air safety

Mar 25, 2014

MH370: Last incomplete ping from jet ‘not understood’

The Inmarsat satellite which provided data crucial to reconstructing the flight path of MH370 to a crash site calculated as being somewhere in a search and recovery zone around 2500

Ben Sandilands — Editor of Plane Talking

Ben Sandilands

Editor of Plane Talking

[caption id="attachment_42839" align="aligncenter" width="610" caption="An Inmarsat satellite: supplied graphic"][/caption] The Inmarsat satellite which provided data crucial to reconstructing the flight path of MH370 to a crash site calculated as being somewhere in a search and recovery zone around 2500 kms SW of Perth recorded a last incomplete and 'not fully understood' standby signal from the Boeing 777-200ER's otherwise disabled ACARS automated reporting system. This new revelation at this evening's media briefing in Kuala Lumpur by Malaysia's  acting transport minister and minister of defence Hishammuddin Hussein is described in a detailed explanation added to the Ministry of Transport Facebook page. This is the relevant part of that document in terms of the incomplete standby ping or 'handshake.'
The analysis showed poor correlation with the Northern corridor, but good correlation with the Southern corridor, and depending on the ground speed of the aircraft it was then possible to estimate positions at 0011 UTC, at which the last complete handshake took place. I must emphasise that this is not the final position of the aircraft. There is evidence of a partial handshake between the aircraft and ground station at 0019 UTC. At this time this transmission is not understood and is subject to further ongoing work. No response was received from the aircraft at 0115 UTC, when the ground earth station sent the next log on / log off message. This indicates that the aircraft was no longer logged on to the network. Therefore, some time between 0011 UTC and 0115 UTC the aircraft was no longer able to communicate with the ground station. This is consistent with the maximum endurance of the aircraft.
The minister said he would not answer technical questions about this or other aspects of the analysis that Inmarsat and the UK Air Accident Investigation Board provided to the Malaysia Government the previous evening (Monday) which caused the Prime Minister Najib Razak to make a late night announcement that the flight had ended in the middle of the southern Indian Ocean and that all onboard were presumed lost. When Hishammuddin Hussein spoke to this revelation his words were almost inaudible for those listening to  videocasts. However the interesting point he was making was that some eight minutes after the last 'normal' standby ping was registered by the satellite at 8.11 am local time  on 8 March on the morning the Malaysia Airlines 777-200ER with  239 people on board departed for Beijing an incomplete 'not fully understood' signal was picked up. At the time of the last normal standby ping at 8.11 the jet had been in the air for seven hours 31 minutes.  It has in earlier briefings been said to have been loaded with sufficient fuel for a total flight time of about eight hours. The Kuala Lumpur-Beijing scheduled flight time was five hours 50 minutes and the fuel load has been described officially as normal when the usual statutory fuel reserves and provision for possible delays or a diversion to an alternative airport were taken into account. The rest of the briefing and the Q and A session seemed to produce little that was new, or audibly new. Hishammuddin Hussein confirmed that the search efforts along the northern hemisphere search zones had ended and that all resources that could be diverted were being sent to Perth to assist in the only search and recovery zone left, which nevertheless covered 469,407 square nautical miles of the southern Indian Ocean , and which is being coordinated by the Australian Maritime Safety Authority, AMSA. That effort to locate and retrieve debris that may be from MH370 will resume tomorrow after being suspended because of very bad and unsafe weather conditions today Tuesday.

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22 thoughts on “MH370: Last incomplete ping from jet ‘not understood’

  1. wendal

    This is the very first we’ve heard about this!!

  2. comet

    Malaysia’s Ministry of Transport LINK placed the technical information on its Facebook page.

    [A big thank you from a tired blogger]

  3. wendal

    Yes comet, they have.

    Included there, for the first time in the saga, is an estimated track map which bears a lot of resemblance to our own red triggers!

  4. comet

    Do we know anything about how the aircraft impacted the water?

    You would assume that if it was an act by an evil pilot that it would have fallen from around 35,000 feet and impacted hard.

    I guess that’s the most likely scenario. But is it an assumption? Or is there evidence otherwise?

    I ask this after the Malaysian government announced (or rather, SMS’d relatives) that there is no possibility of survivors. I assumed this meant there must be some solid evidence that the aircraft impacted hard, rather than an assumption based on the most likely scenario.

  5. wendal

    It has already been mentioned in Plane Talking that the autopilot would likely disconnect on the loss of the second engine failure, resulting in either a spiral dive or a flat spin.

  6. comet

    Unless the pilot decided to do something different at the end.

    I know it’s not likely, assuming his ill intent, but do we really know?

  7. Roger Roger

    What would be the optimum number of search aircraft to give the greatest chance of finding MH370 and which could be managed by the search coordinating body? I think from what I’ve read there is something like 10 at the moment and in the main human sight is being relied upon.

    Would chartering a number of A330’s with the range of 13,400 km (~ 14 hours) or the like give a greater chance of finding the wreckage? Such aircraft would be lightly loaded except for fuel and allowances made for flying at lower altitude. It would take less around 3 hours to get on location compared to the Orion P3 4 hours. They could be filled so the two seats closest to each window on each side are taken up by volunteers, where the seats align with the windows? Then the volunteers could take turns at looking for debris.

    Anyway just thinking about what the possibilities and constraints there are when searching for 239 souls.

  8. wendal

    My assumption would be that whoever “commandeered” the aircraft would not have been able to deceive the other passengers and crew for nearly 8 hous. Much more likely would be a diversion closely followed by slow depressurisation resulting in the majority of the flight being as a ghost plane.

