After French authorities retrieved the MH370 flaperon from Réunion Island, they flew it to the Toulouse facility of the DGA, or Direction générale de l’Armement, France’s weapons development and procurement agency. Here the marine life growing on it was examined and identifed as Lepas anatifera striata, creatures which have evolved to live below the waterline on pieces of debris floating in the open ocean.
Subsequently, flotation tests were conducted at the DGA’s Hydrodynamic Engineering test center in Toulouse. The results are referenced in a document that I have obtained which was prepared for judicial authorities by Météo France, the government meteorological agency, which had been asked to conduct a reverse-drift analysis in an attempt to determine where the flaperon most likely entered the water. This report was not officially released to the public, as it is part of a criminal terrorism case. It is available in French here.
Pierre Daniel, the author of the Météo France study, notes that the degree to which a floating object sticks up into the air is crucial for modeling how it will drift because the more it protrudes, the more it will be affected by winds:
This translates as:
The buoyancy of the piece such as it was discovered is rather important. The studies by the DGA Hydrodynamic Engineering show that under the action of a constant wind, following the initial situation, the piece seems able to drift in two positions: with the trailing edge or the leading edge facing the wind. The drift angle has the value of 18 degrees or 32 degrees toward the left, with the speed of the drift equal to 3.29% or 2.76% of the speed of the wind, respectively.
The presence of barnacles of the genus Lepas on the two sides of the flaperon suggest a different waterline, with the piece being totally submerged. In this case we derive a speed equaly to zero percent of the wind. The object floats solely with the surface current.
This suggests a remarkable state of affairs.
Inspection of the flaperon by Poupin revealed that the entire surface was covered in Lepas, so the piece must have floated totally submerged—“entre deux eaux,” as Le Monde journalist Florence de Changy reported at the time. Yet when DGA hydrodynamicists put the flaperon in the water, it floated quite high in the water, enough so that when they blasted it with air it sailed along at a considerable fraction of the wind speed.
As point of reference, Australia’s CSIRO calculates that that the drifter buoys that it uses to gather ocean-current data pick up a 1.5% contribution from the wind. Here is a picture of one such drifter, kindly supplied to me by Brock McEwen. You can see that more than half of the spherical buoy is out of the water.
It is physically impossible for Lepas to survive when perched up high in the air. Yet the buoyancy tests were unequivocal. So Daniel pressed on, conducting his analysis along two parallel tracks, one which assumed that the piece floated high, and the other in which it floated submerged. For good measure, he also considered scenarios in which the flaperon floated submerged until it arrived in the vicinity of Réunion, and then floated high in the water for the last two days. (Note that he doesn’t present any mechanism by which a thing could occur; I can’t imagine one.)
After running hundreds of thousands of simulated drift trials under varying assumptions, Daniel concluded that if the piece floated as its Lepas population suggests, that is to say submerged, then it couldn’t have started anywhere near the current seabed search area. (See chart above.) Its most likely point of origin would have been close to the equator, near Indonesia. His findings in this regard closely mirror those of Brock McEwen and the GEOMAR researchers which I discussed in my previous post.
Daniel found that when simulated flaperons were asssumed to have been pushed by the wind, their location on March 8, 2014 lay generally along a lone that stretched from the southwest corner of Australia to a point south of Cape Horn in Africa (see below). This intersects with the 7th arc. However, as Brock has pointed out, such a scenario should also result in aircraft debris being washed ashore on the beaches of Western Australia, and none has been found. And, again, the presence of Lepas all over the flaperon indicates that such a wind contribution could not have been possible.
Pierre Daniel’s reverse-drift analysis for Météo France, therefore, presents us with yet another block in the growing stack of evidence against the validity of the current ATSB search area in the southern Indian Ocean.
The most important takeaway from this report for me, however, is the stunning discrepancy between how the flaperon floated in the DGA test tank and the “entre deux eaux” neutral buoyancy suggested by its population of Lepas. No doubt some will suggest that the flaperon may have contained leaky cells that slowly filled as it floated across the ocean, then drained after it became beached. However, I find it hard to believe that an organization as sophisticated as the DGA would have overlooked this eventuality when conducting their wind tests. Rather, I read Daniel’s report as evidence that the French authorities have been unable to make sense its own findings. I suspect that this is the reason that they continue to suppress them up to this day.
