As I’ve discussed in earlier posts, by its own calculations the ATSB has already searched most of the high-probability areas of the Indian Ocean seabed in its quest to find the wreckage of MH370. The only remaining area of relatively high probability that has not been searched is a stretch along the inside the 7th arc.
(In the image above, the area that had been searched prior to the release of the ATSB’s December 3 report is outlined in black.)
Yet this is not where the search is currently underway. According to ship-tracking conducted by Mike Chillit, Fugro Discovery has spent the weeks since the ATSB issued its report searching an area 40 nautical miles beyond the 7th arc, in the pale blue “low probability” area of the ATSB’s heat map.
It’s hard to understand why.
UPDATE 12-22-2015: I was delighted to learn that Richard Cole is back on the case, paralleling Mike Chillit’s work by collecting and collating ship-movement data in order to understand what areas have already been searched. Richard has given me permission to reproduce one of his charts, which shows the situation much more clearly than my amateur effort above. I’ve outlined the area already searched in light blue. One thing I notice looking at this is that the unsearched high-probability area near 87.5 N 37.5 S hasn’t even been bathymetrically scanned yet! Click to enlarge:
Merry Christmas jeff! And to all the dedicated mh370 enthusiasts! Let’s have a grand New Year
@sk999
A delayed thanks for your prompt concise response regarding likelihood of Iridium data. This investigation suffers a lacking component of accurate information sharing and unwillingness to set the record straight when INaccurate, which has fueled frustration and flamed many wild theories. Nice to see an example of how it SHOULD work
@Matty – Perth
Enjoy the beach, free your mind of
this while you are there
@jeffwise
Merry Christmas, I agree, I think 2016 will deliver
AM2,
Much appreciated. I haven’t seen this particular doc, and it clarifies some details I was looking for.
I still think, however, there is a second solution. I will check if I am right.
Susie – I don’t think I’ll ever free my mind of this unfortunately and I continue to have a hard time believing that we had no detection. It wasn’t like 200 tonnes of plastisine, more like a giant chandelier falling. That was one a raucous and violent snap demolition, and a high energy event as Dr Duncan put it. Anyway.
The beach was splendid with a small clean wave, crystal water and even some dolphins zinging around and tomorrow I’m off further south to pretty much level with the priority area so I’ll try to get some snaps looking out that way.
@Matty-Perth
Your frustration grabbed me some months back, your gut belief consistent. Nothing like watching the faces of smiling dolphins to push the other thoughts aside. Hoping for some good pictures
@AM2 If there was a splashdown 200 miles west of Kudahuvadhoo, where would the debris go? It appears that the equatorial counter current would take it to the Southern Equatorial current, and then on to Reunion. If the debris was taken to Reunion, shouldn’t we be looking at Madagascar, Somalia and southern Africa for more debris, instead of wondering why it went there?
Stuart Yeh re-creates a scenario of a cabin fire burning through plane skin that is seen by McKay on the oil rig. Rapid depressurization incapacitates the crew. He explains the Inmarsat data. Does he make sense?
http://works.bepress.com/cgi/viewcontent.cgi?article=1018&context=stuart_yeh
Duncan and MacCauley show a possible splashdown location and time based on sonar that is about 200 miles west of Kudahuvadhoo, where there were at least 6 credible witnesses.
https://drive.google.com/file/d/0B-r3yuaF2p72X0lqWWQtZEtFRTQ/view?pref=2&pli=1
@Trip, We’ve gone over these ideas in the past, indeed have spent more time on them than they merited–none of this fits the data. Eyewitness accounts are notoriously unreliable.
@Trip: you summarize the possibilities very well, except that you’ve made the common mistake of assuming the Kuda mass-sighting and the Curtin acoustic event both could have been caused by MH370 directly. If you accept Curtin’s triangulated event position (just west of Kuda, as you say), you must accept its triangulating event timing: 00:25 UTC. This is 50 minutes before the Kuda mass sighting, seemingly established by its proximity to sunrise at 01:15 UTC.
