Malaysian Airlines MH370 contact lost
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Satellite is normally assumed to be at the equator and 64.5E. My reading suggested that during the flight of MH370 it's position varied between 0.8 and 1.5N because of it's little elliptical orbit up there. I have centered my rings at 1.2N as a compromise.
I can't remember now where the position information came from but armed with Steele's ring diameters and a circle generator, you can put them anywhere you like. It's a 10 minute job to generate your own rings.
I can't remember now where the position information came from but armed with Steele's ring diameters and a circle generator, you can put them anywhere you like. It's a 10 minute job to generate your own rings.
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@ Ulric
The circle generator is no big deal, if you have GE pro you don't need a circle generator.
But the satellite position information is kind of a big deal, that "little elliptical orbit" covers a lot of miles. Since you don't have the KML file do you have the distance you used for the 18:28 ring? (I know where the satellite was then.)
The circle generator is no big deal, if you have GE pro you don't need a circle generator.
But the satellite position information is kind of a big deal, that "little elliptical orbit" covers a lot of miles. Since you don't have the KML file do you have the distance you used for the 18:28 ring? (I know where the satellite was then.)
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I don't think it will help much but here it is
http://www.duncansteel.com/archives/549
If someone hadn't written it, I would have coded my own circle generator - it's easy to do - no need to pay Google for that. The other thing it's useful for is to put range rings around the known and suspected radar installations which might have picked up a trace.
http://www.duncansteel.com/archives/549
If someone hadn't written it, I would have coded my own circle generator - it's easy to do - no need to pay Google for that. The other thing it's useful for is to put range rings around the known and suspected radar installations which might have picked up a trace.
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Swissair 111 had a fire on board which disrupted the systems. We don't know what happened on MH370 but the speculation is that circuit breakers were pulled.
Consider your own PC. If you shut it down normally the event is logged, that is quite different from terminating the power by pulling the plug out (or burning the cables). In that case, you won't get a shutdown log but, depending on how the system is configured, you may get a message on reboot saying that the system was not cleanly shutdown.
Consider your own PC. If you shut it down normally the event is logged, that is quite different from terminating the power by pulling the plug out (or burning the cables). In that case, you won't get a shutdown log but, depending on how the system is configured, you may get a message on reboot saying that the system was not cleanly shutdown.
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Ulric
...before we blame a fellow worker.
In Swissair 111, the SATCOM logged on.
There was no "log off" data available from Inmarsat.
The log on was a "renewal".
The time of the "log off" could not be determined.
It was assumed this was due to a "power interruption".
That's the record. I merely am repeating it.
...before we blame a fellow worker.
In Swissair 111, the SATCOM logged on.
There was no "log off" data available from Inmarsat.
The log on was a "renewal".
The time of the "log off" could not be determined.
It was assumed this was due to a "power interruption".
That's the record. I merely am repeating it.
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INMARSAT 3-F1 Position Data
@Propduffer on 9th Jul 2014, 00:23--
John Zweck, an Australian Ph.D. in math now teaching at UT/Dallas, has posted satellite trajectory data in 1 second steps at:
Aqqa on MH370
About 2/3 down the page:
"The satellite position data from STK in 1 second time steps between March 7th 1100Z and March 8th 1100Z are available in the ECEF (fixed) frame and the WGS 84 frame. The LLA version includes latitude, longitude and altitude (geodetic height) above the WGS 84 ellipsoid and the LLR version includes latitude, longitude and radius from the centre of the WGS 84 ellipsoid."
Followed by links to files in several different formats.
Author's home page:
John Zweck
John Zweck, an Australian Ph.D. in math now teaching at UT/Dallas, has posted satellite trajectory data in 1 second steps at:
Aqqa on MH370
About 2/3 down the page:
"The satellite position data from STK in 1 second time steps between March 7th 1100Z and March 8th 1100Z are available in the ECEF (fixed) frame and the WGS 84 frame. The LLA version includes latitude, longitude and altitude (geodetic height) above the WGS 84 ellipsoid and the LLR version includes latitude, longitude and radius from the centre of the WGS 84 ellipsoid."
Followed by links to files in several different formats.