The East China Sea Air Defense Identification Zone (abbreviated ADIZ) is an Air Defense Identification Zone covering most of the East China Sea where the People’s Republic of China announced that it was introducing new air traffic restrictions in November 2013. (Wiki)
We’ve been talking lately about the lack of Malaysian response to the missing plane. Have we ever heard anything from China ATC? Why didn’t they report the plane missing? China should have been looking for a plane to enter its airspace based on a filed flight plan.
On 25 July 2015, Lao Airlines flight QV916 was turned back by the Chinese.[18] The Chinese MoD has said that the aircraft was prevented from entering Chinese territory due to an inadequate flight plan, and that the incident had nothing to do with the ADIZ.[19] (Wiki)
@Trip, MH370 never got to Chinese airspace, they started turning back right at the border between Malaysian and Vietnamese airspace.
@ Jeff. I understand but they did file a flight plan and they were not where they were supposed to be. China is bureaucratically thorough. Someone would have reported them missing well before the7 hours. China had also just declared the new expanded territory in the South China Sea.
“@Trip, MH370 never got to Chinese airspace, they started turning back right at the border between Malaysian and Vietnamese airspace.”
That is to say, if the radar data is genuinely MH370.
Talking of Chinese airspace, I have been toying with an idea about other sovereign regions, namely the SAR region of states.
[conspiracy warning]
What if the original plan was to dissapear the airplane, including it’s as of yet unidentified cargo on route to China in some state’s SAR region? If there was something on board said state wanted, a plane crash/ditch delivery would have many advantages, as it would provide plausible deniability of responsibility for that crash, while having having responsibility for the search and retrieval of the plane including cargo.
With regards to payment for that cargo in such a scenario, one could imagine donating a billion dollars or so to someone in power via some obscure international transactions.
@Brock OK, so I’ll cop to it: my intention was to further stimulate the debate regarding forward versus reverse drift simulations/modelling; as I had stated, GT’s article was rather over-simplified, while I had indeed not considered that the temporal issue had since been resolved. I had simply latched on to the piece as a totem to move things on this topic. Also, the basic diagram/map of prevailing currents provides a source of edification to MH370 browsers like myself.
It would be great if Dr. Charitha Pattiaratchi were to provide you with permission to post more content as to your conversation with him.
@Jeff While I personally don’t see anything necessarily indicative of (additional) foul play in the buoyancy issues surrounding the flaperon, it is a great thing that you are relentless in pursuit of the ambiguities found in the official reporting re the same.
Trip – very interesting point. I’m sure that if a plane never arrived here from KL someone would be on the phone. You would expect notification in the event of official diversion but a no-show would need action. They never reacted? I’m told in the early days of JORN testing they monitored Changi AP in Singapore and ticked the planes off on a schedule as they took off. They would have been expecting the plane.
@Gysbreght.
I meant the ribs inside generaly. I said the flaperon is watertight sealed as a whole and I don’t know the construction of this flaperon exactly. I cann’t look inside of it offcourse.
From the pictures it looks rather traditional build. That’s all I said.
The time that I made/repaired ribs and other parts was during education and working with the KLM in the mid-80’s. I worked several years there on repair and maintainance. Mostly pre-composit era old fashioned alu handling. Later I worked in the engine overhaul and repair shop.
So I realy won’t pretend knowing how exactly a (B777) flaperon is constructed these days.
But again from what I see it looks rather traditional build. I also don’t see honeycomb top and bottom panels, they look solid composit or alu to me seen from the sides and trailing edge but I cann’t be sure.
@Oleksandr.
Yes I (also?) think 30S (to 32S) could be significant for various reasons.
In my view all the now known data could come together to fit around this lattitudes.
The Inmarsat-data, the found debris and their areas, the lack of found debris in other areas, (in regard to) the drift patterns, the lack of debris in the current search zone, the state the found debris is in and their places on the plane.
There are many open questions offcourse but only looking at the now known data they could fit a crash/ditching area at 32S or some more north.
Then I asume a controled auto-pilot flight until 30S straight with coördinates pushed in long before and after this coördinates pushed in to a well calculated destination around or slightly north of 32S and a controled glide to a well calculated end point somewhere (not that far) outside the current search zone.
Speculation, speculation, I know but it could fit the data now know imo.
@Ge Rijn: The flaperon skin is a honeycomb/composite sandwich, as can be seen where the trailing edge broke off. The sandwich construction eliminates the need for stringers, but not the need for ribs.
