It’s been more than six months since MH370 vanished, and in some ways we know no more now than we did in late March: no new clues have emerged, no more data has been discovered. In a sense, though, we have come a very long way. For one thing, we now understand how many of the “breaking news” developments that occurred in the early days were actually untrue. (There were no wild altitude swings, no “fighter plane-like” maneuvering, and probably no cell-tower connection with the first officer’s phone.) What’s more, thanks no doubt to a drumbeat of public pressure, the authorities have released a tremendous amount of data and provided useful explanations of how that data is being interpreted. And finally, a spontaneous collaboration between technical experts and enthusiasts around the world has provided a trove of insight into avionics, aerodynamics, satellite communications, and a whole host of other topics that collectively shed light on what might and what might not have taken place on the night of March 7/8, 2014.
While a great deal of information has become available, it has not always been easy to find; much of it, for instance, has been exchanged via email chains and Dropbox accounts. For my part, I often find myself rummaging through emails and folders looking for information that I’m pretty sure I’ve seen, but can’t remember where. So what I’d like to do with this post is try to aggregate some of the most basic facts — a set of canonical values, if you will, of the basic data on MH370. Necessarily, some of this data comes with implicit assumptions attached, so as far as possible I’ll try to make these assumptions explicit.
Okay, on to the data. What we know now:
The bedrock data. In the wake of MH370’s data, there were numerous news reports concerning information leaked by anonymous sources from within the investigation and elsewhere that have subsequently been either disproven or inadequately verified. For the purposes of the present discussion, the following are considered the bedrock sources of information upon which our understanding of the incident can be built — the “Holy Trinity” of MH370 data:
- Up to 17:21: radio communications, ACARS, transponder, ADS-B
- 17:22-18:22: military radar track. This information is of uncertain provenance but has been endorsed by the governments of both Malaysia and Australia. Furthermore, it plausibly connects the prior and following data sets.
- 18:25-0:19: Inmarsat data, especially BFO and BTO values. There is some discussion as to how this data is best interpreted, but the numbers themselves are assumed to have been received and recorded by Inmarsat from MH370 via their 3F-1 satellite. The “ping rings” in particular are derived through relatively simple mathematics and should be regarded as established fact unless someone comes up with a specific mechanism by which some other result could be obtained.
Timeline. Courtesy of Richard Godfrey and Don Thompson, here is a basic timeline of MH370’s disappearance (all times UTC):
- 16:41:43 MH370 departs runway at KUL runway 32R
- 17:01:14 MH370 flight crew report top of climb at 35,000 feeet
- 17:07:48.907 Last acknowledged DATA-2 ACARS message sent from plane
- 17:19:29 Last radio voice transmission
- 17:21:04 Plane passes over IGARI waypoint
- 17:21:13 MH370 disappears from air traffic control (secondary) radar screens
- 18:22 Last primary radar fix
- 18:25:27 Inmarsat log-on request initiated by aircraft
- 0:19 Final transmission from aircraft to satellite
A more complete table of values, including the location of the plane at each point in time, can be found here, courtesy of the inimitable Paul Sladen. And Don Thompson has created an impressively detailed breakdown of the sequence of events, with a special focus on radio communications between the aircraft, ground, and satellite, here.
More stuff after the jump…
Physical characteristics. MH370 was a Boeing 777-200ER. Its “zero fuel mass” (ZFM) was 174,000 kg. With 49,200 kg of fuel aboard, its takeoff weight was 223,200 kg. (We know the fuel aboard on takeoff at 16:41 thanks to Paul Sladen’s deciphering of ACARS data shown briefly onscreen during a CNN segment. Note that in a press statement Malaysia Airlines indicated that the fuel load on takeoff was 49,100 kg.) UPDATE: Thanks to the October ATSB report, we now know that the fuel remaining at 17:07 was 43,800 kg.
UPDATE 2: Don Thompson has rounded up four publications which contain a wealth of 777 technical information: Boeing 777 Flight Management System Pilot’s Guide, Qatar Airways 777 Flight Crew Operations Manual, United Airlines 777 Aircraft Maintenance Manual/Satcom System, and Honeywell Multi-Channel SATCOM System Description, Installation, and Maintenance Manual.
