Some new information about suspected MH370 debris found in Africa:
1) Last month I wrote about a photograph taken of the “Rolls Royce” fragment three months before it was discovered by Neels Kruger and turned over to the authorities. This double discovery struck me as such a remarkable coincidence that I reached out to the man who took the photograph, Schalk Lückhoff, a 73-year-old retired doctor who lives about an hour away from the discovery site. I was fortunate enough to catch Dr Lückhoff just before he left on a monthlong photo safari to Kruger National Park. At the start of the interview I was under the impression that Neels Kruger found the piece the second time at Mossel Bay, 10 km from the Klein Brak River, but as Dr Lückhoff makes clear, this is not the case; Kruger also found the piece at at the mouth of Klein Brak river, about 250 m from where Lückhoff had photographed it. (Klein Brak is within the Mossel Bay municipality, hence the confusion.) Below is an edited transcript of our conversation.
SL: I belong to a local photographic club… and I was on my way to photograph fast-flowing water as the lagoon was emptying into the sea, and this was early morning, in fact I saw on my picture the exact time I took it was twenty minutes past seven on the 23rd of December. And I was the first one on the beach and I walked toward the river, and there was this clean piece of beach where no one had walked and I saw this object lying in the middle of it, and I just thought, well, it was probably just an old notice board or something, so I just took a picture in passing and I went on because I was in a hurry to get to the river, you see. And then when I came back later in the day it was gone, but by then there has been a high tide as well and I now, in retrospect I thought that this high tide pushed it into the river, the lagoon, or there’s also lots of holidaymakers that time of year, somebody might have picked it up and carried it into the lagoon, I don’t know… And then what happend was I never paid attention to this because I didn’t recognize it for what it was, as I say I was more interested in the pictures I was going to take, and the result was that about three months later there was a news thingy with the piece that Neels Kruger picked up [specifically, an article by Eugene Gunning in the Afrikaans-language Netwerk 24], and looking at this I thought, ‘This looks very familiar,’ and I went through, went back and looked through my pictures, and I found it there full of barnacles. And that’s the story.
JW: So then you reached out to Eugene Gunning?
SL: Yes, in fact I didn’t know who to contact because I immediately realized this might be important puzzle, or a piece in the puzzle, you see, so I contacted Eugene and he put me on to Neels, and very interesting chat about it, and he put me onto the Australian, what’s it, Transport Safety…
JW: ATSB.
SL: And I contacted them and sent them one of my pictures and they took it from there. They said to me that this was rather important, because it actually puts the date of actually three months earlier, because Neels only found it three months after I did. And what puzzled them was why there were no any marine life on this one, and of course I could explain that, because there’s a whole host of seabirds that nests on the banks of that river every night, I’m sure they must have picked it clean.
JW: Interesting!
SL: What’s your interest in this?
JW: I’ve been covering this for two years now, and of course for a long time we wondered why aren’t there any pieces of this mysterious plane, and then they started to turn up, and like the Australians I wondered, how come it’s so clean? Because there was one that washed up on Reunion Island that had all kinds of barnacles on it. Some people had speculated that some kind of creature might have picked it clean, but when your photograph came out, that was just very powerful evidence that that must have been exactly what happened.
SL: Yes.
JW: How do you think it wound up — you found it at this place, Klein Brak, and then it wound up in I guess, Mossel Bay is 15 km way or something?
SL: Yes, Mossel bay is about 10 km further on. You know, originally I said to Joe in Australia, I said to him that I was, when I walked past there the next day, this thing wasn’t there anymore, and I just gathered that it went back into the sea. And then when Neels picked this thing up, I said, “But it’s highly impossible that anything like that washing back into the sea, with the wind and all the sea currents and stuff around that area, would wash up in exactly the same spot three months later. What are the chances of that? It’s literally zero.” So my deduction was that this thing was washed up in the lagoon and the sandbanks in this lagoon changes all the time, and so does the dunes around there, from the prevailing southeasterly wind in summer, which blows everything up the river, you know, if it floats it will obviously move up into the lagoon, and that’s what I thought. It’s the most logical thing that it could have been in the same area three months later.
JW: So how do you reconcile the seemingly impossible thing? You would expect that the wind would blow it up into the lagoon, but instead it somehow seems to have washed back out into the sea, and gotten—I don’t know, how does it wind up where Neels found it?
