(Updated 12th January 2021)
Floating debris from the crashed flight MH370 has been found and reported to the authorities in 22 locations throughout the Southern Indian Ocean (SIO). A total of 33 items drifted to these locations from the crash site, over a 3 year period. In a previous paper entitled “The Final Resting Place of MH370”, which I co-authored with Bobby Ulich, Victor Iannello and Andrew Banks, we analysed the MH370 flight path from Kuala Lumpur, Malaysia to a last estimated position of 34.2342°S 93.7875°E in the SIO, based on satellite, radar, weather, fuel and aircraft performance data. The purpose of this new paper is to determine the MH370 crash location using an analysis of the oceanic drift of these debris items, independently from any other data.
The MH370 crash location was 34.13°S ± 1.06° near the 7th Arc at a longitude around 93.98°E and the search area is defined as a circle with a radius of 65 nm centred on the crash location.
The updated paper can be downloaded here
@All
Here are links to the videos for BRAN2020 for each year 2014 to 2016.
2014
https://www.dropbox.com/s/9mgn2tauuawzpjt/br20_MH370_IOCC_sp122014.mp4?dl=0
2015
https://www.dropbox.com/s/o4ealp8p4asjr3l/br20_MH370_IOCC_sp122015.mp4?dl=0
2016
https://www.dropbox.com/s/uui5n3kdsrzles0/br20_MH370_IOCC_sp122016.mp4?dl=0
In case you missed them, here are links to the videos for BRAN2015 for comparison.
2014
https://www.dropbox.com/s/ythf1zo6ulngxn5/br15_MH370_IOCC_tp3l1p2dp_arc7_3608_252014.mp4?dl=0
2015
https://www.dropbox.com/s/rfh6itd8ebn20nz/br15_MH370_IOCC_tp3l1p2dp_arc7_3608_252015.mp4?dl=0
2016
https://www.dropbox.com/s/dvp4lzvyz13vcat/br15_MH370_IOCC_tp3l1p2dp_arc7_3608_252016.mp4?dl=0
Nice work, Richard. Thank you.
@All
Here are 4 more links with direct comparisons between BRAN2020 and BRAN 2015 for particular dates.
BRAN2020 Flaperon on 29th July 2015
https://www.dropbox.com/s/bflpmyjg3tfwkqq/br20_MH370_IOCC_tp3l1p2dpf10_20_99_arc7_4408_15%3A.pdf?dl=0
BRAN2015 Flaperon on 29th July 2015
https://www.dropbox.com/s/03ztqc1y0bftbn8/br15_MH370_IOCC_tp3l1p2dpf10_20_99_arc7_4408_15%3A.pdf?dl=0
BRAN2020 Generic on 15th December 2015
https://www.dropbox.com/s/rs4s6dnkt5oyoe9/br20_MH370_IOCC_tp3l1p2dp_arc7_4408_15%3A.pdf?dl=0
BRAN2015 Generic on 15th December 2015
https://www.dropbox.com/s/2hckmy154sagl86/br15_MH370_IOCC_tp3l1p2dp_arc7_4408_15%3A.pdf?dl=0
@All
Finally here are 12 videos showing the Drift Analysis for BRAN2020 and BRAN2015 for both the Flaperon and the generic debris for each year 2014 to 2016 for the full 7th Arc from 8°S to 44°S.
BRAN2020
Flaperon
2014
https://www.dropbox.com/s/1vzlti8k9r7h980/br20_MH370_IOCC_tp3l1p2dpf10_20_99_arc7_4408_152014.mp4?dl=0
2015
https://www.dropbox.com/s/xuw99c70ssudt7x/br20_MH370_IOCC_tp3l1p2dpf10_20_99_arc7_4408_152015.mp4?dl=0
2016
https://www.dropbox.com/s/edg7ahxqgcn9sxe/br20_MH370_IOCC_tp3l1p2dpf10_20_99_arc7_4408_152016.mp4?dl=0
Generic
2014
https://www.dropbox.com/s/k3u9kup71o0wxfg/br20_MH370_IOCC_tp3l1p2dp_arc7_4408_152014.mp4?dl=0
2015
https://www.dropbox.com/s/jzrht83sg05royu/br20_MH370_IOCC_tp3l1p2dp_arc7_4408_152015.mp4?dl=0
2016
https://www.dropbox.com/s/m4foio68f4evqj9/br20_MH370_IOCC_tp3l1p2dp_arc7_4408_152016.mp4?dl=0
BRAN2015
Flaperon
2014
https://www.dropbox.com/s/kcseb5393ag9txv/br15_MH370_IOCC_tp3l1p2dpf10_20_99_arc7_4408_152014.mp4?dl=0
2015
https://www.dropbox.com/s/03fiisygikvpgm6/br15_MH370_IOCC_tp3l1p2dpf10_20_99_arc7_4408_152015.mp4?dl=0
2016
https://www.dropbox.com/s/fjr6ockfw8fu8qw/br15_MH370_IOCC_tp3l1p2dpf10_20_99_arc7_4408_152016.mp4?dl=0
Generic
2014
https://www.dropbox.com/s/81zxcsz7jvuzyen/br15_MH370_IOCC_tp3l1p2dp_arc7_4408_152014.mp4?dl=0
2015
https://www.dropbox.com/s/q9akxa3omo31iim/br15_MH370_IOCC_tp3l1p2dp_arc7_4408_152015.mp4?dl=0
2016
https://www.dropbox.com/s/cae55vl032mjz4b/br15_MH370_IOCC_tp3l1p2dp_arc7_4408_152016.mp4?dl=0
@DennisW
You stated: “I remain disturbed by our lack of pic motive and mindset.”
Zaharie Shah’s home flight computer with a simulation (or perhaps a simulation of a simulation) to the SIO is evidence of planning, but not motive or mindset.
Some have speculated that following diversion the cabin was deliberately depressurised and all the passengers and crew suffered hypoxia. Some have also speculated that the cabin temperature reduced towards the outside air temperature.
I question the last speculation.
The Satellite Data Unit (SDU) logged on to the IOR satellite at 15:59:55 UTC as the MH370 flight was preparing for departure. The SDU had been powered up since 12:50:19 UTC and the IOR logon was performed as a warm start. The BFO took ca. 32 seconds to stabilise at 87 Hz.
https://www.dropbox.com/s/bqzcpa0d983efco/Kuala%20Lumpur%20Logon%20IOR%20Satellite%20at%201559%20UTC%20on%20the%20Ground.png?dl=0
The SDU had previously logged on to the POR satellite at 12:50:19 UTC as the MH370 flight was on the ground in Kuala Lumpur. The SDU had just been powered up and the POR logon was performed as a cold start. The BFO took ca. 163 seconds to stabilise at 347 Hz and reduced by 126 Hz from an initial value of 473 Hz.
https://www.dropbox.com/s/vhqiflqnbqli5ii/Kuala%20Lumpur%20Logon%20POR%20Satellite%20at%201250%20UTC%20on%20the%20Ground.png?dl=0
The next time the SDU logged on to the IOR satellite at 18:25:27 UTC as the MH370 flight was in the air over the Malacca Strait after diversion. The SDU had just been powered up again and the IOR logon was performed as a cold start. The BFO took ca. 158 seconds to stabilise at 144 Hz and reduced by 129 Hz from an initial value of 273 Hz.
https://www.dropbox.com/s/c7rhq4l0u3yc1xf/Malacca%20Strait%20Logon%20IOR%20Satellite%20at%201825%20UTC%20in%20the%20Air.png?dl=0
Both the cold starts at 12:50:19 UTC and 18:25:27 UTC took the same time (163 and 158 seconds respectively) and adjusted by the same BFO amount before stabilising (126 Hz and 129 Hz respectively). There has been speculation that MH370 cabin had been depressurised after diversion and the cabin temperature reduced with time to the external air temperature of -46.9°C at FL360. The SDU is located in the cabin in an overhead rack and is designed to operate between -55°C and + 70°C. Since the cold start logon at 12:50:19 UTC was performed on the ground in Kuala Lumpur the external air temperature was 25°C and the cabin temperature was set at around 22°C, there appears to be little difference in the time taken following the cold start at 18:25:27 UTC in the air and the cold start at 12:50:19 UTC on the ground. I conclude that the cabin temperature where the SDU is located was at a similar level.
The power-on self-test (POST) is a functional test of the SDU upon a cold start. The correct operation of much of the internal circuitry of the SDU depends on clocks derived from the high-stability frequency reference generated by the oven-controlled crystal oscillator (OCXO). Therefore, it is inappropriate to perform Built-In Test Equipment (BITE) tests until this clock frequency has achieved gross stability. If the SDU is powered on after having stabilised at a cold external temperature (e.g., -55° C), it can take several tens of seconds for the frequency drift rate to be low enough before the phase locked oscillators (PLO) that derive the dependent clocks can lock onto the OCXO frequency reference.
The SDU defers testing of sensitive equipment until a positive indication of settling is detected, or sufficient time passes so the lack of settling itself can be classified as a failure. Deferral of these sections of POST also result in normal operation being deferred, including access to the user interfaces and all automatic calibration processing. Consequently, the SDU suspends POST until the SDU detects the first of the following conditions:
– OCXO heater monitor indicates it has achieved operating temperature.
– Power supply unit (PSU) temperature sensor indicates a reading above 25 °C.
– Channel filter module transmit and receive PLO lock detectors both indicate lock.
– More than 4 minutes have elapsed since primary power was applied.
There was not several tens of seconds difference between the two logons and the additional time taken for a cold start logon by the SDU was similar in both cases. I conclude, that the SDU logon at 18:25:27 UTC took place in a normal cabin temperature environment.
My blog post four years ago on this topic. I have not read it carefully again to see if I still stand by it. The BFO at 18:25:27 was virtually perfect with respect to what other sources of info implied about the location, speed, and track of the aircraft.
https://tmex1.blogspot.com/2017/06/and-so-it-goes-182527-bfo-value.html
@DennisW
Your blog post from 4 years does not compare the cold start logon at 12:50:19 UTC with the cold start logon at 18:25:27 UTC, which is the basis of my conclusion about cabin temperature.
Logon 6 in my linked reference was the 12:50 Kuala Lumpur logon at the airfield prior to take off. The similarity to logon 7 at 18:25:27 is obvious. Holland makes the point that logons 1 through 6 were at an airfield, and a different Doppler compensation algorithm is used – closed loop compensation as opposed to the open loop compensation used when airborne. For that reason the logon 1 through data was scaled by a factor of 1/2.
His reasoning is provided but is not clear to me.
@DennisW
Thanks for pointing out that Logon 6 was 12:50:19 UTC. I had read your attached blog but not the embedded Holland paper, as I thought I new the Holland paper. My mistake on the Logon numbering.
It turns out that you have embedded V3 of Holland’s paper dated 15th January 2018 and I have only V1 and V2. I wonder how many other versions there are.
The fact that Holland decided to halve the BFO values for Logon 1 to 6 is based on an assumption that the closed loop compensation was used. His assumption does not explain why Logon 1 to 5 are all different from Logon 6 as they were all on the ground. It is a shame that we do not have the SITA data for all the 9M-MRO flights he is quoting in his paper.
My key point is that the Logon 7 at 18:25:27 UTC was in the air and is identical to Logon 6, both in timeframe and BFO drop to stabilisation. I assert that the same compensation algorithm was used. It begs the question, why was the Inertial Reference System not providing data to the SDU at 18:25:27 UTC?
Irrespective of the assumption used, the time for the BFO values to reach a stable value was the same for Logon 6 and Logon 7, so my conclusion is still valid. The cabin temperature was similar in both cases and at a normal operating level.
