Come on, I do not understand the whole mathematical stuff involved but the handshakes are just that, one transmission for a very short time, giving BTO data which locate the arc and BFO data which tell something about the speed from or to the sattelite. This speed is a function of sattelite movement to the north or south, aircraft altitude, track, horizontal speed and vertical speed. We have an equation with one known (sattelite movement) and 4 unknowns (aircraft data).

Only during the short time of those few handshakes about 1 hour apart from each other the BFO data have to be fullfilled, not for the whole time of the flight. The flight could do circles in between, as long as it reaches the corresponding BTO arc at the next handshake and fullfills the respective BFO data. On what heading, speed and altitude that would take place or if the aircraft is climbing or descending at that very moment is not shown by the data.

Your computation assumes again a given track and a given speed and the computed vertical speed not only for the respective time of the handshake, but over the complete flight. It is the assumption that it was flown on autopilot with one fixed final target until end of the flight.

Yes - the page numbering goes from 92 to 94. There does seem to be a missing page as the para at the bottom of 92 stops halfway through a sentence.

I've just read all the ATC transcripts in the report.

The lack of action and confusion as the events unfolded would be comical if not so serious. All concerned appeared as "rabbits in the headlights" and thus laid down protocols went out of the window.

Why did the Vietnamese wait over 15 minutes before querying the Malaysians as to the location of MH370?

Why did ATC not declare an "uncertainty phase" as per their own laid down procedures?

Why was "aircraft overdue" not declared 30 minutes after the IGARI estimate?

When MAS ops failed to get a response to their ACARS messages what did they hear when they called the aircraft via Satfone? Was it ringing, busy or unavailable?

When they called again a few hours later what did they hear? And, by then, were the SAR team aware MAS ops were able to try to call the aircraft.

More questions than answers I'm afraid...

At an early stage in this sad affair, much was made of a statement by a Malaysian official (the PM possibly?) that the SSR and ACARS systems were deliberately switched off from on-board the aircraft. Later on, something similar was said about the inflight entertainment system.

I'm not seeing any of those statements in this report. There's a reference to how the transponder could be switched off, but not that it was, only that the aircraft dropped off SSR.

Similarly I see a reference to the IFE not logging on to the SATCOM system late in the flight whereas it had previously, but not that this was the result of deliberate action.

Am I missing something in the 500+ pages? Is there something buried in the logs that I don't understand?

I believe this exercise has been done by Inmarsat as part of the work to validate their calculations. I'm not sure now whether I read it in an official statement from the investigation team, from Inmarsat or the independent group coordinated by Duncan Steele. Nevertheless, the data does exist and has been used to discriminate between northern and southern routes.

PS: Inmarsat's own statement - http://www.inmarsat.com/news/malaysi...tails-uk-aaib/

True, but the time of the handshakes was reset by external events a couple of times. Expecting any spoofing attempt (manual or pre-programmed) to take account of that pushes the limits of plausibility.

No Flight ID was present
 

On the page numbered 53, point #4 says...Is this normal after a logon, or perhaps a power interruption? I would have thought that the flight id was available from AIMS?

Pay to fly
 

The report seems, in my view, critical of the FO.

Page 80...
and...

On page 14 we are given the FO's experience...
Pay to fly?

You may have missed the point, I'm not talking about spoofing the data nor assuming that the datas have been spoofed. Whoever was part of the disappearance of Mh370 knew nothing about those data as the rest of the world didn't know either.

All I'am saying is, that the southern arc is one interpretation of the data, even a highly probable one, but it is not an exclusive one as others have stated. The conclusion for the southern arc as the most probable track relies heavily on the assumption of near constant track, near constant altitude and near constant speed, simplified on a flight to a preset target in the south flown by autopilot.

No, it doesn't. Although some reconstructions have been based on those assumptions, that statement is not correct. After 18:40 UTC all BFO values indicate a southward component of groundspeed if one assumes level flight. They also show a smooth progression, increasing almost linearly with time. To support a northern route it is necessary to assume that the airplane was climbing at approximately 3500 fpm at the times of all six 'handshakes' and two 'unanswered ground-to-air telephone calls'. During the first unanswered call at around 18:40 86 responses were received from the aircraft during approximately one minute, all with BFO's of 88 +/- 2 Hz.

A flight at a constant speed South on autopilot fits the INMARSAT data. Data which as you say probably nobody in the world knew was available.

The alternatives, orbits crossing the distance ring (which you did not know about) at precisely the right time at precisely the right velocity (ground speed/track/climb corrected for winds) to look like an aircraft that was on a consistent southerly heading. Yes - it is possible. I challenge anyone to do it.