@Jeff: on the morning of March 8:
1) a lone jumbo jet went missing
2) a lone mass-sighting of a large jet aircraft occurred
It is reasonable to consider the possibility these two events are related.
Further research has shown this sighting to be within MH370 range and endurance limits, and the cover stories Maldivian officials have offered to explain their residents’ mass sighting have been both shifty and shifting.
The same logic applies to the Curtin event: one missing jet, one recorded sound consistent with an ocean impact: it is reasonable to consider the possibility they are related. Further research shows the event position to be within range, and timing to align precisely with fuel exhaustion assuming cruising speed and altitude. And just like the mass sighting, officials seem keen to divert our attention: despite spirited grassroots efforts to correct this, the Australian Senate has chosen very deliberately to disregard Curtin’s triangulated event timing, and to officially record a belief that this event’s timing was actually several minutes later – on the INFEASIBLE side of consensus endurance limits – by citing only an early guess, and ignoring a subsequent refinement.
While I’ve spent relatively little time researching South China Sea scenarios, I’d be surprised if they, too, weren’t worth investigating. I concede that eyewitnesses are notoriously unreliable, but if we’re trotting out gumshoe clichés, how about: “the first place you look is the last place you saw it”?
I’ve heard the argument for rejecting all of the above roughly a thousand times, now: incompatible with the Inmarsat data. I know I don’t need to convince you of the absurdity of continuing to view the ISAT data as sacrosanct. You have already accepted the fundamental conflict this data has with the rest of the physical evidence, and have in fact published speculation suggesting flight MH370 ended thousands of miles from where the full dataset indicates, arguing this data was altered to throw us off the trail.
What I find odd is how easily you can embrace tampering with one half of the ISAT data (BFO) by one superpower (Russia), yet reject as absurd the idea of BFO and BTO tampering by another superpower: the one that actually took this data into their back room for most of the first week of the search, before announcing its indications to the world.
You are free to assume your own nation is not capable of such fakery. But it is a stone cold fact that the US had far more means and opportunity to fake the ISAT data than did any other nation. If the US turns out to have been responsible for MH370’s fate, the motive for such tampering becomes clear.
Many of the paradoxes grassroots investigators have dug up over the past several months – including your own flaperon findings – are in fact resolved most fully by assuming the SIO search is in fact a piece of theatre. When cops seek suspects, they watch to see who is acting suspiciously…
Failure to at least research the SCS and Maldives possibilities, to me, smacks of either blind patriotism or blind fear. I thank my lucky stars I am inflicted by neither.
As Jeff Wise has stated, eyewitness reports can be unreliable.
But what about Earth Observation Satellites (EOS)?
MH370 should have left CONTRAILS which are visible to EOS.
Contrails usually form above 26,000 ft. Military planners have been using Contrail Forecasting charts to determine if aircraft will leave behind persistent CONTRAILS visible to the enemy.
QUESTION: IF MH370 was diverted by those with military expertise and awareness of EOS capabilities, would they have flown the aircraft at above 26,000 ft?
QUESTION: how does that ceiling affect the calculation for the range and final destination?
QUESTION: what EOS systems were observing the area around the Final Major Turn, as well as the SIO?
Australia, India, China, Thailand, and USA could have EOS assets that could be observing this area.
here’s a link to NASA’s CONTRAIL education website.
http://science-edu.larc.nasa.gov/contrail-edu/resources-activities-appleman_student.php
@Brock McEwen: No data should be viewed as sacrosanct. But at some time you have to prioritize the data as the radar and satellite data conflict with much of the eyewitness accounts. Different people subjectively rank the reliability of the scant evidence we have in different ways.