Communications. In addition to a traditional transponder for use with ATC secondary radar, MH370 was equipped with ADS-B equipment that was operational the night it disappeared. The plane was equipped with VHF and HF radios for voice and data communication, which could also be sent and received via a satcom system that relied on one low-gain and two high-gain antennae mounted near the rear of the aircraft. (Specs, courtesty of Don Thompson, here.) These antennae were connected to a Honeywell/Thales MCS6000 satellite communications system located in the ceiling beneath them; this unit received location and velocity information needed to aim the high-gain antenna and to precompensate the transmission frequency via ARINC cable from the Inertial Reference System in the E/E bay. After the plane disappeared from primary radar, Malaysia Airlines made three attempts to reach its crew via satphone, but the calls did not go through; Don’s signal analysis of the three attempted phone calls suggests that the high-gain antenna might not have been working properly, perhaps because the antenna was not steered correctly.
Wind speed and temperature aloft. Stare at this for a while if you want to. If you like your data a bit rawer, you can find historical radiosonde data at the website of the University of Wyoming. For a more granular idea of what the weather was doing on the night in question, Barry Martin has compiled a large table of reanalyzed weather-model data from NOAA here.
Speed. As part of his paper detailing his estimate of where MH370 might have gone, Dr. Bobby Ullich has produced an impressive analysis of MH370’s speed before it disappeared from radar. While I’m agnostic as to the correctness of Bobby’s conclusions, I think he makes an excellent point with regard to the plane’s speed, which is that it clearly accelerated after the diversion at IGARI. The ground speed before the turn was about 470-474 knots, after, it was around 505-515 knots. Given that the winds aloft at the time were somewhere around 20 knots from the east-northeast, this would be broadly consistant either with an acceleration in airspeed or with a steady airspeed in the range of 490-495 knots.
In his ongoing analysis of MH370’s performance, Barry Martin points out that a likely speed for the plane to fly would be “Long Range Cruise,” or LRC, which can be selected through the flight management system. LRC is faster than the Maximum Range Cruise speed and 1 percent less fuel efficient. To quote a Boeing manual: “This speed… is neither the speed for minimum fuel consumption nor the speed for minimum trip time but instead is a compromise speed somewhere in between. It offers good fuel mileage but is faster than the maximum range cruise speed.” LRC is given as a Mach number, and varies with weight. At MH370’s takeoff weight, LRC at 35,000 feet would be Mach 0.84, which translates to 481 knots in a standard atmosphere. At the time, however, the temperature was 11 deg C higher than that of a standard atmosphere, so its true airspeed would be 494 knots.
It’s worth noting as well that Brian Anderson has devised an entirely different means of calculating airspeed, based on the observation that between 19:40 and 20:40 the plane reached its point of closest approach to the satellite; by calculating this distance, and estimating the time at which it occured, one comes up with a groundspeed that turns out to be, by Brian’s (and other’s) reckoning to be in the neighborhood of 494 knots. Brian observes that “by removing the wind vector, the answer becomes about 486 knots TAS.”
Richard Godfrey has run the numbers for the early part of the flight and come up with slightly different figures from Bobby Ullich.
The last ADS-B data shows a speeds around 471 to 474 knots. Last calculated Ground Speed was 474.3 knots. The average Ground Speed required to follow this path from the turn back point and get to Pulau Perak by 18:02:37 for the start of the Beijing Radar Trace is 510.7 knots. The difference between 474.3 and 510.7 is accounted for by an 18 knot head wind that becomes an 18 knot tail wind after turn back. The wind in the area was around 18 knots at the time. This would make the Air Speed 492.5 knots. The Ground Speed required to get from the start to the end of the Beijing Radar Trace by 18:22:12 is 503.6 knots.
He adds:
The major turns and turn back flight path occur at borders between Malaysia, Vietnam, Singapore, Thailand and India. Indonesian Airspace is carefully avoided in the Malacca Strait. The major turns are just out of range of the Malaysian, Thai and Vietnam radars. The Satcom Login at 18:25:27 is just 14 seconds after reaching NILAM which represents the point just out of range of the Malaysian and Thai radars.
Performance. As the plane flew along, it burned fuel, and thus became lighter. As a consequence its optimum altitude — that is to say, the altitude at which it would experience the greatest fuel efficiency — became higher, and its LRC at a given altitude would become lower. Additionally, as the plane moved to higher latitudes, the air would have gotten colder, which would reduce its true airspeed for a given Mach number. All these factors would tend to gradually reduce the measured ground speed of the plane, which is indeed what we see geometrically for straight-line flight through the ping rings. For more on aircraft performance, see Barry Martin’s excellent Analytic Fuel Flow Analysis.