In addition, we now have another mystery to solve about the status of the Inertial Reference System.
@Richard
RE: “Some have also speculated that the cabin temperature reduced towards the outside air temperature.”
I have, for some time, questioned speculation that the cabin temperature reduced to a value well below 0°C. The cabin is easily depressurised by manually opening the outflow valves; there is no need to select the air conditioning ‘OFF’. That being the case, the air conditioning system would attempt to maintain the selected cabin temperature by pumping hot air into the cabin. That air would naturally rise towards the ceiling and would help keep the crown of the fuselage warm.
@Andrew
Many thanks for your comment and questioning the speculation. Ian Holland (DSTG) was one of the sources of the speculation about the cabin temperature being much lower than expected.
Ian Holland states in his analysis of the BFO dated 15th January 2018 (that @DennisW referenced) “Regarding the log-on event at 18:25:27Z for MH370, it was noted that there was a non-zero bit error rate (BER) associated with the log-on request at that time. The associated received signal level and carrier-to-noise density ratio (C/N0) were also unusually low. As such, the first BFO was deemed untrustworthy.”
For the Logon 6 at 18:25:27 UTC, the BER was 5. I agree that this is non-zero, but the range for normal operations in the SITA logs for MH371 and MH370 was a BER between 0 and 68. During SATCOM calls the BER is higher and ranged between 0 and 187.
The received signal level was between -55.33 dBm and -52.34 dBm, which is slightly lower than the mean but not unusually low as Holland claims. The overall range in the SITA logs for MH371 and MH370 was between -67.91 dBm and -40.88 dBm. The mean level was -56.89 dBm.
The carrier-to-noise density ratio was between 30.28 and 43.24, which is slightly lower than the mean but also not unusually low as Holland claims. The overall range in the SITA logs for MH371 and MH370 was between 28.48 and 56.54. The mean level was 41.77.
Ian Holland states in a foot note “An alternative explanation for this outlier BFO could be the unknown conditions of the aircraft between 17:22Z and 18:25Z, for instance the temperature of the SDU might have been much lower than the expected ambient temperature.”
I dispute Holland’s assessment that the BFO at 18:25:27 UTC was untrustworthy and an outlier and contend that the alternative explanation that the SDU experienced a much lower ambient temperature is misleading.
Agreed. There could in theory be a rapid and temporary reduction in air temp upon rapid depressure, but only the air is cooling down, and it will not have much mass. The PAX/cabin contents will still be at room temp and will warm the thin air back up quickly. With passage of time and no heating then the cabin could cool off.
Presumably the SDU has the quartz crystal in an oven with some insulation, so that would be slower to cool, although as we know it is sensitive.
@DennisW, @All,
The Air Data Inertial Reference System (ADIRS) is powered from 3 sources, 115V AC Left Secondary 1 Bus, 115V AC Right Secondary 1 Bus and the 28V DC Bus (Left and Right and Hot Battery Bus).
The Satellite Communication System of which the Satellite Data Unit is the key component is powered only from 115V AC Left Secondary 2 Bus.
For the ADIRS not to be available to the SDU during the reboot at 18:25:27 UTC there must have been a significant failure in the ADIRS and the secondary system SAARU.
Here is a link to an overview of the Boeing 777 Electrical System:
https://www.dropbox.com/s/46ngm51asalcfac/Boeing%20777%20Electrical%20Power%20to%20Systems.png?dl=0
The Air Data Inertial Reference Unit (ADIRU) is the key component of the ADIRS and uses the data from the accelerometers and gyros to calculate inertial navigation data. The ADIRU sends air data and inertial reference data to user systems through the left and right flight control ARINC 629 buses.
In addition there is a Secondary Attitude Air Data Reference Unit (SAARU). The SAARU sends inertial reference and air data to user systems through the center flight control ARINC 629 bus.
@Richard
To clarify, the SDU does not source inertial data directly from the ADIRS. The data is first transmitted by the ADIRS to the L & R AIMS cabinets via the flight control ARINC 629 buses. The AIMS cabinets then output the required data to the SDU via the L & R inertial reference ARINC 429 buses. Note: the SAARU does not provide position data.
Given the power supply redundancy of both the ADIRU and the AIMS cabinets, only a significant power failure would affect the supply of inertial data to the SDU.
@DennisW. The fact that the initial value at 18:25:27 appears to be right before the distictive thermal transient has long led me to suppose that this first datapoint must have been produced by open loop and was therefore immune from the thermal distortion and subsequent settling that affects BFO values using a closed loop feedback.
@Richard. I’ve missed a step in your argument. How do you arrive at the inference that ADIRU must have been off/unpowered at the Arc1 logon?
@Paul
I too believe the 18:25:27 BFO was produced with open loop compensation, and that the accuracy of the BFO contradicts SDU oscillator offsets from cabin depressurization or other thermal stresses.
I am also missing the same step in Richard’s argument.
@Paul
The open loop approach is not immune from thermal transients. The thermal effects to the SDU oscillator are not removed by the open loop compensation, and the resulting changes in the BFO bias go uncorrected.
@DennisW. Are you sure? I thought the idea was that open loop “calculated” the frequency offset required based on doppler calculated in relation to the nominal satellite (or whatever ephemeris was loaded on the SDU software) whereas the “closed loop” was reading a received pilot signal (distorted by the thermal transient) and making frequency offset accordingly. But my understanding of these systems is extremely patchy/neophyte and happy to be educated.
@Paul
What you said above is correct. However, the drift of the SDU oscillator due to temperature and aging cannot be corrected by the open loop method. There is no way to even measure the magnitude of these effects.
@Paul
The current value of the BFO bias can be determined by the GES after correcting for aircraft (the Doppler compensation made by the AES assumes the satellite is stationary over the equator at ~25E, which is an approximation) and satellite Doppler, but the BFO bias cannot be determined by the aircraft AES.
@Paul
I should have made it clear that the BFO bias can be determined by the GES only when the aircraft is stationary at a known location, on the ground at an airport for example.
@DennisW
I think you mean 64.5°E over the equator.
Yes, thx.
@paul smithson, @DennsiW, @Andrew,
Many thanks for your various comments.
We have discussed three intertwined issues:
(1) Ian Holland was primarily focused on the descent rate at end-of-flight.
(2) I was focused on the cabin temperature at SDU reboot at 18:25:27 UTC.
(3) @DennisW and @paul smithson contend that the BFO value at 18:25:27 UTC was determined in open loop compensation.
In this comment, I will focus on the logic behind my contention that the ADIRS data was not available to the SDU at 18:25:27 UTC.
(a) The ADIRU sends air data and inertial reference data to user systems including the left and right AIMS cabinets in the Main Equipment Centre (MEC) through the left and right flight control ARINC 629 buses. The ADIRU uses data from the air data sensors to make air data calculations. The ADIRU uses the data from the accelerometers and gyros to calculate inertial navigation data. The ADIRU has internal redundancy and automatically makes allowances for failures to keep its complete function. After power up the ADIRU runs a self test that last 30 seconds. On the ground after power up the ADIRU will then request the inertial position to be entered by a pilot, which is checked against the GPS. An alignment of the ADIRU may follow which lasts between 7.5 and 15 minutes depending on latitude.
(b) The SDU receives IRS data from the left and right AIMS cabinets through the ARINC 429 buses. This data is used to point the antenna at the satellite. The SDU also runs a self test after power on, which can last up to 3 minutes. If the IRS data is not available in the few minutes after power up, then the SDU uses a closed loop Doppler compensation method based on optimising the power of the received pilot signal. If the IRS data is available then the SDU can point the antenna and uses an open loop Doppler compensation method based on the satellite ephemeris.
(c) A number of SDUs were tested to investigate the effects of power outages on the BFO during SDU power on. Any given SDU displayed repeatable behaviour for a fixed outage duration and similar settling characteristics for outages of different duration.
(d) The SDU Logon at 15:59:55 UTC used the open loop Doppler compensation as the ADIRU was already powered up and the IRS data was available. The BFO values was initially 99 Hz, peaked at 104 Hz and finally settled at 86 Hz after 32.3 seconds. The subsequent 18 BFO values were between 85 Hz and 88 Hz.
(e) The SDU Logon at 12:50:19 UTC used the closed loop Doppler compensation as the ADIRU was not already powered up and the IRS data was not available. The BFO values was initially 473 Hz, which was the peak value and finally settled at 347 Hz after 163.0 seconds. The subsequent 11 BFO values were between 346 Hz and 359 Hz, following a drop of 126 Hz.
(f) The SDU Logon at 18:25:27 UTC used either the open or the closed loop Doppler compensation as the IRS data was or was not available. The BFO values was initially 142 Hz, peaked at 273 Hz and finally settled at 144 Hz after 158.5 seconds.. The subsequent 8 BFO values were between 143 Hz and 148 Hz, following a drop of 129 Hz.
(g) The SDU Logon at 18:25:27 UTC shows the exact same settling characteristics as the SDU Logon at 12:50:19 UTC, where the settling time was 158.5 seconds and 163.0 seconds respectively and the settling drop in BFO value was 129 Hz and 126 Hz respectively.
(h) The SDU Logon at 18:25:27 UTC was conducted in the same environmental conditions as the SDU Logon at 12:50:19 UTC, namely a cabin temperature at a normal operating level around 22°C.
(i) The SDU Logon at 18:25:27 UTC therefore must have used the same closed loop Doppler compensation method as the SDU Logon at 12:50:19 UTC in order to show the same drop in BFO values (126 Hz to 129 Hz) in the same time period (158.5 seconds to 163.0 seconds) under the same environmental conditions. The SDU Logon at 18:25:27 UTC did not show the expected additional several tens of seconds for the frequency drift rate to be low enough before the phase locked oscillators (PLO) that derive the dependent clocks can lock onto the OCXO frequency reference after being powered on after having stabilised at a cold external temperature.
(j) The SDU closed loop Logon at 18:25:27 UTC required a much longer time period than the SDU open loop Logon on the ground at 15:59:55 UTC which lasted only 32.3 seconds .
(k) The open loop compensation is essentially the same method as the one we use in our BFO calculations in the flight path analysis by using the aircraft and satellite data to determine the relative velocities for the partial SDU compensation without the z axis component.
In summary it appears that the SDU Logon at 18:25:27 UTC in the air over the Malacca Strait shows the same characteristics as the SDU Logon at 12:50:19 UTC on the ground in Kuala Lumpur. As the IRS data was not available on the ground in Kuala Lumpur due to the cold start power up of the aircraft, I conclude that the IRS data was not available for the SDU Logon at 18:25:27 UTC.
@Richard
Good points. I was not aware that the SDU could use the closed loop method in the air.
@DennisW
In order for the SDU to perform the partial compensation on the BFO data, the closed loop calculation is being applied continuously.
As Chris Ashton et al. of Inmarsat explain in their paper dated 4th September 2014:
“The aircraft terminal adjusts its transmit frequency to compensate for the Doppler induced on the uplink signals by the aircraft velocity. Aircraft latitude, longitude, track and ground speed are used to calculate the Doppler shift the signal would experience if the satellite was at its nominal location over the equator. This only partially compensates for the Doppler associated with the aircraft’s velocity as it does not allow for vertical movement (which introduces discrepancies when the aircraft is climbing/descending) and the satellite is rarely at its nominal location: these small errors are immaterial to the communications performance, but do affect the BFO.”
@Richard
Thinking about it some more, I don’t see how the closed loop method could be used in the air. The unknown aircraft Doppler would greatly corrupt the process. Is there any way you can check that out?