Before we put the blame for corrupted satellite data at the feet of either superpower, let’s put the satellite data aside for the moment. The problem with ANY scenario which ends in the sea is that the absence of floating debris is not consistent with a flight terminating on water–be it a crash or soft-landing. The absence of debris for a water termination is even harder to explain as you move north on the 7th arc or off the coast of the Maldives, as the probability of finding floating debris should increase. The lack of floating debris, however, is consistent with a successful landing on an airstrip.
What about the flaperon? You can easily make the argument that the recovery of a single piece of the aircraft is less likely than recovering nothing at all. An objective analysis of all the data has to include the possibility that the flaperon evidence was planted. This possibility is not easy for many to accept. Perhaps the release of the investigative results from the French analysis of the flaperon will put many of these questions to bed.
I have heard the argument that debris from MH370 might have been recovered from the shores of the Maldives, positively identified, and not disclosed. I don’t think it is likely that all the evidence could have been gathered by authorities and kept from the public.
I have not yet seen a proposed scenario without major holes that have to be explained, even if you ignore the satellite data.
@Trip: Stuart Yeh’s explanation of the BTO data is complete nonsense, as I have said twice before on this blog. He confuses internet network latency with latency of the underlying satellite communications protocol. He should either educate himself or consult somebody knowledgeable in the field.
@VictorI
“The absence of debris for a water termination is even harder to explain as you move north on the 7th arc or off the coast of the Maldives, as the probability of finding floating debris should increase. The lack of floating debris, however, is consistent with a successful landing on an airstrip.”
but we do have floating debris albeit only a piece, when you move north on the 7th arc probability of ditching with just a little debris increases because water surface becomes calmer
@StevanG: If the plane crashed near Christmas Island, there should have been a lot of debris recovered. If the plane soft-landed, there should have been an opportunity for passengers and crew to attempt an escape, and rafts and bodies should have been recovered. We’ve discussed this before. In my opinion, this is one of several major flaws in this scenario. You don’t agree. Let’s not rehash old discussions.
@Trip and Brock
It seems most likely to me that the “Curtin Boom” was caused by some geological event (earthquake etc.). I was not suggesting it was connected with the Maldives sightings. Unfortunately, the Scott Reef and Dampier recorders off the NW coast of Australia only operate for 5 mins out of every 15. I don’t know whether the recorders at Cape Leeuwin and Rottnest have the capability of detecting anything coming from north of Indonesia e.g. SCS or last radar position – I guess a direct line is required for detection, does anyone know? (see http://www.nature.com/news/sound-clue-in-hunt-for-mh370-1.15390).
So the most interesting aspect for me is the lack of acoustic evidence and debris from a crash in the search area (or anywhere even close) which would make finding the plane in the current search area very surprising (to say the least). I am discounting the flaperon at this stage until we get a detailed report (if ever).
“MH370 should have left CONTRAILS which are visible to EOS.”
Contrails (particularly persistent ones) are not as ubiquitous as you might think. Their formation requires the relative humidity at high-altitude flight levels to be 100%. You can even test this (as I have done) if you are able to decode GDAS files. I fetch them from here: ftp://arlftp.arlhq.noaa.gov/pub/archives/gdas1/ Just wait for a day when persistent contrails are visible in the sky, then pull up the appropriate data file and extract the humidity information. In every case, the relative humidity (the RELH field) is essentially 100% for at least one pressure level in the range 150-300 mbar.
The GDAS model for any of the reasonable paths of MH370 show that the humidity never comes close to 100%. It is for this reason that I think any claim for the existence of a contrail from MH370 in satellite imagery is simply wrong.
I have some questions for all the debris experts posting here, of which there seem to be a large number.
1. Many aircraft have crashed into the ocean or sea over the years. What is the longest time interval and/or furthest distance from any of these incidents for debris to have washed ashore and been identified as coming from that particular aircraft?
2. What is the typical fraction of mass of an aircraft and its contents to survive on the surface as debris, with the remainder presumably sinking to the bottom?
@Victor: I agree with everything you say – because it strongly supports my call for a stiff audit of search leadership.