The Satellite. From 18:25 onward the sole evidence we have of MH370’s fate comes from the analysis of a handful of electronic exchanges between the plane and Inmarsat satellite 3F-1, which occupies a geosynchronous orbit above the equator at 64.5 degrees east longitude. Its position was not fixed; two years before, due to the fact that its hydrazine thrusters were getting low on fuel, Inmarsat had begun to let its inclination slowly increase. By March 7/8, it had reached an inclination of 1.7 degrees. Paul Sladen has published a table of ephemera. Here is a chart produced by Duncan Steel, showing the progression of the subsatellite point during the course of MH370’s final hours (click to enlarge):
The Search. Via Don Thompson: As announced at a JACC press conference 28th April, on the occasion of the end of surface search, “Australia has been coordinating the search for 41 of the 52 days since MH370 went missing. In this period, more than 4.5 million square kilometres of ocean has been searched. There have been 334 search flights conducted, an average of eight a day for a total of over 3000 hours.”
On September 24, 2014, the ATSB announced that “over 106,000 square kilometres of the wide search area have been [bathymetric] surveyed.”
Inmarsat Raw Data and ATSB report. For two months after MH370 disappeared, members of the press and the general public begged and pleaded for the authorities to release the raw data logs of transmissions between Inmarsat and the missing plane. On May 27, 2014, they finally did.
In June, the Australian Transport Safety Board released a report (later updated) that provided even more useful information, this time explaining how the raw data had been interpreted. More recently, Inmarsat’s Chris Ashton was the lead author of a paper in the Journal of Navigation explaining how the company conducted its analysis.
Thanks to these documents, we now have a much better understanding of what transpired, and have the wherewithal to undertake a critical assessment of the official investigation–which, as I described in my last post, seems to be paying off.
Burst Frequency Offset is a measure of how the signal received by the satellite from the airplane has been shifted by various factors. You can measure how closely a prospective route matches the values recorded from MH370’s actual flight by using Yap’s BFO calculator.
End of the flight. The BFO data associated with the final “half ping” at 0:19 is anomalous in comparison to the preceding pings; it values that could not be generated by any combination of speed, location or heading that is physically possible for a 777. The data is compatible with a steep descent into the ocean at an acceleration of 0.7 g, which Mike Exner, Victor Iannello and others have interpreted as a spiral dive resulting from the fuel tanks running dry. There is some dispute at present as to whether fuel exhaustion would result in such a dramatic maneuver. While plans to enlist a professional-grade simulator are underway, John Fiorentino reports that he has already researched such an experiment, and says that the plane did not spiral dive but instead descended wings-level in a phugoid oscillation, that is to say, with the plane pitching down and gaining speed, then pitching up and losing speed, then pitching down and gaining speed, and so on. I’ve excerpted his report here.
More to come…
Hi Jeff,
Good idea to sum up what we know.
I wonder whether the following statements are correct (strictly speaking):
“18:28:05.904 BFO data shows the aircraft heading north-west on 300 degT in line with the radar trace.
18:40:08.068 BFO data shows the aircraft heading south on 180.83 degT and second major turn.”
As I pointed out earlier, and can be easily veryfied with Yap’s BTO&BFO Calculator, the BFO is insensitive to longitudinal (east-west) velocity. It does provide latitudinal (north-south) velocity, but that value depends on the AES FFB (Fixed Frequency Bias) that is not precisely known. Therefore any value of latitudinal velocity derived from the BFO should state the FFB assumed. The heading results from the combination of the latitudinal and longitudinal components of velocity, and requires knowledge of the variation of BTO, and that is not exactly known at 18:40 UTC, but has to be estimated/extrapolated.
>> There were no wild altitude swings, no
>> “fighter plane-like” maneuvering, and
>> probably no cell-tower connection with
>> the first officer’s phone.
Q1: Is there any basis for these multiple assertions, and if so, what exactly is it?
Q2: What is the current status of the Independent Group’s assertion of a loitering period after the retreat from Malaysian airspace?
Jeff,
Great article here and a very useful reference tool on MH370.
