[Editor’s note: One of the most intriguing clues in the MH370 mystery is the fact that the airplane’s satcom system logged back on to the Inmarsat network at 18:25. By understanding how such an event could take place, we can significantly narrow the range of possible narratives. In the interest of getting everyone on the same page in understanding this event, I’ve asked Mike Exner for permission to post the content of a detailed comment he recently provided. One piece of background: a lot of us have been referring to the satellite communications system aboard the aircraft as the “SDU,” but as Mike recently pointed out in another comment, it technically should be called the “AES.” — JW.]
Until we have more evidence to support the theory that the loss of AES communications was due to the loss of primary power to the AES, we must keep an open mind. Loss of power may be the most likely cause (simplest explanation), but the fact is we do not know why the sat link was down between 17:37 and 18:25. My reluctance to jump to the conclusion that it must have been due to the loss of primary AES power is based on decades of experience in the MSS (mobile satellite service) industry. It’s not just another opinion based on convenience to support a theory. Let me elaborate on a few possible alternative explanations.
The potential for loss of the pilot carrier, due to the orientation of the aircraft in relation to the satellite, was increased as soon as the airplane turned WNW. Between the time of this turn (circa 17:50) and the time of the FMT (final major turn circa 18:25-18:40), the aircraft was flying more or less toward the satellite where the antenna pattern was near a null. Don and I have both looked at the antenna pattern in some detail and concluded that the antenna pattern and coincidental direction of flight were unlikely to be so bad that the pilot carrier would be lost due to this geometry. Moreover, according to a MAS Press Conference on March 20, 2014, there should have been an ACARS message transmitted at 17:37, but none was received. ( bit.ly/QFbF6C ) At 17:37, the aircraft was still over Malaysia SW bound, so the HGA pattern would not have been an issue at that point. Taken together, loss of the pilot carrier due to antenna orientation appears to be a possible, but unlikely explanation for the outage.
Ionospheric scintillation has also been suggested as a possible explanation for the loss of service during this period, but there have been no reports of other aircraft in the vicinity suffering a loss of service, so this explanation is also unlikely. (Note: Ionospheric scintillation in the equatorial regions can be a big problem for VHF and UHF communications, but it does not affect communications in the L band as much.)
The MCS6000 AES, located in the back of the airplane, requires a continuous feed of INS data (position, speed, etc.) via an ARINC 429 link from the computers in the front of the plane. If the AES stopped receiving INS data for any reason, then it would not have been able to steer the HGA, or compute the required Doppler corrected transmitter frequency. Thus, it is very likely that the AES would be out of service if there was any loss of this 429 data link, or the information carried over the link. Given that there was no VHF voice communications after 17:19:24 and the Transponder Mode S data was lost after 17:21:13, it is certainly possible that the INS data flowing to the AES was disrupted due to a common failure in some piece of equipment in the E-Bay. This explanation for the loss of service cannot be dismissed as easily as the two previous theories.
However, there is one additional observation that tends to favor the loss of primary power theory over the loss of INS data theory (or the other two theories above). We note that when the AES logged on at 18:25:26, the BFO values for the first few minutes thereafter appear to have been drifting in a way that is more consistent with a restoration of primary power event than a restoration of INS data event. If the AES power had been on during the outage, the oven controlled reference oscillator would have maintained a stable frequency and there should not have been any significant BFO transients following the 18:25:26 logon.
In summary, there are multiple alternative explanations for the AES outage, but loss of primary power is the most likely explanation. Like so many other necessary assumptions, like the mode of navigation after the FMT, we have no choice. We must base the search on the most likely assumptions while maintaining an awareness that few of the assumptions have probabilities of .999.
@Matty
I agree with the AP point. Find it hard to believe that it flew to fruition @ altitude without a lick of debris.
I think by the time we heard the final “Goodnight” the first O was already locked out & all passed shortly afterward the first left turn.
As for his state of mind. He had practiced how he was going to spend that time. But how he passed his psychotic time is anyone’s guess while flying into the history books & oblivion. I’m also still of the mind to say that the run down the straights was a final good bye of his own design then out to sea.