Author's home page:
John Zweck
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Confusion over BTO and Ping Angles
When the Signaling Unit Logs for 9M-MRO were released, Inmarsat described the BTO as being the round trip delay "relative to a terminal at a nominal fixed location". There were two different interpretations as to where that terminal sat - one had it at a fixed point on the earth, the other had it at a fixed point from Perth (and thus acting as a single constant offset to the round-trip delay.) These two interpretations led to different predictions for ping elevation angle as a function of time, up to 2 degrees.
The first interpretation seemed to make sense because its predictions matched well with the "7 Data Point" graph that showed ping angles for several times during the flight (aside from a puzzling constant offset in angle.) At the time, this graph seemed to provide the most reliable ping angles.
However, it is now clear that this first interpretation is wrong. Equation 1 in the ATSB report can be rewritten to show that the BTO is, indeed, just the round-trip delay plus a constant bias. Tables 1 and 2 of the ATSB report reinforce this view. Table 2, in particular - BTO Calibration at Kuala Lumpur - shows that the BTO and path length were both increasing at a time when the plane was sitting on the ground. The increase in path length was consistent with the increase in round-trip path between Perth and Kuala Lumpur in Table 1, and was due mainly to the satellite-Perth leg.
As a further check, I recomputed ping angles for both the portion of the flight where we have ADS-B data and for the later portion where one can make use of the ping ring plots in Figure 18 of the report. I get consistent agreement between these ping angles and the newly-interpreted BTO, with a spread of 0.2 degrees in elevation angle. These angles differ from those on the 7 Data Point graph by a peak-peak of 2 degrees - ouch!
Thus, we conclude that the "7 Data Point graph" is flawed. Perhaps it was drawn in a rush by someone for one of the family briefings. Its purpose was to show that the plane did not go to Beijing, for which high accuracy was not needed, but was not intended for anything else.
Duncan Steel's Ping Ring radii in message #549 posted on April 5, 2014 are derived from the 7 Data Point graph and thus are wrong. Unfortunately, Richard Cole's BTO model is also the wrong one, and his Appendix B distances are likewise wrong.
For what it's worth, I was following the wrong interpretion as well, until being confounded by the Kuala Lumpur BTO measurements. Since there is interest, I will give my values for BTO and such in a follow-on message.
The first interpretation seemed to make sense because its predictions matched well with the "7 Data Point" graph that showed ping angles for several times during the flight (aside from a puzzling constant offset in angle.) At the time, this graph seemed to provide the most reliable ping angles.
However, it is now clear that this first interpretation is wrong. Equation 1 in the ATSB report can be rewritten to show that the BTO is, indeed, just the round-trip delay plus a constant bias. Tables 1 and 2 of the ATSB report reinforce this view. Table 2, in particular - BTO Calibration at Kuala Lumpur - shows that the BTO and path length were both increasing at a time when the plane was sitting on the ground. The increase in path length was consistent with the increase in round-trip path between Perth and Kuala Lumpur in Table 1, and was due mainly to the satellite-Perth leg.
As a further check, I recomputed ping angles for both the portion of the flight where we have ADS-B data and for the later portion where one can make use of the ping ring plots in Figure 18 of the report. I get consistent agreement between these ping angles and the newly-interpreted BTO, with a spread of 0.2 degrees in elevation angle. These angles differ from those on the 7 Data Point graph by a peak-peak of 2 degrees - ouch!
Thus, we conclude that the "7 Data Point graph" is flawed. Perhaps it was drawn in a rush by someone for one of the family briefings. Its purpose was to show that the plane did not go to Beijing, for which high accuracy was not needed, but was not intended for anything else.
Duncan Steel's Ping Ring radii in message #549 posted on April 5, 2014 are derived from the 7 Data Point graph and thus are wrong. Unfortunately, Richard Cole's BTO model is also the wrong one, and his Appendix B distances are likewise wrong.
For what it's worth, I was following the wrong interpretion as well, until being confounded by the Kuala Lumpur BTO measurements. Since there is interest, I will give my values for BTO and such in a follow-on message.
