An article published in Aviation Week on 20 October 2014, contains an interesting look at the continuing saga surrounding the original Inmarsat data. It compares that data with that released by the Malaysian MoT, the continuing reassessments being made by the ATSB on where to search, and the conclusions of the so-called Independent Group who have continued to point out the errors they claim have been made by the ATSB's panel of experts.

Links in the article will show that the movement in the ATSB priority search area has always been in the direction of the location that the IG have been promoting.

The ATSB's MH370 Flight Path Analysis, which is a PDF file.

The nature of the data leads to uncertainty here. I believe the ping arcs can be established with good certainty - many have repeated the calculations - but these only establish the distance from the satellite at the times of the pings. To establish a position on the final arc requires assumptions to be made and in particular, assumptions about the position and timing of the final turn south. The movement of the priority search areas over time thus reflects changing support for the various assumptions which could be made. Sadly, the hard data does not favour one assumption over another and so the range of possible endpoints is very wide indeed. At the moment, the Independent Group clearly has the floor and the search area seems to have moved to match the assumptions which underlie their calculations.

To highlight your point; the assumption that the aircraft remained at a constant altitude during the unanswered satphone call between 1839~40, is really what everything hinges on. If it was climbing, then a turn to the south hadn't occurred prior to that time.

It all hinges on the path taken between the 18:29 and 19:40 arcs. One crucial question is which direction the aircraft was travelling in when it crossed the 19:40 arc - E-W or W-E. The data doesn't tell us the answer to that.

mm43,

Agreed, except that in your last sentence "climbing" should be "descending" (approximately 2500 fpm at the speed and heading at the end of the primary radar trace).

Gysbreght,

If the aircraft had maintained the assumed PSR track, I accept your RoD. OTOH, think of a heading on which it could have been climbing.

As Ulric has said, we really can't be sure where the aircraft went after 1829 and until it turned up 'somewhere' on the 1940 arc. That 'somewhere' makes all the difference to the outcome.

Exactly right. Some views I've seen expressed put the 19:40 arc at the western extremity of the flight path, some have it crossing EW and some WE. The data we have doesn't distinguish one from the other but the assumption you make at that point can cause any plausible course solution to move the endpoint thousands of kms.

I have to admit defeat and hope that the investigation team have followed the right hunch. Hopefully, they do have some information which can be used to favour a particular path.

We can take the view that the final major turn is bracketed by the 182815z observation and the cluster corresponding to two telephone call attempts around 1840z. The BFO for the latter has azimuth solutions to the south, whereas a risk analysis for the former provides strong support for flight continuing along on the track as it existed at 182212 depicted in the Lido Hotel radar photograph.

A game of overfitting rapidly ensues if an additional turning point is assumed to have occurred between 1840z and 1941z.

map
 

Is there an up-to-date map locating the relevant timepoints in the flight sequence?
I know these maps continue to evolve..........

Gysbreght, any azimuth solution very close to due south will be numerically unstable where very small speed changes cause relatively large azimuth changes. Azimuth solutions are essentially symmetric about north/south, with a small latitude-dependent phase shift that depends also on the flight path angle in non-level flight. A prime example of this instability can be seen in the 1827z BFO cluster.

Solutions in general are not due south. For example at 1941z the choices are about 30 degrees either side of south at normal cruising speeds.

See http://www.aqqa.org/MH370/models/aqq...muth_v3-5.xlsx for an analytic azimuth model.

I find it increasingly hard to believe that the plane will be found using the Inmarsat data in the public domain. There are too many unknowns in the publicly released information, and these unknowns create a myriad of potential solutions such that the search area is huge. We had a much better idea where to find AF447 and the Titanic.

I sincerely hope authorities are in possession of more information than has been released to the public.

I had always been struck by the early US government statement that the plane flew for hours and likely crashed in the Indian Ocean.

Have a look at the following:

MH370: US sends ship to Indian Ocean on new ?indication? of crash site | euronews, world news

So by 1051 (CET) on 12/3, the US was stating they had indications the plane flew on for some hours and went down in the Indian Ocean, and were already moving a USN ship. Subsequent reports confirmed these indications were the hourly satellite pings. This report would have been early in the day in the USA. The fact they had already moved a ship means they had this information for at least some hours - possibly even 11/3

http://www.inmarsat.com/news/malaysi...tails-uk-aaib/
Malaysia sates they were told (by Inmarsat) about the satellite pings on 13/3.