Chris – The scaffold of assumptions again? The ATSB AP scenario is an oxygen deprived one at 35,000 approx? This could easily be way off which is why as a non mathematician I stuck me head out very early and said “no plane” even if it did head all the way down there. Pilots to a man will say AP is the way to go but this wasn’t a normal flight. Watching the doco but I feel more inclined than ever to think the AES(Satcom) was switched off/on deliberately but I still lean away from Shah. Would a lover of aircraft would do that, a dedicated aviator? I think he had too much respect for the profession. When AAF447 went awry the Captain was asleep and only about 80 mins into it? The Vietnam ATC handover would be a logical point for the senior pilot to head out for whatever. Been said it had to be a skilled aviator but it didn’t really do anything that funky – they turned it around and flew off, and the coey is fully qualified. If you can fly a 737 you can fly a 777. Not fundamentally different, could even be easier??
@Matty
Yeah…..nothing at all normal about ANY of it. The Indonesians & Egyptians still, to this day, refuse to believe those two occurrences. Truly mind boggling behavior makes it damn near impossible to believe. While at the same time, we round and round different theories, I myself return to the same scaffold of assumptions. I think the coey had to much to live for to have pulled it off. Shah’s wife had left him just hours before the flight took off. Could this have been the final mental trip wire? One thing for sure. The first left turn made him committed. Deviating the a/c with heavy w/pax, at that time made it a hijacking. Hijacking means tough prison time, while suicide, relieves him of everything and on his own terms with his own mysterious destination, for all to ponder.
Airlandseaman,
I think you contradict to yourself with regard to AP, and I already explained why. There is still possibility that MH370 was flown on the AP, but I think the probability to find MH370 in the place indicated by IG is an order lower than you presented it here.
However, I suggest dropping this topic for a while, as this discussion is not productive. I hope you can find time to comment a number of other questions.
Btw, what is the best estimate of the Inmarsat satellite position and speed 23:15 in ECEF? I realized that I am still using interpolated ATSB table.
——
Dave Reed,
The scenario you suggested is very unlikely. BFOs form a trend line. If someone was manually flying the aircraft in the way you described, what would be the probability for BFO samples to form a line of 7 of 8 values (more exactly clusters of values)? Such a coincidence is of very low probability.
@Oleksandr
Who’s to say that he didn’t use AP for the last 30 min’s or so. I think he ditched her with about 3000 lb’s (300 Gallon’s) of fuel, sinking her before running out of fuel. And if the BFO & BTO info., is so accurate, why do we have a 21,000 square mile haystack to search? I’m Not in anyway degrading the efforts nor science behind it all, but keeping an open mind to the human element of it might prove fruitful.
@Oleksandr I’m trying to follow your reasoning but got confused by two of your recent statements:
“My latest run already converged to |BFO residuals| <2.5 Hz. All trajectories end up around 100E.”
“what is the best estimate of the Inmarsat satellite position and speed 23:15 in ECEF?”
Wouldn’t a model that converges BFO’s and can project all MH370 trajectories have to have realtime ISat positioning built-in? Or are you looking for validation of your ISat ECEF model? Is your model published?
I certainly don’t claim it’s the ‘best’ but FWIW my ISat model calculates: 18171.48km, 38056.17km, 694.95km 258.89km/h for 23:15. What does your model currently use for 23:15?
On the question of why the AP was used…
It seems that some non-pilots (and a few pilots lacking heavy metal experience) are having difficulty understanding why the AP is almost certain to have been used. I’ve attempted to explain this several times, but perhaps not clearly enough. The AP is used almost universally at cruise altitude because it is difficult to fly the airplane without the AP. It is not just for “lazy pilots”. It takes considerable skill and concentration to fly a 777 at 35,000 feet and 480 kts without venturing out of the very small box defined by stall on the slow side, and over speed on the high side. Plus, at this speed and altitude, the stick and rudder become quite sensitive to small changes. It is not easy.
I have 48 years’ of flying experience as a licensed pilot. I’ve flown many small SEL planes and sailplanes over those years, but never anything like a 777, until November 2, 2014. Beginning back in May 2014, I began consulting with some of the many airline pilots I know, asking for advice on MH370. One such pilot took a strong interest in the IG work. We discussed many details about the electrical, fuel, communications, navigations, and other systems. In addition, Paul started working with one of the airlines to arrange a 777 Class D simulator for testing some end of flight scenarios. Paul finally got the go ahead in late October and we went to the simulator on November 2.