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Ping Ring Data
Here are the ping ring data. Ang is the elevation angle. Ang and Arc are computed from BTO using a spherical Earth model. (I do convert geodetic to geocentric positions where appropriate.) The "Measured Ang" is either computed based on the known longitude and latitude at the time during the early phase of the flight or read off of Fig. 18 in the ATSB report. For the latter, I actually create my own graphics with ping rings overlaying an Earth map at the appropriate place and compared them with the Google Earth version in the report.
UT BTO Ang Arc "Measured" Source of "Measured"
deg km "Ang"
16:30 14933 46.90 4134 46.9 long = 101.69, lat = 2.72
17:07 15620 45.69 4253 45.6 long = 102.79, lat = 5.23
18:25 12520 53.31 3504 53.2 Fig 18, ATSB report
18:27 12533 53.28 3507
18:28 12490 53.39 3496
19:41 11500 56.17 3226 56.1 Fig 18, ATSB report
20:41 11740 55.41 3298 55.4 Fig 18, ATSB report
21:41 12780 52.44 3589 52.3 Fig 18, ATSB report
22:41 14540 47.86 4039 47.7 Fig 18, ATSB report
24:11 18040 39.87 4834 39.8 Fig 18, ATSB report
24:19 18400 39.10 4911
Long, lat are geocentric. 17:07 position taken from ATSB report.
UT BTO Ang Arc "Measured" Source of "Measured"
deg km "Ang"
16:30 14933 46.90 4134 46.9 long = 101.69, lat = 2.72
17:07 15620 45.69 4253 45.6 long = 102.79, lat = 5.23
18:25 12520 53.31 3504 53.2 Fig 18, ATSB report
18:27 12533 53.28 3507
18:28 12490 53.39 3496
19:41 11500 56.17 3226 56.1 Fig 18, ATSB report
20:41 11740 55.41 3298 55.4 Fig 18, ATSB report
21:41 12780 52.44 3589 52.3 Fig 18, ATSB report
22:41 14540 47.86 4039 47.7 Fig 18, ATSB report
24:11 18040 39.87 4834 39.8 Fig 18, ATSB report
24:19 18400 39.10 4911
Long, lat are geocentric. 17:07 position taken from ATSB report.
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@SK999
I don't know who you are and you only have four posts here, but everything you say checks out and you just saved me the trouble of contacting Richard to see what his take on all this is. So I'll go with your number for the 18:28 ring distance: 3496km = 1887.7nm rounded to 1888 nm. For the Satellite location at that time, my location checks with Vinnie Boombatz's link: 18:28:15 at 1.5691n 64.5286e.
So there we have it, AFIK everything is reconciled. We now have a solid Longitude to plot from at 18:28, and the Latitude can't be very far from MEKAR, the southernmost Latitude possible is 6° N - the FIR boundary, (we can be virtually certain the plane didn't cross into the Indonesian FIR there.) The northernmost Latitude is more open to debate; some people here apparently believe the plane went as far north as IGOGU or IGREX, I see the path most likely being IGEBO ---> POVUS , maybe as far north as NOPEK - but that's a separate subject.
So thanks Ulric, Vinnie and SK999 along with MM43 who started this thread.
I don't know who you are and you only have four posts here, but everything you say checks out and you just saved me the trouble of contacting Richard to see what his take on all this is. So I'll go with your number for the 18:28 ring distance: 3496km = 1887.7nm rounded to 1888 nm. For the Satellite location at that time, my location checks with Vinnie Boombatz's link: 18:28:15 at 1.5691n 64.5286e.
So there we have it, AFIK everything is reconciled. We now have a solid Longitude to plot from at 18:28, and the Latitude can't be very far from MEKAR, the southernmost Latitude possible is 6° N - the FIR boundary, (we can be virtually certain the plane didn't cross into the Indonesian FIR there.) The northernmost Latitude is more open to debate; some people here apparently believe the plane went as far north as IGOGU or IGREX, I see the path most likely being IGEBO ---> POVUS , maybe as far north as NOPEK - but that's a separate subject.
So thanks Ulric, Vinnie and SK999 along with MM43 who started this thread.