@DennisW
The general SDU documentation talks about the open loop method based on the Satellite-Relative Velocity providing the Open-loop Doppler Compensation and the closed loop method based on the Current Antenna Gain providing the Antenna Gain Variation Compensation.
https://www.dropbox.com/s/mcswllu30k580mo/Open%20and%20Closed%20Loop%20Compensation.png?dl=0
If you think about it you realize that using the received carrier for frequency adjustment will double the Doppler shift since you receive a Doppler shifted signal and it gets shifted by the same amount again on the return path. Hence the need for the factor of 1/2 in BFO measured value. That is OK for a near stationary aircraft. The only Doppler is due to satellite motion. Add in a totally uncompensated aircraft Doppler, and the closed loop method falls apart.
@DennisW
The loop phase shift corresponding to a relative phase shift between the signal transmitted by the AES to the satellite and the signal received at the AES from the satellite is measured.
The AES knows the expected pilot frequency and compares the actual received frequency. The AES attributes the difference entirely to the AES motion Doppler. The satellite motion is ignored. Surely this method gets better when the AES motion is much greater than the satellite motion, because the satellite motion is small compared to the aircraft motion in the horizontal aircraft plane.
I agree with you and with Ian Holland that the OCXO transient effect needs to be halved, as it effects both the transmitted and the received signal.
I do not understand why you think the Pilot frequency received – Pilot frequency expected = AES motion Doppler equation falls apart for an aircraft in the air moving at a normal cruise speed.
Why do you think this equation is not used and the aircraft motion Doppler is uncompensated?
@Richard
How does the AES know the frequency of the received signal? The only reference it has is its own SDU oscillator. Plus that the received frequency is significantly offset by an unknown aircraft Doppler. Without being stationary or without the ADIRU the AES has no way of knowing how to compensate its own oscillator. Am I out to lunch here?
@DennisW
The aircraft satellite communication system operates at L Band, transmitting signals to the satellite at 1.6 GHz and receiving signals from the satellite at 1.5 GHz. Several channels are used in each case and you can easily work out the frequency from the assigned channel number.
For example, the L Band frequency used from the aircraft to the satellite for a given channel number = 1,611,500,000 + (channel number * 2,500) Hz. At 18:25:27 UTC the channel number was 14,049, so the frequency was 1,646,622,500 Hz.
Similarly the L Band frequency used from the satellite to the aircraft has an assigned channel number. Without being stationary and without the ADIRS, all the SDU knows is the Pilot frequency received – Pilot frequency expected = AES motion Doppler. This value will only be meaningful once it has stabilised after about 3 minutes.
Meanwhile all the SDU can do is move the antenna to maximise the current gain of the received Pilot signal in a continuous optimisation process. The SDU also knows the minimum acceptable signal level required to be received from the satellite. Without the ADIRS, the SDU does not know where to point the antenna, so it is a process of trial and error, but the SDU knows what the Pilot frequency is and what the minimum acceptable signal level is, so it has to hunt until it captures a signal.
Of course, this is not the best way and is not how it is supposed to be, but what else can the SDU do when the ADIRS is not available?
@DennisW
You are not out to lunch at 10:49 CET.
But I am out to lunch at 13:40 CET.
Yes, satellite Doppler is a relatively small number compared to aircraft Doppler in flight. Without the ADIRU info the AES has no way to know what to do to compensate the aircraft Doppler for its speed and track.
@DennisW
Here is my apology letter to you.
There were 36 SDU Logons in the last 24 hours of 9M-MRO operations, covering both the MH371 and MH370 flights in totality.
Out of 36 Logons:
(a) 11 were interrupted between 7 seconds and 22 seconds into the process.
(b) 3 failed after only 2 seconds.
(c) 22 completed the process taking on average 75 seconds.
Details are in the linked table in .png and Excel format:
https://www.dropbox.com/s/w7cukkccb45zehb/MH371%20and%20MH370%20Logon%20Results%20Table.png?dl=0
https://www.dropbox.com/s/r4hg9d44hve31e5/MH371%20and%20MH370%20Logon%20Results%20Summary.xlsx?dl=0
There were 3 time periods in this 24 hours where the SDU was powered down completely:
(a) For an outage of up to 3h 48m 30s ending at 07/03/2014 12:50:19 UTC.
(b) For an outage of up to 1h 17m 39s ending at 07/03/2014 18:25:27 UTC.
(c) For an outage of up to 8m 29s ending at 08/03/2014 00:19:29 UTC.
I again checked the time intervals between key milestones during the Logon process, together with the bit error rate (BER) and decoding the message sent or received by the aircraft for each Logon process. There were 15 normal Logon processes lasting an average of 74 seconds, where each one of the six time intervals were all within the mean ± 1 standard deviation for that time interval. Because the aircraft uses the aloha protocol slot allocation, there were 7 Logon processes where one of the six time intervals was outside the limit of ± 1 standard deviation in one direction, but sometimes the next time interval compensated in the other direction and the overall average time for the Logon process only extended by a second to 75 seconds.
The Logon process time following a power outage is quite different from the normal time of 74 seconds. The SDU Logon took 225 seconds at 12:50:19 UTC, 159 seconds at 18:25:27 UTC and only 9 seconds at 00:19:29 UTC. In each case the process was different. There are four information steps in the Logon process:
(a) Confirmation of the 9M-MRO identification.
(b) Confirmation of the Flight Number e.g. MH370.
(c) Confirmation of the Aircraft Time e.g. 16:01 UTC.
(d) Confirmation of the In Flight Entertainment (IFE) Logon.
The final Logon at 15:59:55 UTC to the IOR satellite prior to the departure of MH370 from Kuala Lumpur completed all the information steps taking a little longer than the average process time at 84 seconds.
The previous Logon at 12:50:19 UTC to the POR satellite on the ground in Kuala Lumpur completed only steps (a) and (d) in 225 seconds and experienced a high BER of up to 32, possibly due to the proximity of buildings.
The next Logon at 18:25:27 UTC to the IOR satellite in the air above the Malacca Strait completed only step (d) in 159 seconds and experienced a BER of 5 only on the first transmission.
The final Logon at 00:19:29 UTC to the IOR satellite at the end of flight performed none of the information steps (a) to (d) and the process was interrupted without completing.
The Logons at 12:50:19 UTC, 18:25:27 UTC and 00:19:29 UTC use the same data code and are all SDU Logons following a power outage. The Logon at 12:50:19 UTC and 18:25:27 UTC are different in that the information step (a) was included at 12:50:19 UTC but excluded at 18:25:27 UTC. In both cases the information steps (b) and (c) were excluded. There was also a BER detected in both cases.
Unfortunately the data we have is not conclusive. It is not possible to draw any conclusion from the similarities between the Logons at 12:50:19 UTC and 18:25:27 UTC, because following a more detailed analysis, there are still significant differences between the information passed and the BER values experienced. Both Logons were incomplete and took much longer than other normal Logons on the ground or in the air, where the ADIRS can safely be assumed to have been available.
@DennisW is right, we cannot conclude that the slow SDU Logon at 18:25:27 UTC was because of non availability of the ADIRS. It is possibly due to the fact that the aircraft was turning, climbing or descending, but there is no direct evidence that the ADIRS was unavailable. It is unlikely that the Logon slowness was due to the fact that the cabin temperature was close to the outside air temperature as @Andrew points out the air conditioning system would attempt to maintain the selected cabin temperature by pumping hot air into the cabin. According to Thales, If the SDU is powered on after having stabilised at a cold external temperature (e.g., -55° C), it can take several tens of seconds for the frequency drift rate to be low enough before the phase locked oscillators (PLO) that derive the dependent clocks can lock onto the OCXO frequency reference. In my view, we cannot explain a more than doubling of the Logon process time to 159 seconds from the expected 74 seconds, by a cabin temperature under 0°C.
@DennisW, I apologise that I had insisted the ADIRS was not available for the SDU reboot at 18:25:27 UTC. It was an unproven hypothesis. I still do not understand what caused the unduly long SDU Logon time, assuming the ADIRS was available and the beam antennae on each upper side of the fuselage were pointing correctly. Is it possible that there is blind spot, if the aircraft is climbing and pointing directly at the satellite?
No need to apologize, Richard. I did not regard your view as unreasonable or hostile.
@All,
Further to my question yesterday as to why the SDU Logon at 18:25:27 UTC took an unduly long time, I decided to analyse why the Bit Error Rate (BER) was non-zero (BER value was 5) during the SDU Logon Request.
In the last 24 hours of 9M-MRO operations, the BER was non-zero on 156 occasions out of a total of 5,029 signals transmitted by the aircraft. I decided to discount the 64 occasions at the gate, 31 occasions during taxiing, the 10 occasions during each SATCOM call (at a higher bit rate) and when the BER value was only 1. That left 15 occasions during the cruise, 4 during the climb and 2 during the descent with a significant BER. In total there were 20 occasions during the flight of MH371 and one during the flight of MH370.
All 20 occurrences of a BER > 1 during the flight of MH371 happened when there was a climb, descent, turn, strong crosswind or crossing a weather front (possible turbulence). The attitude of the aircraft in relation to the direction of the satellite was changing significantly.
15 occurrences were accompanied by an anomaly in the BTO value. The associated carrier-to-noise density ratios (C/No) were all unusually low.
For MH370 at the Logon Request at 18:25:27 UTC, we also note an anomaly in the BTO value. We know that at 18:25 UTC in the Malacca Strait there was no weather front or strong winds. I therefore conclude that MH370 was executing a significant turn, climb or descent at 18:25:27 UTC and this caused the BER and low C/No ratio. In turn this also caused the unduly long time for the SDU Logon.
Later during the flight of MH370 two SATCOM calls were made by ground operations at Malaysia Airlines to the aircraft. Each SATCOM call lasted just over 63 seconds. During both SATCOM calls, the total of 80 communication messages logged all had a high C/No ratio. Both SATCOM calls had a zero BER during progress of the call. Both SATCOM calls had 10 non-zero BER values at the end of the call during the status report and channel release phase.
I conclude that the SDU was operating correctly from 18:25:27 UTC to 00:19:37 UTC and the ADIRS was providing antenna pointing information to ensure correct SATCOM operation. The BTO and BFO values from 18:27:04 UTC until 00:19:37 UTC are reliable and can be used to determine the aircraft-satellite distance and relative velocity, track and rate of climb (ROC), including the negative ROC at the end of flight.
The high BER at 18:25:27 was not due to low signal level. It was due to a collision with another packet from a different AES on the random access channel. We know this from the normal rcv pwr and low C/N0 data. This was confirmed by Inmarsat in a meeting I had with them at their NOCC in London in December 2017.
@ALSM
I agree that there was a non-zero BER at 18:25:27 UTC and this was likely due to a packet collision.
When I referred to the fact that the SDU was operating correctly from 18:25:27 UTC, I was referring to the overall status of the SDU and the subsequent logon sequence. I was NOT referring to the specific communication BER at 18:25:27 UTC, which I view as part of normal operation.
@Richard
Impressive forensics! I came to the same conclusion using a very simple argument. The location, speed, and track of MH370 at 18:25:27 can be inferred from other data. In fact, 18:25:27 was the last time those parameters were observed independent of Satcom data with a degree of confidence. The BFO value logged at 18:25:27 agreed perfectly with those observations. IMO this strongly suggests:
1> ADIRS was functioning correctly at 18:25:27
2> The aircraft was not subjected to a depressuring event prior to 18:25:27
@Richard. As you know the CSIRO’s BRAN2015 model has been upgraded to BRAN2020. The attached addresses the differences between BRAN15 and BRAN 20 drift outcomes:
https://www.dropbox.com/s/dzx16lvnvmzpn0h/BRAN2015%20modelling%20comparison%20with%20BRAN2020.docx?dl=0
@David
Many thanks for the useful analysis and comparison of BRAN2015 and BRAN2020.