For months, Paul had been stressing that the 777 is always flown using the AP at cruise altitude because of the tedious concentration needed for manual flight at cruise altitude. All the other professional pilots I know agreed (over 10). After completing 3 hours of end of flight test scenarios, Paul insisted that I try flying the airplane without the AP to give me a taste of what it is like. Almost immediately after disengaging the AP, I had a sense of what he was talking about. I found my eyes glued to the flight director and my mind riveted to the small center box. It was very difficult to look away for even a few seconds without getting out of the box. After 5 minutes, I was exhausted! We ended that simulation and then went to SFO for a couple of patterns. I shot two landings and found the 777 easy to fly manually at pattern speeds (<200 kts). So there is a big difference between flying a 777 at 200 kts and 500 kts. I hope this explanation will clarify the reason why professional pilots insist the plane would not be flown manually for any extended length of time, and why the AP mode has been assumed by the IG and now the ATSB and many others. It is no accident or coincidence that the path models fit so well when the AP is assumed to be engaged.
@airlandseaman, I’d like to add another reason why straight-line flight on autopilot would be expected: It would be extremely boring to fly a plane over the open ocean, at night, at 35,000 or 40,000 feet. Whichever direction you went would look the same. There would be no reason or motive for turning left or right, no obstacle to avoid (unless of course there were thunderstorms in the way). If you have a destination in mind you will flight straight to it; if you don’t, I suppose you could just head off in any direction, but there would never be much incentive to, say, suddenly make a 5 degree course correction to the left, which is why the ATSB’s early curving path scenarios always seemed unlikely to me.
@ALSM
I want to start out by saying, that I’m in no way an expert. I was an AC lineman, ground support. I’ve towed & fueled just about everything from B-52’s to 152’s, but with a facisnation for both Aerspace & MH370. I also honestly appreciate the patience the group has had with novices, such as myself.
With that said. Shah had 18000 hr’s of flight time, not counting @ home simulator time. We’re not dealing with a Mike Exner, nor a Jeff Wise. We’re dealing with a psychotic. Normal pilots will fly at altitude with the AP. Absolutely nothing about this is normal after the Agari turn. We’re quickly approaching a year and If the AC plunged from 35000 feet, why not even a single seat cushion, luggage, or anything thus far? That is why I brought up the last 30 min’s or so without the AP & 3000 lb’s of fuel left on board + the human element of a man bent on doing this.
“I might be insane, but I’m not stupid.”
— ghost of whoever took MH370
Stupid be, as psychotic does.
@Matty,
The earnestness is commendable. I have NO information as to what the investigation of Zaharie’s flight sim turned up.
IIRC, at first it was reported to be basically ‘pristine’ (nothing incriminating per se). Then, later on, reports about island landings in the pacific, dg, SIO and the like (Dennis may know more in this regard).
As for my reference (if this was your intent) to his ‘now we can do some real flying’ comment, post his integration of the flight sim motor…this is first hand from Shah himself. Please see his over 700+ fb posts, sift through and do your finest. Or his youtube page (if this is still active). I’ll try later when I have some more time.
@Chris Butler
I agree that these last 30 minutes are the particularly relevant time frame. Whether Zaharie was in straight-line AP or fooling around at the controls for the 300 or so minutes prior is really immaterial (in a sense).
What is VERY MATERIAL to the end outcome here is that he was alive and in control. This potential circumstance effectively opens up innumerable possibilities as to the terminus. Was he aware of the BTO/BFO? Indifferent? Unaware? Did he manipulate it? Etc…
The engine flame-out, fuel exhaustion, phugoid end of flight scenario seems pretty unlikely whether one believes it was Zaharie or not (one only need believe in a deliberate diversion to debunk this with common sense).
This scenario is supported by fuel-endurance models and BFO interpretation, along with the regrettable AP assumption.
Maybe some of the tweakers could take a closer look at these end data and think a bit more out of the box…just a genuine suggestion, not by any means a repudiation. Perhaps something interesting could be ascertained previously not considered (though this does seem quite remote).
Spencer
@Spencer
I wholeheartedly believe he was in full control of the AC when he ditched her. Figuring in the human element. It was he last flight & knowing he was causing the greatest aviation mystery of the 21st century, he wanted FULL control from beginning to end.
Just to reiterate a few pertinent questions that have been asked earlie by several posters:
1. What kind of person was controlling the autoflight systems (autopilot, autothrust, FMS) ?
2. What inputs did he or she make to those systems?
3. When did that person make those inputs?
4. Did that person take control of the airplane when the autopilot disconnected at fuel exhaustion?
Oleksandr,
I don’t think the scenario I presented is likely, as I said in my earlier post. However, the scenario need not require large deviations from a constant heading or constant speed. Consider for example, the decompression scenario presented by the IG. They have considered it to be less likely because the BFO fit isn’t as good as for a AP flight at LRC conditions. But if we assume that the pilot was flying at 10,000 feet, only infrequent departures from constant heading and/or speed can yield a good fit to the BTO/BFO data. FWIW, I do think the current search area is the best place to look. On the other hand, I suspect that any “increasing confidence” in the current search which is solely based on further analysis of the Inmarsat data probably contains an element of circular thinking.