OT break; interesting swedish armed forces ad
https://www.youtube.com/watch?v=J-Oab6nvJuE
@Trip,
Singapore called Kuala Lumpur on behalf of Hong Kong around the time when MH370 didn’t show up in Chinese airspace (21:09 UTC). It seems they pressured Kuala Lumpur into issuing a distress phase and declaring the aircraft missing.
@Ge Rejin For what it’s worth in terms of speculation, from my perspective and then after having completed a probability tree, the intended destination for the aircraft post-diversion became a lost cause somewhere between the fly-by of Penang and the FMT. Meaning, there was some element of internal (or, less likely, external, as I wouldn’t put anything past the Malaysians) intervention where the hijacker(s) lost control of the aircraft.
If we take @Jeff’s speculation/reference to a “lower and slower” curving flight path to port, does this necessitate human input, or could damage (e.g., on onboard explosion leading to depressurisation) to the aircraft produce such flight behaviour? Can an autopilot system be ‘corrupted’ or impaired by gross damage to the aircraft?
Apparently I still have a problem reconciling a flight to the point of fuel exhaustion with human input until the time/point of termination of flight.
We do have AF 1558 perhaps initially being directed out over open water before being escorted to Newcastle Airport; we could consider that perhaps MH 370 was likewise directed to fly out over open water after having returned to Malaysian airspace. As I have stated previously, if there is any sort of hulking conspiracy or large-framed mess of incompetence yet to be discovered, odds are that it begins and ends with Malaysia and its response to the hijacking.
One problem with my hacking away at conspiracy intrinsic to Malaysia is that I know to a high degree of certainty from direct sources that the Aussies in general don’t know all that much about MH 370 in terms of its flight back over the Malay Peninsula, and then despite the ADF/RAAF presence at Butterworth. The fact that the Aussies don’t appear to be in the know and have not pressed the issue with the Malaysians rather supports the statements by various members of the Malaysian leadership that they remain in the dark as much anyone else.
FYI, a 2007 Statement of Evidence to the Parliamentary Standing Committee on Public Works Re Butterworth and submitted to the Australian Department of Defence put the RAAF Butterworth staffing levels at 40 (34 in support, 6 in surveillance and response operations), while there are another 120 members of a rifle company on station.
@Gysbreght.
You are right. The trailing edge clearly shows honeycomb on second ‘zoom-in’ view.
It seems although no ribs or other supporting structures were in this trailing edge as you look at the end-spar. Maybe you know if there where?
@Rand.
Yes I agree. All kinds of scenarios still are possible.
The point I wanted to make is that all the now know data would fit with an area around or slightly north of 32S whatever the causes.
It’s just my opinion that it’s more logical to asume a completely controled flight when everything points to a controled flight till disappearing from primary radar.
And even beyound that, for it can hardly be a coincidence the plane made that turn to the south shortly after leaving primary radar covered air space. Imo someone must have known this primary radar reach.
Imo everything is much easier explained when you asume a completely controled flight.
Inside or outside, who did it and why are big questions but not that relevant to the point I wanted to make.
The now know data could combine and fit the area I mentioned.
And imo a completely control flight would be the most logical and less complicated to asume at this time.
@Ge Rejin Only largely speaking re controlled flight, one still needs to reconcile this assumption with an intended destination at the point of diversion, while any destination in the SIO has a lower probability; the FMT itself represents a radical departure in the behaviour of the aircraft up until it was executed and a new flight equilibrium was apparently obtained; and, finally, that the aircraft apparently flew to the point of fuel exhaustion.
If we assume 1. all aircraft take-off (or are diverted) with an intended destination; 2. the aircraft was hijacked; 3. the aircraft never reached its intended destination; and 4. it flew to the point of fuel exhaustion (rather than to a point for an emergency landing); the logic follows that the aircraft was hijacked while some as yet unknown causal factor prohibited the hijackers from reaching their intended destination; and the flight ended most likely at the point of fuel exhaustion, indicating most likely ‘less than’ in terms of human input.
@Ge Rejin Duibuqi, wo bu hui xie hanzi. Wo zhu zai Dong Jing, danshi wo zai Shanghai shang ban; yi ban wo zai Dong Jing, yi ban Shanghai. Ni zai Shanghai ma?
@Ge Rijn:
This drawing shows a skin splice at about 2/3 of the span, which could be the location of a rib:
https://www.dropbox.com/s/p5h0fcwf6p14okp/B777_flaperon.jpg?dl=0
@Rand.
Yes I can go a long way with this.
