Search crews in the remote southern Indian Ocean have completed a task so vast and technically ambitious that it once seemed impossible: to scan a three-mile-deep, 120,000 sq km swathe of seabed using a side-scan sonar “towfish” in hopes of finding the wreckage of missing Malayia Airlines 777 MH370. After considerable delay due to mechanical problems and bad weather, the final square miles were scanned on October 11 by the research vessel Fugro Equator. The $180 million project turned up no trace of the missing plane, though searchers did find several long-sunken sailing ships.
The Fugro Equator will next use an AUV, or autonomous sub, to scan selected areas where the rugged seabed topography was too rough for adequate imaging by the towfish. “The total combined area of the spots that will be surveyed with the AUV is very limited, but still required to ensure that no area has been missed,” says Fugro spokesman Rob Luijneburg.
The Australian National Transport Board (ATSB), which is overseeing the search, expects this fill-in work to be completed by the end of February.
The fact that that the Pennsylvania-sized towfish scan had been completed was first noticed by Richard Cole, a space scientist at University College London who has been meticulously logging the search ships’ movements via online tracking services and then posting charts of their progress on Twitter. “At the completion of Equator’s last swing in mid-October the target of 120,000 square kilometers had been achieved, at least as far as my calculations show,” Cole wrote me last week. Both Fugro and the ATSB subsequently confirmed Cole’s observation.
The 120,000 sq km area has special significance in the effort to find MH370, because ministers from the four countries responsible for the search have made it clear that if nothing turns up within it, the search will be suspended. Unless new evidence emerges, the mystery will be left unsolved.
Plans to search the seabed were first mooted during the summer of 2014, after officials realized that metadata recorded by satellite-communications provider Inmarsat contained clues indicating roughly where the plane had gone. At first, investigators were confident that the wreckage would be found within a 60,000 sq km area stretching along the 7th ping arc from which the plane is known to have sent its final automatic transmission. When nothing was found, ministers from the four governments responsible for the search declared that the search zone would be doubled in size.
In December, 2015, officials declared that the search would be completed by June, 2016. In July of 2016, Malaysia’s transport minister indicated that it would be finished by October; weeks later, a meeting of the four ministers pushed the completion back to December. Last week, the Australian Safety Transport Board announded that “searching the entire 120,000 square kilometre search area will be completed by around January/February 2017.”
In an email to me, ATSB communications officer Dan O’Malley said his organization will issue a report on the seabed search once the full scan is completed. Under ICAO guidelines, Malaysia will only be obligated to release a comprehensive final report on the investigation once it has been formally terminated; so far, Malaysia has only talked of suspending the search, not ending it.
The bulk of the work has been carried out by ships pulling a sidescan sonar device on a long cable. This so-called “towfish” uses reflected sound waves to create an image of the sea floor. By sweeping up and down the search zone in much the same way that a lawnmower goes back and forth across a lawn, searchers have been able to build up a comprehensive image of the search area’s bottom.
But, just as a landscaper might have to use a weedwhacker to clean up areas around rocks or stumps, searchers will have to fill in gaps in the scan where underwater mountains, volanoes and escarpments have prevented the towfish from getting a close enough look.
“A total area for search by the AUV is difficult to give because it concerns a number of relatively small spots that all are relatively difficult to reach and in difficult terrain,” Luijnenburg says.
The fill-in work will be carried out by an Autonomous Underwater Vehicle deployed from the Fugro Equator. The Kongsberg Hugin 100 is capable of diving to depths of up to 15,000 feet and can maintain a speed of 4 knots for up to 24 hours before being retrieved by the mothership. Whereas the side-scan sonar of the towfish has a resolution of 70 cm, the AUV’s sonar has a resolution of 10 cm, and so can image the seabed in much greater detail, as well as taking photographs when necessary.
