UPDATED: See end for description of possible northern route
On Saturday, March 15, Malaysian authorities released an analysis of satellite data that dramatically narrowed the possibilities for where missing Malaysia Airlines Flight 370 had gone after it disappeared from radar on March 8. Over the course of the following week, Inmarsat released further information that not only showed where the plane went, but also indicated how it got there. The results are shown on this chart. We still don’t know if the plane headed north or south, but if it went north, it made landfall near the western India-Bangladesh border and proceeded along the Himalayas to Central Asia. If it went south, it passed over western Indonesia and out over the southern Indian Ocean.
How are we able to determine this? The procedure requires a bit of explanation. Inmarsat is a communications satellite in geosynchronous orbit over the Indian ocean. That means it remains in the same place in the sky, like it’s sitting on top of an invisible pole. Because it’s so high up, it has a straight line-of-sight to virtually the entire eastern hemisphere. That’s great for radio communications: if you can see it, you can send it a message, and it can send that message along to anyone else in the eastern hemisphere, or to a base station that can then relay it to anywhere in the whole world.
Every hour, Inmarsat sends out a short electronic message to subscribers that says, “Hey, are you out there?” The message contains no information as such; the satellite just wants to find out if that particular subscriber is out there in case it wants to talk. Kind of like picking up your telephone just to see if there’s a dial tone. On the morning of Saturday, March 8, MH370 replied seven times to these pings, saying, in effect, “Yup, I’m here.” The line was open for the plane to communicate with the outside world. But the system that generates the messages themselves, called ACARS, had been shut off. So nothing else was communicated between the satellite and the plane.
All the same, those pings tell us something important about MH370: they allow us to narrow down its location. Because light travels at a certain speed, and electronics take a certain amount of time to generate a signal, there’s always a length of time between the satellite’s “Hey!” and the airplane’s “Yo!” The further away the plane is, the longer it takes to say “Yo!,” because it has to wait for the signal from the satellite to travel that extra distance.
Imagine you and I are in a darkened room. You have no idea where I am, except you know that I’m holding one end of a taut, 20-foot rope, and you’re holding the other. Therefore I must be 20 feet away. You don’t know where I am, exactly, but you know that I must like somewhere along a circle that’s 20 feet in radius, with you at the center:
Now, it happens that in this room there are walls and pieces of furniture, so you’re able to rule out certain spots based on that, so instead of a whole circle, you have pieces of circle, or arcs.
MH370 was in an analogous situation. When Inmarsat pinged it at 8.11am, the amount of time it took the plane to reply allow us to calculate its distance from the satellite, just as if it was holding a taut piece of string. Instead of furniture, factors such as speed and fuel capacity provide other limitations of where it could be, so its range of possible locations is also not a circle but a series of arcs:
Note that these arcs do not represent the path that the plane took, but the range of possible locations at 8.11am. That particular ping tells us nothing at all about how the plane got to wherever it happened to be. So at this point all we know is where it started (it disappeared from Malaysian military radar at 2.15am at a spot between the Malay Peninsula and the Andaman Islands) and where it ended up. It could have taken any of a zillion routes to get from its start point to to its final recorded location somewhere on that last arc.
Remember, however, that Inmarsat received six earlier pings as well, and from them we can narrow down the range of possibilities dramatically. The first was received at 2.11am, just before MH370 disappeared from Malaysian military. Its length indicates that the plane must have been somewhere on the green circle at that moment:
Of course, thanks to radar we happen to know in this case pretty much where the plane really was at this time — around the area of the pink dot.