@ChrisButler (and all):
I’ve posted this previously.
If you watch the FourCorners documentary, it appears that the early reporting around these three issues —
1. Simulator
2. Why wife ‘left house’
3. Zaharie attending Anwar trial
— was inaccurate. Per his family, Zaharie Shah’s wife did not “leave” him. She went to stay at another house while he was away. It’s a cultural custom: the wife (and/or daughters) don’t stay in the home alone if the husband is away.
http://v.youku.com/v_show/id_XNzE1MDI4MjI0.html
@spencer
Nothing I would call reliable relative to info on the simulator destinations. Just stuff you find Googling – Maldives, Sri Lanka, Diego Garcia,… All from questionable sources.
@N-Mama
Never thought documentaries could be so wrong. Especially regarding the wife.
Thanks
@Chris et al,
I don’t see how it’s possible to fly a 777 for 5 hours, at altitude, by hand. While the pilot may have had 18,000 hours, little of that would have been real life, high altitude, manual piloting. Who would let him? So he may have simulator practice, but realistically it would be very hard to get that kind of experience. Recall that after AF 447, concerns arose about the lack of high altitude proficiency, even among veterans.
BUT…
The autopilot theory is based on circular logic. It is required because a straight line flight requires it. But the straight line flight is an assumption, not a fact. It is based on a destination that fits numerical data that some of us question. It is also based on an idea that a straight path is somewhat more likely than a twisty path. However, that idea itself is based on an assumption that the AP was used. If we assume it was flown by hand, we’d also assume it didn’t fly particularly straight.
We just don’t know that the plane flew a straight line, and as a result, the autopilot use is irrelevant.
@ChrisButler:
“Never thought documentaries could be so wrong. Especially regarding the wife.”
So does that mean that you are privy to other (factual) information that proves that Shah’s wife did leave (split with) him? If so, please share it.
Jeff,
1. You showed a ping ring graphic on March 22, which indicated that MH370 flew (north or south) in a corridor between the 18:25 and 0:11 rings. In that timeframe, you said that Inmarsat told you that the 19:41 and 20:41 BTOs were greater than the 18:25 BTO.
Now we see that the ‘rock-solid’ 19:41 and 20:41 BTOs are now located approximately 150 NM and 115 NM with lesser equivalent values. It also appears that the 0:11 ring was increased by about 30 NM.
How did this all happen ?
Further, the BTOs form a ‘near perfect’ set and ‘straight’ line flight path. I have analyzed other flights (handshakes with normal power) and estimate that there is an 80 % probability that the BTOs will have an error of 40 NM and a 20 % probability the BTOs will have an error of 100 NM.
As far as I know, Malaysia / Inmarsat has not provided any explanation.
2. Regarding the ‘straight line’ flight path, the mode, and a 40 knot wind from 240 degrees that nite.
It is my understanding from Dr. Ulich, that a straight line flight path is only possible using the WP mode and human inputs would be required. The only other possibility would be constant thrust (without yaw correction) and no human input.
In constant thrust mode, Dr. Ulich and I think the plane would crash in 1 or 2 hours at the most.
Does anyone know otherwise ?
3. Regarding the IG straight line path and final location of approximately S38 E88 at 490 knots.
Based on the March 22 BTOs,one could construct a curved path to this location (or within 150 NM), without explicit knowledge of the wind and constant thrust dynamics. A possible and consistent flight mode would have to be determined. This curved path would have to be based on either human inputs or some non AP mode that would keep the plane from crashing into the SIO.
Also the speed for the curved path would need to increase by at least 3.5 %.
This all seems to be highly improbable.
Hi Benaiahu,
Not necessarily “real time ISat positioning built-in”. I am using linearly interpolated Table 4, p. 56, ATSB June, and minimization approach similar to those of Yap and Sk999.
Do you have all the ISat velocity components?