Meanwhile, as the AUV work progresses, a Chinese vessel will deploy an Remotely Operated Vehicle (ROV) to take photographs of targets previously identified as being of interest. The ATSB has stated that none of these targets are “category one” targets, namely those likely to have come from MH370, however. Says Cole, “In the absence of category one targets there must be a list of targets from the sonar search that look the most interesting, so the question is how far down that list they are going to go.”
While the fill-in work must be carried out in order for the work to be declared 100 percent done, little prospect remains that the missing plane will be found in the southern Indian Ocean.
NOTE: This story was updated 10/26/2016 to include comments from Fugro spokesman Rob Luijnenburg.
@Richard Cole
Good news. Only north around 34S they’ve been searching allready.
Won’t they mean north around 32S?
@Richard Cole, Thanks for the link. I wouldn’t be so quick to assume that this proposal will be approved; this kind of extension seems to be exactly what the tripartite announcement about the suspension of the search seems intended to forestall. Unless new information has come to light that they haven’t told us about.
There is no analytical basis for searching in a new area. Based on the mention of the 34th parallel, and the relatively small proposed budget, I suspect that their plan might be to finish searching out 15 nm or so from the 7th arc up to the “100 % confidence” point, as described in an earlier post: http://jeffwise.net/2016/09/08/commentary-on-neil-gordon-interview/
The odds of this being successful are really low. My hunch is that the main motive behind keeping the search going is simply to delay the admission of defeat.
@Ge Rijn
I guess we have to see how wide and how deep the new search area will be. Sounds like it will be an extension of the northern part of the current searched area up to 33S, plus some new area north of that. The (modest) price of 30M AUSD suggests a total area well short of 60,000sq.km.
Worth noting the “back to first principals” meeting of experts. Of course, if you use the same experts, and the same data, you’re likely to arrive at the same conclusion. However, if they are willing to radically revise their assumptions, I wonder how far they’ll be willing to go. To abandon the assumption that the plane was traveling south at 18:40? To abandon the assumption that the BFO data is unimpeachable?
@Jeff
The promised report will give the detailed basis of the proposal. We can judge if it is believable.
I don’t think it would get this far in the Australian system if it were to be slapped down by Australian politicians, that’s just causing embarrassment. It might fail at the international level, which would be out of Australian political control.
@Jeff
Do you mean unimpeachable BTO data?
@Richard Cole
Yes, we also don’t have new information they probably have.
If this information is worth a 30 Million it has to be very good new information IMO.
There is still no conclusive anwser (to the public at least) if the outboard flap was retracted or deployed f.i.
Something like this would make a huge difference.
Hope to see a report soon after this meeting.
@Richard, No, I mean BFO. I’ve asked Inmarsat, the ATSB and the DSTG how they can be sure that the data wasn’t tampered with, and the only answer I’ve ever gotten was “we’ve worked with what we were given.” This seems a major oversight to me.
@Jeff Wise
I probably miss something here but wasn’t it Inmarsat who delivered the BTO and BFO data straight from their own computers?
I mean they were not ‘given’ to them?
@Ge Rijn, I don’t doubt that Inmarsat passed on the true BFO and BTO values that they recorded. The question is: how does Inmarsat know that hijackers didn’t tamper with the SDU so as to generate misleading BFO values? Recall that when Najib announced in March 2014 that the plane had certainly gone south, the BFO values were the only evidence to that effect. But these values were generated by an SDU that was known to have undergone a very unusual change of state (either powered down or logged off and on for some other reason) at a potentially significant moment (right after leaving primary radar coverage).
Later, Victor Iannello suggested that the observed BFO values could be generated by a plane flying north if a single parameter (satellite inclination) were changed in the SDU’s internal log. Research by Victor and by Gerry Soejatman suggested that the possibility of BFO spoofing in this manner had been widely known within the satcomm industry. And Michael Exner, himself a satcomm industry veteran, has said that a spoof would not be technically difficult. It seems to me fairly obvious that under the circumstances the integrity of the BFO values should at least be examined. Yet the ATSB has never acknowledged the existence of the issue at all.