@All
I first discussed the implications of the absence of MH370 Debris on the coast of Western Australia (WA) in an article written together with Duncan Steel on 11th May 2016.
http://www.duncansteel.com/archives/2631
When David Griffin published his BRAN2015 data, it showed that 3.8% of the 86,400 trials ended up beaching on the WA coast. 1.6% of the trials came from the crash latitude area between 32.6°S and 37.1°S.
It is interesting to note that the more recent David Griffin publication of his BRAN2020 data, gives a different picture. The new data shows that 1.6% of the 86,400 trials ended up beaching on the WA coast and only 0.3% of the trials came from the crash latitude area between 32.6°S and 37.1°S.
Here is a link to the summary table of the results comparing BRAN2015 and BRAN2020 beachings in WA:
https://www.dropbox.com/s/39huezao8dqd4mh/BRAN2015%20vs%20BRAN2020%20generic%20comparison%20results%20summary.png?dl=0
Here are a set of links for each crash latitude area from 8°S to 44°S for BRAN2015 beachings in WA:
https://www.dropbox.com/s/84kz1k9ur3t0xf6/BRAN2015%20DG%20Red.png?dl=0
https://www.dropbox.com/s/n14o0n4soiq9l4u/BRAN2015%20DG%20White.png?dl=0
https://www.dropbox.com/s/efusszpwidugbax/BRAN2015%20DG%20Yellow.png?dl=0
https://www.dropbox.com/s/p0a49f3aiwhzazm/BRAN2015%20DG%20Magenta.png?dl=0
https://www.dropbox.com/s/fjv31571l9q1x2g/BRAN2015%20DG%20Black.png?dl=0
https://www.dropbox.com/s/c2n0fl455u0qu9t/BRAN2015%20DG%20Cyan.png?dl=0
https://www.dropbox.com/s/znv27u3ipr8gc65/BRAN2015%20DG%20Green.png?dl=0
https://www.dropbox.com/s/pqq85ot46za1449/BRAN2015%20DG%20Blue.png?dl=0
Here are a set of links for each crash latitude area from 8°S to 44°S for BRAN2020 beachings in WA:
https://www.dropbox.com/s/6f4xltfxxuji6j3/BRAN2020%20DG%20Red.png?dl=0
https://www.dropbox.com/s/4snv1b5ptfr47if/BRAN2020%20DG%20White.png?dl=0
https://www.dropbox.com/s/1swvxmbu3xtio8p/BRAN2020%20DG%20Yellow.png?dl=0
https://www.dropbox.com/s/5vlt75yuo04fvjv/BRAN2020%20DG%20Magenta.png?dl=0
https://www.dropbox.com/s/57ukvcdvk48id9f/BRAN2020%20DG%20Black.png?dl=0
https://www.dropbox.com/s/9wva124uycv2sbg/BRAN2020%20DG%20Cyan.png?dl=0
https://www.dropbox.com/s/kkp3kz0rx5arj7k/BRAN2020%20DG%20Green.png?dl=0
https://www.dropbox.com/s/9mef9kquyzfo6vr/BRAN2020%20DG%20Blue.png?dl=0
@Richard
The Bran data suggests a significant amount of debris will reach the shore of WA from crash latitudes 30S to 35S. Yet no debris has been found in WA despite significant beach cleanup activities. What do you make of this?
@DennisW
The BRAN2020 data shows that 114 trials (0.13%) out of a total of 86,400 trials beached in WA from a crash latitude between 30°S and 35°S.
https://www.dropbox.com/s/27s2amh4t5kozou/BRAN2020%20WA%20Beachings%20Crash%20Latitude%2030%C2%B0S%20to%2035%C2%B0S.png?dl=0
The beach cleanup activities in 2014 and 2015 covered a maximum of 571 km (2.75%) of beaches out of a total WA coastline of 20,788 km (including offshore islands).
As 34 debris items have been reported and all things being equal, there is a 2.75% * 0.13% * 34 = 12.155% probability of finding a debris item beached in WA during a beach cleanup (1 chance in 8).
@Richard
I am not fond of your probability estimate, particularly the 20788 km coastline estimate. I just don’t think it is possible to calculate the probability of finding a piece of debris (if it is there) can be reliably estimated. One can say that if the plane crashed in the 30S to 35S arc length:
1> some pieces of debris would have reached WA
2> WA was subjected to beach cleanup efforts
3> no MH370 debris has been found (discounting the towlette)
The likelihood of finding debris anywhere is relatively small, but a lot of it has been found.
@DennisW
Fair enough! You asked my opinion and I responded.
If you don’t like my response, that is fine by me.
Let me put my response another way.
(1) Very few items of debris would have reached WA.
(2) WA has a huge coastal length much of which is inaccessible.
(3) There are a few beach clean ups in some populated areas.
(4) It is no surprise to me, that no MH370 debris has been found in WA.
@Richard
Richard, I don’t think that saying that there were a few beach clean ups in some populated areas is an accurate way of describing The Tangaroa Blue Foundation’s work on Western Australian beaches.
Figure 83: Australian beach search locations to the ATSB’s The Operational Search for MH370 dated 3 October 2017 provides an overview of the search efforts (further and more specific details are available from the Australian Marine Debris Initiative database). Between June 2014 and December 2015 there were nearly 500 beach clean ups run by Tangaroa Blue on Western Australian beaches.
It is true that the significant majority of those were conducted south of Kalbarri (~ 27.5°S) but there were also five conducted on the remote beaches near Lake McLeod (~24.1°S) and a handful of others on more northern beaches. In any event, almost all the predicted landfalls on Western Australian beaches are south of 26°S (ie on beaches that were well covered by clean up efforts).
Nice post, Mick. My feelings, exactly. Don’t filter the observables to conform to your believables.
@Richard
Fair enough.
The beach search effort in WA has exceeded the effort in the rest of the Indian Ocean shoreline combined. Of course it is possible, if not likely, that WA debris will not be found if the plane crashed 30S – 35S for reasons you state.
BTW, my initial response to your BRAN post was motivated by my surprise. Surprise that terminal latitudes North of 35S could deposit debris on the shores of WA. That, in my view, is a potentially serious issue with the latest IG report.
@Mick Gilbert, @DennisW,
Let us stick to the facts.
Fact 1: 571 km out of 20,788 km coastline searched is 2.75%, which is a small proportion and represents only a few of all possible locations.
Fact 2: The BRAN2020 data shows that out of a total of 86,400 trials only 114 trials beached in WA from a crash latitude between 30°S and 35°S, which is 0.13% and a very small proportion and represents a very low likelihood.
Fact 3: The BRAN2020 data shows that out of a total of 86,400 trials only 135 trials beached in WA from a crash latitude between 7.87°S and 30°S, which is 0.16% and a very small proportion and is not a “potentially serious issue” with my latest drift analysis nor the previous UGIB flight analysis.
https://www.dropbox.com/s/hdq18bvish8fxaq/BRAN2020%20WA%20Beachings%20Crash%20Latitude%207.87%C2%B0S%20to%2030%C2%B0S.png?dl=0
Yes, it is a fact that the coast of WA has received many more hours of searching than any other shoreline area of the Indian Ocean. No debris has been found. Alternate conclusions are that the aircraft terminated farther North on the 7th arc or the drift model is wrong.
@DennisW
And alternative conclusions have nothing to do with “Don’t filter the observables to conform to your believables”.
Or the nature of the crash was not as violent as supposed, less pieces.
@Richard
Richard, your Fact 1 is way, way off base. The entire mainland coastline of Western Australia is only about 13,000 kilometres.
More to the point, however, in this case we’re not talking about the entire coastline. In this case the predicted beachings occur exclusively on the length of the coastline between the northern tip of Dirk Hartog Island (~24.5°S) and Augusta (~34.4°S). That’s only about 1,500 kilometres of coastline, with the vast majority of that being long, relatively straight undulating beach lines with an absence of offshore islands or formations.
In fact from your modelling it appears that the overwhelming majority of the likely beachings occur along about a 1,000 kilometre stretch of coastline between Dirk Hartog Island and around Yanchep, just north of Perth (~31.5°S). Again, that is made up virtually exclusively of long, relatively straight undulating beach lines.
It is along those stretches of coastline that the majority of the Tangaroa Blue beach clean ups were conducted. You really only need to superimpose Figure 83: Australian beach search locations onto your beachings map to see the very high degree of overlap.
And bear in mind that we are talking about an informed group of searchers here – while collecting all man-made materials was their primary aim they had been notified by the ATSB of the need to be vigilant for possible aircraft wreckage. And who doesn’t want to be the person to find a clue to a mystery?
Now, whether anything beached at all is a very different matter. Your modelling suggests a very low likelihood in that regard. However, if something did beach along that 1,400 kilometer stretch of coastline then there would have been a very good chance that it would have been found and identified.
Apologies, ‘relatively straight undulating beach lines‘ should have read ‘relatively straight or smoothly undulating beach lines‘. Easily searched, in other words.
Yes, Richard’s coastline analytics are grossly in error. Rather odd for Richard.
A lot invested in 34.2S? Taversky has a lot to say about that.
@DennisW
I have been wrong before and I can be wrong again.
@Mick Gilbert
I stated “out of a total WA coastline of 20,788 km (including offshore islands).” I did not state that the mainland WA coastline was 20,788 km. You are either not following the thread or deliberately trying to twist my words.
Since 14 out of 33 MH370 floating debris items were found on offshore islands in Mozambique, Mauritius, Madagascar and Tanzania, it is important to include offshore islands in the analysis, otherwise you are distorting the facts.
I have analysed the excellent Tangaroa Blue reports in great detail, with the help of residents of WA. All beach cleaning activity in 2014 covered a length of 556 km and all beach cleaning activity in 2015 covered a length of 571 km. I took the 571 km as the larger of two figures for my calculation.
Andrew Banks has explored the entire coast of WA by air at low level when in the Air Force. There are many people on the beaches at various times of the year, especially south of Geraldton (28.8°S). However, a large part of the coast between Geraldton and Shark Bay to the north is inaccessible, as shown in the attached photos. There are many ‘grey nomads’ and fishers/campers/wind-surfers with 4WDs on many beaches, far from towns. The fact remains relatively few MH370 floating debris items arrive on the coastline of WA from anywhere along the 7th Arc from 8°S to 44°S. According to BRAN2020 the total is 1,339 out of 86,400 trials (1.55%).
https://www.dropbox.com/s/5sz6h264441ppc5/Aerial_Shots_edel_land.jpeg?dl=0
https://www.dropbox.com/s/6wc015zn0kcqy33/Zuytdorp_Cliffs.jpeg?dl=0
@Richard
Richard, I am not trying to twist your words at all.
The point that I was making was that your Fact 1, categorising the beach search effort at just 2.75 percent of the the total Western Australian coastline, is misleading.
Your own modelling shows that the vast majority of of the coastline doesn’t come into play rather that the overwhelming majority of the likely beachings occur along about a 1,000 kilometre stretch of coastline between around 25.5°S and 31.5°S. The beach search effort along that stretch of coastline runs much higher than 2.75 percent.