I was just thinking over the weekend that when one looks at the overall generalized description of the MH370 event it replicates most other airline disasters:
1. ATC loses all contact with airliner
2. Loss of all comms
3. A diversion way off course
4. An ultimate crash
But this one has it’s idiosyncrasies and complicates my KISS (keep it simple, stupid) theory in that:
1. No MayDay call or hijacking code reported
2. Strange reboot of the SDU and plane initiated log on request mid-flight about an hour after original diversion (17:24 / 18:25)
3. Extraordinary length of flying time overall after original diversion hours before any crash
4. Secondary diversion into the SIO (or intended destination Perth?)
5. No ELT signals
I am still not so sure about the co-pilot’s cell, maybe it was a leak that was just redacted like everything else just to keep all things close to the vest, to be divulged if and when ready. But the timing of it, if true, does fit the time they were near the various airports, and they certainly had their choice of airports at one point but no landing (that we know of keeping in mind Victor’s Banda Aceh).
Does anyone know what EXACTLY is it in the BFO or BTO calculations of the unanswered sat phone call that was tweaked to determine the earlier turn south? Since the call originated from MAS on the ground is there something that can determine distance from them to object called?
Cheryl
Good questions.
A1: The radar track shows that the plane was traveling at around 500 knots groundspeed — close to its maximum speed, meaning it had no time for fancy maneuvers. Apart from the turn near Penang, the track is just about perfectly straight.
A2: The loitering period was surmised as a way to explain the ATSB’s conclusion that the plane most likely had ended its flight at a fairly northerly part of the southern arc. After the ATSB shifted its search zone further south, the surmised loitering period was shrunk or done away with entirely; if the plane loitered at all it was likely for less than 12 minutes.
Nothing was tweaked with regard to the cell phone call; the ATSB simply decided to use a data point in their analysis that they had decided to leave out of it previously. No one outside the organization seems to know why.
>> and they certainly had their choice of
>> airports at one point but no landing
Which tends to suggest that a non-lethal outcome may have been on the menu, but was ultimately rejected, as does the advance-and-retreat on the homeland, the satcom reboot and (if the IG’s assertion is true) the subsequent loitering before the suicide turn.
@jeffwise
The leaked report that the plane made major changes in altitude (which is quite compatible with the loose language of “tossed around like a fighter jet”) is corroborated by the cellphone tower story (confirmed by a US official) and by eye witness reports. That’s not proof, but it is evidence. Has anybody qualified evaluated the primary radar data and determined that these reported altitude changes are spurious?
Thanks, Jeff. That answers my sat phone question.
That answers my loitering question as well. I asked that here how the earlier turn south affected Kate Tee’s sighting and the loitering period. Mr. Lauren H. I believe answered about Kate’s yacht and it’s GPS and possible timings of MH370 crossing her, and now Jeff has explained that the loitering time is now considerably shortened or nullified.
Could there have been any scenario whereby they couldn’t land, i.e. a landing gear /hydraulics malfunction or something else going on as well as whatever else was happening, thinking along the lines of a series of mechanical malfunction events going on? They are way off course, something is drastically wrong, yet no landing near various airports. I think the landing gear has redundancy as well, set up with various back up systems? But then again they are at 35,000 ft. in altitude near those airports according to the chart above, at what altitude would they know if they did not have functionality of the landing gear? And could a semi-conscious, impaired pilot have sent the plane into the SIO, avoiding further loss of life on land, knowing a crash was inevitable?
Hi Jeff,
While I agree with your reply A1 to Luigi Warren, IMHO that does not exclude rapid large altitude excursions occurring during the turn near IGARI. The kinetic energy at 500 kt TAS is equivalent to 6562 ft altitude.
Hi @Gysbreght,
I commented on DS some time back regarding the assertion that BFO is insensitive to longitudinal velocity (east-west), which I believe to be in error, while the plane is at similar latitudes to the satellite.
Please see:
http://www.duncansteel.com/archives/930#comment-10972
for more detail why I think that is so.
Cheers,
Will
Hi MuOne,
Your comment on DS is in error. You ignore the fact that the AES compensates for the frequency shift due to the airplane motion relative to the geostationary reference position of the satellite. The BFO is almost insensitive to any aircraft speed when the satellite passes the equator, i.e. when it is close to its reference position.
No, I did not switch Vx and Vy.
