Malaysian Airlines MH370 contact lost
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MH370: Transport Ministry releases preliminary report, cockpit-air traffic control recordings - Nation | The Star Online
Had the MoT lost sight of reality when it suggested such "possible routes" ?
Maybe that routes skimming around the Indonesian airspace are conceivable ?
Which kind of route (compatible with both the BTO and the BFO) would you suggest between 18:28 and 19:41 ?
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Had the MoT lost sight of reality when it suggested such "possible routes" ?
If they would just release the 18:07 ACARS information, along with their actual radar track, the search for the resting place of 9M-MRO would probably become unnecessary.
Which kind of route (compatible with both the BTO and the BFO) would you suggest between 18:28 and 19:41 ?
I believe that my proposed flight path is supported by OleOle's BFO hypothesis, and it is not the only solution bypassing Indonesian territory that fits the current understanding of BFO information. There is nothing to support the flight passing over Indonesian territory, yet there is strong evidence (Indonesian statements) to the contrary.
There is nothing to support the flight passing over Indonesian territory, yet there is strong evidence (Indonesian statements) to the contrary.
You seem to have unswerving faith in the Indonesian statements, yet discredit the information released by the Malaysians as a 'smokescreen'.
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I don't see any reason for treating one set of statements differently to another. In God we trust. All others must bring data.
http://www.lockheedmartin.co.uk/us/n...duction-r.html
http://www.lockheedmartin.co.uk/us/n...duction-r.html
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Put another way - bandwidth.
In some areas the data link from the VHF ground station may have a very low bandwidth with limited capacity and slow speed. The satellite link will have the necessary high-speed links from ground station to the main base system. All that is necessary is to ensure that the satellite bandwidth is sufficient for the maximum traffic levels.
While it would be very expensive to increase satellite bandwidth it would involve fewer agencies and be more easily achieved on an international scale than for national agencies.
In some areas the data link from the VHF ground station may have a very low bandwidth with limited capacity and slow speed. The satellite link will have the necessary high-speed links from ground station to the main base system. All that is necessary is to ensure that the satellite bandwidth is sufficient for the maximum traffic levels.
While it would be very expensive to increase satellite bandwidth it would involve fewer agencies and be more easily achieved on an international scale than for national agencies.
The customers will be the ones having to upgrade their existing SATCOM systems to obtain the increased bandwidth.
However, most transoceanic aircraft are already capable of ADS-C over SATCOM that will work on current low bandwidth systems, and all they need to alter is the reporting rate. As was recommended by the French BEA after the AF447 crash.
I don't own this space under my name. I should have leased it while I still could
Ian, I am a tyro there but surely the aircraft narrow or slow connection is not a problem for the satellite companies. It must mean their uplink is slow but not a problem for the satellite.
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Question for Ian W
[mm flynn] 2 - People have represented that Malaysian Airlines did not use the satcom for ACARS, yet the official preliminary report declares it did,
Thank you for sharing your knowledge.
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my understanding was they subscribed to RR but VHF only.
The satcom would be on for the satphone so it would look for a logon, how you stop the RR acars going via sat when you don't pay for it I have no idea, but suspect something like lack of a data key would lead the satellite to ignore it.
The satcom would be on for the satphone so it would look for a logon, how you stop the RR acars going via sat when you don't pay for it I have no idea, but suspect something like lack of a data key would lead the satellite to ignore it.
anyone comment on this?
(the post from duncansteel.com) :
Byan C.
2014/07/03 at 08:22
I woke up wondering if Duncan thinks I’m some kind of crackpot, so I thought I should send you a clearer explanation. If R represents satellite to plane distance, s, p, r reresents the satellite, plane, and reference satellite respectively. Numbers 1 and 2 represents two points in time and x, y, z are the coordinates. Then,
(x-xs)^2 + (y-ys)^2 + (z-zs)^2 = Rs^2
(x-xr)^2 + (y-yr)^2 + (z-zr)^2 = Rr^2
x^2 + y^2 + z^2 = r^2 where r = earth radius and recognizing that
xs^2 + ys^2 + zs^2 = (r+H)^2 where H is the satellite height above the earth. The same applies to the reference satellite.
Converting BTO data to velocities yield:
V-Vsp-Vps = Vpr
Assuming a constant satellite velocity the Vsp + Vps = Rs2 – Rs1
Similarly, Vpr = Rr2-Rr1 or Rr2 = Rr1 + Vpr
This is where I got into trouble. Since Rr2 depends on Rr1 if I don’t check the methodology using the course defined by the BTO data, I don’t get a good fit to the BTO data at 19:40. After solving, I plug the plane velocities derived from (x2-x1)/(t2-t1) to a program the solves based on the distance traveled between 2 ping rings. This routine calculate the BTO values based on the actual Vsp at time t. Comparisions indicate that my solution using average Vsp values is yielding reasonable results. To calculate values using the actual Vsp value at time t involves solving 10 equations with 10 unknowns. The good news is that the solution would reduce to a quadratic equation. It is interesting that the solution for the equations based on distance traveled yields 2 roots with different latitudes. The solution to the equations based on velocities yields 2 roots with different longitudes. 1 to the west of the satellite and 1 to the east, effectively resulting in 1 solution. As a check, I plugged in Ra and Rs values for the northern and southern paths, it duplicates those paths.