Let me add that when I asked Inmarsat how they knew that the data was good, they said that they were satisfied because when they did their math, the numbers worked out. But I see evidence that the numbers don’t “work out.” That is to say, there are several ways in which the BFO values may be problematic:
1) Flight path analysis based on BFO error minimization puts the plane winding up north of Broken Ridge; analysis based on BTO alone puts it significantly south of Broken Ridge. Thus in this sense the BTO and BFO values don’t match well, as they should if they were generated normally.
2) Search officials have long said that they cannot make sense of certain 18:25 BFO values.
3) The 18:40 BFO value now appears to have been misunderstood as well; if the plane really were heading south at that time, it should have been found by now.
4) Ditto for the 0:19 BFO value.
@Jeff Wise
Clear. In that way the data were ‘given’ to Inmarsat too indeed. And you don’t suspect Inmarsat of tampering with those data.
I well remember your thoughts and articles on possible tampering with the BFO-data.
I am in no position to say anything substantial on this possibility (by lack of knowledge) but I take it from you and the experts you name, it is possible.
I only have an own opinion on the connection made to the last radar-contact at 18:22 and the start of the re-log-on sequence just ~2 minutes after.
IMO those events hardly can be related by a timed spoofing.
There is no way a pilot or anyone on the plane could have known exactly when they were out of radar-range. And this was only one radar-station (Butterworth)..
There are no radar-detection systems on the plane.
So IMO a spoofing of the SDU timed to log-on so shortly after out of radar range cann’t be related. Just my opinion.
The re-log-on at 18:25 and the sudden ‘out of (Butterworth) radar range’ at 18:22 must be related IMO too, but in a different way.
@Ge Rijn, You wrote, “The re-log-on at 18:25 and the sudden ‘out of (Butterworth) radar range’ at 18:22 must be related IMO too, but in a different way.” And what that might be?
I should point out, btw, that if the highjack of MH370 was accompanied by a BFO spoof, then it was pulled off by someone with state-level resources, for whom the disposition of primary radar surveillance would be a trivial matter.
@Paul Smithson
I wouldn’t put too much reliance on the Malaysians turn back trace. I don’t like making light of such weighty matters, but it looks as if one of them got their pet spider to do the graphics.
@Jeff Wise
We are cross-writing 😉
As I see it, flight paths based on error minimization are the more valuable ones.
The other flight paths are based only on auto-pilot constraints.
What I understand they took an overlap of both but with the basic assumption it must have been a complete ghost flight after FMT.
I have the opinion it’s there where they went ‘wrong’ basically.
It was by far not the most logical assumption IMO (as I stated here often as you know).
Clearly those BFO values leave quite some room for interpretation.
What I read (and understand) about it they can mean a turn, a steep descent or a spoof.
Then there are two different kinds of communication involved from different channels.
The ‘pings’ and the two SATCOM-calls which make it even more complicated IMO.
I personally rely more on the debris finds and the drifter based drift-data now.
To me they just confirm MH370 went down in the SIO and at least north of 35S around the 7th arc (+/- 100 miles).
And with the ending of this search it must be north of 33S and probably more north/east till at least 30S IMO.
The 00:19 BFO’s in this regard can mean a steep turn and ’emergency’ descent leveling out the plane at lower altitude.
IMO it can mean a lot of things.
Otherwise there would not be so much discussion about them I assume.
@Jeff Wise
‘And what that might be?’
IMO a sudden disapperance from Butterworth radar at the edge of their range can only be caused by a fast and steep descent where the plane dived under their radar-horizon.
I speculated about a possible cause for such an event some (long) time ago.
You know it’s a wild one but I guess you are used to them by now.
To repeat this scenario..
The plane was shot at by the Malaysian Airforce just before out of radar range at 18:22.
The left engine was taken out forcing it to make a steep descent disappearing from radar suddenly.
Left engine IDG not longer available triggered the log-on.
The jets had to return to base due to range limits and could not verify if the plane was brought down.
The plane flew on for a while with a burning engine (the plane Kate Tee saw?). Though the engine fire went out later.