    But as you say, we don’t know anything at this time.

  9. cud chewer

    I don’t get the bit about a last incomplete ping.

    What process would initiate it? The report seems to say that its the earth station that initiates the process. Why would it do this again so soon?

  10. comet

    I wonder if the Malaysian government should have waited until some wreckage of the plane was positively identified before declaring “no survivors”.

    The same could be said for the Australian government, which switched from search & rescue mode to search & recovery mode, based on the Inmarsat evidence relayed by the Malaysian government.

  11. michael r james

    Could that last ping be related to power failure on the plane in its death dive? Or is the system (ACARS?) run off a battery system that wouldn’t be affected. Or, perhaps when the main power fails the (ACARS) system reboots (after changing to a battery backup) and in this process automatically sends a ping as a system check? And of course it is incomplete because of the crash. In which case this partial ping is at the ocean crash site.

    All of these (and similar) options seem a bit too obvious not to have been considered so I suppose not. OTOH the communication of some very obvious things has been pretty lamentable during this whole business.

  12. cud chewer

    All I can say is there is something very interesting about that incomplete ping.

  13. Bradley Sherman

    There is no reason to insinuate actions by the pilots or other malefactor. The Payne Stewart plane was accompanyied by military jets and the crash was observed. There were no communications from the pilots. The year-long major NTSB investigation was inconclusive because of the extensive damage to the aircraft. Certain possibilities were listed concerning depressurization, but pilot suicide or misdeed were not among them. –bks

  14. comet

    I think a hard impact into water is the most likely scenario.

    But I just ponder the possibility that a controlled flight into water would be a remote possibility. With life rafts and rain, it would be survivable for some time. In the past, people have survived eating sea creatures and rain water for over a year while adrift.

    I only ponder it because the Malaysian government said it would be impossible to survive.

  15. Sandy G

    I personally think they were wrong to say there was no hope for survival before debris has been found. Particularly given the fact that it is not even known for certain whether or not the plane ended up in the Indian Ocean. “Most likely”, and maybe even very likely, but not certain.

    And I agree with you, comet, that even were there a crash landing, shocking examples of survival do exist. The weather down there right now mitigates against survival, I would think, even if they were in rafts, unless there would be survival gear including warm clothing. But we simply do not know enough IMHO.

  16. Tom W

    Interesting to read that they checked their technique with the satellite logs of six other 777’s from the same day to confirm its validity. Would be interested if they can ascertain whether the ‘incomplete ping’ has anything to do with a crash process. You should probably re-post their diagrams here.

    Wonder if the (known?) track around Indonesia is consistent with any normal routes or waypoints, and if the southern turn could be explained by any automatic process.

  17. discus

    I can only surmise that the aicraft ran out of fuel therefore losing all normal a.c. Electrical buses. At that point the RAT would be deployed to supply centre system hydraulics and limited a.c. Power. The acars / satcom may be on a standby or emergency a.c bus supplied by the RAT , reboot and provide an incomplete or faulty handshake. Im not 777 rated so im making some assumptions based on what may occur on other aircraft.

  18. RiskMan

    The partial handshake at 8:19 am was likely to be triggered by a diagnostic command in the event of abnormal operating conditions. If it was a standard reboot, the transmission would be obvious to the investigators.

    But given all the high tech analyses, there is still not a single low tech sighting of actual debris. If the aircraft dived from cruising altitude, there will be many smaller floating debris. Unless the search was in the wrong area, or the debris moved further after two weeks, or the aircraft did not dive and sank largely intact thereby trapping most debris.

    The Inmarsat indicated a south heading and predicted a track. We all know that a small error at the starting point and angle will result in a bigger diverged error after 8:11 am. Asking a human question, what is the likely heading that the pilot would program into the FMS? Knowing that the pilot was deliberate and calculative to avoid detection, why then pick a random heading? South pole? Between two airports?

  19. Michael Michelssen

    If they “found” pieces of MH370 and took picture (which is a joke, looks like it’s taken somewhere between WW1 and WW2) why can’t they just take these coordinates, point satellite to that location and take HQ photos? I guess because the answer is simple – this is just a cover-up, they are still “buying” time before everything is staged as planned. Reasons for this “theory” – there are so many communication systems on Boeing 777. Couple of VHF radios, SatCom systems, CPDLC, ACARS and transponders. Yeah, all these systems can just stop working. Also, Boeing 777-200 engines are RR and they transmit EVERYTHING to RR base until BOTH engines (for some reason) die – and we haven’t heard anything from RR. Give us satellite images from 9th of March, take pictures above Maldives and Diego Garcia US base, there we can find answers.

  20. Confirmed Sceptic

    Every one of your statements is incorrect. Were you looking for another site?

  21. James Brown

    I dont believe the pings come from the ACARS system. They come from the Satellite comms system which includes a phased array antenna and its controller which is responsible for maintaining a link via Inmarsat so that phone, data and SMS contact to the aircraft is available.

    This raises the question as to why no one phoned the aircraft via Inmarsat. Does anyone know whether there is a standard Inmarsat phone number for each aircraft?

  22. Confirmed Sceptic

    Yes, there is. I asked the same Q last week. I guess that in the critical hours they all thought that the aircraft was somewhere near IGARI intersection, where it went dark.

    I will bet that all airline SOP and ATC standard procedure will now be to attempt satcom contact until after last fuel endurance. If MH had, they would have had a data point including position.

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