Imagine my shock after I got this debugged (I keep reversing signs in my vector math) and I get a result that indicates the plane took a large circular path to the south heading eventually back to KLIA. I almost fell off my chair. I was not expecting this. I have to admit that I have not been that excited about anything in a long time, hence my need to hurriedly share this with someone.
I’m sharing this at this time because I believe the actual solution will be difficult to achieve. I could sove the 10 equations, but developing reasonable flight paths is beyond my ability.
I indicated that I thought we should keep this private because if there is a 3rd flight path, this will cause hugh controversy and we need to be certain before presenting such a result. Perhaps, my results are just a fluke of the data, but since I achieved these results with absolutely no manipulation of the raw data, I feel like it needs to be pursued further.
(the post from duncansteel.com) :
Byan C.
2014/07/03 at 08:22
I woke up wondering if Duncan thinks I’m some kind of crackpot, so I thought I should send you a clearer explanation. If R represents satellite to plane distance, s, p, r reresents the satellite, plane, and reference satellite respectively. Numbers 1 and 2 represents two points in time and x, y, z are the coordinates. Then,
(x-xs)^2 + (y-ys)^2 + (z-zs)^2 = Rs^2
(x-xr)^2 + (y-yr)^2 + (z-zr)^2 = Rr^2
x^2 + y^2 + z^2 = r^2 where r = earth radius and recognizing that
xs^2 + ys^2 + zs^2 = (r+H)^2 where H is the satellite height above the earth. The same applies to the reference satellite.
Converting BTO data to velocities yield:
V-Vsp-Vps = Vpr
Assuming a constant satellite velocity the Vsp + Vps = Rs2 – Rs1
Similarly, Vpr = Rr2-Rr1 or Rr2 = Rr1 + Vpr
This is where I got into trouble. Since Rr2 depends on Rr1 if I don’t check the methodology using the course defined by the BTO data, I don’t get a good fit to the BTO data at 19:40. After solving, I plug the plane velocities derived from (x2-x1)/(t2-t1) to a program the solves based on the distance traveled between 2 ping rings. This routine calculate the BTO values based on the actual Vsp at time t. Comparisions indicate that my solution using average Vsp values is yielding reasonable results. To calculate values using the actual Vsp value at time t involves solving 10 equations with 10 unknowns. The good news is that the solution would reduce to a quadratic equation. It is interesting that the solution for the equations based on distance traveled yields 2 roots with different latitudes. The solution to the equations based on velocities yields 2 roots with different longitudes. 1 to the west of the satellite and 1 to the east, effectively resulting in 1 solution. As a check, I plugged in Ra and Rs values for the northern and southern paths, it duplicates those paths.
Imagine my shock after I got this debugged (I keep reversing signs in my vector math) and I get a result that indicates the plane took a large circular path to the south heading eventually back to KLIA. I almost fell off my chair. I was not expecting this. I have to admit that I have not been that excited about anything in a long time, hence my need to hurriedly share this with someone.
I’m sharing this at this time because I believe the actual solution will be difficult to achieve. I could sove the 10 equations, but developing reasonable flight paths is beyond my ability.
I indicated that I thought we should keep this private because if there is a 3rd flight path, this will cause hugh controversy and we need to be certain before presenting such a result. Perhaps, my results are just a fluke of the data, but since I achieved these results with absolutely no manipulation of the raw data, I feel like it needs to be pursued further.
pardon, forgot to copy his autocorrection
"Byan C.
2014/07/03 at 22:34
I noticed a few typos in my last post. The most significant being that the differences in sat distances should have been divided by (t2-t1). On further reflection and trying a few different scenarios on my constant speed course calculator I’ve deduced the following.
If the radar data does not absolutely preclude a more north-western starting point(this matches the BFO) data better, then you need to proceed south for the next 4 ping rings at about 450 kts. The curious thing is that you can set a slightly north easterly course fo the last ping ring and it does not seem to affect the BTO values. I now think that the more northerly starting point and the interesting fact that you can turn to the northeast on the last ping ring is why my results obtained from not assuming a plane sppeed appears to suggest a route roughly returning to KLIA."
BFO/BTO was also a typo
"Byan C.
2014/07/03 at 22:34
I noticed a few typos in my last post. The most significant being that the differences in sat distances should have been divided by (t2-t1). On further reflection and trying a few different scenarios on my constant speed course calculator I’ve deduced the following.