A few months ago I began questioning whether other flight modes besides AP hypothesis, such as AT, TOGA, or “engine failsafe” can fit BTO/BFO. The answer is yes. I have not published the model yet as it is still in the process of tweaking, and it will take some time to write a proper description. In brief a former AP mode (results were quite close to Yap’s) gradually became a system of 9 ODEs:
dX/dt = U(u,v,w,X,Y,Z);
dY/dt = V(u,v,w,X,Y,Z);
dZ/dt = W(u,v,w,X,Y,Z);
d(mu)/dt = Fx;
d(mv)/dt = Fy;
d(mw)/dt = -mg + Fz;
d phi / dt = psi;
d psi / dt = Fphi;
dm/dt = -f(thrust,…);
where X,Y,Z are the coordinates of the aircraft in ECEF, U,V,W are the aircraft velocity components in ECEF, u,v,w are the aircraft velocity in a local coordinate system, m is the aircraft’s mass, phi is the orientation of the fuselage (slightly different from the heading), psi is the horizontal angular velocity of the fuselage, f(thrust,…) is the fuel consumption rate, Fx, Fy, Fz, and Fphi represent respective projections of the thrust, Coriolis and wind forcing. The forcing depends on the ambient conditions, which are sourced from ARL NOAA GDAS.
All this stuff is solved in Matlab. Unknown coefficients are found by the minimization of a target functional. But surprisingly I am getting very realistic values. Earlier in this thread I posted other interesting observations with regard to this class of models.
@N-Mama
No…I meant that the doco said that they had split up and to straitened me out on the point.
@ JS & all
OK…If I understand what I’m reading. IF ever there was a time when a 777 crew had to bring in an that AC during a stressful non AP five or six hour flight….it’s doomed?
I know some might think it premature to condemn Shah. I don’t see other scenarios from anyone that has that Ah Ha moment.
Airlandseaman,
I agree with JF: your explanation is similar to Baron Münchhausen story how he pulled himself from a swamp.
An interesting thing: try to exchange the words “AP” and “cruise altitude” in your post 9:24 AM. You will get:
“On the question of why the cruise altitude was used…”
@Greg,
I have never analyzed a constant thrust mode, but I suspect that it may be possible for the plane to continue flying until fuel exhaustion with the appropriate lateral and vertical navigation modes selected. I don’t know any reason why it would only fly 1-2 hours.
Using waypoints is not the only way to fly a “straight line.” One can also do it by setting a True Track bearing on the Mode Control Panel.
Jeff,
1. You said “There would be no reason or motive for turning left or right, no obstacle to avoid (unless of course there were thunderstorms in the way).”.
So, what was a purpose for FMT? Why would someone have a purpose before 18:40, and loss it after 18:40?
2. You say “but there would never be much incentive to, say, suddenly make a 5 degree course correction to the left, which is why the ATSB’s early curving path scenarios always seemed unlikely to me”.
The answer might be Coriolis + wind. This is not an assumption, but rather output from my recent model.
@Oleksandr,
Thanks for the reply. I think many people have always understood that that other flight modes are ‘possible’. The issue is MH370 is missing, an unprecedented mystery, so it becomes which flight modes are most probable to begin finding MH370.
For me, AP for the bulk of the final leg makes sense as the primary flight path. I would have to find my childhood Spirograph in the attic to draw out flights paths that end too far north. I’m not a pilot and reading @airlandseaman’s recent posts give me a deeper understanding why AP is primary. Naturally that doesn’t make it a reason not to explore other possibilities, I think most are open to anyone publishing alternatives for a good healthy peer review. Equally because other flight modes are possible doesn’t mean AP for the majority of final leg is incorrect.
Use at your own risk:
R_x (km) = -1.60527229800967E-12*(T)^5 + 9.17162902048147E-10*(T)^4 + 1.10805191255592E-07*(T)^3 – 0.000114163627976565*(T)^2 + 0.130358828466639*(T) + 18122.8691382455
R_y (km) = -9.56698498200126E-10*(T)^4 + 6.68991672712018E-07*(T)^3 – 0.0000907808504085745*(T)^2 – 0.068205161786766*(T) + 38079.9805575933
R_z (km) =-1.09916437157706E-14*(T)^6 + 1.22719073429888E-11*(T)^5 + 1.26005991618042E-08*(T)^4 – 0.0000122205717848198*(T)^3 – 0.00791807752957273*(T)^2 + 3.83412558954144*(T) + 828.487249135608
V_x (km/h) = -1.60527229800967E-12*(T)^5 + 9.17162902048147E-10*(T)^4 + 1.10805191255592E-07*(T)^3 – 0.000114163627976565*(T)^2 + 0.130358828466639*(T) + 18122.8691382455
V_y (km/h) = -6.96259913061348E-16*(T)^6 + 2.22213732737006E-12*(T)^5 – 1.38289167271898E-09*(T)^4 – 2.7149739781613E-08*(T)^3 + 0.000153297911473779*(T)^2 – 0.0186745056991172*(T) – 3.84894039671643
V_z (km/h) = 4.51811423941723E-16*(T)^6 – 4.54382109886909E-12*(T)^5 + 3.9647671927409E-09*(T)^4 + 2.96205360096854E-06*(T)^3 – 0.00219373707811439*(T)^2 – 0.950355494898756*(T) + 230.047163998822
T= Elapsed Time in minutes (16:30 basis = 0 minutes). For range of flight only.