The fact that no 370 debris has been found on the western coast of West Australia is not much indicative of where 370 crashed, since the 7th arc is very far from the shore. The Leeuwin current keeps that coast very clean. The fact that no debris has been found in the south coast of West Australia nor the south coast of South Australia, New Zealand, nor Tasmania is indicative of a crash site north of 36°S. The fact that all recovered debris has been found in Southeast Africa point to a crash site at least that far north, probably further.
Prof. Chari Pattiaratchi has always said the crash site is between 28° S and 33° S. And since he told me where to go look, I’m standing by that, and support searching wider there. The Broken Ridge area south of around 32° is also rough terrain where wreckage could have been missed. However 34° and 35° are also well worth a look, but have already been more substantially searched.
@All
I agree with Geoffrey Thomas, that it is time to end baseless conspiracy theories for MH370.
https://www.airlineratings.com/news/time-end-baseless-conspiracy-theories-mh370/
I am all for new ideas, but I am unwilling to believe the Inmarsat data was spoofed, the radar data was faked, the 34 items of debris were planted, the captain’s home flight computer data was a cover up and the co-pilot’s mobile phone capture near Penang was falsified.
All we know from the conspiracy theorists is that MH370 went either North, East, South or West. MH370 cannot be in Kazakhstan and the South China Sea and Vietnam and Cambodia and Diego Garcia and the Malacca Strait and off the coast of Sumatra …
I have one message for the science denying tin foil hat conspiracy theorists out there:
Man walked on the moon
9/11 was an Al Qaeda terror attack
Trump lost the election
The world is round
And 370 crashed somewhere in the Southern Indian Ocean
Interview with Prof. Chari Pattiaratchi
https://www.airlineratings.com/news/passenger-news/mh370-lies-southern-indian-ocean-says-oceanographic-expert/
I’d disagree with the Professor’s statement that, ‘… previous aircraft accidents have shown that a crash at sea will create a debris field of many thousands of pieces.’
The amount of floating debris liberated by a crash into the sea seems to vary considerably, apparently driven by the nature of impact.
At one end of the scale you have Flash Airlines Flight 604, a Boeing 737-300 that impacted the waters of the Red Sea not far from where it took off from Sharm El Sheikh International Airport, Egypt in 2004. The impact was at over 400 knots, and fairly nose down (25.4° down pitch). The accident report has a very detailed table of the recovered floating wreckage – less than 100 items in total.
EgyptAir Flight 990, a Boeing 767 (so, more comparably sized to a B777) was crashed into the Atlantic Ocean about 100 km south of Nantucket Island, Massachusetts in October 1999.
That crash also produced very little floating debris, less than 200 pieces in all.
At the other end of the scale you have the crash of Swissair flight 111 into the Atlantic Ocean just off Peggy’s Cove, Nova Scotia in 1998 and Larry Vance’s oft quoted claim that it shattered into more than two million pieces.
The first thing to note about Mr Vance’s claim is that he is not referring to the floating debris rather that two million is an estimate of all of the recovered debris. As the accident report makes abundantly clear somewhere between 95-98 per cent of the wreckage by weight did not float; it was recovered from the seabed.
@Mick Gilbert
You are again playing with semantics and perceptions. You state you disagree with Prof. Charitha Pattiaratchi that “… previous aircraft accidents have shown that a crash at sea will create a debris field of many thousands of pieces.”
Are you seeking to imply that the MH370 floating debris field was not many thousands of pieces.
In case you missed it in my drift paper on which you are commenting “The crash weight of MH370 was 174,369 kg. The 33 debris items found have a total weight of 161 kg. The total number of debris items would be 35,740, if the aircraft fragmented at the same rate as the 33 debris items found. Heavier items like engine cores and under carriage would sink. Lighter items and even hybrid structures, like the Flaperon at 40 kg and Outboard Flap at 39 kg, floated because of the trapped air in the honeycomb parts. It is possible that several thousand items floated to the surface. Some of these items would have subsequently sunk, due to water soakage and marine growth. Some of the items would have never beached.”
Once again, please stick to the facts.
Of course the crash of 370 resulted in thousands of pieces of floating debris. The aircraft tragically shattered on impact. Most were probably small composite honeycombed debris from the cabin and wing. I only found and handed in 19, and 15 other private citizens found the rest. I’m sure I missed a lot as they were buried in sand or still floating around. And when I showed photos and samples to local people many said they saw things like that earlier but did not pick them up. There was never an organized government search effort for beached debris in east africa, aside from briefly in La Reunion and Mauritius. By the time the aerial search reached the right ocean and right hemisphere, the field had already dispersed.
@Richard
Richard, speaking of sticking to the facts please read what I wrote. I wrote that,
“I’d disagree with the Professor’s statement that, ‘… previous aircraft accidents have shown that a crash at sea will create a debris field of many thousands of pieces.’”
I am not playing with semantics at all. Professor Pattiaratchi’s statement is wrong. Previous aircraft accidents do not show that a crash at sea will create a debris field of many thousands of pieces.
The matter is very easily settled. Simply point readers to the previous aircraft accidents where a crash into the sea liberated ‘many thousands of pieces‘ of floating debris (they are few and far between) and then compare that to the number of accidents that produced floating debris fields of less than one thousand pieces (that would be the majority of such crashes). The data does not support the Professor’s contention.
As to the extent of the floating debris field left by MH370, I wouldn’t speculate because what previous aircraft accidents have shown us is that the amount of floating debris liberated seems to depend on the nature of the impact (that is speed (both vertical and horizontal) and, likely more importantly, the aircraft’s attitude and orientation on impact).
Did MH370’s initial floating debris field consist of thousands of pieces? Maybe, but based on previous similar accidents, it is far more likely that the floating wreckage items numbered fewer than that.
@Mick Gilbert,
I apologise for being misleading, it was certainly not intentional.
To be clear, I agree with you that Prof. Charitha Pattiaratchi should have used the word “may” instead of “will” in the statement you quoted and found “wrong”. I was not trying to defend Prof. Charitha Pattiaratchi’s statement, nor was I wanting to comment on your research into other aircraft crashes, I was wanting to make a point specific to MH370.
In my paper and in my blog in my role as a contributor, I have stated that “The total number of debris items would be 35,740, if the aircraft fragmented at the same rate as the 33 debris items found.” and “There were items found from every part of the aircraft, nose, tail, wings, engines and cabin. Debris items comprise both interior and exterior parts, which implies the aircraft broke up on impact.” and “Following the crash of AF447 in the Atlantic Ocean on 1st June 2009, around 1,000 items of floating debris were found and recovered within the first 26 days.” I am not saying that there were 2 million parts, nor am I saying there were less than a hundred parts, which you quote from your research. I conclude in my drift paper “I would expect, that at least 300 and possibly many more items beached, somewhere at sometime.” What conclusion do you come to regarding the number of MH370 floating debris items? What conclusion do you come to regarding the crash latitude of MH370?
As far as Western Australia is concerned I have stated “Since 14 out of 33 MH370 floating debris items were found on offshore islands in Mozambique, Mauritius, Madagascar and Tanzania, it is important to include offshore islands in the analysis, otherwise you are distorting the facts.” Why do you think it is misleading to include offshore islands? What conclusion do you come to regarding the crash latitude of MH370 particularly from the absence of finds in Western Australia?
In my role as moderator, I have only warned one contributor for offering pictures of body parts of MH370 passengers, which I deemed insensitive to the NOK. I have not banned anyone from this web site or blog and allowed everyone to make their arguments, even if I personally disagree.
@Richard
Richard, thanks for that – I thought that we may have been talking about different things regarding the Professor’s statement. The ‘many thousands’ line is a bit of a pet peeve of mine; it’s one of those things that sounds as though it should be right but that is contradicted by the data.
Regarding including the island coastlines, I have no real issue with that if it is restricted to islands in the range of latitudes where you expect beachings to occur. Tangaroa Blue routinely clean up some of the coastal islands in that zone – eg Morley Island, Gun Island, Murray Island, Middle Island, the Numbered Islands, etc
Regarding Western Australian beachings, I think the telling factor is that your modelling predicts very, very few for your range of crash latitudes on the 7th arc.
With regards to your estimate of 35,740 debris items, that’s most assuredly an interesting approach. If we run with that and then apply the Swissair 111 experience where at least 95 percent of the debris sank, we have 1,787 pieces of floating debris. That strikes me as being a there or thereabouts estimate.
Separately, and going back to Australian beachings, would it be an overly onerous task to produce a beaching map for 7th arc latitudes between say 38.5°S and 41.5°S? I suspect those latitudes would put a far bit of debris onto southern Western Australian beaches as well as the Great Australian Bight and western Tasmania.
@Mick Gilbert
I think your ball park figure of 1,800 MH370 floating debris items is well founded. Some will have subsequently sunk. About 50% of the remainder would have beached somewhere at sometime.
I am considering how to refine my analysis of the WA beaches where clean ups took place in 2014 and 2015 versus the number of trials that would have landed there and in which time frame and from which crash latitude.
@Richard
Richard, I’ve done a quick review of Tangaroa Blue clean ups from between 1 June 2014 and 31 May 2015 in the region bounded by Kalbarri (~ 27.7°S) and Alkimos (~ 31.6°S). It wasn’t as extensive as I had inferred from just looking at the Australian Marine Debris Initiative maps.
I make the clean up effort for that region for that 12 month period to be:
5233 Kalbarri 5km
5123 Glenfield Beach 1km
5128 Nth Glenfield 1km
5125 Sunset beach 4km
5124 Bluff point 1km
5120 Geraldton .8km
5119 Pages Beach 1.5km
5127 Point Moore 1.2km
5121 Greys Beach 1.5km
5123 Separation Point 1.5km
5130 Back Beach .4km
5126 Tarcoola Beach 1km
5129 Sth Geraldton 2km
5199 Turtle Bay 1.12km
4624 Morley Island 2.67km
5200 Gun Island 2.165km
5202 Murray Island 1.04km
5201 Numbered Islands 4.881km
5203 Middle Island 2.55km
5442 South Bay 1km
5443 Sandy Cape 1km
4986 Sandy Cape .5km
5445 Sandy Cape Sth 1km
5444 Catalina Bay 2.62km
5446 Pumpkin Hollow 1km
5447 Pumpkin Hollow Sth 1km
5441 Nth Jurien Bay 2km
5439 Nth Jurien Bay 1km
5440 Nth Jurien Bay 1km
4952 Jurien Bay .5km
5312 Dobbyn Park .5km
5458 Jurien South 1km
5459 Booker Valley 1km
5460 Booker Valley Syh 1km
5448 Hill River Mouth 1km
5449 Hill River Car park 1km
5450 Hill River Sth 1km
5451 Hill River 1km
5452 Hill River Sth 1km
5453 Hill River 1km
5454 Grey South 1km
5455 Grey South Sth 1km
5456 Grey South 1km
5457 Wedge South 1km
5303 Nr Ledge Point 1km
5099 Seabird 2km
5419 Yanchep 1km
5115 Yanchep Beach 1km
5287 Yanchep Beach 1km
5113 Alkimos 1km
That’s just under 69.5 kilometres in total. That would be about 5.5 – 6 percent of that stretch of coastline.
@Mick Gilbert
Reading the Tangaroa Blue reports for 2014 and 2015 again, they include a significant number of debris items from the beach clean ups in the Cocos Islands. The number of items far outweighs the number found on mainland Western Australia per km of beach searched.
@Richard/Mick
Estimating the number of debris items generated by the crash of MH370 is complicated by the erratic conduct of the search efforts. If the search had been conducted at a consistent level of effort in areas likely to receive debris you could make a reasonably good guess from the Weibull analytics. As it stands now, I am not going to toss my hat in that ring.