On Friday, March 21, an Inmarsat spokesman told me that “the ping timings got longer,” meaning that the distance between MH370 and the satellite grew increasingly bigger, and never smaller. That means that at no point during its subsequent travels did MH370 travel any closer to Inmarsat. So from the 2.11am ping data alone, we can rule out every spot within the green arc:
MH370 never traveled anywhere in the shaded area. (Of if it did, didn’t stay there for long; by the end of the hour it had to be outside.) We also know that it never was further away from the satellite than it was at 8.11am, so we can exclude everything east of that, as well. Finally, we can rule out some chunks close to its starting point for other reasons:
So just from the 2.11am and the 8.11am pings, we know that MH370’s route of flight must lie within either of these two broad swaths — one lying to the north, and the other to the south. Bear in mind, the reasoning that we’ve just gone through doesn’t tell us anything about whether the plane went to the north or two the south. Because of the symmetry of a circle, the possible paths are mirror images of one another. However, we’ve vastly reduced the range of flight routes that MH370 could have taken. For instance, a popular theory circulating on the internet posits that MH370 tucked in close behind a Singapore Airlines flight, “SIA68,” in order to hide in its radar shadow:
This new Inmarsat data rules out that possibility. It also rules out the idea that MH370 flew south through the middle of the Indian Ocean to avoid military radar. If the flight went south, it would have had to have gone through Indonesian radar coverage.
Interestingly, on March 19, the website Antara News reported that “Indonesian Defense Minister Purnomo Yusgiantoro said the Indonesian military radar placed in the country’s western-most city of Sabang did not detect an airplane flying over Indonesian territory.”
On March 22, 2014, CNN reported that China, India, Pakistan, Myanmar, Laos, Kyrgyzstan and Kazakhstan have told investigators that “based on preliminary information, their nations had no radar sightings of missing jetliner.”
So far, we haven’t talked about what we can deduce from the remaining five Inmarsat pings, the ones received at 3.11, 4.11, 5.11, 6.11, and 7.11. It should be possible, based on the presumed speed of the plane and the distance between the successive arcs, to make some reasoned guesses about how the plane traveled from one to the other. I haven’t seen the data yet—I’m working on it—but earlier this week the Washington Post published a map that showed what appeared to be the results of just such analysis as applied to the southern route, carried out by the NTSB:
This appears to be why the nations assisting the investigation have poured so many assets into searching that particular stretch of southern ocean. If MH370 took the southern route, it would have had nowhere to land, so it must have crashed and its debris must still be floating somewhere in this area.
Of course, the information we glean from Inmarsat data about MH370’s flight route is, by itself, symmetrical around an axis that runs from the spot on the ground underneath Inmarsat to the point where the aircraft was last observed. So assuming that the NTSB’s interpretation of the southern route was only based on factors of speed and arc spacing, it should be applicable in mirror form to the northern route as well. I’m working on that right now.
UPDATED 3-23-14: Okay, I feel a little slow on the uptake on this one, but it turns out that if you flip the NTSB’s guesstimated southern route, you come up with a northern route that looks pretty much like this one published in the Daily Mail (I know, I know):
Basically, you make landfall in the vicinity of Bangladesh, skirt along the border between India and Nepal, then cut across northeastern Pakistan and Afghanistan before winding up in Uzbekistan or Kazakhstan. This may be why Malaysia recently asked Kazakhstan if it could set up a search center there.
Kazakhstan would not be a bad place to try to hide an airplane. It is larger than Western Europe with a population of just 17.7 million. Its expansive, sparsely populated steppe and desert terrain make it perfectly suited as a touchdown spot for Soyuz space capsules. The country gained independence from the Soviet Union in 1991 but its communist-era ruler, Nursultan Nazarbayev, remains in power. He is a close ally of Putin, and two days after MH370 disappeared told the Russian premier “that he understands the logic of Russia’s actions in Ukraine,” according to Reuters.
We still need an explanation for how the plane flew so far in the wrong direction. If anyone on that plane was alive, and I do mean anyone not just the pilots, surely some attempt would’ve been made to turn back toward land.
And if no such attempt was made, then I believe we have two possible explanations:
1) no one WAS alive, the ghost ship scenario
2) the controls were so badly damaged by [the catastrophe] that turns were impossible. Does anyone know what the prevailing wind direction is in the area?