Let me know if you spot issues.
“A simple reason to head west. Would likely be spotted after sunrise.”
https://twitter.com/KeyserSquishy/status/446662106176159744
@Nihonmama
Why not just land at an airport? And if staving off an attack on the cabin w/o comm capabilities, figure in a holding pattern over land until the military can escort you down. Why fly out to that inhospitable sea?
Greg,
Why do you think “In constant thrust mode, Dr. Ulich and I think the plane would crash in 1 or 2 hours at the most.”?
P.S. Just to make sure that everybody understands that the thrust itself (as the force) is not constant.
ALSM – I could write what I know about satellites on a postage stamp but in you I see an encyclopedic inquiring mind bent around assumptions that have solidified in your thinking. There was no requirement for this plane to fly a steady course. No ATC to bark at him, no alarms going off – who cares if it wanders, gets “out of the box” There was no box. Bit like a solo yachtsman, they don’t follow a beam.
In WW2 the Berlin trip was 10 hours of concentration and muscle – without heating. What does it matter if it meanders a little if you are basically aiming at the south pole? He was free as a bird after the turn south – if there indeed was one. We are punting on the mental state of the pilot.
Oleksandr,
Probably constant throttle mode is more accurate if it exists.
I want to know the mode with no human input after 18:40, no AP mode, and if it could stay in the air in a curved path for 5.5 hours to S38 E88.
Benaiahu,
Thank you. In my understanding you used a higher order fitting of the values in ATSB table, right?
Indeed, the existance of other flight modes do not invalidate the AP hypothesis. However, the major problem with the AP is the failure to explain itsef in any logical way, particularly FMT, and the sequence of events that occured before and after 18:22.
It is just strange to me that some are contemplating about probabilities and reasons why MH370 is not found where it was predicted to crash.
“Why not just land at an airport?”
MH370 flew right by Langkawi — and didn’t land.
“And if staving off an attack on the cabin w/o comm capabilities”
Was there an attack on the cabin?
“figure in a holding pattern over land until the military can escort you down.”
But, IF “an attack on the cabin w/o comm capabilities”, would the next logical (read: SOP) action (after presumably thwarting the hijackers) be to circle over land? And, without comms, how would the (presumably Malaysian) military (which apparently “missed” 370 crossing back over peninsular Malaysia) have been informed that 370 needed an escort down?
“Why fly out to that inhospitable sea?”
The response of those who believe MH370 was a pilot suicide (I do not), would be: to ditch the plane where it wouldn’t likely be found. But if that was the main goal why didn’t the pilots just continue (east) and ditch near the deepest place on earth — the Marianas Trench? (IF feasible they could reach it).
Did MH370 fly to the SIO? The data says “yes”. The search in the SIO to date has not found anything to support the data.
Greg,
With the help from Gysbreght and Don, besides AP, it appears that the aircraft could be flown in:
1. Auto-throttle mode (AT).
2. TO/GA mode (in case of aborted landing).
3. “Engine failsafe” mode. This is when engines loss communication with FMC.
I hope Gysbreght and Don correct me if I am wrong.
I don’t know for how long, but as long as the aircraft is capable to maintain its stability in the air, why not for 6 hours?
If will not fly to S38 E88 in this mode. So far my predictions for this mode are 99-101E, 27-29S.
Finally don’t forget that the AP modes are likely possible to terminate up to ~96E. Specific location 38S,88E corresponds to a particular scenario within the “AP class” of scenarios (I mean FMT assumption).
At Igari the pilot threw away the manual, I just don’t see why it’s “almost certain” he picked it up again re AP.