If the radar data does not absolutely preclude a more north-western starting point(this matches the BFO) data better, then you need to proceed south for the next 4 ping rings at about 450 kts. The curious thing is that you can set a slightly north easterly course fo the last ping ring and it does not seem to affect the BTO values. I now think that the more northerly starting point and the interesting fact that you can turn to the northeast on the last ping ring is why my results obtained from not assuming a plane sppeed appears to suggest a route roughly returning to KLIA."
BFO/BTO was also a typo
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Malaysian Airways did not subscribe to Rolls Royce or Boeing health monitoring. ACARS was set up to only operate over VHF and the only INMARSAT subscription that the airline had was for satellite phone.
ACARS was set up to make routine reports at 30 minute intervals.
There was no connection of any sort between ACARS and SATCOM this was disabled as the company did not want to pay the subscriptions.
yeah he is a bit clumsy in explaining (probably not the lecturer but still good at math) but certainly makes point which has not been disproven yet
I have also mailed ATSB and got the same response, I doubt they even look at that given they probably get tons of crazy conspiracy mails on a daily basis, sorting everything out would take significant amount of time.
I have also mailed ATSB and got the same response, I doubt they even look at that given they probably get tons of crazy conspiracy mails on a daily basis, sorting everything out would take significant amount of time.
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From "MH370 Data Communication Logs.pdf"
Page 36:
17:07 - Last Acknowledged Ground to Air DATA-2 ACARS Message. Link lost at sometime between here and 18:03:41.
7/03/2014 17:07:48.907 IOR-R1200-0-36ED IOR 305 4 R-Channel RX 0x62 - Acknowledge User Data (R-channel)
18:03 - No Response to Ground to Air DATA-2 ACARS Data. Link lost at sometime between 17:07:48 and here.
Page 37:
7/03/2014 18:04:29.413 IOR-P10500-0-3859 IOR 305 10 P-Channel TX 0x61 - Request for Acknowledge (RQA) User Data
18:04 - Last of five requests for Acknowledge to the Air DATA-2 ACARS Data at 18:03
18:05:11 - Data-2 Ground to Air transmission, automatic ACARS retransmission after expiry of 90 sec timer. Terminal is not responding.
IMHO, this indicates that ACARS transited by SATCOM. At least some of them. From the comments, these ACARS are about "AIR DATA-2". From memory, these data contains ??? and fuel remaining at 17:07 (all the contents had not been published).
Page 36:
17:07 - Last Acknowledged Ground to Air DATA-2 ACARS Message. Link lost at sometime between here and 18:03:41.
7/03/2014 17:07:48.907 IOR-R1200-0-36ED IOR 305 4 R-Channel RX 0x62 - Acknowledge User Data (R-channel)
18:03 - No Response to Ground to Air DATA-2 ACARS Data. Link lost at sometime between 17:07:48 and here.
Page 37:
7/03/2014 18:04:29.413 IOR-P10500-0-3859 IOR 305 10 P-Channel TX 0x61 - Request for Acknowledge (RQA) User Data
18:04 - Last of five requests for Acknowledge to the Air DATA-2 ACARS Data at 18:03
18:05:11 - Data-2 Ground to Air transmission, automatic ACARS retransmission after expiry of 90 sec timer. Terminal is not responding.
IMHO, this indicates that ACARS transited by SATCOM. At least some of them. From the comments, these ACARS are about "AIR DATA-2". From memory, these data contains ??? and fuel remaining at 17:07 (all the contents had not been published).
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From "MH370_Considerations on defining_FactSheet.pdf" (ATSB 26 May):
The final ACARS transmission was at 17:07 UTC and provided location reports from the initial stage of the flight as well as a recording of the aircraft fuel remaining.
And from ""MH370 Data Communication Logs.pdf":
All the transmissions (RX and TX) between 7/03/2014 17:06:49.406 and 7/03/2014 17:07:46.905 (pages 30 to 36).
The fact that channels are assigned and user data acknowledged implies that the communication(s) were established. The SATCOM use and the known ACARS timing published are in same minute. So, my understanding is the data transmitted via SATCOM were, at least part of them, ACARS.
And voice by SATCOM use C channel.
But I can be wrong!
The final ACARS transmission was at 17:07 UTC and provided location reports from the initial stage of the flight as well as a recording of the aircraft fuel remaining.
And from ""MH370 Data Communication Logs.pdf":
All the transmissions (RX and TX) between 7/03/2014 17:06:49.406 and 7/03/2014 17:07:46.905 (pages 30 to 36).
The fact that channels are assigned and user data acknowledged implies that the communication(s) were established. The SATCOM use and the known ACARS timing published are in same minute. So, my understanding is the data transmitted via SATCOM were, at least part of them, ACARS.