The problem I see is not overtly modeling all the other 'ideas' and showing where they fall down. If instead of repeatedly reassessing the one path, someone had set up a relatively straight forward computer model to vary the assumptions made within their possible limits and falsify (disprove) these alternate ideas. There might be a small family of possible tracks that would work. However, looking at the 'search area' which is very imprecise, I think that it may have been defined by an approach of varying the assumptions within their feasible limits, plus uncertainty due to error.

I have a feeling we will eventually find out.

Yes why not blame the controllers for not responding immediately to a routine event as if it was an emergency.

All controllers have had aircraft handed to them that do not call. It is not a startling event, in some instances such as crossing from oceanic to en-route airspace it is relatively normal to get a delay. SSR responses drop out and return to the extent that many ATC computer systems 'coast' a pseudo response to show the controller where the aircraft should be if it continued on its previous vector (some even turn that coasting response at waypoints).

So it is 1am on a quiet weekend night and an aircraft handed off drops off your radar. Not your problem - you handed it off. The receiving controller gives it a bit then buzzes you and says hey MH370 has not called me, is he still with you? You call, (it's not your problem really) and no answer. No he's not with me. END. The aircraft was handed off and not in my airspace. Yes the controller could have alerted people but they would have said where is it - it's in Vietnamese airspace and they know about it - why are you telling me then?

All these hindsight ideas of how controllers _could_ have responded are just that. About as useful as comments on how pilots _could_ have responded.

I hope that what this incident leads to is a far more rigid approach to aircraft dropping out of surveillance contact. The only way that things would have been different is a full scale emergency response when surveillance is lost. But remember that this is such a routine occurrence that coasting is built into ATC system software, so it will need to be very carefully done. I suspect that ADS-C SATCOM and VDL2 (VHF Data Link) will be mandatory for commercial aircraft within 5 years with continual ADS-C SATCOM at a 4 minute update rate (that supports RNP-10). Then when ADS-C SATCOM from an airborne aircraft stops reporting a full scale emergency will be declared.

However, in MH370's case would that have helped? Only if the military primary radars had immediately started tracking the aircraft. But what then? They see the aircraft out into the Indian ocean going West. No-one has interceptors on alert that would be able to fly into the Indian Ocean. Then outside primary radar cover MH370 turns South. And from then on we are where we are now - but without the search of the South China Sea.

Now that a factual report has been released, we can at least focus on it.
I find the following timing sequence of particular interest.

UTC

1701:43 a/c at 34998ft
1706:43 a/c at 35004ft
1707:56 with over 12 minutes to run to IGARI, crew report level at 350 without previous ATC instruction to report reaching or when level.
1708:02 ATC response instructing to maintain level.
1719:26 8.26nm to IGARI ATC release a/c
1719:30 a/c acknowledges
1720:31 a/c at IGARI
1720:36 MODE S off
1721:13 a/c drops off primary radar, turns left and then right before commencing descent and increasing speed.

It is inconceivable that between 1720:30 and 1721:13, in 73 seconds, a failure of all electronic/electrical systems may have ocurred so as to render all communication systems and life support systems inoperative and yet allow the aircraft to execute two turns before descending and continuing to follow a diversionary routing, towards an area outside all radar coverage.

Ian W

Having spent a lot of the last 12 years going back and forth over IGARI (4 years B772 and 8 years B744) I'm well aware of the ATC set up and their capabilities. I am very surprised that no "overdue" action was taken..

Chronus,

Quite obvious really, the autopilot is also knocked off so the a/c is randomly roaming the skies after the single mechanical failure event.

@ Chronus: "It is inconceivable that between 1720:30 and 1721:13, in 73 seconds, a failure of all electronic/electrical systems may have ocurred so as to render all communication systems and life support systems inoperative and ....."

Some kind of outstandingly & extraordinarily different fault has to rise which could be 1 in 1000 - some thing that aviation industry encountered first time !

Or else, some one "forced" that fault ............. either in MAS ..... or in cockpit ...... or perhaps under the cockpit.

Goodness knows, there are so many questions that have been asked, discussed, and discarded. One that has consistently been on the forefront of my mind is why, that after one year, not one piece of the airplane or the contents therein have been seen or recovered. Yes, the oceans of the world are big, but sooner or later, they return things to land, somewhere.

Ian W If we assume that the disappearance was deliberate by person unknown, then after 1 year of not finding one single scrap from the aircraft, one can also assume that whoever did so was aware. He would have gone through every possible scenario of a search operation. So far he has succeeded.

I don't believe there's any way to tell for sure why the IFE didn't connect to the ground after the final SATCOM logon to the satellite. It could be the aircraft was out of fuel and the IFE had no power. It could have failed. It could have been turned off. The aircraft could have hit the sea before the IFE noticed the SATCOM connection was up and set up its connection to the ground. All that's known is that it didn't connect to the ground after the final logon, and didn't explicitly disconnect from the ground before that.

MH370 report: Underwater locator beacon battery had expired

Locator beacon battery had expired over a year before departure.