Does the new interpretation of the data/pings indicate heading or routing? If they indicate heading, then wouldn’t Inmarsat’s conclusions be correct? If it is routing, then wouldn’t that leave the possibility that there were multiple headings over those five or six hours?
Just heard on CNN they did use the spot beams on IOR S/C to distinguish the direction. If true, I’d call that solid proof.
(what’s wrong Jeff, didn’t think Christmas Isl a plausible alternative scenario… if low on fuel from low-altitude flying? It IS smack on the 8:11 ping-arc. I emailed Marty Savidge and asked him to have Mitchell try landing his sim on the C-Isl strip, then remove the Inmarsat antenna and throw it in the lagoon… let’s see if he can put it down there)
I’m still concerned about the overall solution. If they have independent spot beam data, I’m ready to agree…it went south for sure. However, if they descended to 12000 feet and slowed down to 250 kts or so, and stayed there, rather than climbing back to 37000 feet (why?), the same handshake data can be fit to a shorter path ending up further north. According to the Delta 777 manual, the fuel burn per hr is about 90% of what it would be at 37000 feet and 475 kts. So the fuel time would be about the same or a bit more, but the path would have to cut through the circles with a more easterly heading (for the same radial velocity at a slower speed). It is only by assuming they climbed back to 35-37000 feet that the data fits a more southerly path that went farther.
The more I think about it, the more concerned I am about the remaining hidden assumption that they were at FL35-37, thus 450-500 kts. Let’s assume for now that the earth shape or spot beam data definitively shows what hemisphere they were in. Even if that is true, there are still an infinite number of possible “generally southerly solutions” that will fit the 7 handshake circles depending on the assumed speed. All solutions require the same radial velocity (to meet the Doppler solution), but the direction is not uniquely determined without a speed assumption. If they were at 12000 feet, they certainly were not going 475 kts. If they were going 250 knots, they would have to be going nearly due east to cross the 7 handshake rings with the same radial velocity as they would in the NTSB assumed southbound path. Inmarsat needs to explain.
I really have no knowledge whatsoever about satellites or flying like most of you here, so I apologize for my stupidity on the subject, but I’m obsessed with this mystery and have a burning question:
How can any definitive conclusion about direction be reached when all the input they have is the Inmarsat hourly ping data (which gives us north/south corridor), and several assumptions; altitude/fuel/speed for determining distance, and ping data from “previous MAS Boeing 777 flight paths” to compare with data from MH370 for determining direction. (At least this is what they say they used to arrive at their conclusions and admitted it was very limited data to work with).
I understand WHY they would use the comparison to previous 777 flights, it’s because they really don’t have anything else and they were asked to come up with an answer. And in their comparisons, they found a flight match for the southern route but could not find any matches for the northern route so it was ruled out.
Again, maybe I’m missing a whole lot here, but wouldn’t this mean that for a match to be found, they’d have to also be relying on the assumption that MH370, wherever it went, traveled a known flight path? If it does, is this really a reasonable assumption in ruling out the northern route? If I were going to steal a plane, I certainly would want to stay out of the main corridors.
@airlandseaman
Absolutely ! – there are a ton of assumptions in all this. Inmarsat proved the plane was in the southern hemisphere. Plane could be almost anywhere along the southern arc. Plane could have flown in circles in theory, as long as it was heading away from the satellite when the ping was happening each hour. Its been suggested on this blog Christmas Island. Could perhaps work. But if you assume a straight line, 35-37000 ft, and 450 or so kts – ie an autopilot zombie plane – its down by south indian ocean. I still want to see the 7 ping arcs. Then we can see where straight lines get us, or where we get to if under constant pilot variable control.
Its been so frustrating watching CNN and seeing Wolf Blitzer bad mouth Chris McLaughlin cause he hesitated when Wolf asked if the plane definitely went south and into the indian ocean. Thats a compound question. Inmarsat ONLY proved the plane went south. McLaughlin was clear with Anderson Cooper this morning and evening.