1. All aircraft take-off with an intended destination. Imo there was a intended destination from take-off, namely a certain point in the SIO.
2. The aircraft was hijacked. Yes, but imo by its own captain, makes the most sence till now.
3. The aircraft never reached its destination. No. Imo it could have reached its destination.
4. It flew to the point of fuel exhaustion.
Not necessarily. The hijacker (pilot) could have dumped the remainging fuel near reaching his destination for reasons of avoiding explosion on ditching and fuel traces.
This all would aquire skilled human interventions only a very skilled pilot could perform. Not that it happened this way.
But it’s possible and imo given the data now available the less complicated and most logical to asume.
@Rand,
You said
“@Ge Rejin Duibuqi, wo bu hui xie hanzi. Wo zhu zai Dong Jing, danshi wo zai Shanghai shang ban; yi ban wo zai Dong Jing, yi ban Shanghai. Ni zai Shanghai ma?”
WTF? Google translate recognizes that as Chinese, but fails to translate it into english for me.
Sprung?
@Rand.
No I never met Dong Jing or ate noodles in Shanghai.
@Ge Rijin and @MuOne Lol… I can’t write Chinese characters, sorry. And while I live in Tokyo (Dong Jing), I work in Shanghai. I spend half of my time in Tokyo, half in Shanghai. I was hoping that you (Ge Jin) lived in Shanghai, so that I could perhaps develop an MH370 buddy, in the flesh, so to speak.
@Rand,
You said long ago that Singapore offered its radar data to Malaysia without being asked:
http://jeffwise.net/2014/12/15/russian-military-planes-transponders-off-provoke-alarm-in-europe/comment-page-1/#comment-65485
Well, the Malaysian air force quickly knew that a Singaporean airborne radar saw MH370 turn back. It seems however that the Malaysians weren’t notified about the later presence of a Singaporean airborne radar in the northern part of Malacca Straits.
Why the Singaporeans were quick to report the turn back but not their presence in Malacca Straits? Do you think they were involved in some way?
Get Rijn, Barry Carlson,
So far the results of drift studies only reinforce 30S. I have summarized a number of other “suspicious” coincidences in my earlier papers. The most notable, in my opinion:
– The existence of uncontrolled (ghost) flight modes, which fit Inmarsat data and terminate around 30S.
– Original data-driven approach by ATSB indicates the area around 30S is the area of the highest probability.
– Curtin ‘boom’ in consistent with the origin at 29S.
So now we have that drift studies also appear to be consistent with this area.
Generally, I lean towards the idea that ATSB must define two more priority search zones: one concentrated around 30S (from 28S to 32S), and the other one – around 20S. The latter still requires more work to be defined more accurately. In my opinion it is silly to waste money to search low-probability outskirts of the high-probability priority zone.
Ge Rijn,
Sorry for misspelling your name. Sometimes autocorrection sabotages my posts.
@Rand @Gysbreght.
@Rand. That’s nice. Didn’t understand a word but gave you an answer anyway, lol too 🙂
@Gysbreght. Thanks for that drawing. No inner ribs visible but I guess if they are from alu they would be constructed with open holes in it. The outer ones are completely closed offcourse. This could be of importance for if the outer skin is penetrated through at least the center-section would fill up with water over time leaving only buoyancy to the honeycomb and maybe the leading edge front section.
@Oleksandr. Get Rijn is actualy a nice ‘misspelling’. It’s what I try to do lately 😉
@Oleksandr, What ghost flight modes exist that end near 30S? Pretty sure that’s wrong.
@Rand, Though the name looks like it could be Chinese, our friend Ge Rijn is Dutch.
@Jeffwise lol, I haven’t been spelling it Get Rijn, but then I have been only thinking of it but also spelling it as Ge Ri Jin. Anyway, a bit of levity is always nice when airliners take up and completely disappear and not much levity is otherwise to be found amidst the numbers of those mourning without closure all whom have been lost.
Jeff,
“What ghost flight modes exist that end near 30S? Pretty sure that’s wrong.”
For example, VNAV FPA = 0.1 deg capped by ALT = FL200, constant TAS; LNAV disengaged.
Respective trajectory is similar to CTS model I offered earlier, which could correspond to “engines failsafe” mode, which has not been discarded by anybody yet as impossible. The only notable difference is that the altitude of FPA+ALT model is ~3 km at 19:41 vs ~5 km predicted by CTS model.