The pilot/hijacker confronted with a failed mission chose to devert the plane to the SIO into oblivian. It flew on on lower altitude ~25.000ft on one engine. Crashing north of the current search area.
Events like this would certainly be embarrissing to the Malaysian military and government also.
Oke, my fantasy probably is on the run with me again.
But point is something critical happened around 18:22 and just after.
But IMO it was not a spoof.
@Ge Rijn, Of course, the mystery of the 18:22 radar return isn’t just why it disappeared at that point, but why it appeared having vanished over Pulau Perak 20 minutes before.
To add to this.
Statements of the Malaysian government the plane was not regarded ‘hostile’ when it passed over their peninsula can not be taken serious IMO.
These would be ridiqulous statements given by any government. And for that, they are not believe-worthy by any means.
They just lie IMO.
They try to cover-up a serious failure.
They try to cover-up the truth to save their asses.
It’s always the the same in those dictator/semi-democratic states.
@all
The news story also says Malaysia Airlines may give NOK lawyers access to many airline records. Presumably we’d here still be on the outside looking in.
As far as search, they seem to be talking about the area where the Dong and Furgo are now. Finding something there?
@Jeff Wise
Oke I’m on it now. This gap is also a very strange artefact I agree.
Maybe also a dive under the radar. He wanted to take a look on the island once more as with Penang?
Unexplained. Where was the plane in those 20 minutes? IMO it must have descended quite low to get invisible to that Butterworth radar and ascent steep after this to get visible again.
It’s just a mind-boggling mystery still.
We need more clues/evidence.
@TBill
One thing I’m almost sure of blogs like this (like Jeff Wise) and sites like Duncan Steel (and others sure) are read by officials connected directly by the search. It gives a chance to influence their perception.
And I believe it does over the years.
It’s something like the Bellicat-group doing internet-research on another level but still a bit the same in a way.
To me it’s not just responding to Jeff or anyone on this blog.
To me the more importance of it all here is to show awareness people are dedicated and very critical -with arguments- to find a solution to this mystery.
To add to the relieve of the victims of this tragedy in a way.
It may be hard to them sometimes to read all that gets written here.
But for me and I guess for most of us this is the goal: clear anwsers to the victims.
JeffWise said: “mystery”…”of the 18:22 radar return isn’t just why
it disappeared at that point, but why it appeared having vanished over
Pulau Perak 20 minutes before”
Are you referring to the Lido graphic? because the markings, in fact,
don’t vanish “over Pulau Perak”, but quite a way beyond it.
@buyerninety, No, I feel that it is unwise to base any analysis on the Lido image, which was never endorsed by any search officials. Nobody knows where it comes from or what it is supposed to represent (though some obvs have their theories.) Instead, I am going on the description of the primary radar data provided in the “Bayesian Methods” paper.
My assumption is that the investigators are smart, competent people who understand the technical details of the case and have access to all data. Where I think they might have gone wrong is in the conclusions they have drawn from this information — though not unreasonably so. But if they tell us, for instance, that there is no autopilot roll mode that will deliver MH370 north of 33 deg S from a final major turn before 18:40, then I see no reason not to believe them.
Likewise, if they say that there was no primary radar trace between 18:02 and 18:22, I will take them at their word.
Jeff,
“Of course, the mystery of the 18:22 radar return isn’t just why it disappeared at that point, but why it appeared having vanished over Pulau Perak 20 minutes before.”
What mystery? What radar return are you talking about? It seems you are permanently lost in your pet theory.
@Ge Rijn, Your post above. So very true. If 239 were murdered in any other way, the investigation to who did it and what happened would never stop. We (whoever fits the shoe puts it on) owe it to the victims to find out what happened and who committed this atrocius crime!
JeffWise , possibly your comments re; Pulau Perak are due to a
misremembering of the F.I. . Here is what is stated in the F.I.,
(I have abridged it slightly, to omit non relevant information):.