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Are you sure? While we all know PCs routers etc have log files which almost always log a shutdown request, these are only visible if you have access to the PC (or wreckage in this case). I am pretty certain there is nothing detectable outside the aircraft that lets you know if the RT, transponding or ACARS was powered down at the device or lost power. I don't have any specific details on the Satcom, but all of the information so far suggest the link communications are a logon/authenticate and then periodic status checks, but no expectation of a logoff or shutdown message when the system is powered down normally. So that to gives no clue as to why it stopped responding.
I would certainly expect the FDR to be able to answer many of these questions.
In any event, it is moot as I don't think there is any sensible scenario where someone is carfully following a power down protocol.
I would certainly expect the FDR to be able to answer many of these questions.
In any event, it is moot as I don't think there is any sensible scenario where someone is carfully following a power down protocol.
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That sounds like you are done and everyone can move along now nothing to see anymore..thanks for your help
You were quite certain based on one set of KLM that you had a done deal.., and asked for agreements by everyone. Until you were given the set corrected and now you are are sure as God made little green apples that it is a virtual..certainty...
almost a fact..is not the same even as almost the truth..But thank you for your help and take care too.
This man says in item 8 there is a significant degree of inaccuracy..in the whole ping matter to begin with.
Malaysian MH370: SATCOMS 101 (Part One) | Air Traffic Management | Air Traffic Management - ATM and CMS Industry online, the latest air traffic control industry, CAA, ANSP, SESAR and NEXTGEN news, events, supplier directory and magazine
I am just curious if there is any information how defective inmarsat equipment has behaved in the past..spurious bursts ..as they do have a return defective equipment policy and secondly can a defect like that collapse a planes electronics ..
Thank you
You were quite certain based on one set of KLM that you had a done deal.., and asked for agreements by everyone. Until you were given the set corrected and now you are are sure as God made little green apples that it is a virtual..certainty...
almost a fact..is not the same even as almost the truth..But thank you for your help and take care too.
This man says in item 8 there is a significant degree of inaccuracy..in the whole ping matter to begin with.
Malaysian MH370: SATCOMS 101 (Part One) | Air Traffic Management | Air Traffic Management - ATM and CMS Industry online, the latest air traffic control industry, CAA, ANSP, SESAR and NEXTGEN news, events, supplier directory and magazine
I am just curious if there is any information how defective inmarsat equipment has behaved in the past..spurious bursts ..as they do have a return defective equipment policy and secondly can a defect like that collapse a planes electronics ..
Thank you
JamesGV:
Sorry, I neglected to answer your question. Once logged off, the flight crew would need to log on again through one of the flight deck CDUs. There are two types of log on available - auto, where the system will log on to the best available satellite; or manual (constrained), where the system can be constrained to log on to a particular satellite. I could be wrong, but I think that once the system is manually logged off, it will not log on again until one of those options is selected.
Note: I am only trying to explain how the system works on the flight deck. I am not inferring what may or may not have happened in the case of MH370.
As a way of "resolving" this "log off and Log on" issue which is believed to have occurred at "some time prior to 1825 UTC" and "at 1825 UTC", you are saying with your time on T7's it is possible to "force" a "log off" without de-powering the system...and without leaving the flight deck.
Assuming you did this. The system has power but is "off line", how would you "log on" again ? Would this be something that would be "automatic" ? Or a "manual" function ?
Assuming you did this. The system has power but is "off line", how would you "log on" again ? Would this be something that would be "automatic" ? Or a "manual" function ?
Note: I am only trying to explain how the system works on the flight deck. I am not inferring what may or may not have happened in the case of MH370.
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I fly the B777 and SAT COM LOSS is very common, it dates back from B777 rolled out.
After a while datalink will be lost too, then com is re established, datalink follows soon after. This happens several times during any flight. I am amazed nobody mentioned it.
After a while datalink will be lost too, then com is re established, datalink follows soon after. This happens several times during any flight. I am amazed nobody mentioned it.
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An issue is... there is no notification if ACARS "dumps".
Post ETOPS after oceanic entry, if you don't update, you won't know.
And SATCOM can (and does) go "offline".
The next log on is a "renewal" not "initialisation".
If VHF/HF is required and not attained (as can be in an incident), what do you report ? You simply can't.
Is there an AUTO INIT issue on the B777 (all series), especially earlier series?
Post ETOPS after oceanic entry, if you don't update, you won't know.
And SATCOM can (and does) go "offline".