@Littlefoot – I never did get around to posting the video of Tom Foreman explaining that Inmarsat used the shape of the earth in the calculations – someone else did post it though – http://www.youtube.com/watch?v=-JfiF98EE04
As I noted two days ago, an analysis if the Inmarsat data may have shown a Very subtle Doppler shift in the engine signal from 370. This is a frequency shift ( not related to the time delay analysis of the handshakes) and it could give a N-S distinction. It is not going to be trustworthy, however.
So one piece of identifiable debris and our guessing game on this web site is over. No debris, it will continue and drive us crazy.
No , sorry Mr Ch.McLaughlin, it could NOT give a N-S distinction. Once (approximately)Longitude 88 east was crossed we need to observe handshake signal exchange from/with the next Sat. at 25 east. Converge the rings
and you have the positions exactly for time 08.11 Singapore time.Uighurs (they should hold chinese passports) were onboard in large numbers,some knew as well as the flight crew knew the destination may not be ZBAA/PEK .Bejing,china. Flashing the transponder again after 1:10 min off-time reveals the need of collision traffic indication info at 29500 feet, to find and meet up for radar piggy-back Singapore flight 68 who was cleared to Barcelona on 30000 feet.
Arthur
Why do you say the Doppler shift can give a N-S distinction but is not trustworthy? Inmarsat modeled N vs S formulas – they looked at other N vs S bound Malaysian Air flights – I can imagine KL to Perth vs, KL to Beijing. They report that their formula correctly identifies which flights are N vs S – then they tested against the data for the missing MH370. Whats not trustworthy. It should be 100% trustworthy. There should be no question it went S not N. Now did it go due south to the indian ocean? thats another matter. Could it be somewhere else along the south arc? like north of Australia? Like sitting on Christmas Island? Maybe. Or was there – refueled and took off? Sure. But all not very likely. Its likely it was a zombie plane – flew 7+ hrs on auto pilot at normal speed and altitude straight until the fuel ran out and that assumption puts it approx where they are searching. It glided down into the ocean (or if pilot awoke as they decended, he tried to ditch and made a soft-ish landing? that would all explain minimal break up and debris – did anyone get out on rafts – unlikely – and at this point they havent survived. Its funny, on the one hand folks in China are upset that Malay Air is no longer considering north route and on the other hand upset that if it was the south route why didnt we get down there sooner to look for survivors. cant have it both ways. no one reasonably knew were this was – inmarsat data never meant to be used for this and great thinking and testing of hypotheses allowed them to refine the search options.
Measuring frequency shift of the proximity speed is not conclusive,it cannot make sense.I invite all hobby and pro mathematicians to give their shot tiger_2@hotmail.com . We
will find this Boeing.Southern Arc does not make sense if on Capt. Shah’s hard drive night formation establishment maneuver and if his Collision warning radar display can only flash up upon turning on his mode A , C , and S transponder
when he was searching the night sky for the piggy-back shadow of Singapore at 30000 , his transponder is registration emitting and Altitude 29500 feet . ELT and blackbox may have been stolen and dumped before the flight. e.g. in USa the black market of stolen AIRbags is currently 65 Billion$ according insurance sources. An Item , that is never checked for presence in cars and only once in so many weeks in commercially operated airplanes according maintenance inspections.
Hi Jeff,
I believe your green circle assumption is flawed. The statement by Inmarsat was that it was always receding, in effect.
However, the plane could have been approaching the subsatellite position from 2:11 to 3:10, then turned north or south away from the sat at the last minute. Though far fetched, it could have been approaching 0N 64E for 59 minutes every hour and receding for 1 minute. If this happened even one time, the green circle is incorrect, by possibly 560 miles.
That could easily restore Keith Ledgerwood’s route as a solution to the north. It also might cure the problem of the plane turning only a few minutes after radar loss. It didn’t need to – any time within the next hour could still lead to a receding Doppler.