At 1752:35 UTC radar return was observed to be slightly south
of Penang Island.
After the last radar return disappeared from KL ATCC Primary Radar
at 1752:35 UTC, the Military Radar continued to track this radar
return as it headed towards Pulau Perak, a small island over the
Straits of Malacca. The time registered over Pulau Perak was
1802:59 UTC.
The tracking by the Military continued as the radar return was
observed to be heading towards waypoint MEKAR, a waypoint on N571
when it disappeared abruptly at 1822:12 UTC, 10 nautical miles
after waypoint MEKAR.
@buyerninety, Check out the book version of “Bayesian Methods in the Search for MH370.” On page 19: “The radar data contains regular estimates of latitude, longitude and altitude at 10 s intervals from 16:42:27 to 18:01:49. A single additional latitude and longitude position was reported at 18:22:12.” The topic is dealt with in some detail.
Obviously, the DSTG report directly contradicts the FI; I feel that it should be preferred as it is later and the FI contains numerous obvious errors.
@Oleksandr, Stop sniveling. The radar data has nothing to do with my or anyone else’s theory.
JeffWise, OK, just saw your most recent reply above.
(Oleksandr, I think it is just a mis-remembering on Jeff’s part).
Jeff, in regard to the Lido graphic, I can understand your
skepticism in regard to Lido graphic markings (which have the
appearance of ‘radar returns’.)
For myself, I have noted an unusual thing about them – that ‘gap’
area is almost a close match for what was seen when I
observed (via FlightAware) the path of many aircraft along the
Malacca Strait.
In Flightaware, in about the area of the Lido ‘gap’, aircraft
(mainly MAS, because that was what I was interested in) would
fail to display their Height/Speed details, and instead show
‘Estimated’, which I took as meaning their feed had been lost
from the input to the Flightaware receivers.
Perhaps that area (was) a bit of a marginal reception area?
NOTE – I say ‘was’, because tonight , on rechecking Flightaware,
I find that aircraft now don’t loss their Height/Speed details
there anymore. (Huh? Perhaps Flightaware have boosted or put on
more receivers, or perhaps are sourcing their feed more directly
from MAS).
@buyerninety, Note that FlightAware uses volunteer ADS-B receivers, which are different from secondary radar, which in turn is different from primary radar. So I wouldn’t necessarily infer a gap in one would necessarily mean a gap in the other — though all three will presumably get gappier the further you get from land.
@Jeff
you said:
“@buyerninety, No, I feel that it is unwise to base any analysis on the Lido image, which was never endorsed by any search officials. Nobody knows where it comes from or what it is supposed to represent (though some obvs have their theories.) Instead, I am going on the description of the primary radar data provided in the “Bayesian Methods” paper.”
I carefully laid an airway map over the area to the West of the Malay peninsula along with the primary radar data from Figure 4.1 of the “Bayesian Methods…” book and the Lido Hotel graphic. The result is as shown in the last figure of the linked blog post below. The Lido Hotel graphic lines up almost perfectly with the “Bayesian Methods…” primary radar track. Also the BFO value at 18:25:27 is in perfect agreement with the observed value of 142Hz if one assumes the aircraft took the slight bend to the North (track 296 degrees) toward Nilam at ~500 knots ground speed.
http://tmex1.blogspot.com/2016/10/bto-games.html
@Keffertje
So I hope all just go on keeping things sharp.
It only will lead to thinking twice every time, for the ones who keep an open mind, with better outcomes in the end I’m sure.
I must say this blog has done a hell of a job turning every stone till now and certainly not without results IMO.
@all
…the recent reference to the Singapore AWACS plane got me re-reading VictorI’s June post about that, and also Victor’s thought experiment re: 180 magnetic south heading.
The 180 south mag heading makes a curved path, not unlike the McMurdo path. I have to correct my prior statement… I should say there are 2 ways to get a curved flight path (with no pilot actions): (1) waypoint such as McMurdo or (2) 180 mag heading south.