@sk999: I am not a “debris expert”, nor have I ever held myself out at as one. But since it is hard to interpret the sarcastically wide net you’ve cast as being meant to exclude me, I will respond:
1. I reject the implied basis of this question, which seems to be: “until MH370 is the world record holder for absent debris, please let’s everyone not even trouble to investigate and assess the specific case at hand”. I don’t care how long it took for debris to wash ashore in cases which are irrelevant.
2. Again, I’m not an expert, but prior comments in this forum contain the answer you seek. While floating items from a total break-up may actually form the minority by mass, it would seem they invariably constitute the majority by VOLUME: a plane is designed to maximize strength:weight ratio – many of a modern jet’s lightweight metal components apparently float even if much of their hollow innards become damaged and waterlogged.
Brock,
First, thanks for the reply. While my reference to “debris experts” was a bit of whimsy, the questions were not. Putting aside the Reunion Island flaperon, how significant is the apparent lack of debris from MH370 with regard to where it may have come down? Is it highly significant? Or is it meaningless? Indeed, how would one even know how to decide?
Any statement about significance needs a foundation. Gut instinct is not enough. Given that, like you, I am not a “debris expert”, here is how I would approach the problem. I would look at all past incidents that bore some resemblance in key parameters to MH370. There are many. BOAC 781. Flying Tiger 739. Varig PP-VLU. TWA 800. Swissair 111. N844AA. Egyptair 990. OB-1303. Air France 447. Lots of others. I have dug through some of the accident reports to see if there is any mention of debris washing ashore. There is only one – Swissair 111. Given that this particular plane came down only 5 miles from shore, such a result is not unexpected. I am hoping that others may have made a more extensive search of the records. I haven’t found anything else yet. Hence question 1.
Regarding question 2, do you have actual numbers? Even if approximate?
@VictorI
“If the plane soft-landed, there should have been an opportunity for passengers and crew to attempt an escape, and rafts and bodies should have been recovered. ”
not if the water broke in quickly and people started to panic
One aspect of the signal data I’d hoped was nailed down 18 months ago (by much taller foreheads than mine) has always bothered me. This latest mess with engine 1 flameout time might bring it to the fore:
Of the several key BTO-generating time sets, only two require an adjustment to back out a logon request delay: the large set at the gate, and the lone value which generated the hypercritical 7th arc.
The value of this adjustment (4,940 microseconds, I believe) was deduced by simple comparison with adjacent BTO values also generated from the tarmac. The 7th arc correction was then assumed to be precisely equal to the latter.
This is deemed, I’ve been led to believe, a safe assumption because the variance of the several imputed logon request delays while on the tarmac was a scant 20 microseconds or so.
The ATSB’s 99% confidence interval for the position of Arc7 is +/-10km (5.4nmi). This equates to a 50 microsecond error.
But my untrained eye did not see any error component for the logon request offset specifically. Has a 99% c.i. for this offset been either
a) incorporated in the ATSB’s global error analysis above, or
b) firmly established as tiny – even considering potential environmental effects at 00:19 UTC?
Another 50 microseconds of variance from this source could move arc7 a further 5 or 6 nmi.
Just trying to run down all possibilities. Thanks in advance to any who can confirm/correct.
https://www.atsb.gov.au/publications/2014/mh370-burst-timing-offset.aspx
Sk999,
My useless comment.
Although in contrast to Brock I think your questions are highly relevant, I believe there is no reliable ‘statistics’, and no accurate answers. Depends on.
I recall I saw somewhere a paper, suggesting some recently found wreckage in/near Bermuda was carried by the Gulfstream 200 nm (?) from the presumed crash location before it reached the bottom. I will try to find a reference. The same could happen in case of MH370. I am quite sure unexplored underwater currents, especially near the Brocken Ridge, keep many secrets.
So, focusing on the refinement of the current search area without taking into consideration a number of principal effects, which could take place, is fundamentally flawed.
Seasons greetings and wishing you all a safe and prosperous 2016.