Gysbreght,
It would certainly be possible for MH370 to make rapid climbs and dives, but climbs must necessarily be slower, which reduces the average speed.
The official investigators have explicitly taken such altitude changes off the table, partly for the reason I cite and partly due to the fact that there is no evidence for them.
Jeff
Jeff,
Under “Physical characteristics” you wrote
” Its “zero fuel mass” (ZFM) was 174,000 kg. With 49,200 kg of fuel aboard, its takeoff weight was 223,200 kg”.
Just to be clear about these important data – my understanding was that 49,200 kg fuel on board was reported in an ACARS status message at 17:07 UTC. Wouldn’t that make the weight at 17:07 to be 223,200 kg?
I’ve updated the post thusly:
MH370 was a Boeing 777-200ER. Its “zero fuel mass” (ZFM) was 174,000 kg. With 49,200 kg of fuel aboard, its takeoff weight was 223,200 kg. (We know the fuel aboard on takeoff at 16:41 thanks to Paul Sladen’s deciphering of ACARS data shown briefly onscreen during a CNN segment.)
Luigi Warren,
It’s a long read, but take a look at this Vanity Fair article on the 2006 Brazilian crash of a Boeing 737 passenger plane following a mid-air collision with a private jet: http://www.vanityfair.com/magazine/2009/01/air_crash200901
The private jet had been flying with its transponder turned off. Brazilian military radar tracks showed the private jet rising and falling rapidly in altitude, even though it was on autopilot flying straight and level at 37,000 feet. Unfortunately, the 737 was flying at the same altitude, and the fatal collision occurred.
@PhilD
It has not been claimed that the plane made “rapid” changes in altitude, only that it was flying very low — 1 to 2 miles above the earth, rather than the normal ~7 miles — by the time it reached Malaysia. Three lines of evidence suggest that this is in fact correct: reports from military radar operators, the report from the police investigation that the co-pilot’s cellphone reconnected with a Malaysian celltower, and eyewitness accounts from fishermen at Kota Baharu. I’m not seeing a convincing case for dismissing those data, especially coming from the very same people who decided to drop the satcom call data from their model for six months, then reintroduced it, all while offering up various pretentious models predicting widely different trajectories incorporating sheer guesswork about what a pilot would “normally” do under conditions that are clearly completely abnormal and undefined.
Luigi, what I’m trying to do here is to aggregate information that represents the consensus view of the independent experts. What you say may be true, but right now the majority of people who’ve been looking closely at the issue don’t believe it is.
@jeffwise
And I’m just trying to tease out the basis for these assertions to see if they should be given any more weight than previous claims regarding satellite images of debris, data recorder pings, projected terminii of the plane, etc.
@All
Just some food for thought……….
Michael Crichton (best known for his novels but also a graduate of Harvard Medical School and a former postdoctoral fellow at the Salk Institute for Biological Studies) warned his audience of the dangers of “consensus science” in a 2003 speech.
The following are excerpts…………..
“I want to pause here and talk about this notion of consensus, and the rise of what has been called consensus science. I regard consensus science as an extremely pernicious development that ought to be stopped cold in its tracks. Historically, the claim of consensus has been the first refuge of scoundrels; it is a way to avoid debate by claiming that the matter is already settled.”
Whenever you hear the consensus of scientists agrees on something or other, reach for your wallet, because you’re being had.
Let’s be clear: the work of science has nothing whatever to do with consensus. Consensus is the business of politics. Science, on the contrary, requires only one investigator who happens to be right, which means that he or she has results that are verifiable by reference to the real world.
In science consensus is irrelevant. What is relevant is reproducible results. The greatest scientists in history are great precisely because they broke with the consensus. There is no such thing as consensus science. If it’s consensus, it isn’t science. If it’s science, it isn’t consensus. Period.”
–Michael Crichton
No doubt Michael Crichton would have run his blog differently.
Geysbreght, ref your post Sept 30, 2014 at 6:28 AM
You mention fuel remaining at 17:07, we have no information on fuel qty after 16:41.
Two reports of fuel qty exist: 1) 49100kgs at take off stated by MAS at a press conference or in a media report and 49200kg evidenced by the ‘OOOI’ report sent as an ACARS message at 16:41.
There are no further reports of fuel quantity remaining at 17:07.