Shrinking the green circle would both allow a northern “shadow” trip or a southern trip away from Indonesia’s radar.
Slight clarification – Inmarsat said the “ping timings got longer.” This could be interpreted in two ways – they were stretched, as in receding due to the Doppler effect, or they were late, as in farther away. I’m assuming the former.
@Lee Schlenger; @Arthur T
I watched Tom Foreman’s explanation live. I don’t understand the earth shape argument. It sounds like something got twisted in translation from engineering to English. The fact that the earth is not perfectly round and homogeneous in density does cause orbital anomalies that are detectable, but I don’t see a direct connection to the N-S ambiguity resolution. I think it is more likely that the relatively high orbital inclination of the s/c, caused in part by such “fat earth” anomalies, was exploited to help resolve the ambiguity. Think of this way. The satellite is moving north and south in a skinny figure 8 pattern, one procession per day. At each handshake, the s/c was in a slightly different place. Positioning by triangulation normally takes at least 2 or 3 ranges measured at the same time from 2 or 3 places. But if one adopts a few assumptions about the velocity of the aircraft (assumed constant), and solves all 7 sets of the equations corresponding to the 7 handshakes, all in one grand solution (Kalman, Least Squares, etc.), I think the subtle change in satellite position will give a weak position solution for all the handshakes. Maybe this is what Tom was referring to.
Arthor: There was no engine data being transmitted. The Doppler on the handshake packets should be easy to measure and it provides the radial velocity, but no tangential velocity component. For an aircraft with a 45 degree antenna elevation angle, flying directly away from the sub-satellite point, the combined up/dn Doppler would be ~1kHz change in the 1.5/1.6 GHz carrier. If the aircraft was flying tangential to the LOP, the Doppler would be zero. But without knowing the speed AND the Doppler, you cannot resolve direction.
” the Washington Post published a map that showed what appeared to be the results of just such analysis as applied to the southern route, carried out by the NTSB:”
That map is bunk! If you take a look at the full map in the Washington Post (as linked above) then it shows a ‘Position of satellite’ at approximately latitude 2 deg south, longitude 56 deg east (to repeat: 2 SOUTH and 56). In fact the sub-satellite point (i.e. the drop line from the satellite to Earth’s surface) was NORTH of the equator throughout the flight of MH370, and also close to longitude 64.5 degrees east (NOT 56 degrees!).
Further, the four red ping arcs shown are concentric. This is also bunk because the satellite moves in declination/latitude over time. At 08:11 MYT (00:11 UTC) the satellite’s declination was 0.589 degrees north; at 05:11 MYT (21:11 UTC), the time of the earliest arc shown in that graphic, it was almost one degree north of there (close to declination 1.5 deg north).
See my further comments and graphics at duncansteel.com
Does anyone know how accurate the aircraft’s INMARSAT transmit frequency is maintained? Is it locked to it’s recieve signal? In order to calculate the true velocity of the target it’s essential to know the exact frequency of the transmitter. Any thoughts?
I am sure it uses a NOC generated pilot carrier, or a local oscillator or both, locked to a GPS time base. The system has to do this to minimize loss of bandwidth allocated to the uncertainty. The L band spectrum is an extremely limited and extremely expensive resource on the space segment, so everything is done to squeeze the max utility. In any event, the Doppler is probably accurate to <10 Hz. The Doppler is typically measured so that the return link carrier can be biased to hit the spacecraft in the center of an FDMA channel. I'll check for a source to confirm, but that is SOP for narrow band systems.
Thanks airlandseaman.
OK, So if I can wrap my head around this. If the net velocity of the target is minus 100 mph (departing the location of the satellite) we’d see aprox. minus 200 Hz shift in the receive frequency?
With a system stability better then 10 Hz this becomes workable.
It’s interesting that INMARSAT not only archives the DATA but the Rx frequency and return delay for every transmission(amongst other parameters I’m sure).
That’s quite a system!
This was just released but theguardian.
