the plane plunged into the SIO (as we are currently defining the SIO).

    If by that you mean that the area being searched by ATSB is very unlikely to yield a result and your alternative Christmas Island solution (which requires dropping inconvenient Inmarsat data when it doesn’t match) is very likely, that is a ridiculous over-statement. But perhaps you don’t.

  43. @DennisW

    >It is very unlikely that the plane plunged into the SIO

    I disagree, should this flaperon be from MH370, I think it will provide additional data that can lead to fine tuning the final resting place.

    Looking at available, various, and even conflicting drift models it’s hard to imagine one could rule the SIO ‘unlikely’.

    I feel this discovery would strengthen the work that the IG developed from the Inmarsat and radar data made public. In the future perhaps the IG, some IG members, or ATSB will offer up new analysis with this new data point. I hope so, and look forward to any well developed analysis.

    The debris discovery should also chase away the staunch SIO naysayers. Your comment catches me by surprise, please explain.

    I’d like to take the time to thank Victor, Jeff, and several others (the technically capable ones) for exploring northern land routes and other viable alternate options while waiting for debris. You fellas poured a lot of excellent solid efforts into alternate possibilities that could have been possible with the data in hand. Many people do not seem to understand the reasoning or importance behind exploring alternate theories. Others who do not seem to appreciate or comprehend the complexities of pulling those degrees of freedom together to even form possibilities. Others are likely just plain ignorant, mean, or jealous. I for one, tip my hat with a thanks.

  44. @Benaiahu: Thank you for the kind words. We all make judgments as to when to leave a scenario on the table and when to take it off. By my nature, it was hard for me not to explore northern paths in parallel with southern paths with the lack of debris. At this point, however, I find it hard to leave the northern paths on the table.

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