Jeff W – “I think this might be the year…”
I think you are right. The year of the 2nd interim report, the end of the search and hands being thrown in the air as the authorities run out of money and give up.
Sadly, this has always been the case since the wheels passed the threshold.
Where is that bloody debris? A few more clues to tie some points together is well overdue.
I agree with Sharkcaver
@Sharkcaver, jG
Thanks for jumping the gun on the New Year with your positive commentary.??!!!…..what motivates you to share that thought…..is it establishing an “on the record” if the plane isn’t found?
Clarification: I was wrong to try to whip up the value of this offset (at the gate, I was subtracting T-channel values from adjacent R-channel values). On closer inspection, the correct values to use are the LONE pair of R-channel log-on records:
0x10 – Log-on Request (ISU)/Log-on Flight Information (SSU), and
0x15 – Log-on/Log-off Acknowledge
…at 15:59:55.413 and 16:00:13.406, respectively.
The BTOs for these two records are 19,380 and 14,820 microseconds, respectively. This suggests a 4,560 microsecond adjustment to back out of the 00:19:29.416 BTO of 23,000. The adjusted BTO would be 23,000 – 4,560 = 18,440.
This seems to be broadly corroborated by the correction given in Ashton’s paper, which purports to have derived a fixed value of 4,600 from historical data. No mention of a confidence interval was given.
Has Ashton given precision to the nearest 10 microseconds? Are we safe in assuming the volatility of this value is negligible? If “yes” to both: are we comfortable attributing 100% of the 40 microsecond gap between the actual MH370-at-the-gate-specific calc above and Ashton’s value to the intrinsic random noise already covered by the 50 microsecond confidence interval?
The IG appears to have used Ashton’s 4,600. I presume the ATSB did, as well. If the precise imputed adjustment of 4,560 is used instead of 4,600, the 7th arcs move 40 microseconds – or roughly 4 nmi, by ratio analysis – further OUT (i.e. southeast), because the adjustment reduces, leaving a larger implied aircraftsatellite range.
If I have correctly worked this through, then the potential concern I identified in my previous post (that imprecision in estimating the adjustment term may have left high-probability turf unsearched INSIDE Arc7) is still potentially valid – but now this possibility is swimming against the current of a 4 nmi bias going the other way.
All thoughts keenly appreciated.
http://journals.cambridge.org/download.php?file=%2FNAV%2FNAV68_01%2FS037346331400068Xa.pdf&code=679c254f6568e91f1339879b90c07d0c
@susiecrowe 1 year and 9 months of fruitless waiting leads me to this conclusion. I’m entitled to my opinion.
@susiecrowe SERIOUSLY? Everyone IS entitled to their OWN opinion in this public forum, if you feel the need to continue playing moderator please go start your own forum elsewhere…
Whilst I fully accept that, in Jeff’s words, “Eyewitness accounts are notoriously unreliable”, it is surely important to draw a distinction between unreliability and worthlessness. I have spent the last several years researching testimonies to unusual and anomalous events using a research archive of over 6000 such events at the University of Wales, Lampeter and I have come to the conclusion that in many cases eyewitnesses are more reliable than they are given credit for: even when they are narrating odd or unusual events. Work undertaken by Elizabeth Loftus and others has certainly made clear that memories embedded in testimonies are often more like stories told by the village story teller than accurate images and sounds recorded on a camcorder and yet nobody disputes that eyewitness testimony is of some value. In fact, we trust witnesses to tell us something of what happens all the time, even though we might reasonably subject their testimonies to an appropriate hermeneutic of suspicion. It happens in courts of law on a daily basis. And this, I have found, goes for anomalous events as much as it does for more mundane ones. If the plural of anecdote is not data in the strictest sense it still surely counts for something.