I have to say I have a huge problem with an active pilot on a suicide run to the sio until fuel exhaustion. That to me seems the least likely. As I’ve said before I don’t believe you can hold a suicidal impulse for 7 hours. And a fellow pilot is not going sit idly by the cockpit door waiting for you to open it. I believe either the crew was holding the plane or hijackers took control.
Crazy theory warning
As was pointed out the plane actively stayed in Malaysian airspace until fmt. I think that is a big clue. That means whoever was in control wanted to deal with the Malaysian government and did not want foreign involvement. This could mean either the flight crew or hijackers were negotiating. Since most terrorists want their exploits to be known and we have heard nothing I would assume they were not involved. If China could have pinned this on the Uyghurs they certainly would have. See the train station in kunming. Plus I don’t think terrorists could fly as accurately through the waypoints in the malacca straits.
So one or both pilots put the plane in a holding pattern while someone negotiated with the government. Over what? If this isn’t about Uyghurs then that leaves zaharie’s political leader who was convicted and jailed that same day. I think someone on the ground was negotiating while Zaharie held the plane. When the negotiations dragged on and no one wanted to make a decision, the pilot realized he needed to find a place to land. Unfortunately he ran out of fuel before he could get to a runway. CI? All the government needed to do was divert attention long enough for the debris to scatter. How do the bfos match a holding pattern? Malaysia has a corrupt government and there is much they are not sharing. Could the plane have been shot down either purposefully or by accident. We still need to reconcile mike McKay. We can’t discount all eye witnesses.
May I ask – Chillit is proposing a ‘triangulated’ position somewhere near the Zenith Plateau.
I don’t understand how he figured it out, but seeing as it ends up about where the pings were heard by OS, I wondered whether anyone would like to take a look – it’s all on Twitter.
https://twitter.com/mikechillit?lang=en-gb
@Trip
Your feasibility incorporating Zaharie’s intent without malice seems to best fit his profile. His name is so often tossed around in the suicide scenario without explanation of why. The why is because pilot culpability seems the most logical explanation, not because his history shows him to be an unstable vicious individual.
@Oleksandr, Is this the idea that the lateral navigation system is turned off and the plane just flies straight like an arrow, being pushed around by the wind and Coriolis forces? If so, I would regard that idea as highly, highly speculative at this point; I don’t see how under such conditions the plane would stay within 30 degrees (or whatever) of its original heading over the course of six hours.
Jeff,
Re: “Is this the idea that the lateral navigation system is turned off and the plane just flies straight like an arrow, being pushed around by the wind and Coriolis forces?”
Yes.
“If so, I would regard that idea as highly, highly speculative at this point”
Why speculative? You are forgetting that in contrast to an arrow, B777 is equipped with IRUs and feedback system, which stabilises angular rotation.
Re: “I don’t see how under such conditions the plane would stay within 30 degrees (or whatever) of its original heading over the course of six hours.”
Well, the math says that it can. Why would the aircraft significantly change its heading? On this side I have no doubts at all.
@jeffwise: There is no autopilot mode where (fictitious) Coriolis forces alter the course of the plane as there is no Control Wheel Steering (CWS) mode for a B777 as there is for a B737.
The possibility of an automated flight that ends near 29S was discussed on this blog. It requires a loiter between 18:40 and 19:41 and a descent of -0.1 deg Flight Path Angle (FPA) and a constant magnetic heading. The summary is in this figure:
https://www.dropbox.com/s/ky9je0mepq228ax/Magnetic%20Heading%20w%20Constant%20Descent.png?dl=0
Kate may have seen the Singaporean AWACS aircraft providing some kind of operations support or SAR for 9M-MRO. It seems to be in about the right location to generate the “loiter”
@VictorI, Thanks for refreshing our collective memory. As I recall this is the only autopilot-only endpoint that anyone has managed to come up with in the SIO outside of the current seabed search area.
CWS is an autopilot mode for thev B737 and other non-FBW airplanes.
The B777 autopilot does not have a CWS mode, but the basic Fly-By-Wire (FBW) flight control laws act in a similar manner with autopilot off.
Thanks @Victorl and @Jeff for clarification re a 29S terminus. And hi, Cat.
@ Susie Crowe
In this scenario neither side would want to be blamed and both would want their involvement kept secret. Zaharie is not suicidal. Fariq would follow orders of his captain, Asian obedience. Basically a hijacking gone wrong. I believe this would be consistent with both drift and Inmarsat analysis. And also Kate tee.