:Don
The question of whether the plane came in low on its return to Malaysia, as suggested by radar operators’ evaluation, the police investigation, and eyewitness accounts, is decidedly non-trivial. It may not shift the projected termini of the plane in the SIO beyond the margin of error, but it is clearly heavily freighted with implications regarding what actually happened on the plane. What those implications are would have to be reconstructed in light of the totality of the evidence. For example, it might indicate an attempt to land after a catastrophic systems failure, or a plot which involved the possibility of a landing, or an attempt to avoid radar, or an attempt to threaten targets on the ground. I would also argue that a descent makes sense in a variety of scenarios, while there is very little logic in the plane’s zigzagging back to Malaysia and then up to the tip of Sumatra and then down to the SIO while remaining at normal cruising altitude. That is another reason for taking the evidence that it did descend very seriously — even if you can draw a straight line between two points without acknowledging a change in altitude.
Luigi, PhilD
Primary RADAR, radio detecton and ranging, without secondary reporting from a target, can’t discriminate that target’s altitude. It can only determine distance to a target and, over time and interpolation between target sightings on successive antenna scans, it can determine speed.
The Brazilian civil aviation authority issued a report following the investigation into the Embraer Legacy – B737 collision: that might be better reference material than Vanity Fair.
Jeff Wise and GuardedDon,
Apologies and thanks for correcting my faulty memory. I agree that the ACARS report said 49,200 kg fuel onboard at 16:41.
Hi Jeff,
Any chance that the ‘raw’ Inmarsat Burst Timing data for the handshakes is now available ?
(before any analysis or signal processing/filtering was performed)
Ideally, the ground station raw timestamps of the transmitted signal and the received/detected signals,
both to 10 microseconds accuracy.
Did Inmarsat ever provide you with an explanation as the difference in their original and final estimates of the 19:41,
20:41, 21:41 handshakes ?
John:
Thank you so much for the brilliant quote by Michael Crichton, who hooked me as a young kid with The Andromeda Strain.
This — “The greatest scientists in history are great precisely because they broke with the consensus.” — is everything.
Greg, I just added a section to the post — as a shortcut, you can find the raw data here: http://031c074.netsolhost.com/WordPress/wp-content/uploads/2014/09/MH370-Data-Communication-Logs.pdf
I didn’t ask that question of Inmarsat but they probably revised their calculations as they came to understand the dynamics of the system more accurately.
Hi Jeff, all,
I’m rather concerned about the apparent consensus for the interpretation of 18:40 BFO value.
For me the most basic scenario would be that the pilots have been facing a serious situation; decided to return and logically would want to land the plane asap. Apparently in nearest lightly-populated area, i.e. somewhere in the Nicobar/ Aceh region. It is unknown if they managed to land, however to me it seems likely that they have attempted.
In this scenario the ac typically would be descending at 1840, at unknown rate. Therefore, in my opinion, concluding from 1840 BFO that ac was flying south at that time is rather speculative.
In my opinion we should regard all BFO values as speculative. To say that most people view that interpretation of the 1840 BFO value as most likely is not to say that many people would stake their lives on it.
GuardedDon,
In the Gol B737 crash in Brazil, 3D Radar supplied an estimated altitude once the transponder on the private jet was off. As noted on p. 274 in the CENIPA report that you referenced, these estimates of altitude became very erratic as the distance from the radar site increased. Something similar may have happened with the radar data for MH370 assembled by Malaysia.
The author of the Vanity Fair piece was William Langewiesche, who is a pilot and writer, first for the Atlantic Monthly and now Vanity Fair. An old interview with him is here: http://www.avweb.com/news/profiles/182912-1.html?redirected=1
Make of that what you will.
CENIPA report: http://web.archive.org/web/20110604124906/http://www.ntsb.gov/Aviation/Brazil-CENIPA/Midair_Collision_Final_Report_1907_English_version.pdf
@jeffwise: You are quite brave in attempting to assimilate the “what we know” data. One can assign a “correctness probability” for every data point. But there are two problems: 1) Determining the cutoff probability for accepting the data as “fact”, and 2)Different people will assign a different correctness probability to each fact. These cannot be determined by consensus, as the previous posts have demonstrated. Perhaps it is up to you to decide what to accept and what not to accept as fact for the purposes of this part of your blog. After all…it is YOUR blog. Or, you can allow debate in attempt to reach a consensus on many data points, which I think will be unlikely.
