Malaysian Airlines MH370 contact lost

[mm_flynn]

Originally Posted by Ian W

From way back in the thread.
Malaysian Airways did not subscribe to Rolls Royce or Boeing health monitoring. ACARS was set up to only operate over VHF and the only INMARSAT subscription that the airline had was for satellite phone.

ACARS was set up to make routine reports at 30 minute intervals.

There was no connection of any sort between ACARS and SATCOM this was disabled as the company did not want to pay the subscriptions.

Ian,

You have said this several times. Yet it (the ACARS over satcom part! not necessarily the RR or Boeing monitoring) is wholly inconsistent with all of the official statements by the Malaysian CAA. Do you have an actual source or is it a repetition of a prior assertion in the thread?

[BOAC]

mm - if there is 'Acars Data' floating around as you say, where is it and what does it contain?

[mm_flynn]

The Malaysian CAA hasn't released the content of the data stream and I seriously doubt it is relevant. there will have been all of the normal messages and then the 1:07 packet will all most surely be a top of climb report or a routine monitoring report. But the CAA has declared that it was received, they declare it was received via satcom and Inmarsat logs show a set of data packets at exactly the same time.

The ACARS data is irrelevant, I am not in any way suggesting there is data post the 1:20ish loss of comms and transponder. The relevant point is, the earlier statements in the thread that MAS did not use Satcom for their ACARS are clearly not correct. It may well be true that MAS did not subscribe to RR or Boeing monitoring service - but that is irrelevant to the loss of this aircraft.

[BOAC]

It would still be useful to know what data was being sent from Acars via SAT as there should be no reason why the data should stop at loss of comms - that I can see. Eg if any nav data................?

[Ian W]

ITU involvement in Aircraft Tracking

ITU to assist in real-time monitoring of flight data

ITU Membership calls for development of standards for aviation cloud

Geneva, 25 June 2014 – ITU has established a new Focus Group on Aviation Applications of Cloud Computing for Flight Data Monitoring. The group will study the requirements for the telecommunication standards to enable an ‘aviation cloud’ for real-time monitoring of flight data, including those for the protection, security and ownership of flight data and the technical mechanisms and policies to govern access to these data.
The formation of the Focus Group comes in response to the call from the Minister of Communications and Multimedia, Malaysia, Mr Ahmad Shabery Cheek in March 2014 urging ITU to develop leading edge standards to facilitate the transmission of flight data in real-time. Subsequently, an “Expert Dialogue on Real-time Monitoring of Flight Data, including the Black Box – the Need for International Standards in the Age of Cloud Computing and Big Data”, held in Kuala Lumpur, 26-27 May 2014 with the participation of airlines, aviation bodies, avionics and ICT companies, service providers, civil aviation authorities, the International Civil Aviation Organization (ICAO) and other international organizations, issued a communiqué outlining a roadmap for the way forward.
Participation in the Focus Group will be open to all interests, including non-members of ITU, and it will work in close collaboration with ICAO, ICT solution providers, aircraft manufacturers, airlines and other standardization expert groups.
ITU Secretary-General Hamadoun I. Touré said that the call from Minister Shabery for an international effort to find solutions to monitor flight data in real time has been given top priority by ITU and its Membership.
“ITU has a long history of developing international telecommunication and ICT standards, policies and regulations and is offering to bring this competence to assist aviation,” said Malcolm Johnson, Director of ITU’s Telecommunication Standardization Bureau. “I applaud our membership for the urgency with which it is addressing this issue by responding so quickly to Malaysia’s call for ITU action.”
The new Focus Group will study advances in cloud computing and data analytics to develop use cases for the application of state-of-the-art data analytics and data mining techniques in real-time. It will develop technical reports to provide the foundation for standards-based aviation clouds. In close collaboration with ICAO, the envisioned reports will address questions surrounding the type of data to be transmitted and the periodicity and reliability of its transmission, as well as the mechanisms to enable data security and privacy and the prevention of data misuse. The reports will be the basis for the development of telecommunications standards providing security and providing interoperable and secure aviation cloud systems.
Note to the editor: ITU-T Focus Groups are formed in response to immediate ICT standardization demands, charged with laying the foundation for subsequent standardization work in membership-driven ITU-T Study Groups. Focus Groups are open to organizations outside ITU’s membership and they are afforded greater flexibility in their chosen deliverables and working methods.
For more information, please contact:
Sanjay Acharya
Chief, Media Relations and Public Information, ITU


See ITU to assist in real-time monitoring of flight data

[Ian W]

I am wondering what other people think about the involvement of the ITU when the ICAO, RTCA, EASA, ARINC/SITA INMARSAT/Iridium, are already heavily involved and have experience of aviation requirements and knowledge of existing systems, communications and standards.

ITU may also be less aware of the niceties of CVR issues and FOQA data.

[MG23]

I'm guessing this will somehow involve X.25, sixteen layers of different protocols on top of each other, and about a billion configuration options where any misconfigured option will prevent you from talking to anyone else.

[Ulric]

I agree. I think it is highly unlikely that a ping coincidentally occurs at the furthest westerly extent of the track.

[Ornis]

From the website:

About ITU. ITU is the leading United Nations agency for information and communication technology. For nearly 150 years, ITU has coordinated the shared global use of the radio spectrum, promoted international cooperation in assigning satellite orbits ... ITU is committed to connecting the world.

Nearly 150 years doing what? ITU was founded in Paris in 1865 as the International Telegraph Union.

Sounds to me like more empire building from the UN, using an "excuse-me" from Malaysia.