Also if I hypothetically thought I was intentionally ditching a plane, letting the plane slowly descend 100ft/min to about 34S seems reasonable assumption (as Victor needed for BTO/BFO data match).
buyerninety:
“I think it is just a mis-remembering on Jeff’s part”
No, it is not just mis-remembering.
—–
Dennis:
“The Lido Hotel graphic lines up almost perfectly with the “Bayesian Methods…” primary radar track.”
Somehow I don’t find this surprising. ATSB 2014 also lines up almost perfectly with Lido image.
—–
Jeff Wise:
“Stop sniveling. The radar data has nothing to do with my or anyone else’s theory.”
I don’t have any idea what you are talking about. It it clear that DSTG was given only one point 18:22. The reason is clear to me. But it is a real puzzle why you are trying to mispresent this piece of information? What is your purpose, Jeff? Why are you twisting data, observations, etc? Especially if they don’t fit your theory? Stop trolling please.
@Oleksandr
“Somehow I don’t find this surprising. ATSB 2014 also lines up almost perfectly with Lido image.”
Yes, my observation did not add anything new. Just trying to dispel the notion that there is a residual mystery here. I think the data we have hangs together rather well as far as the track over the Malay peninsula and beyond is concerned.
@Oleksandr, It seems that lately you are becoming more and more rude and less and less constructively engaged in this conversation. You claim that I am misrepresenting information — I have no idea what you are talking about. I clearly cited the source of my assertion about the primary radar data. Nor do I have any idea what you are talking about when you talk about twisting data that doesn’t fit my theory.
I am almost out of patience.
@JeffWise
Just so you can see what I am talking about, here is a pic
I took from FlightAware of that ‘Gap’ area (in FlightAware,
representated by a flightaware track, Gap=grey part of line),
(i.e. where Height/Speed would be replaced with ‘Estimated’.)
http://www.msfn.org/board/uploads/monthly_2016_11/5818c95264614_mas186GAP8Sep16.png.5895a51eee295d4f09b332cc251ca47e.png
Please note, this was back in September 2016 – now the ‘Gap’
seems to have disappeared, at least as at date of this post.
——-
The details loss as aircraft (travelling westwards) pass roughly
directly ‘due north of WITN’ still seems to occur, no surprize
about that. (Again, grey line is loss of ‘Height/Speed’ details.)
http://www.msfn.org/board/uploads/monthly_2016_11/5818ca1e066ad_routeMAS186UTC7Sepapprox1500hrdep.png.cb14b719b30c84cb017ea3b858a472c5.png
—–
@Oleksandr, no need to start a war, there are plenty of more
major things to get upset about than this minor point, let’s
let it pass, and for forum readers, our posts above ‘will speak
for themselves as to accuracy’.
Cheers
The fact that the Malaysians only gave a single point at 18:22 to the DSTG is not sufficient reason for doubting the authenticity of the radar data shown on the Lido Hotel image. The Factual Information also makes it abundantly clear that the military have more radar data than they are willing to release for publication.
Dennis,
“Just trying to dispel the notion that there is a residual mystery here.”
Of course no mystery. We all know this. Only newcomers can get confused.
—–
Jeff,
Re “I am almost out of patience.”
Should I consider this as a warning message? You know, I don’t really care.
@Gysbreght
True. And for my last post for a while, isn’t it correct that
they omitted all height information about Penang Island, along
the area of the flight track that would actually be the descent
(and the afterward Penang ascent, in this case) phase for a
transit of the the waypoints associated with a preparation to
land? I believe they omitted that height information because it
is likely that MH370 did descend and ascend about Penang Island,
and they’re embarassed that such a low level flyby (probably
at speed, Mach 0.83 or higher) could occur without an interception
attempt by Malay Defence (which is also a low transit, close to
the area of Butterworth IADS).