Now maybe Malaysia got the date wrong. Or maybe Inmarsat (UK) shared with US before Malaysia - perhaps from a concern that Malaysia was being less than completely transparent. Maybe.

Or maybe there is another explanation.

It is generally accepted satellite tracking of submarines exists. It is also accepted there is satellite monitoring for the heat signatures of ballistic missile launches (although presumably such systems would not be looking in this area). But there is plenty of satellite surveillance of the earths surface.

You also have to wonder what technology has been developed since 9/11. It is presumably possible to track a large plane by its heat signature. You would imagine there has been research into tracking aircraft, and subtracting verified flights in order to identify rogue aircraft. This would seem a sensible area to research in the post 9/11 world. Such technology would have been very useful during the many hours that MH370 kept flying.

Anyway, hopefully there is additional information available even if it is not in the public domain.

I'm sure the BBC documentary a couple of months ago went into that in some detail, but I can't remember exactly who told who what and when.

The 4 Corners ABC documentary went into this. Just double checked and it says Inmarsat privately handed over the data to it's distributor on the 11th March, who in turn passed it to Malaysia.

However, Hishamuddin dismissed the possibility that the plane continued to fly on the 13th March. He actually made a point to dismiss it. It was another two days before they abandoned the search in the South China Sea.

My money would be on poor communication and incompetence on the part of Malaysia and Hishamuddin's ever present foot-in-mouth syndrome..

RR PDA numbers
 

Have the 9M-MRO RR PDAs surfaced here? Or any difference in fuel in left vs. right tank? I ask because the IG received a 3rd hand report yesterday from someone attended a meeting in Perth on Oct 22, saying that an official member of the search team stated that one engine flamed out ~1 hour before the other. We are very skeptical, but trying to find out if anything like that has ever showed up here.

Thanks Exoixx. That fills in a few blanks. I never saw that story. Will try and find it on line.

The timing still looks very odd.

MH370 goes missing on evening of 7 March UTC, and the world knows its missing by morning of 8 March UTC. The circumstances of disappearance are highly unusual from the outset - e.g. no distress call.

Inmarsat hand the information over on 11 March UTC. 4 days later. After Inmarsat had specifically very recently looked into applying this technology to track a missing plane (as a result of AF447).

I find it difficult to believe Inmarsat took days to discover they actually had this information. Or that it would take 4 days to deduce the plane kept flying for many hours after lost contact.

Did someone at a high level (political rather than Inmarsat) sit on this for a long time? Just one of the many questions surrounding the early response to this incident.

Like you we would also be interested in such info. The short answer is no, but it would be interesting to know.

Whatever the fuel imbalance (if any) noted in the last ACARS to RR, there is no way of knowing if that was or wasn't corrected later in the flight.

Fuel Imbalance and cross feeds
 

See page 970 here: https://db.tt/4EXSNq5o for info on fuel imbalance and cross feeds.

There's no quoted Limitation/"maximum" in the manuals (whilst gross imbalance obviously isn't desirable I suspect for certification purposes the aircraft would have to be controllable one wing tank full, the other wing tank empty (e.g.holed)).

Balancing, when called for, is performed as ALSM/the FCOM 2 describes.

1. It was a weekend. Someone probably to had to go and look at the data in their time off, when the news reports already seemed sure it had crashed not long after takeoff, where it would be relatively easy to find.
2. The BBC documentary said their first thought was that someone was spoofing the system, pretending to be the aircraft. That probably involved pulling in experts from other companies to verify that it wasn't. Again, on a weekend.

So, you're probably already up to the 10th by the time everyone is available who needs to be available.

Then don't forget getting authorization to release the data and getting the report that was being handed over double checked by lawyers that nothing was going out that would be detrimental to INMARSAT. Calculations and documentation re-checking amendment and reapproval by senior management after all hoops jumped through.

I know some companies where that would take a month.