The next log on is a "renewal" not "initialisation".
If VHF/HF is required and not attained (as can be in an incident), what do you report ? You simply can't.
Is there an AUTO INIT issue on the B777 (all series), especially earlier series?
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@sysconfig
In the same vein of sarcasm I thank you for your comment.
But it should be pointed out to you that the above exchange was needed in order for everyone to "move on" with the same point of reference.
Up until this discussion, there had been no way for any but the most diligent and up to date sat engineer types to know the location of the plane at 18:28, because of a mistake that had been made early on. If you will read sk999's post on the previous page you will learn that Duncan Steel's Ping Ring radii are wrong, as is, Richard Cole's BTO model, and I dare say that without the above conversation mm43's graphic on this page would have carried forth the same error.
I'm glad to see that you made it as far as two posts, but it seems that it's time for you to get a new handle (probably once again.)
In the same vein of sarcasm I thank you for your comment.
That sounds like you are done and everyone can move along now nothing to see anymore..thanks for your help
Up until this discussion, there had been no way for any but the most diligent and up to date sat engineer types to know the location of the plane at 18:28, because of a mistake that had been made early on. If you will read sk999's post on the previous page you will learn that Duncan Steel's Ping Ring radii are wrong, as is, Richard Cole's BTO model, and I dare say that without the above conversation mm43's graphic on this page would have carried forth the same error.
I'm glad to see that you made it as far as two posts, but it seems that it's time for you to get a new handle (probably once again.)
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very nice map mm43, as usual. what is the average ground speed of this great circle trajectory ?I tend to agree with OleOle when he suggests that the 18:40 BFO value of the C-channel Rx (during the Call Progress - Test ) around 90 Hz is strongly indicative of a south bearing at 18:40. It may allow the A/C to fly around the Indonesian air space, crossing it only in a tangential way (flying around Banda Aceh). I am running a new MC simulation assuming the south turn is one minute before 18:40 and taking in account the 88 Hz BFO value at 18:40.
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Originally Posted by Hyperveloce
...what is the average ground speed of this great circle trajectory ?
Start of track = 6.9752N 93.1072E, 172.4814T 131.144NM from VOCX
End of track = 29.8542S 98.4167E
Initial HDG = 172.3201T
Final HDG = 171.2092T
Dist = 4114660m 2221.739NM
Elapsed Time = 4.6405HRS - 4H 38M 26S
Ground Speed = 478.766KTS
Sorry about the "accuracy"
Someone else asked for positions crossing each ring. I'll calculate those when I get some time.
As I've previously said, the graphic is just speculation based on the ability to derive a GC track at around 0.84 Mach. With regard to the southward turn at 1830, I assume that any turn or climb taking place at that time could provide the apparent BFO change.
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I have created a Google Earth KMZ file with accurate rings and track plots at 20 kt intervals from 490kts to 410 kts and projected where 390 and 370 kts would fall on the 00:11 ring. ( I didn't include the 00:19 ring because I felt it would add more clutter than information.)
I chose a different route than mm43, I plotted what is probably the shortest route possible; I made the route through the strait pass south of MEKAR and from the 18:28 ring the route went direct to IGEBO and POVUS.
I included stuff from east of the 18:28 line, but the purpose of making this kml file available is for the 19:28 line and the southern route.
The KMZ file is at: https://www.dropbox.com/s/jz4d1j674o8g2a3/MH370.kmz
Pictures of the Google Earth presentation are at:
http://i1349.photobucket.com/albums/...psa1a0ba64.jpg
http://i1349.photobucket.com/albums/...ps31397ae3.jpg
I chose a different route than mm43, I plotted what is probably the shortest route possible; I made the route through the strait pass south of MEKAR and from the 18:28 ring the route went direct to IGEBO and POVUS.
I included stuff from east of the 18:28 line, but the purpose of making this kml file available is for the 19:28 line and the southern route.
The KMZ file is at: https://www.dropbox.com/s/jz4d1j674o8g2a3/MH370.kmz
Pictures of the Google Earth presentation are at:
http://i1349.photobucket.com/albums/...psa1a0ba64.jpg
http://i1349.photobucket.com/albums/...ps31397ae3.jpg