Surely private communication companies can come up with straightforward solutions acceptable to ICAO and airlines that meet ITU approval (if needed).

[AreOut]

me too, I'd put it some ~200 miles lower

[FE Hoppy]

The ITU have responsibility for anything the transmits in any spectrum. ICAO the UN, BT or the BBC all work to ITU standards. So the ITU will define a new standard for a new data transmission regime

[cribbagepeg]

ITU, satcom and ACARS

ITU is a UN body funded by countries hosting the major players in their sphere of influence, with lobbying by those players aimed at preserving their monopolies or at least dominant positions within their respective industries. In this case, I suspect the satcom carriers and perhaps a/c nav equipment providers would be the major forces. Follow the money.

Satcom LINK management, as outlined very early in this very large body of comments, uses "pings" to set up and maintain said link between the a/c and ground. A link to an a/c may be used to carry communications under subscription agreements between that a/c's operators and the satcom provider.

The takeaway summary: satcom link messages exist without ACARS data messages, the latter being subject to subscription payments. Please don't conflate the two.

[IanWorthington]

I'm guessing this will somehow involve X.25, sixteen layers of different protocols on top of each other, and about a billion configuration options where any misconfigured option will prevent you from talking to anyone else.

Could be worse, they could get SITA involved.

[FoolsGold]

I remain confused as to ACARS and Pings

ACARS is, I believe, a maintenance information collection and transmission system. The next stop will have manuals open to the correct pages and spare parts close at hand and appropriate test equipment since they have received information as to what systems have reported error states en route. Reports go to the cockpit after a one minute suspense window that groups them by priority.

A "Ping" is merely an electronic handshake at the network level and does not mean anything at all about intending to transmit information or expecting to receive information; it is simply confirmation of the existence of a network connection.

Now for some reason the Carrier did NOT pay to have its ACARS data sent via satellite so the question for me is: Why would anyone try to disrupt the ACARS system if it was known that the Carrier did not pay to have ACARS data transmitted. Does such an attempt to disrupt the ACARS system indicate lack of familiarity with the carrier's operations?

[BuzzBox]

Two points:

First, ACARS is not simply a 'maintenance information collection and transmission system'. Broadly speaking, it is a communications and reporting system that is used to transmit all sorts of information to and from the aircraft. That information includes maintenance and systems data that is sent automatically by the aircraft to the airline and airframe/engine manufacturers. The system is also used by the crew and airline personnel to send operational information to and from the aircraft, including operational messages, weather reports, NOTAMS, flight plans and ATC clearances, etc.

Second, although there has been speculation here on PPRuNe that MH did not pay to have ACARS data sent by satcom, I don't believe that has been verified. Indeed, the Malaysian Ministry of Transport's MH370 Preliminary Report states:

'It was later established that the transmissions from the Aircraft Communication and Reporting System (ACARS) through satellite communication system occurred at regular intervals starting before MH 370 departed Kuala Lumpur, Malaysia at time 12:56:08 MYT and with the last communication occurred at 01:07:49 MYT'.

That report seems to indicate that ACARS transmissions were sent via satcom.

Position information is sent automatically by ACARS together with the engineering data. The crew would not necessarily know whether that information was being sent by VHF or satcom. If MH370 was the result of a deliberate act to make the aircraft 'disappear', then I would think the culprit(s) would make every effort to disable any systems that could transmit its position.

[porterhouse]

then I would think the culprit(s) would make every effor

making "every effort" doesn't necessarily equate with succeeding.

[Hyperveloce]

BTO values in the communication log

From the communication log, I get the following BTO values
TimeBTO=[0 12 13 25 37 118 191 251 311 371 461]; % min from 16:30
BTO =[14920 14940 14920 15200 15600 12500 11500 11740 12780 14540 18040]; % µs
and applying the BTO formula (1) page 54 of the ATSB report, I get the following ping ring radiuses:
PingRad =[2243 2241 2238 2267 2309 1904 1758 1798 1953 2194 2621]; % NM
and the following elevation angles:
ElevAng =[46.72 46.76 46.81 46.27 45.48 53.10 55.87 55.12 52.17 47.63 39.70]; % degrees
(I have also generated kml files for these ping rings to compare visually with those of the figure 18 of the ASTB report)

Do you get similar values ? (radiuses and elev. angles). They seems to differ from Duncan Steel's.

[jimjim1]

ACARS data

BOAC mentioned:-

It would still be useful to know what data was being sent from Acars via SAT

Perhaps ...

I seem to recall reading on pprune that the engines were leased from RR (power by the hour?) and that RR used ACARS for engine data. Perhaps RR paid for satellite acars for their data?

There would likely be engine start messages, who knows? Once in the cruise no more messages due to stable engine operation?

I forget now, is there some evidence that the satellite acars was turned off or disconnected leaving the bare satellite terminal doing its ping thing? I vaguely recall that there is. Presumably fuel exhaustion would generate some engine acars messages but none were received.

So many questions, so few answers.

[matkat]

My knowledge of engine health monitoring is a few years out of date but IIRC the engines were reporting continuously from start to shutdown, would expect RR to have a similar system however I fail to see what good this would be as they only transmitted engine useage/health monitoring parameters but no positional data.

[Ian W]

Before the hamster wheel spins up again - this was all discussed earlier in the thread and discounted.

The engine health monitoring to Rolls Royce and the aircraft health monitoring to Boeing via ACARS were both inactivated with no subscription paid. There was no subscription for any ACARS activity over SATCOM only over VHF and that was routine 30 minute reporting the last of which was at 1.07. The only reason that the SATCOM was operative at all was the SATCOM phone facility was still available.