I have held off for a very long time from posting my own suspicion that there is more to some of those Maldivian reports than has been granted in some quarters. In fact, I sometimes wonder if the preference for the INMARSAT data over the testimonies of some (potential) eyewitnesses is telling us more about what we accept as reliable than it is about anything else and I wonder if it is time to re-examine our own assumptions and presuppositions in all this. After all: it’s 2016 tomorrow and this mystery stubbornly persists. Still no plane and no debris; apart from a single flaperon and a very delayed report.
@Susie:
“Jumping the gun” – where do you draw that inference from after nearly two years of fruitless search sans a single flaperon?
I’m sorry for you if you take my commentary as a sarcastic “positive note” to all for the new year.
To answer your question:
“what motivates you to share that thought”
From day one, almost everyone from the “authorities” down to those in the aviation industry, number crunchers and forum chasers have said the chance of finding the remains of the aircraft will be a lucky streak. Not under estimating the size of the task of a search of the SIO.
Most make the personal admission it is with high possibility it will never be found. With remaining time, favoured search area and funds depleting, that possibility only increases.
Do you have a differing opinion to share?
History will be the only thing that writes the record.
P.S. – DW, I think I missed something of late – Grab your bat and come back to the plate. Be brave and show them you have a bigger set than they expected. With the bases loaded, you may just hit a homer.
Or maybe it will be found in Kazakhstan.
@Mark Fox
As 2015 closes, the Inmarsat data “camps” are circling their wagons, more questioning the “ping” validity after the SIO search produces zilch. It could be said the $150 million+ allocated was in part from individual’s interpretation of events not dissimilar to eyewitness’s accounting, both being intangible but 1 with major “skin in the game”.
The surreptitious nature of this unprecedented flight precludes protocol and the ineptitude of the governing bodies hasn’t garnered respect.
Clearly volumes of interest remain from people committed to finding this plane which, when all said and done is the breathe that keeps this investigation alive.
@Sharkcaver
Did not intend to dispute or question what I highly regard as your opinion, I’m sorry, Being an eternal optimist that thinking stymies me and I tend to see it as unproductive.
Ditto what you said to DW. Happy New Year
@Mark Fox: The Maldives sightings are burdened by one enormous problem: Namely, they require the BTO and BFO data to have been corrupted, which in turn requires a complicated and sophisticated plot. Then, having accepted that, we must also accept that the plane flew all the way to Maldives, and for some reason was flying really low, even though it neither landed nor crashed there. So where do we go from there? For the sake of these villagers, we’ve thrown out every usable piece of data concerning the last six hours of the flight, and all we’re left with is this one dubious and inexplicable fact, from which it’s impossible to go any further toward coming up with a plausible theory.
So if I seem hostile to the Maldives sightings, it’s because they are a dead end, and as such an active impediment to solving this case.
@Susie/Sharkcaver
Of course, one can never shut off your brain. The analytics have been beaten to death, and I see little to be gained from firing up my Matlab program. I have nothing left as an input that would be anything more than a tweak. As I said, I am done with that unless a new idea comes streaking into my life like a meteor – not likely.
There is this curiosity to consider. Sorry if it is off topic for this particular blog area.
http://tmex1.blogspot.com
@Jeff
Agree relative to the Maldives.
@Mark: thank you for your comment. I found it brilliant.
@Jeff: I could snidely point to parallels between the weaknesses in the Maldives scenario you abhor, and the Russian scenario you’ve published, but my new year’s resolution is to stop both generating and criticizing outside speculation. I resolve instead to join forces with as many outside observers as I can – even those whose speculation does not match mine – & demand clarification from all inside officials who have made claims which wilt under scrutiny. I hope you agree that this includes Ibrahim Faisal’s bizarre claims regarding flight DQA149.
@Susie, sharkcaver, et al: I think this illustrates perfectly the difference between expectation and hope. I sense Susie felt her high hopes were being dumped on by sharkcaver’s low expectations, whilst I sense sharkcaver felt precisely the converse. I respect (and share) both Susie’s high hopes and sharkcaver’s low expectations. But if my new year’s resolution to turn up the volume on our demand for public accountability catches on, it will raise my expectations. I hope.