My own opinion of the crash latitude remains to the North of 25S. The median latitude of all the debris finds is 23.7S, and while a symmetrical latitude dispersion associated with the drift West is a shaky assumption, it is as good as any. Also the absence of any debris found in the search of WA supports a crash latitude North of the area already searched.
From an information theory perspective searching areas that have not been searched yields a higher information return per unit area searched – another reason to continue North from 25S.
I am about ready to give it up. Victor’s site has gotten totally goofy with the uncritical “support” of WSPR. I am not an advocate of the last IG report. Probably best to just bail out at this point. Goodbye.
@DennisW
Many thanks for your many excellent comments.
Please reconsider!
@Richard, Mick Gilbert, DennisW (comeback!), BG370.
About what the debris tells us, the quantity is one thing.
Another is the character.
@DennisW and the Bayes equations disclose that the prospects of a find in a previously searched area is low. I make it just a few percent. Even allowing for there to be an area of difficult-to-search terrain, that reducing the probability of an earlier find there to say 50%, that area would need to be a large part of the total recommended area to lift the prospects of the total much.
The gross Bayesian prospects of a search of an unsearched glided area, supposing a pilot, would be enhanced even were the probability of it being there somewhat less. Those prospects per unit area could also be greater were the glide area constrained, as UGIB has done.
To me the principal reason to suppose that there wasn’t a pilot was the UGIB conclusion that engine bleed would have been off for some time, to provide with reasonable probability the fuel needed to reach their LEP. That would have frozen a pilot without very heavy clothing. Concealing that might present a problem and would saving a few hundreds of pounds of fuel warrant all that?
Certainly if instead a pilot present was assumed, indeed that would lead to a reduction in that enough-fuel probability. However that should be weighed against the above search prospects without one.
And yes there are other factors that also to enter the balance, such as the final dive needing explanation. Lack of IFE connection after those final transmissions could result from the pulling out of that dive leading to APU fuel starvation. But against such as those, I hypothesise that in his planning, a suicidal pilot apparently intent on hiding that the aircraft had turned south, would have stayed to check the area was clear before downing it. Thence his length of glide would be determined by him needing the visibility, downwards and radially, for the final descent. In that case, there being no pilot, as the UGIB fuel quantity apparently prefers, would be explained by things not having gone to his plan like, as the ATSB has speculated, he suffered decompression sickness.
Enter the character of the debris. My observation is that the size of the flaperon, flap and aileron parts, the engine cowl and nose gear door, together with most parts being from the wings, engines and some empennage tearings, might contain a clue. While IMO they could result from a wing break in a high g spiral, the possibility that there was a Comoros type ditching, probably at speed with flaps-up should not be dismissed.
On the other hand (once again), MH17 debris from the final impact included a quite large outer flap part.
For my part, flutter is less likely, because there were no empennage control surfaces recovered.
All in all, and on balance I suggest the debris does not rule out that there was a pilot. In view of search success probabilities should search of likely glided areas assume priority if based on the UGIB LEP?
line 10, commencing, “would be enhanced…”, should have ‘prior’ before ‘probability’
@David
David, the character of the debris is most assuredly interesting and perhaps instructive bearing in mind the heavy hand of survivor bias in the sample.
With regards to the debris having possibly originated from a failed ditching attempt, I think that debris item 22 – part of the right vertical stabilizer panel – may be instructive. Item 22 suggests that the vertical stabiliser did not survive intact. I have looked at 15 other ditchings and controlled flights into water involving jet aircraft and could not find any evidence of damage to the vertical stabiliser in any instance.
I like your wing break hypothesis. I think that it offers the best explanation for reconciling debris like the flaperon that evidences a lower energy impact with the items that could only have been produced by a very high energy impact.
@Mick Gilbert. I agree. I had it in mind that that piece was removed when the vertical stabiliser was struck. However studying the below afresh that gives more the appearance of having been torn in a stabiliser disintegration. The mixed compressive and tensile failures of the inner skin appear to be the result of buckling as it was peeled away.
http://mh370.mot.gov.my/Appendix1.12R-Item22RightVerticalStabilizerPanel.pdf
So less likely to be a ditching and therefore less likely to be piloted, thus reducing the case for priority going to a search of glide area.
@Mick Gilbert
Many thanks for your list of beaches. I will use that list to see which CSIRO trials beach and from what crash latitude.
@Mick Gilbert
The beaches I have analysed so far do not show any CSIRO trials beaching.
The beach clean ups are mostly on popular beaches, which are generally the more sheltered beaches.
The trials beach mostly on the more exposed beaches.
I will continue through your list and report the full results.
@Richard
Thanks Richard. That list is just down to Alkimos (just north of Perth). I haven’t yet looked at clean ups on Perth beaches or south of Perth down to Cape Leeuwin. I’ll look at pulling those southern clean ups out and get the details to you.
@Richard
Richard, here’s Tangaroa Blue clean ups from between 1 June 2014 and 31 May 2015 from where I left off down to but not including Dunsborough.
5060 Mullaloo .75km
5187 Hillarys .5km
5052 Sorrento Beach 1.4km
5167 North Beach, Mettams 1km
5084 Scarborough Beach 2km
5105 Grant Street beach 3km
5659 Cottesloe Beach 0.02km
5654 Leighton Beach 1.5km
From Mullaloo to Sand Tracks beach the beaches are generally quite popular
5404 Rocky Bay, Rottnest Island .7km
5400 Parakeet Bay, Rottnest Island .4km
5398 Geordie Bay, Rottnest Island .6km
5405 The Basin, Rottnest Island .5km
5402 Pinky Beach, Rottnest Island .4km
5403 Thomson Bay, Rottnest Island .4km
5399 Bickley Battery beach, Rottnest Island .5km
5934 Bathers Beach, Fremantle .2km
5058 South Beach, Fremantle .8km
5944 Nth CY O’Connor beach 1km
5181 CY O’Connor Beach 1km
5334 Sth CY O’Connor Beach 2km
5426 Coogee Beach 1km
5111 Ammunition Jetty Coogee .18km
5033 Woodman Point Groin 1.7km
5341 Woodman Point Beach .71km
5340 Challenger Beach .55km
5357 Kwinana Horse Beach .53km
5082 Rockingham Foreshore 1km
5355 Point Peron .7km
5354 Point Peron Foreshore .23km
5526 Safety Bay Beach .4km
5038 Warnbro Beach 3km
5050 Port Kennedy beach 4km
5131 Singleton Beach 1km
5046 Doddi’s Beach, Halls Head .4km
Singleton to Falcon Bay is well populated
5032 Falcon Bay Foreshore 1.4km
5083 Whitehills Beach 3km
5101 Myalup Beach 5km
5190 Binningup Beach 2km
5191 Binningup Beach Sth 1km
5093 Buffalo Beach 12km
6167 Nth Bunbury .4km
5361 Jetty Baths, Bunbury .2km
7926 Koombana Bay, Bunbury .5km
5422 Rocky Point to Bunbury Back Beach 2km
5999 Rocky Point, Bunbury .6km
5424 Bunbury Back Beach 1km (second clean up of same beach 5823)
5912/3 Bunbury Back Beach Sth .5km
5821 Hungry Hollow Beach 1km (5037, 5168, 5359, 5826, 5998 and 6310 of same beach)
5825 Hastie Street Beach .5km
5914 Mindalong Beach .5km
5094 Minninup Beach 11km
5132 Stratham Beach 4km
5160 East Busselton Foreshore .4km
5095 Geographe Bay 1km
5188 Geographe Bay, Dolphin Road to Vasse Diversion Drain 5km
5096 Sandy Bay, Holgate Street to Dolphin Road Boatramp, Busselton 1km
5015 Abbey Beach 3km (also 5021 and 5169)
5030 Newtown Beach 1km
5528 Abbey Beach Boat Ramp 3km
5049 Marybrook Beach 1.8km
5114 Quindalup Beach 1km
Why would one exclude offshore islands and sandbanks ? They are ususally outside the reefs and thats where debris washes ashore. Most of the debris I found were on offshore islands. The three confirmed pieces were found by others on Pemba, Ilot Bernache, and La Reunion.
3500 pieces of floating debris were recovered from Air France 447 in the immediate aftermath of the crash, and they knew where to look. MH 370 probably produced much more if it was a higher speed impact, as pointed to by most evidence.
Give Prof. Chari due credit. He was the oceanographer who predicted 370 debris would still be floating after more than one year, while government investigators and officials claimed it would have already sunk. Chari predicted where debris would go and when it would arrive, which directly resulted in finding half of the recovered debris.
@BG370
Blaine, no one was suggesting excluding islands or offshore formations from the search effort. The point that was being made was that when calculating search coverage achieved by beach clean ups it makes no sense including the coastlines of the myriad islands off say the Prince Regent River region of northern Western Australia for the simple reason that no modelling shows likely beachings in that area.
With regards to the AF447, I’ve seen the ‘3,500 pieces of floating debris’ reference before, notably in some work done by Dr. Goong Chen, but that number does not tally with the official Bureau d’Enquêtes et d’Analyses (BEA) records. The BEA’s final report on AF447 says that there were about 1,000 pieces of floating wreckage although their map of all of floating debris found between 6 and 26 June suggests less than 1,000 items.
And I am more than happy to give Professor Pattiaratchi due credit for his work in his field. He has undoubtedly made a very significant contribution to the search for physical evidence of MH370’s crash in terms of oceanography and his predictions regarding drift and beachings. But when it comes to making predictions about the break up of the aircraft on impact, that’s not his field of expertise. There’s certainly no disrespect meant there.
@Mick Gilbert
Here are the results of the drift analysis using BRAN2020 to the first area in Western Australia between 27.5°S and 29.5°S where 19 beach clean ups over a total length of 36.3 km were conducted.
I caution not to over analyse the results, which show no trials actually beaching on a beach where a clean up was performed. There were some trials beaching just south of Geraldton. There are no trials beaching on offshore islands, but this could simply be due to the definition of the WA coastline embedded in the CSIRO model.
https://www.dropbox.com/s/chvg2ub37j5s8dm/WA%20Beaches%2027.5%C2%B0S%20to%2029.5%C2%B0S.png?dl=0
P.S. The crash latitude colour coding is purposely shifted inland for legibility.
@Mick Gilbert
Here are the results of the drift analysis using BRAN2015 to the first area in Western Australia between 27.5°S and 29.5°S where 19 beach clean ups over a total length of 36.3 km were conducted.
https://www.dropbox.com/s/duhucl5s28cgkh6/WA%20Beaches%2027.5%C2%B0S%20to%2029.5%C2%B0S%20BRAN2015.png?dl=0
@Richard. FYI here are CSIRO’s BRAN2015 WA beachings, numbering 197, though not with crash latitude discrimination:
http://www.marine.csiro.au/~griffin/MH370/br15_pwent2d/br15_beaching_map_GDP_WAnonflap_36_08_25.html
That was illustrated at Fig 3.2.1, lower, P.18 of:
https://www.atsb.gov.au/media/5772119/mh370_ocean_driftv29.pdf.
Incidentally I see that BRAN16 differed from BRAN15 also, as does BRAN20.
@Mick Gilbert
Here are the results of the drift analysis using BRAN2020 for the second area in Western Australia between 29.5°S and 31.7°S where 31 beach clean ups over a total length of 33.1 km were conducted.
In this area there is a significant overlap of CSIRO beachings with the 31 beach clean ups.
https://www.dropbox.com/s/zozg8z9o3yenufa/WA%20Beaches%2029.5%C2%B0S%20to%2031.7%C2%B0S%20BRAN2020.png?dl=0
Same old song … sorry.