Much more detail on the INMARSAT tracking.
http://www.theguardian.com/world/2014/mar/25/mh370-relatives-of-lost-passengers-protest-against-malaysia-live-updates
Update: Found several documents confirming use of a pilot carrier. Doppler estimates should be very accurate.
News reports, however, continue to confirm that the Inmarsat solutions all depend on a critical assumption: constant speed (and direction). For example:
“These pings from the satellite – along with assumptions about the plane’s speed – helped Australia and the US National Transportation Safety Board to narrow down the search area to just 3 per cent of the southern corridor on 18 March.
“We worked out where the last ping was, and we knew that the plane must have run out of fuel before the next automated ping, but we didn’t know what speed the aircraft was flying at – we assumed about 450 knots,” said McLaughlin.”
http://www.telegraph.co.uk/technology/news/10719304/How-British-satellite-company-Inmarsat-tracked-down-MH370.html
Unless they are adding independent data not disclosed, like Australian OTHR data, there is no solid basis for the 450 kts assumption. In fact, it could be argued that 250 kts is more likely if they descended to 12K feet. Why would they have gone back up?
@ManvBrain: I also heard for the first time this morning in an interview on CNN that the aircraft slant range decreased initially, then increased. No disclosure of which handshakes were showing smaller circles. This means that the aircraft, flying at lower speed and altitude might very well have gone northwest, then returned in a more eastbound direction way north of where they are looking.
Will someone PLEASE put me in touch with the right Inmarsat cone heads? I think the satellite 1.7 degree inclination angle can be exploited by using a single simultaneous solution for all the range and Doppler data producing an unambiguous, if somewhat noisy PATH…not just rings and radial velocity that require a speed ASSUMPTION to put the plane in the current search area.
Thanks for the link Gordpata. However, there’s nothing new there in McLaughlin’s interview. The correlation with other 777 flights is not unexpected given that they are assuming 450 kts. Change that one ASSUMPTION and you get a different path altogether, much further north and east of where they are looking.
Jeff: I’ll call in a minute.
Trivia: Najib Razak’s future son-in-law Daniyar Kesikbayev is Nursultan Nazarbaev’s step-nephew who’s apparently wanted by Interpol.
@ airlandsea , @ LeeS :
If you stayed up late enough last night you may have caught the presser w/ AU Min of Def. He made reference to NOT ONLY pings, but also to engine performance data. So it very well could be that InMarsat’s satellite is doing more than handshakes with each aircraft, those handshakes may be data acquisition from each aircraft’s engines, going to RR, and that data is only interpreted for and shared with those airlines which are PAYING for engine-data-interpretation service. IF that is the case, then they (in consult w/ RR) may have been able to glean from that data climatological info like relative humidity, whether or not craft was over salt-water, etc … (?)
I am a fan of a good conspiracy plot, AND I have to accept Inmarsat’s conclusion of the Southern track b/c i’m not smart enough to disprove it. However, assumptions based on altitude, and speed, should not have been made, not when radar-interpretation-specialists (from western countries) have been going over the data now for more than two weeks and have determined that the craft was at 12 K altitude while still in the Malaysia/Indonesia area. No reason to assume a return back to 35-37 K feet, is there?…
Those of you who are pilots — If there is no one capable of controlling the craft, or if flight-management inputs are non-operable, and the craft is in a fugoid/dutch-roll, its going eat up a lot of lateral space and altitude (and with that, fuel also) without really making much forward progress, correct? So if that was the case, it could have been anywhere along that Southern arc at 8:11, couldn’t it have?
Has anyone read this?
http://www.themalayonline.com/what-you-think/article/information-provided-to-mh370-investigation-by-uk-aaib
There’s one very puzzling piece of info in there: apparently there was an additional partial ping out of the hourly routine at 01:19! A contact was tried, but not completed. Now, what could this mean? 01:19 is a crucial time, since it’s the time of the last radio message of the copilot, that everything was allright. But this partial ping might indicate, that it wasn’t. Could it tell the time, when the ACAR was turned off/lost?