Although only the southern end of this search area is still being investigated. The more northern part (but south of 29S) has long since been given up. For example, the area around the Inmarsat hotspot has never been searched completely.
@VictorL. The picture shows at 00:19 29S and circa 98E. Can you tell me how much variation in lattitude is possible in this configuration/calculation?
Re: Coriolis and autopilot modes, if you’re not in LNAV (navigating via waypoints) or TRK HOLD (a rhumb line that will stay on course no matter the crosswinds), that is, the plane is in HDG HOLD mode (the aircraft is kept pointed at a particular azimuth), then the aircraft will indeed experience Coriolis perturbations. E.g., if one is in heading hold mode with the compass set at TRUE with a course of 180 (due south) over a trip of a couple of thousand miles, you will indeed experience a significant drift to the east.
If a 777 had an “inertial” navigation mode (as might be expected if the autopilot was off and the human pilot was incapacitated), the aircraft would fly a course that “feels” straight, the aircraft heading would also change to the left, leading to an even bigger Coriolis effect; however, 777s (nor 737s) will do this, no matter how well trimmed. You can’t just let go of the controls, walk away, and expect it to fly a straight line.
Been away from reading this blog awhile due to work but can’t help but be bewildered by @sajid”s narration as to what happened over the UK and the prompt military response.
But to excuse the Malaysians of adopting a “hoping for the best” mindset in the scenario MH370 is a bit too kind I guess.
I suspect it goes deeper than that. For instance, observe this unfolding scenario in Sarawak East Malaysia right now. A chopper goes missing at 5pm but DCA and emergency response only being activated 4 hours after the fact, as indicated by the time stamp on this news report culled from a government mouthpiece:
http://www.nst.com.my/news/2016/05/143757/missing-heli-last-known-location-over-swampy-coastal-area-zahid?m=1
Some emergency response SOP they have in place in those parts!
@Warren Platts: I don’t know where you are getting this, but in HDG HOLD mode, the plane does not experience Coriolis force. The plane will maintain a constant heading, either true or magnetic, and will be influenced by wind but not Coriolis forces. In TRK HOLD, there is no influence of wind on the path.
And the CWS mode of a B737 would indeed experience the Coriolis effect as the wings would be kept level and not navigate to a constant heading or track.
I do agree that if a pilot was flying a B777 manually and stopped providing inputs, the plane would eventually develop a steep bank.
@Victor: respectfully disagree. Just to keep the example simple, imagine a 777 experiencing no wind, proceeding due south (180) from the equator in HDG HOLD mode with compass set on TRUE. There will be a huge easterly component, on the order of 1,000 mph. In other words, even though it’s pointed due south, it’s actually traveling faster to the east than it is to the south. As it moves south, this easterly momentum component doesn’t go away, but the earth’s surface slows down, so it aircraft will appear to drift east.
The only thing autopilot “cares” about in HDG HLD is that the nose is always pointed at the South Pole. Or, at least that’s what I think. For there not to be a Coriolis effect in HDG HOLD mode, the autopilot would have to somehow automatically compensate for Coriolis. Is that what you are saying?
Just to add on how information flow operates in Malaysian aviation circles, observe the reaction of related agencies to the chopper thingy:
http://www.thestar.com.my/news/nation/2016/05/05/missing-copter-rumours-not-true/
The same muddled mindsets that bedevilled MH 370, just saying.
Are you perhaps suffering from a wee bit of mode confusion ???
Victor,
“in HDG HOLD mode, the plane does not experience Coriolis force”
The plane indeed does experience Coriolis force regardless flight mode. And wind impact. The other issue is whether wind and Coriolis forces are corrected or not. LNAV is responsible for this, but in my understanding it is possible to disable LNAV from MCP. Also, note certain LNAV modes become unavailable when some failures occur (ADIRU, FMC, …).
With regard to VNAV, FPA switches to ALT HOLD when plane reaches specified altitude. FPA +0.1 deg with ALT set at approximately FL200 also fits Inmarsat data.
@Gysbreght: there’s a guy on a.net whose job is to take out 777’s fresh from the Boeing assembly line out for test flights before they are handed over to the customer to make sure everything works correctly. He said he’s tried it multiple times: letting go of the controls to see what will happen. He said sooner or later, it starts banking. He never let it go until the overbank protection kicked in, but presumably it would. He said that some simulators will keep flying straight, however.
A 787, in contrast, is designed to keep flying in a straight line, according to the a.net pilot.