Hi Jeff ~
I enjoy reading your blog!
http://jeffwise.net/2014/09/29/mh370-what-we-know-now/
Regarding the I3F-1 satellite, “Its position was not fixed; two years before, due to the fact that its hydrazine thrusters were getting low on fuel, Inmarsat had begun to let its inclination slowly increase.”
Thanks for reminding me about the hydrazine thrusters. Launched in1996 and with a 13-year life expectancy, have the thrusters stopped to reserve the hydrazine needed for de-orbit? Could the wobble of an orbital degradation drift be a root cause of the SATCOM jitter? Or, could the jitter be an issue associated with the possible effects of moon forces and solar wind plasma on some SDU hardware component?
~LG~
My understanding is that they don’t de-orbit geosynchronous satellites, but park them in an orbit farther out — they have to keep enough fuel until the end for that.
The satellite wobble is what makes the BFO interpretation possible. It has nothing to do with the jitter issue.
@Nihonmama
You’re quite welcome re: Crichton, I admired him greatly.
I think Jeff took me the wrong way. I have no intention of trying to tell anyone how to run their blog. But “food for thought” is often very tasty, even if it sits on the plate untouched.
Best regards
Yes, I suppose this will just be one man’s assessment of where the consensus currently stands. BTW, those who say that consensus is somehow antithetical to science clearly don’t understand what science is and how it works. There is no objective standard for truth; there is no lightbulb in the sky that goes off when someone lights upon a correct idea. Consensus is all we have. If Einstein was right and no one believed him it would have done nobody any good at all.
And for those who say that consensus isn’t important, and haven’t managed to get anyone to come around to their point of view — congratulations, mission accomplished!
@JeffWise
JeffOn: “In my opinion we should regard all BFO values as speculative.”Off
JohnFOn: So, can we interpret that as questioning Exner’s interpretation of the BFO values — specifically that the Boeing 777 was
in a “spiral dive” at 00:19:29?
@JeffWise
I guess I have to disagree with Jeff once in awhile…… 🙂
Anyway, I’ll simply cast my vote for Crichton rather than getting overly philosophical.
I hardly ever use anything “wiki” but I have a program on my computer that scans my selected input for what might best be called “quality” and I came up with this….
A proposition is generally considered objectively true (to have objective truth) when its truth conditions are met and are “bias-free”; that is, existing without biases caused by, feelings, ideas, etc. of a sentient subject. A second, broader meaning of the term refers to the ability in any context to judge fairly, without bias or external influence (see journalistic objectivity); this second meaning of objectivity is sometimes used synonymously with neutrality.
Thus the gap between science and politics!
@Greg Yorke at Sept 30, 2014 at 1:19 PM
Greg, over at “ds.com”, I posted an explanation for the periodic variation between the log-on checks.
Malaysia did not release I/Q “raw” data, we understand that’s not recorded, only a subset of metadata from datalink level frames or “signalling units” as the frames are termed.
:Don
Hi Gysbreght,
Duh! Thanks for that.
I think I see my error now. I am looking at the full doppler effect rather than the BFO. that is of course resulting from the compensation algorithm.
I shut up now.
Cheers
Will
In reference to the epistemological debate, it would seem that science is grounded in both consensus and singular discovery. Thomas Khun’s concept of ‘paradigm shift’ encapsulates how the scientific process is punctuated by ‘revolutions’ that reshape the generally accepted paradigm (consensus). Thus, the scientific process would appear to require both singularity and plurality in a quantum dance of discovery. Mr. Crichton’s rhetorical reach was pretty, but he could have simply indicated the term ‘confirmation bias’ and warned us of the danger of this particular shadow in science. However, in this instance he took things further in his exhortations to his audience, really only trading one form of shadow for another. For one need only flip over any individual revolution in thought to find the madness that works at its core.
(Wary of topic creep – unable to resist.)
The bad kind of consensus is one that develops for UNscientific reasons (“group-think”, trust in authority, profit motive, religious/political conviction, etc.). This holds science back – particularly when it props up tired, old ideas.
The good kind of consensus is one that develops for scientific reasons (emerging data, technology, logic, analysis, etc.). This drives science forward – particularly when it promulgates refreshing new ideas. Jeff argues the point eloquently.