And voice by SATCOM use C channel.
But I can be wrong!
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About the "circle path": I am afraid it is the result of oversimplification of the sat and the airplane relative trajectories.
Why using a constant speed for the sat? Inmarsat 3F1 data are available.
In my very simple model, I don't use spherical coordinates but Lat, Long and Altitude, because it is easier (for me) to "see" the data. It is not very accurate because "my" Earth is spherical, but just for "see" what can be deduced from the "faint" known data, I think it is enough.
I suspect the circling trajectory obtained by Byan C is from not taking in consideration the fact that all airplanes flying along a "straight" line are, in fact, flying on a circle around the Earth. If the simplification include flying in a (flat) plane, the only way to follow the BFO values is to "curb" the trajectory in the (flat) plane...
Why using a constant speed for the sat? Inmarsat 3F1 data are available.
In my very simple model, I don't use spherical coordinates but Lat, Long and Altitude, because it is easier (for me) to "see" the data. It is not very accurate because "my" Earth is spherical, but just for "see" what can be deduced from the "faint" known data, I think it is enough.
I suspect the circling trajectory obtained by Byan C is from not taking in consideration the fact that all airplanes flying along a "straight" line are, in fact, flying on a circle around the Earth. If the simplification include flying in a (flat) plane, the only way to follow the BFO values is to "curb" the trajectory in the (flat) plane...
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Yes, I am not at all sure about the "circle path" because it seems to imply such variations of speed and heading. I am also unclear about what failure conditions could cause an aircraft to fly such a path.
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Two lots of ACARS appears in the Inmarsat logs. You'll notice that the first message of each request is different.
The first request is:
17:06:49.406 ... R-Channel RX 0x22 - Access Request (R/T-Channel)
The RX indicates the direction of transmission which means that the aircraft had triggered the sending of ACARS data.
This is followed by a minutes worth of RX and TX messages until the final acknowledge at 17:07:48.907. I interpret this as the period when the ACARS data being sent and accepted. This means that ACARS-over-satellite must have been enabled.
The second request:
18:03:41.405 ... P-Channel TX 0x71 - User Data (ISU) - RLS
In this case the difference is that this is a TX. This means that the request came from the ground. My assumption is that someone (probably ATC) phoned either Boeing or Rolls-Royce to ask if they knew where the aircraft was and this request was triggered by Boeing/RR.
You'll notice that there are no RX messages following the second request so for some reason the aircraft was unable to respond. There are many reasons for a non-reply. It's possible that ACARS was turned off or unpowered. However ACARS-over-satellite needs needs a functioning SDU so it's also possible that this was unpowered.
The first request is:
17:06:49.406 ... R-Channel RX 0x22 - Access Request (R/T-Channel)
The RX indicates the direction of transmission which means that the aircraft had triggered the sending of ACARS data.
This is followed by a minutes worth of RX and TX messages until the final acknowledge at 17:07:48.907. I interpret this as the period when the ACARS data being sent and accepted. This means that ACARS-over-satellite must have been enabled.
The second request:
18:03:41.405 ... P-Channel TX 0x71 - User Data (ISU) - RLS
In this case the difference is that this is a TX. This means that the request came from the ground. My assumption is that someone (probably ATC) phoned either Boeing or Rolls-Royce to ask if they knew where the aircraft was and this request was triggered by Boeing/RR.
You'll notice that there are no RX messages following the second request so for some reason the aircraft was unable to respond. There are many reasons for a non-reply. It's possible that ACARS was turned off or unpowered. However ACARS-over-satellite needs needs a functioning SDU so it's also possible that this was unpowered.
I'm quite sure there was no failure before 2:22 MYT, after that maybe but it's only speculation based on satcom restart (which doesn't automatically imply failure).
the thing is there are many paths that could fit BFO&BTO values within margin of error, especially since we don't have a clue if any of speed/altitude/heading were constant at all
P.S. http://www.duncansteel.com/ group has made the new statement
this figure is interesting to me
http://www.duncansteel.com/wp-conten...-Figure-1a.jpg
anyone tell me why they assume constant heading from 19:41 onwards for a flight that drastically changed its heading 3 times in first ~2 hours?
the thing is there are many paths that could fit BFO&BTO values within margin of error, especially since we don't have a clue if any of speed/altitude/heading were constant at all
P.S. http://www.duncansteel.com/ group has made the new statement
this figure is interesting to me
http://www.duncansteel.com/wp-conten...-Figure-1a.jpg
anyone tell me why they assume constant heading from 19:41 onwards for a flight that drastically changed its heading 3 times in first ~2 hours?
My assumption is that someone (probably ATC) phoned either Boeing or Rolls-Royce to ask if they knew where the aircraft was and this request was triggered by Boeing/RR.
Last edited by BuzzBox; 16th Jul 2014 at 09:23.