Ah, if only DrB would include that in his figuring…
Here’s an example of a Penang landing descent phase, not a 777
unfortunately, but a 737…
https://flightaware.com/live/flight_track_bigmap.rvt?ident=CSN395-1476509216-airline-0093
https://flightaware.com/live/flight/CSN395/history/20161017/0915Z/ZGGG/WMKP/tracklog
Waypoints used would be ENDOR MEKAT KENDI
@Buyerninety
So the implication is (correct me if wrong) MH370 made a commercial plane “look alike” approach to Penang. We can argue about if this was due to mechanical issue or rouge intent. The suggested low altitude around Penang explains the probable FO cell phone connection to the cell tower. If foul play was the intent, we are left to ponder if the selection of MH370 to Beijing was preferred, or if it would have been easier to take a flight to the EU to save the effort of the Penang fly-by.
@Oleksandr, Yes.
@TBill:
It is easier to orchestrate a fake emergency if you have any drums and strings to play on. And what the use of all that experience and expertise if all you need is to perform a turn.
New report from ATSB, 2 Nov 2016 (download PDF)
https://www.atsb.gov.au/publications/investigation_reports/2014/aair/ae-2014-054/
“MH370 – Search and debris examination update”
@AM2
Thanks for the link.
I guess many of us need some time to digest this information after reading..
@Ge Rijn
BTW, I should acknowledge that I found a link to this pdf on Reddit.
“I guess many of us need some time to digest this information after reading..” Agreed. But my first impression from the new drift modelling (e.g. see figs 10 and 11 showing arc between approx 22s and 44s), is that the debris is unlikely to have come from this whole area which includes the current search area. So perhaps further N again or somewhere completely different.
@Ge Rijn
I took a pass through it. No surprises, really. It did not invoke any feelings of eureka. More or less reinforced what most of us have been gravitating to.
Figures 9 and 10 of the new ATSB report suggest that the favored starting locations for the flaperon and other debris are the yellow and white zones. The yellow zone extends approximately from -30 to -34 along the 7th arc, while the white zone extends from -26 to -30. (Unknown if parking is allowed in either zone).
From my report back in January, magnetic heading and magnetic track uncommanded autopilot routes (starting near IGOGU) end up around -33 to -33.6 along the 7th arc. Neither fit the BTO data as well as routes that end up further South, but both fit the BFO data better.
The route that best fits both the BTO and BFO data (constant mach but variable heading) ends up at -32.4 deg. It is close to (but not identical with) a constant magnetic heading route.
All of these routes end in the yellow zone. An error of +/- 1 degree in latitude on any of these routes would not be unreasonable.
It should be noted that, as far as we know, no one has demonstrated the actual performance of a B-777 flying for 5 1/2 hours in either heading or track mode. Further, the accuracy of the GDAS wind/temperature model is poorly known, and there are reasons to thinks the errors in the SIO are larger than what the DSTG assumed. Topic for another time.
The Lido radar data seems real enough – why were they not provided to the ATSB and DSTG? Possibilities:
1. Radar hardware was way out of calibration, and the RMAF would be embarrased to acknowledge it.
2. Radar was subject to some sort of interference that rendered the data unreliable. It has happened more than once in previous air crash investigations.
3. Somebody accidentally erased the data, and all the DSTG received was somebody measuring a point off a printout of a Google Earth plot. Think Nixon tapes.
Correction – Reference to Figs 9 & 10 should actually read Figs 10 & 11.
Re the presented analysis of the inner part of the right outboard flap.
There is no information in the report on “the outboard end” of the right outboard flap.
Why ?
The failure mode of the flap support bracket was what I wanted to see – and we get – “nothing”.
Why ?
@DennisW,
“There is really no way to know if the assumption of a constant BTO bias is a valid assumption.”
Did you write this? I seem to recall you putting full faith in the BTO. Since the logged BTO is the difference between the actual and the bias, this would seem to contradict your previous statements.
Given that I’ve been concerned about the possibility of the logged, “offset” BTO values being off by the width of a slot, and that I’ve been suspicious of the need to calculate the bias value when it was supposedly subtracted by the software at the time the value was logged (and thus known), this is an interesting development.
Please explain.