We can all agree, I think, that we should strive to eliminate the former, and embrace the latter.
Problems arise when the latter is painted as the former. An example which springs to mind is the way in which “deniers” attack the good consensus forming around climate science.
Regardless, I have a feeling we will all attack Jeff whenever “consensus” data undermines our pet theory…
@Brock:
I think you’ve got it about right.
Brock – Ironic, because Crichton was a climate sceptic and was campaigning specifically at the time against UN climate science which itself is badly corrupted by politics. I know what John is saying – consensus can be the enemy in the absence of validation. Because of politics people think they are drowning in CO2 yet it’s been 10-15 times higher in the past and wildlife flourished, and it didn’t prevent one ice-age. 399ppm is a mere 0.0399% of the air we breathe, humans are responsible annually for a maximum of 3% of it, and greenhouse is up to 90% water vapour – so when satellites detect no warming for the last 19 years do you reconsider or go harder? The climate establishment has done the latter, because of consensus/politics and fear of stepping outside of it. The net warming trend is 0.8 celsius, and some of the rises and falls in the 19 year hiatus are up to 0.7 celsius. How many people in the street know that?
Consensus without validation is a danger but we won’t be waiting much longer.
Okay, Matty, I’m not going to delete this, but please, nobody respond with their views on climate change — I really don’t want this thread to veer wildly off topic. Focus, people!
@Matty-Perth
Don’t want to wander off topic, but enjoyed your post.
I wrote a few articles about “climate change”……one title….Gore on Climate Change – Some Inconvenient Goofs.
Anyway they’re at my newsvine blog.
BTW – Christine Negroni will be in your neck of the woods in a few days looking into MH370.
Jeff – agreed, with hindsight not one for the dinner party unless you have hired security.
IF…the high priority search areas don’t yield anything I’ll be interested to see the implications on the subsequent modeling as it means some stuff gets taken off the table progressively? Could it open up again, to a degree?
Jeff Wise
GuardedDon
Bobby Ulich
Re: Inmarsat ‘raw’ handshake data.
I have estimated the ‘raw’ Inmarsat handshake data using a method I think Inmarsat/ATSB may have used for this interesting signal processing problem.
Based on this method, Inmarsat/ATSB have ‘calculated’ the radii for the handshake rings.
See the following link (Page 9 and 10) for details and a brief explanation.
https://www.dropbox.com/s/efpm4qpwl28bwp2/MH%20370%2020140809.pps?dl=1
If this is the method they used – I think it is a reasonable approach.
A few warnings,
1. For each assumed flight path (as shown) -you will get different results for the calculated handshake radii.
2. It may favor a south turn relative to a north turn.
3. If south – the route shown on Page 9
(~ the Bobby Ulich route) may tend to favor this route over other south routes.
In the absence of any compelling arguments to the contrary, I find the striking consensus between military radar operators, police investigators, US intelligence officials and eyewitnesses on the ground rather more impressive than the claimed consensus among BFO tweakers at the ATSB and the IG on the question of whether the plane descended to a low altitude on its return to the Malaysian homeland.
Luigi – on the possibility of witnesses: It’s claimed that Shah’s simulator had remote IO airstrips in it for his personal practice. Are they referring to real or fictional strips, because it doesn’t leave much if they are real ones. If is was Maldives for instance, and people there saw a large jet flying low with a red stripe down the side and reported as such before MH370 was officially missing you would sit up. But it doesn’t fit the data…..
As I said earlier IF.. the priority areas reveal nothing it’s back to the calculators with some tighter assumptions by exclusion? That makes everyone a bit wrong and underlines how much rule of thumbery is involved. IF. It’s at an interesting point.
@Victor – I have to agree with you about the fact “cutoff” difficulties, but on that note I’d like to commend both Jeff and Duncan for setting those rules the way they did. It was obvious early on that the cutoff was very different between the two. Neither is right or wrong, and the different rules ensured that the blogs were not simply mirrors of each other. Each blog tested theories differently, which I’m sure I’m not alone in appreciating.
In the end, if the plane isn’t found in one of the lat/long locations identified on Duncan’s blog, it will probably be the result of one of the slightly less orthodox* theories on Jeff’s blog.
*It would be a little unfair to call anyone’s theory a “conspiracy theory” given the lack of transparency throughout this story and the number of times the establishment has congratulated itself on finding the plane’s route.