Another tidbit, fror what it’s worth: the AAIB still favores the human perpetrator theory, as communicated to the BBC. I’d like to hear their reasoning. Is it just the fact, that the chain of disastrous events, that led the plane into the Southern Indian Ocean, is so darn unlikely, or are there additional pieces of information and data, which point to human intervention?
How can the assumption be made that the aircraft maintained a single heading from the point of last contact? From the loss of contact in the South China sea to the last radar contact in the Malacca straight there were multiple heading changes. Assuming the report of the three waypoint changes in the Malacca straight is accurate and if the plane was under some control, then there can be no confidence in assuming the plane flew a single heading north or south. Only that the plane was somewhere on the arcs each hour.
Someone earlier noted that Chad Myers drew a nice straight line to south and then went on dismissively waving his hand over the north. Hypothetical: From 2:11 – 4:11 the flight continues northwest. 4:11 -5:11 Heads north. 5:11 – 7:11 west north west. 7:11 – 8:11 north. I just randomly made that up, but could the pings plot a route, north or south, something like that?
Correction!!! I was too quick here: the additional partial ping was at 00:19, one hour before the copilot’s last radio message! The ACAR system was definitely still working then.
The article is still interesting. And they are investigating this additional ping.
Littlefoot — No, that 00.19 is UTC, meaning 8.19am Malaysia time. It came after the final full ping. Inmarsat says it’s still trying to figure out what it’s all about
Wow.
Thanks, Jeff, I was too quick here.
Still, the article is interesting.
Maybe engines stopped working at 0:19 UTC.
Still unclear how much data RR and Inmarsat have. Engine data could give air speed. And radar data of Indonesia?
Could the partial ping have been from loss of power/ shutdown? Signing off?
No, Gene, I’m sorry, that I spread misinformation, by making assumptions about the timing too quickly. Basically it was the very last signal of the plane. It came at 08.19 Malaysian time after the last completed ping,which was at 08:11.
@ Little / @ Jeff :
That IS interesting. Eight minutes after 8:11. We might assume it’s a ‘sign-off’ message, saying ‘bye-now,’ at power-down, but Inmarstat would know that it was that, THEY would recognize it as being ‘normal,’ and they would not be curious.
So… what?.. a “hey, I’m in trouble, i’ve got a problem” message?…
@Gene
No – Inmarsat analysis proves it went south. However the assumptions about altitude and air speed is what gets you to the south indian ocean. But put those assumptions aside. The plane ended somewhere near that south arc. THERE IS NO LAND anywhere along the arc other than back up by Indonesia – and radar would have seen it – or perhaps christmas island – and the 2000 australian citizens living there might have phoned CNN by now if a plane landed there 2 weeks ago. there is no where along the south arc that the plane could have landed safely. Thats why Malay air could say it was lost. whether it REALLY is down in the south indian ocean – who knows – thats based on assumptions of speed and altitude.
@Lee
Thanks for the clarification. I asked because an earlier post by airlandseaman stated both speed and direction were assumed. As for the Christmas island assumption, please direct your comments to Gwiz.
I’m just a layman but note that the plane’s radio contact was switched off, or broke down, yet left the Immarsat responder alive, so it must have independent power. Can the satellite, or a ship, not interrogate it even though it may be under water?
It looks like all the “hourly ping” reports were another urban myth. Here’s what AAIB reported to the MH370 Investigation team.
1. 00:30 ACARS Message
2. 00:43 ACARS Message
3. 00:55 ACARS Message
4. 01:07 ACARS Message
5. GAP in ACARS and Handshakes
6. 02:25 ACARS Message?
7. 02:27 ACARS Message?
8. 02:29 ACARS Message?