Link below to a drift graphic based on David’s posted reference to Griffen et. al. “mh370_ocean_drift.v29′.
The debris graphics in David’s link are all very similar. They show about a 4 degree Northern drift bias from the 7th arc in the debris crossing of the Pacific. The median location value of all the debris finds is 23.74S 39.87E. That would imply a 7th arc starting latitude of about 27.74S assuming the debris finds were an accurate representation of the debris distribution. The search was far from extensive, and I believe that more searching would produce a median find latitude farther North (what else would I say?). In any case, I submit that this data supports searching North from 25S along the 7th arc rather than researching the area around 34.2S. The lack of any debris found by the WA search effort also lends support to this conclusion.
https://photos.app.goo.gl/tkLLpZPTX6Ru9qFE7
Prof. Chari Pattiaratchi has always said the absence of debris along the western coast of West Australia says nothing about the latitude where 370 crashed along the 7th arc . He has always said the origin of the 370 debris is between 33°S and 28°S, and that those latitudes need to searched wider from the 7th arc. The last search was unfortunately narrowed when it reached those latitudes. One also needs to question whether the 7th arc is properly calculated in the right place, but that is a matter for the mathematicians, physicists, and satellite experts to determine.
BG: As many have noted, the available hard data is sparse. One of the few solid, verified data sets we have is the BTO and related calibration data. From that data set, we can be very confident of the 7th arc location. Post event tests conducted by Thales show that the arc is known within ±5.3 nm with 99% confidence. That is the only parameter we have (after 18:25) with such accuracy mand confidence.
Re: “…arc is known within ±5.3 nm with 99% confidence…”, that is the “digital noise level” measured by Thales. To be more complete, we have to add an additional error budget of about ±2 nm for I3F1 orbit error, 7th arc 9M-MRO altitude uncertainty (±1.5 nm) and other minor terms.
@Mike
Like you, I have high confidence in the BTO accuracy over a continuous time interval of SDU operation in a stable environment. I have not seen any data relative to the stability of the bias offset through an on/off power cycle of the SDU. Can we be confident that the power interruption and restoration did not result in a change in bias offset? We have no way to determine BTO bias after the plane left the ground at KL. Although the accuracy of the BFO and BTO data at 18:25:27 suggests that it was unchanged or very little changed.
Dennis asked: “Can we be confident that the power interruption and restoration did not result in a change in [BTO] bias offset? We have no way to determine BTO bias after the plane left the ground at KL. ”
Actually, we do have a good source of data that confirms the BTO Bias is essentially constant from power on to power on time. We know the BTO Bias remained the same from MH371 to MH370 following several hours of power off time on the ground at KL. Steve Kent (sk999) published a paper (Jan 1, 2018) in which he showed the residual BTO errors during the MH371 flight were close to zero on average, using the same BTO Bias derived for MH370 at KL circa 16:00.
http://bit.ly/3quWO0A
In addition, we know that (1) Inmarsat, in their JON Paper, did not indicate that any any change was expected following a power off period, and (2) the 1st arc(s) at 18:25 are consistent with the final radar at 18:22:12.
Thx, Mike. I always wondered what the point of Inmarsat (in their seminal paper) measuring it at KL was. I would think the AES internal delay would be constant across the same SDU type – purely a function of the HW design.
Great ! If the computations are that accurate then it should not be too difficult to go back and find the plane.
@BG370
I can assure you that the 7th Arc is calculated in the right place.
The calculations have been performed by many mathematicians, physicists and satellite experts.
Inmarsat who owns the satellite have published their data. Duncan Steel a satellite expert has checked the satellite ephemeris and epoch changes. Barry Martin and Henrik Rydberg both mathematicians have checked and compared the Inmarsat data with Duncan Steel’s data.
When Ocean Infinity started their first search, they asked Mike Exner to define the 7th Arc at 0 feet, 20,000 feet and 40,000 feet, which he did. Mike asked me to check his calculations before sending it to Ocean Infinity, which I did.
I have compared Inmarsat, Duncan Steel, Barry Martin, Henrik Rydberg and Mike Exner’s calculations and the 7th Arc is correctly defined.
That is good input from Blaine re: Dr Chari’s analysis. That’s the kind of information I am looking for: in other words, do Dr Chari and Dr Griffen endorse areas like 38 South, Xmas, 20 South, whose advocates always say the drift evidence supports their area?
DennisW is basically saying above he feels the drift data proves a more northern end-of-flight terminus. I am not convinced by Dennis alone unless Dr. Chari and Dr. Griffen agree with that. I see ultra deep spots at 20-22 South, so in the past I have been interested and can still get interested in that area, but right now I am thinking it went South like the simulator data, and I submit, the BTO/BFO data says.
For Blaine, I would say Arc7 is mathematically accurate, but there is an increasing possibility (if not a probability) that Arc7 is not the end of the flight. Aside from glide potential it is possible the Satellite signal at Arc7 came before fuel exhaustion.
As Richard point out, lack of a debris find is a weak piece of info. About all you can say is that it “supports” a more Northern crash latitude.
Probably the best reasons to search North are:
1> That path is not tied to a murder-suicide scenario. Which I have never warmed up to, but constitutes an opinion not a fact.
2> More info results from searching areas that have not been searched. That is a “geek” reason, and requires a longer term view of the exercise.
@DennisW
How do you assess the fact that Zaharie Shah’s home flight simulator revealed a simulator run to the SIO until fuel exhaustion?
@DennisW
Yes ruling out an area is progress, assuming there is a future. That is partly why searching 20-25 near Arc7 is supportable. Ultimately I agree with you that the “Golden Rule” of not allowing consideration of active pilot input past Arc2 is the Achilles Heel of the search. We were able to glean quite a bit from the simulator data re-review above, and I think similarly the end-of-flight MH370 might be better interpreted, including location. I am open but not with you on Xmas right now, I think the data suggests it negotiated somehow the winds below 22 South.
@ TBill Prof. Chari does not support a search at 38 S because a lot of debris would have gone east, and he does not believe the flaperon would have arrived as early as it did. If the crash site were at 20 S the flaperon and other debris would have arrived much earlier. Prof. Chari does not recommend searching north of 28°S or south of 35°S.
@Mick Gilbert
Here are the results of the drift analysis using BRAN2020 for the third area in Western Australia between 31.7°S and 33.7°S where 61 beach clean ups over a total length of 97.9 km were conducted. This is the populated area around Perth, so there were many more beach cleanups over a larger length of beach.
In this area there are very few CSIRO beachings and hardly any overlap with the 61 beach clean ups.
https://www.dropbox.com/s/y8h7lroyu5tgqcr/WA%20Beaches%2031.7%C2%B0S%20to%2033.7%C2%B0S%20BRAN2020.png?dl=0
@Richard
I cannot reconcile the simulator data with any likely flight path.
@TBill
Xmas Island has been off my list more quite some time now. I have petty much settled on Victor’s Cocos flight path with the runway alignment path of 152 degrees (the flight track after autopilot approach and subsequent passing over the runway). The Cocos scenario resonates with my conviction that the PIC would have chosen a path with “bailout” option – the reason for my earlier modeling of the Xmas Island path. 7th arc termination is at about 22S using this model.
@Mick Gilbert, @DennisW,
Having analysed the 3 areas of the Western Australia coast line defined in detail by Mick, covering a total of 111 beach cleanups and a total length of beach cleanups of 167.3 km, here is the combined result.
A total of 491 trials using BRAN2020 reached this part of the coastline from 27.5°S to 33.7°S (a total distance as the crow flies of 668 km).
https://www.dropbox.com/s/chvg2ub37j5s8dm/WA%20Beaches%2027.5%C2%B0S%20to%2029.5%C2%B0S%20BRAN2020.png?dl=0
https://www.dropbox.com/s/zozg8z9o3yenufa/WA%20Beaches%2029.5%C2%B0S%20to%2031.7%C2%B0S%20BRAN2020.png?dl=0
https://www.dropbox.com/s/y8h7lroyu5tgqcr/WA%20Beaches%2031.7%C2%B0S%20to%2033.7%C2%B0S%20BRAN2020.png?dl=0
The largest number of trials from any crash latitude was 196 out of a total of 86,400 came from a crash latitude between 37.09°S and 40.64°S (marked in cyan). This represents 0.23%.
If we use the MH370 floating debris metric of 33 items weighing 161 kg and the ZFW of MH370 was 174,369 kg, then there were 35,740 MH370 debris items.
If we use the Swissair 111 metric that 95%-98% sunk, then the floating debris would be between 715 and 1,787 items.
If we use the Air France 447 metric, then the floating debris found in the first 26 days was around 1,000 items. This value aligns with the Swissair 111 metric and sits between the estimated 715 and 1,787 MH370 floating debris items.
Assuming there were 1,000 MH370 floating debris items represented by 86,400 trials and 196 trials out of 86,400 from a crash latitude between 37.09°S and 40.64°S beach on the Western Australian coastline, then at most we could expect to find two MH370 floating debris items from the most likely crash latitude area.
The next most likely crash latitude area was between 32.59°S and 37.09°S (marked in black), where 109 trials out of 86,400 originated. At most we could expect to find one MH370 floating debris item from this crash latitude area.
Of course, if MH370 crashed outside these two areas, then we would not expect to have found any MH370 floating debris on the Western Australia coastline.
Out of the 491 trials that beached, some of the trials beached in locations where there was no beach clean up. It is also not clear whether all the offshore islands were included in the CSIRO definition of the Western Australia coastline. I do not believe the evidence is conclusive and that it is possible to determine the crash latitude from the absence of finds in Western Australia.
@Richard
Thanks for all of that work, Richard. Apologies for the tardy response.
I will get around to listing clean ups south of that last set at some point. It would be interesting to see the distribution of beachings for the remainder of South West beaches (Dunsborough to Albany) particularly from the more southern crash latitudes. I suspect that there might be better clean up coverage across that region.
I tend to agree that the absence of finds in Western Australia is not a great discriminator of possible crash latitude.
@Mick Gilbert
No apologies needed! We are all giving our time for free in the search for MH370.
I would really love to complete the exercise from Dunsborough to Albany for the South West coast. There are 388 trials beaching, which is more than any of the other areas and there is also a good chance that there is a significant overlap to beach clean ups.
https://www.dropbox.com/s/kvclcvshqzu0h2c/WA%20Beaches%2033.7%C2%B0S%20to%2035.7%C2%B0S%20BRAN2020.png?dl=0
The importance of the Dunsborough to Albany area is that almost all trials beaching originate from south of 37°S. If there is a significant overlap between beach clean ups and trials beaching, this makes a crash latitude south of 37°S unlikely.
@DennisW
You state “I cannot reconcile the simulator data with any likely flight path.”
Why do you think it is unreconcilable for @DennisW?
It was reconcilable for @TBill (please see his guest post)!
So why do you think Zaharie Shah ran a possibly unreconcilable simulation to the SIO until fuel exhaustion?
Just for fun?
Or are you implying the data is fake?
Or perhaps was planted? If so by whom and to what end?
@Richard
I don’t think the simulator data is fake or was planted. Yes you can construct an analytically reasonable path to the simuator coordinates (as well as to just about any 7th other arc coordinates). My lack of reconcilabilty is a result of a more holistic approach to path selection – math, fuel, debris finds, and motive (human behavior).
@DennisW
Please allow me to explain my holistic approach.
1. MH370 was captured on Malaysian Military radar in the Malacca Strait at 18:22:12 UTC. The indicated position generally aligns with the Inmarsat Satellite data for the 1st Arcs after the system is powered back up and the logon sequence runs between 18:25:27 UTC and 18:28:15 UTC.