@Oleksandr,
The basis for my polynomial expressions of Inmarsat movement in ECEF is based on the satellite data provided in Richard Godfrey’s spreadsheet. Inmarsat’s/ATSB’s reported data points aligned well with Richard’s data so I felt comfortable using it as a dataset.
I think we may all struggle with the FMT due to lack of raw data, as well as pre post 18:22. Do I detect that you understand exactly what happened? I don’t understand why these struggles are unique to a flight path with significant employment of AP.
I am VERY appreciative of all the tireless, high quality, efforts by the IG to date, if you can produce a significant alternate scenario in a spreadsheet (or similar form) that would be very interesting to evaluate. In particular how much piloting, and skill level, required to support the long journey.
Maybe MH370 made the FMT and ‘set the controls for the heart of the artic’ and tried to set her down ‘gently’ when fuel got scarce? Regardless, this incident is a significant head scratcher right now.
Benaiahu,
Thanks for the clarifications.
Brief comments in reverse order:
1. “Maybe MH370 made the FMT and ‘set the controls for the heart of the artic’ and tried to set her down ‘gently’ when fuel got scarce?”
(1) Who? (2) It was unrealistic to get to the Arctic. (3) Why AES was shut down? (4) Why did AES come back? (5) Why nobody picked the calls? (6) Why nobody used sat phone to make a call on the return of AES? (7) Why did MH370 turn westward at Penang? (8) Why did not it fly over Langkawi (a shorter path to MEKAR)? (9) Why was it [likely] flown manually from IGARI to Penang?
2. “Do I detect that you understand exactly what happened?”. I am not sure about your question. No, I don’t know what happened, but one of the possible explanations I can suggest is the tire burst (nose landing gear). In contrast to AP, this scenario is consistent with everything, though it involves some coincidences. It even has a motive: a struggle for life. So far there were no serious attempts to disqualify this scenario. Note, I am not saying that hijacking (by whoever) is unlikely.
3. “I don’t understand why these struggles are unique to a flight path with significant employment of AP”.
A number of reasons.
If hijacking:
– What is a motive?
– Why constant altitude?
– Why a curved path via Penang?
– Who engaged AP again, when, and for what?
If mechanical failure:
– Watch “Children of magenta”.
– Why a single FMT towards the middle of nowhere?
– Why AP was engaged again?
– Why didn’t they attempt to land, or at least change altitude?
On top of it AP is inconsistent with the radar data with regard to altitude… IG discards this radar data on the basis of low accuracy and incompatibility with the AP. Why not to make theory consistent with the data instead of discarding some data on the basis of inconsistency with the theory?
Oleksandr,
Your S28 E100 location is very interesting.
I have a straight line path from the 18:40 position to S28 E99 at 373 knots which satisfies the March 22 BTOs. This path would correspond to wind forces balancing (any) differential thrust.
If the forces were not balanced – I have
another path that would go to Christmas Island at 260 knots.
I have also assumed the BTO error for the 0:11 arc is approximately 150 NM.
It appears that the probability that the plane flew to the West of S28 E99 is very low.
I think you are on the right track with your analysis.
A possible flight to the south is all about the stability.
Having said all this about the south route – I think it is more likely that MH370 actually continued flying
in the same direction of about 300 – 320 degrees at 18:40.
@N-Mama
I,m only trying to explain the unexplained. The circle of info seems to “circle back”.
The flight time was too long to be an accident, but also too long, but a planned even.
@Oleksandr
Hijacking, agreed would be an end game and vocal & eventful occasion. The world hasn’t hear a peep.
Hi Oleksandr,
Re: ‘set the controls for the heart of the artic’, sorry it was an, age appropriate, tongue in cheek comment referring to an old Pink Floyd tune. However, what’s generally inferred is that someone set the electronics to fly the 777 towards the SIO. The IG uses the term Auto Pilot, I’m not astute enough to know the exact meaning but to me that translates to a flying mode that allows the 777 to fly with reduced focus (of whoever is piloting) to a location in the SIO. Regarding ‘landing’, due to lack of debris to date, I’ve wondered if a sea landing might have been attempted.
As to the other questions listed in item 1, heck if I know, there are multiple possibilities for each question. No matter what scenario is presented an equal number of questions can be generated. Even after MH370 is found and recovered, we may have solid theories but never know for sure.
Re Item 3, thank you for your thoughts. I have my ideas on plausible answers but naturally they are only gut feelings since I have no data that leads to conclusions for such questions
Regarding your closing comments, so far (IMHO) the IG, and a handful of other sharp technical outsiders, are the only folks that seems to stay in close proximity to ‘data’. They also seem to graciously address the softer situational, practical, and probability issues with seemingly less technically oriented folks.