9. GAP > 1 hour in ACARS and Handshakes
10. 03:40 First Handshake Ping
11. 04:40 Second Handshake Ping
12. 05:40 Third Handshake Ping
13. 06:40 Fourth Handshake Ping
14. GAP >1 hour in ACARS and Handshakes
15. 08:11 Final Ping (or partial transmission?)
Note: There have been many conflicting reports about whether RR received engine data after 01:07. Engine data is reported via ACARS, not Pings. The new time line above raises the question: Were the 3 closely spaced transmissions just prior to 02:30 the last ACARS messages, containing some engine data?
@ Gene / @ Lee :
Haha, I mentioned Christmas Island after noticing it IS the only landmass with an airstrip which sits on the Southern arc, but as Lee wisely points out, as these are 2000 Aussies living there and not primitive jungle people, the world would have heard about it. Even if it landed dead-stick and silent, and somehow got refueled, they would have heard it on take-off .
Let me be serious though… We can back up our computers these days using ‘cloud-based’ backup service like Carbonite. It’s tech-possible to have FDR and CVR data bounced off a satellite hourly, or twice hourly, from every commercial aircraft, captured and stored by its airline. We don’t know how this aircraft impacted the water, it may have been a nose-in crash, may have been a pancake-plosh. It may have been a survivable (by some) crash. We won’t know, unless and until that FDR is found, if ever. With such a system in place, Malay-Air would have known, within hours, where their craft went down, how it went down, and search & rescue assets could have been on the way. Without such a system, now there are only search and recovery involved; no ‘rescue.’
@airlandseaman, I suspected already, that the pings weren’t scheduled strictly hourly. Thanks for confirming that. But the last, apparently ‘incomplete’ one was at 08:19, only 11 minutes after the last ‘regular’ one at 08:11. And that needs additional explanation. What triggered that incomplete ping, and why can’t they explain it just yet? I’m sure, we all have something in mind, but I will leave it to the experts…
Littlefoot: Can you please provide the source for the 08:19 time? Note that the 08:11 time does not fit the hourly ping pattern either.
This continues to be the best discussion of these issues I’ve been able to find. I’ll leave the mathmatical analysis to those of you who are clearly more qualified, but I would really like to know if the conclusion that the plane went south is predicated on the assumption that the plane maintained a constant speed and heading. Those seem like crazy assumptions if it is true that the plane was changing heading, altitude and speed between when the transponder was turned off and when the plane was last tracked on military radar.
The coverage is unclear, but it seems to suggest that inmarsat’s analysis is based on the assumption that after it left radar coverage it made one more dramatic turn and then maintained a constant speed/heading. What is the basis for these assumptions? They certainly are not consistent with the plane’s behavior prior to 18:15 UTC.
@airlandseaman, why is there noted ‘ARCARS Message?’ at points 6,7 and 8 of your list with the contact times? Weren’t we told, that there were no more ARCARS transmissions after 01:07? Why do they assume, there could’ve been 3 ARCARS transmissions between 02:25 and 02:29?
@airlandseaman, I gave a link to a report in my comment at 10:19 am today. It’s very interesting for many reasons.
Wait a minute guys…
The media got more than ten days ago from Inmarsat ‘ping-data’ of pings supposedly at eleven minutes after every hour, From that CNN and all the rest .came up with their ‘arc-graphic’ of a Southerly and Northerly arc. Everyone assumed that was eleven minutes after the hours.
Inmarsat yesterday said they’ve refined their data and were confident enough to exclude the Northerly arc.
Now… are yous saying now that Inmarsat has said there were NOT ping-returns at eleven minutes after the hours?… that they were even ‘irregular.’?
@airlandseaman (and everybody else, who reads this report and my comments), please note, that I mentioned a wrong time first. Jeff corrected me. The last partial ping was 08:19 malaysian time.
@JJinJupiter
I have exactly the same questions. The current conclusions mathematically plot a nice curve or a line very nicely on an X and Y axis grid between point A and B. My problem is that I have done cross country flying with private pilots and experienced bush pilots and to get from A to B they didn’t necessarily follow a single straight line.