2. MH370 was shown to have head southwards between 19:41:03 UTC and 00:19:29 UTC by an analysis of the BFO data by Inmarsat.
https://www.dropbox.com/s/ari41jyg4ezked5/Inmarsat%20BFO%20Comparison%20to%20Northern%20and%20Southern%20Route.png?dl=0
3. There are three basic options for a single Final Major Turn (FMT) after completion of the logon sequence at around 18:28:15 UTC, an early FMT directly after the logon, a middle FMT before the first SATCOM call at around 18:38:30 UTC and a late FMT at around 18:45:47 UTC to line up later with the 2nd Arc at 19:41:03 UTC.
These 3 options (depicted in the link below) allow without further turns or changes of altitude to reach crash latitudes around 39.4°S, 37.6°S and 35.7°S respectively. However, a late FMT would require a descent during the first SATCOM call in order to match the BFO during the first SATCOM call. If MH370 subsequently stayed at a lower altitude the fuel usage would increase and 35.7°S would no longer be reachable. Even if MH370 subsequently climbed to a fuel efficient cruise flight level, the fuel usage overall may increase and reduce the reachable end point from 35.7°S slightly to between 34.0°S and 35.0°S.
https://www.dropbox.com/s/t9kp44u7zah0x2t/FMT%20Variations.png?dl=0
4. The drift analysis using 86,400 trials from the CSIRO model of the Southern Indian Ocean for crash latitudes between 8°S and 44°S for the Flaperon found in Reunion and taking into account the windage exhibited by an authentic replica of the debris item based on sea trials excludes a crash latitude north of 23°S.
https://www.dropbox.com/s/3t0hb6rons6slg4/C2%20Flaperon%20-%20Crash%20Latitude%20Discrimination.png?dl=0
The arrival time of the Flaperon at Reunion after 508 days aligns with a crash latitude south of 31°S, given the fact that debris item was full of barnacles and the beach where it was found is cleaned every day, in other words, the Flaperon did not arrive very long before it was reported.
https://www.dropbox.com/s/k82m0jqet1hah0e/Flaperon%20Trials%20-%20Transit%20Time%20vs%20Crash%20Latitude%20-%20Reunion.pdf?dl=0
5. The absence of MH370 debris finds in South West Australia, where extensive beach clean ups were performed may indicate when the analysis is completed, that at least 4 or 5 debris items should have been found, if the crash latitude was south of 37°S and there were around 1,000 MH370 floating debris items.
https://www.dropbox.com/s/kvclcvshqzu0h2c/WA%20Beaches%2033.7%C2%B0S%20to%2035.7%C2%B0S%20BRAN2020.png?dl=0
6. The above facts are confirmed by the absence of an automatic logon at 00:19:29 UTC to the POR satellite and aligns to a crash latitude further west than 105°E, which would exclude the area around Christmas Island. On the ground in Kuala Lumpur (101.7°E) MH370 automatically logged on to the POR satellite at 12:50:20 UTC, although slightly outside the Inmarsat coverage overlap area between the IOR and POR satellites.
https://www.dropbox.com/s/2e6sy9opm68ompd/Inmarsat%20Satellite%20Coverage%20and%20IOR%3APOR%20Overlap%20Region.png?dl=0
7. The above facts are confirmed by a simulation run made by Zaharie Shah and recovered from deleted files on his home flight simulator ending at fuel exhaustion in the Southern Indian Ocean. Please see the separate post by Bill Tracy on this web site, where he analyses the possibility that the magnetic South Pole was considered as an end point during the simulation exercise. The UGIB paper also posted on this web site considers the alternative that the geographic South Pole was used during the actual MH370 flight. This simulation to the Southern Indian Ocean until fuel exhaustion is an indication of both planning and intent.
I conclude that MH370 ended within 65 nm of the 7th Arc between 31°S and 37°S and most likely between 34°S and 35°S.
I accept the point you make that this area has been searched to a width of 25 nm before, which makes the likelihood of a crash location outside the previous search area higher. This in turn implies that it was more likely, that there was an active pilot until the end of flight.
@Richard
Why do you think the plane was diverted?
Who do you think was the PIC?
How do you account for the EOF BFO history?
(dive -> glide -> dive)?
(No inflight entertainment login at 00:19)?
@DennisW
1. The plane was diverted as a desperate measure against a corrupt Government in Malaysia, by a person with the means, motive and opportunity.
2. The PIC was Zaharie Shah.
3. The end of flight dive and the downwards acceleration as shown by the BFO data is not possible without pilot input pushing forward on the yoke, which implies either an active pilot or a person slumped over the control column. The dive-glide-dive required to reach a further flight path of 65 nm from the 7th Arc, requires an active pilot.
@Richard
Why no IFE login if the initial dive was followed by a glide?
I doubt much can be said about debris arrival times due to
1> There were a number of typhons in the Pacific during the time the debris was in
transit West. You cannot model the effects a typhon.
2> There is no way to know how long a piece of debris spends in the area
surrounding a coastline. In the case of the flaperon it was reported as being
seen “bobbing” in the surf long before it washed ashore and found. The debris
finds can only establish an upper bound on the drift transit time.
@DennisW
The reason that the IFE was not received is because one of the following occurred:
• the IFE system was selected off from the cockpit overhead panel at some point after the 18:25 logon
• the IFE and/or SDU unit losing power (APU flame-out)
• the IFE and/or SDU becoming inoperative (due to impact with the water) before the connections could be set up
• an unusual aircraft attitude breaking the line-of-sight to the satellite (aircraft transmission not received by satellite).
The IFE was expected at 00:21:06 UTC, which is 97 seconds after the last satellite logon process started at 00:19:29 UTC.
At a horizontal velocity of 400 knots, MH370 would travel 19.96 km.
At a horizontal velocity of 500 knots, MH370 would travel 24.95 km.
In the Boeing end of flight simulations in case 4 the aircraft reached a horizontal velocity of 612 knots.
In the Boeing end of flight simulations in case 10 the aircraft reached a horizontal velocity of 609 knots.
In the Boeing end of flight simulations in case 6 the aircraft reached a horizontal velocity of 599 knots.
In the Boeing end of flight simulations in case 3 the aircraft reached a horizontal velocity of 577 knots.
Personally, I believe that the aircraft has been missed in the previous search. You do not believe the aircraft was missed. Therefore I state there are circumstances where the IFE logon was not received and the aircraft was piloted up to 65 nm away from the 7th Arc. If the IFE was switched on in the cockpit and the aircraft attitude allowed SDU communication and the APU still powered the SDU, then the aircraft possibly travelled 16.5 nm with or without an active pilot. If either the IFE was switched off or the aircraft attitude prevented SDU communication or the APU no longer powered the SDU, then the aircraft may have been piloted up to 65 nm away from the 7th Arc.
@Richard
Yes, the debris could have been missed. I would estimate that probability as about 10% based on comments in the AF447 search report. I am not qualified to form my own opinion.
I do think that MH370 went down very close to the 7th arc. You really want to endorse a dive, glide, dive EOF?
Drift trials are obviously dependent on the ocean conditions during which the trials were made – wind, current, tropical cyclones, seasonal variability,… The trial conditions can never replicate the conditions present at the time of the event. Also, I do not see how a tropical cyclone can be modeled, but I won’t quarrel about that assertion. In my view the disperion of debris in latitude, and the drift bias North or South is about the best you can do (the geometric center of mass in reverse). Once again, I am not qualified to form an opinion on the subject.
As far as human behavior is concerned, all we can do is guess based primarily on how and why we would behave faced with a similar situation. I do not believe the preferred outcome of the hijacker was to end the diversion with a crash in the SIO, and that outcome was a plan B, resulting from an unsuccessful plan A. Flying parallel to the coast of Australia makes no sense with murder-suicide as plan A.
My version of events may not be correct, but it is holistic. It takes into account all the observables in what I believe to be a logical manner consistent with rationable human behavior. Your version creates many unanswerable questions for me.
As far as lack of IFE logon after 00:19, I agree that the IFE might have been switched off in the cockpit or in the MEC BAY. The cockpit “IFE PASS/SEATS” off switch (which I believe that button was a retrofit addon for MH370) is controversial because some say that OFF switch would not stop the IFE logon. I consider it another unknown that Boeing would have to confirm. But there is always the MEC Bay, and I feel the pilot might have wanted the IFE off, because the IFE computer and other computer memory can be thought of as a secondary black box.
However, what I favor is the pilot was active and was managing the SATCOMMs logons. The Arc7 re-logon might have been a mistake or intentional.
@Tbill
The MEC bay is not accessible from the cockpit. It is accessed from the forward galley. Yes, I don’t believe the cockpit switch would disable the IFE login only the IFE availablility to the PAX.
@DennisW
The effect of tropical cyclones in the Southern Indian Ocean is included in the CSIRO model.
The CSIRO model simulates not only the ocean transit but the passage of debris items near the coast line.
Johnny Begue and his team discount the reports of the Flaperon being seen bobbing in the surf or beaching and re-beaching from their long experience with debris items that have beached in their area.
@Richard
I assume you believe that the decision for suicide and murder (“desperate measure”) by Shah was made prior to departure from KL. There was never an intention to land the plane and free the PAX? The intention to fly South and crash in a remote area of the SIO was the plan from the getgo? Frankly, that makes no sense in the context of making a statement to a “corrupt govenment” and your fellow citizens.
@DennisW
I have made it clear, that in my view the home flight simulator provides evidence of the planning and intent before the flight commenced.
Desperate people will take the law into their own hands. We have seen other examples of that both in the aviation world and more recently in various other countries in the world in the non aviation domain.
If you look at the sim data like I do, I see a possible 1MBD defiance rationale for the apparent choice MH150 in the sim work. Can you imagine if that had happened? There would have been no question of motive. MH150 was skipped for unknown reasons, and MH370 was chosen perhaps due to Anwar guilty verdict, but it is a little harder to explain the motive in that case.
I do think it was probably a plan over some months, but I am recently aware some feel it could have been a last minute weakness. Not my fav theory but OK since you ask (if it was remote SIO plan)that thought is out there.
@TBill
MH150 uses three cockpit crew members. I think that influenced the decision to use MH370. I don’t think the Anwar verdict was a factor in the planning.
@Richard
Of course, in your scenario the choice of path is quite puzzling. If the “desperate act” was to commit murder-suicide why not fly further West after the FMT? Complicate the search by crashing much further from the obvious WA search staging area. Flying parallel to the coast of Australia makes little sense.
Even an “armchair” hijacker like myself would have thought of that.
@DennisW
You argue that the goal was Cocos Island to the East and now you question why I do not select a flight path further to the West. You cannot have it both ways.
Fact is, that MH370 has not been found in the last 7 years. In that sense, the search was complicated enough to prevent the best minds with the best resources from finding MH370 so far. The Ocean Infinity technology is very advanced and they have successfully found other wrecks on the ocean floor.
Zaharie Shah was not an armchair hijacker. This was a carefully planned and executed hijacking.
That’s always been the question (where was MH370 heading in the SIO?) and for some of us easy to answer: to a hard to find crash location such as Broken Ridge. The other benefit there is a back up option to COCOS if needed and also a rogue flight west looks like a suicide flight. To me looks like 180 S was the initial plan, and since MH370 was fuel-short compared to other flights (eg; MH150) there might have been a need to stop short of 45S1 or Mag south pole.
@TBill
I don’t think it was possible for MH370 to reach 45S. That is one of the reasons I don’t put a lot of weight on the sim data to infer a flight path. I regard the sim data as a strong indicator of intent.