@Brock McEwen
Your integrity once again. Last July when I jumped in here, the immediately apparent intellect was (my word I think was daunting) far beyond my reach. My husband has been fighting Stage 4 throat cancer and was not expected to live past June. Spending 20-25 hours a week at doctors/hospitals, this place bridged those time gaps while enabling me to become distracted by fighting for someone else.
Possibly because I have little else to offer or possibly because of my optimism or maybe just plain naïveté, it is my heartfelt commitment to try and keep you guys going. Not easily impressed, I was and continue to be awed by the time that has been devoted and the sacrifices you all have made, although it can get snarky at times, it remains a place of decorum with probably the best opportunity to nail this thing down.
Happy New Year
@sk999
I understand your point about relative humidity being less than 100%.
HOWEVER, if MH370 was deliberately diverted by those who planned meticulously for most eventualities, we can assume that they wouldn’t have left to chance the possibility of persistent CONTRAILS, and so would have flown MH370 at a lower ceiling.
If I were to do end-of-flight scenarios, I wouldn’t use the ceiling of 34000 ft as the only altitude for calculations.
…HAPPY NEW YEAR to all!
@DennisW:
In your blog you discuss Figure 5.4 of the “Bayesian Methods” paper, and you comment on the “geographic dependency” observed by the authors of the paper. The following paper discusses Schuler oscillation as an error source in Inertial Navigation systems:
http://www.strapdownassociates.com/Schuler%20Oscillations.pdf
I’ve compared a Schuler oscillation to the pattern of BFO errors in that Figure 5.2 here (add the hypertext prefix and //): i.imgur.com/BxklZba.jpg
Interesting out of curiosity?
Happy New Year to all!
Brock,
Happy New Year!
Those issues were mostly discussed:
1. There are two arcs: the nominal 7th arc and actual 7th arc – don’t confuse them.
2. BTO is truncated, not rounded.
3. The actual location of the 7th arc depends on altitude. Thus you have possible deviation of the actual arc from the nominal arc comprised of the: error in BTO measurement, truncation error, error in the bias, and the uncertainty in altitude.
4. There are no environmental effects affecting BTO. At least practically notable. This is in contrast to BFO.
5. I am still missing something in these ATSB estimations of the error. Why do they originally took for the calibration 17 samples, 7 of which had errors falling in 1% of non-exceedance? If I recall correctly, the errors were of ~17 km distance equivalent. Perhaps I missed explanation, perhaps ATSB is wrong, perhaps mh370 hardware had a problem already on the ground.
6. Note that errors in BFO and BFO bias affect position along the arc, not only radial coordinate.
Hope this clarifies.
MH370 Seabed Search Concentrates on Lowest-Probability Area ?
From ATSB’s August 2014 report: “As the BEA found in their study, in the case of an upset followed by a loss of control, all the impact points occurred within 20 NM from the point at which the emergency began and, in the majority of cases, within 10 NM.”
The seabed between +/- 20 NM from the 7th arc has been searched and nothing was found. Wouldn’t it then be logical to assume that there was human control until the end, and that the airplane continued up to 100 NM beyond the 7th arc? What logic dictates the current search between 25 and 40 NM from the 7th arc?
@Gysbreght: Happy New Year! Yes, this is exactly my point. Once one comes to the conclusion that there is no wreckage within the area that a ghost plane would have ended up in (and different people have different criteria for reaching this conclusion, which is why the search continues beyond a distance that I think the plane could have reasonably been expected to travel unpiloted) then the inevitable conclusion, to my mind, is that the plane must have been under active control until the end. That is to say, the outcome was not the result of an accident or a plan gone awry, but was overtly intentional. If we can reach a consensus on this point, then it will be a major step forward, because the number of possible scenarios will have been reduced to one: either suicide, or non-suicide. We’re all familiar with the arguments for and against Zaharie taking the plane on a long circuitous path to self-destruction. The alternative–non-suicide–would posit that whoever took the plane not only did not intend to kill themselves, but did not kill themselves and in fact took the plane somewhere else. The latter is obviously a tough pill for many people to swallow but given the vastly reduced range of possibilities perhaps some will be willing to give in a more serious look.