Unfortunately when arguments are limited blog words about unpublished model output results it’s effectively big hat no cattle.
That said, I am certainly game for seeing your analysis, recommend transitioning it from blog words to a spreadsheet in order to get some critique, refinement and ultimately enhancement or shelf. FWIW I have several MH370 spreadsheet models that ended up on the shelf, not for lack of effort, they just didn’t pan out.
The world hadn’t heard a peep about 9-11 until that morning, or if it had, it was a well-kept secret. There’s no reason to discount a hijacking solely because we haven’t heard anything yet.
To an extent, the same “absence of evidence” rules should apply to debris, radar, hijacking chatter, etc.
But debris drift is not human controlled, while the release of data IS. That puts them in different categories – the lack of debris will ultimately suggest there was none, while the lack of any hijacking chatter suggests either that there was none, OR that it was highly disciplined.
If any government had knowledge suggesting a hijacking, we would expect that to remain a secret until the plane was accounted for. The last leak any government wants is a story about a perfect hijacking.
Note the complete lack whatsoever of any theory about WHY the plane is missing from any government. No speculation on malfunctions, hijacking, suicides, nothing. No leaks from anyone about anything except “confidence.” If not one person in an investigative agency has leaked a theory about anything, why would we assume we’d hear about a hijacking? We could just as easily say:
“If there was a mechanical failure, we’d hear some chatter at Boeing about it by now…”
@JS:
“Note the complete lack whatsoever of any theory about WHY the plane is missing from any government.
If any government had knowledge suggesting a hijacking, we would expect that to remain a secret until the plane was accounted for. The last leak any government wants is a story about a perfect hijacking.”
YES. YES. YES.
>Malaysian) military (which apparently “missed” 370 crossing back over peninsular Malaysia)
@Nihonmama, @Jeff, @All,
I’m perplexed (imagine that). Per Hishammuddin’s own words (4corners), somehow MH370 was identified as being friendly in REAL TIME, that evening. This is ostensibly (according to Hishammuddin) the reason that fighters were not scrambled.
Who identified MH370 as being friendly, if not the military? SSR? What am I missing? I don’t see how such a determination could have possibly been made, unless someone knew that 370 had diverted??? In which case the entire SCS search was predicated on a proven falsehood.
Can someone please explain this away, or show me where I am faltering in my understanding of events?
Cheers
Spencer
@spencer:
“… unless someone knew that 370 had diverted???”
Your understanding is not faltering Spencer. You just woke up.
Now ADD:
“why would 370 have gotten a notification about US naval exercises in the Malacca Strait?”
http://www.twitlonger.com/show/n_1skbadj
@Nihonmama
Given some thought to what you said about the direction claimed by IG. Did Shah have any connection to Australia in any way? Relatives, vacation spots? I’m also perplexed at the supposed route. Splashing down between Australia & Diego Garcia would pose a far greater challenge when considering search & recovery.
JS/Nihonmama – While arguing this point with Rand a while back I speculated with the term – the one that got away. They know it’s a hijack but ostensibly don’t seem to care, but it’s getting some funny treatment. The ATSB narrative includes AP and unconscious passengers, but it’s an accident. The investigation says a diversion but the terror angle is played down or avoided, the Indon radar thing is shelved, meanwhile our intellectually lazy media hasn’t caught up yet that the AES very possibly was switched off as well. I don’t see how they(govts) could all be so apathetic about such a loose end as a 777 that disappears under those circumstances. Maybe they aren’t, but has there been a quieter investigation? I said it all last year ad nauseum – it doesn’t look right.
It would have left a very large debris field, and made an audible whack when it hit the water but nothing on either score. There is a view that moving the search scuppered the chances of finding debris but it wasn’t moved before the delicate surface radar on the sub trackers was put to use for no result. Those crews headed off with the belief they going to turn up debris and kept coming back slightly embarrassed/exasperated on the nightly news, I remember it well. Kind of looks like it had to go down in one large bit but the bathy should have indicated something?
Nihonmama – KaChing!
He didn’t have to go so close to the Australian mainland? It would have been dramatically more difficult had he not. Is that spot on the 7th arc the sort of place you would input to the AP? You would think not?
@Matty
I think your on to something Matty. Your “Meandering out of the box” theory holds water IMO. Less the debris, acoustical signature of an AC that size plunging from 38000 feet.