@Susie, I am incredibly moved. Thank you for your support, encouragement and good wishes. I hope that you find peace and health in 2016.
That is one step too far for me. Whoever took the plane may have been ignorant of the plane’s range limitation, like in the case of the Ethiopian highjacking.
@Gysbreght, I don’t think so, because the last four hours of the flight are not consistent with trying to reach someplace (Christmas Island advocates would disagree, but as often stated before it seems to me that if whoever took the plane wanted to reach Christmas Island, they would have reached it, there would be nothing particularly challenging about doing so.) I can understand someone, given the implications of intentionality, saying “All right then, it was suicide, case closed,” but I would urge them to apply more rigor before abandoning a northern route. Many people feel that it’s implausible, but that’s just a feeling. I feel that Victor, Gerry S, and I have shown that a spoof scenario is possible; if people feel that they can demonstrate a reason why it is not, it would seem to me worth the effort to do so.
@jeffwise:
IMHO showing that a spoof scenario is possible requires more than a theory.
@Gysbreght, We could argue about epistomology, but I believe that ultimately it will come down to the physical evidence. Perhaps more debris will be discovered, in a way that nails down an SIO impact. Perhaps the French will release the results of a proper forensic examination of the flaperon, which will clarify whether it was planted. Either/both should/could happen with in the coming calendar year.
@Oleksandr
I”ll take a look at it (the New Year has started in typical fashion, and I am not at my best today). I thought the Schuler error was characterized by zero mean (but it has been awhile since I even looked at it). Also my recollection of the error magnitude is that it is small relative to the magnitude of position error needed to generate the BFO error shown in “Bayesian Methods” (on the order of degrees).
Gysbreght,
R.E. Schuler oscillations – I was not aware of them before. It took some thought, but yes, I see how they work. The period (84 minutes) depends only on the mean density of the Earth. There was a thread on pprune a while ago regarding how often pilots recalibrate thier IRU systems, and one pilot said he did it if the velocity error exceed 3 knots (while parked at the gate). A 3 knot uncorrected error in the direction of the satellite changes the BFO by 8 hz. Projection effects reduce this amplitude, but it still big enough to warrant further consideration.
The ADIRU is only one of several navigation systems on the plane. GPS (which is available to the FMC) would provide information of much higher accuracy. What source or combination of sources goes to the AES, and does the source change depending on roll mode? The Mumbai-KL flight was undoubtedly in LNAV mode and under control of the FMC for most of the flight; the biggest oscillation in the BFO plot occurred while negotiating the NILAM to VAMPI portion of N571 (the reverse of MH370; this location was determined by looking at Flightaware charts of recent MH195 flights).
What if the plane were in AFDS heading or track mode? In that case only the ADIRU would be used to control the motion of the aircraft, but the GPS might still be monitoring it and providing accurate information to the AES. Assuming that the latter situation pertains, then I do not think Schuler oscillations are a factor in the BFO.
As an aside, I found the following document describing a current Honeywell Inertial Reference System to be quite informative with regard to measurement accuracy of both IRS and GPS systems:
https://aerospace.honeywell.com/~/media/Products/Navigation%20Systems%20and%20Sensor/Sensors%20and%20Inertial%20Products/Laseref_VI_FINAL.ashx
@Sk999
I am getting a 404 error on your link. Could you please check it? Thx.
I could not get Oleksandr’s imgur link to work either. Maybe a New Year mental impairment?
Let’s try that again.
https://aerospace.honeywell.com/~/media/Products/Navigation%20Systems%20and%20Sensors/Sensors%20and%20Inertial%20Products/Laseref_VI_FINAL.ashx