SL: In retrospect I doubt whether it washed back into the sea. It was just my original impression, because it wasn’t there after the next high tide. I didn’t go up along, I had no reason to walk up the riverside at the time, and this thing was lying right at the river’s mouth, on the east of the side of the river, just at the mouth where the sea washed it up. During the course of the day, it was midsummer, it was our holiday season and that whole area there are hundreds of holidaymakers bathing in the sun and sitting there, kids playing in the river and the lagoon and so on, so it’s not impossible that anyone might have picked it up and even carried it up higher into the river, I don’t know. I can only speculate. But all I can say is, I think the chances that it washed out to sea and then came back three months later is impossible. So the only chance is that this thing somehow, either by human hand or by wind and water and what have you, ended up in the deeper part of the lagoon, and probably floated around there until it beached where Neels eventually found it. But who knows, you can only speculate on it.
JW: I quickly glanced at a map the other day. Where Neels found it wasn’t near the lagoon was it?
SL: It was on the bank, in fact it was exactly, we had to pinpoint it on Google and we measured it, it’s about 250 meters north of where I saw it the first time. And it was actually lying next to some washed up logs there on the edge of the sand. But now if you look at your Google Maps, it looks different from what it looks like now, or what it looked like in December, because that river, as the tide goes in and out, the sandbanks alters all the time. So you can’t—I’ve got a picture of exactly what things were like at that time in December. All I know is that there were lots of holidaymakers in that area every day. This thing might have drifted up in the river with the next high tide, and perhaps helped by the wind which blows upriver, and it might have beached somewhere and got covered in sand by kids playing or whatever and when the beach changed again, we’ve recently had a fair amount of rain in January and February, and often that river comes down and brings lots of logs and all sorts of stuff down. It might have washed open again. As I say, one can only speculate.
JW: I misunderstood, I thought he found it 10 km away.
SL: No, no, no, no! Actually, he gave me the spot on Google Maps and also the, he told me where to look, there’s a big log that’s lying there on the riverbank which has been lying there for more than a year now, since the last big flood we had, and he picked it up just next to that. I actually walked the distance the other day to go and pinpoint the area.
JW: So people were saying Mossel Bay but they really meant Klein Brak.
SL: Yes, it’s all in Klein Brak, in fact where he found it is about 250 meters from where I saw it.
JW: Did you only take the one picture at the time?
SL: You know what happened is, at the time I actually took two pictures, and some time in January my picture library became so big that I started removing some duplicates, and in fact I now realize that the other one was removed at that time. But what I did was, I had two and I just left the better one. You couldn’t really choose between them because they were taken at the same time and with the same camera.
JW: Same angle and everything?
SL: So this was the better picture… It’s such a coincidence, if I didn’t pick up that newspaper article, I wouldn’t even have known that I had the picture.
2) It occurred to me that the Lückhoff photograph would provide an important data-point for reverse-drift models, so I reached out to the GEOMAR institute in Germany, whose work I’ve described previously. I asked “Is your team looking at updating its findings in light of this new data, which provide a much narrower time window for the arrival of this debris?” I received the reply, “Such an endeavour will require a significant amount of time and effort in terms of the coordination and analysis. Given the lack of response from the Australian search authorities, and the still large uncertainty concerning the beaching of the debris, we do not intend on refining our analysis further at this stage.”
3) In another amazing coincidence, it turns out that Hong Kong-based aviation journalist Florence de Changy, who has made many important contributions toward solving the mystery of MH370, has a son who went to university in Canada with a young man whose brother found the most recent piece of debris in Mozambique. He wrote to Florence:
The piece was found right by a lodge called Cristina’s Lodge located on the Macaneta Peninsula on Sunday, 22nd of May, 2016. The piece was roughly 1 x 1.5 meters and about 15 cm thick. It did not have any metal on it and had the honeycomb inside. Hence, it was not very heavy and could be easily carried by one person. It did not look necessarily old and seemed as though it had only been on the beach for less than a week. The first time we found it (22/05/2016) it was at the high water line and it was fully exposed. It was found when it was low tide. We initially left the piece there but when we came back on the 28th of May, it was pushed a little higher up the beach by the ocean. It was not very noticeable and my mother found it when she was looking for drift wood along the beach. I got into contact with BBC on Thursday, 26nd of May, and they put me into contact with the Australian Transport Safety Board. I gave the piece to Eng. Jeremias Fr. Chito, a Technical Administrator at the Civil Aviation Center in Maputo, Mozambique.
Based on the photos’ metadata, they were taken at location S25 51 48.51, E32 44 38.25 (-25.863475, 32.743958) on 5/28,2016 at around 1:07 pm. Here’s one photo; the full set of 13 in high resolution can be found in this Dropbox folder.
The following is outside of a new Jeff’s topic.
A while ago I mentioned that there are autopilot-constrained AFDS-controlled flight modes ATT (roll) and V/S followed by automatic switch to ALT (pitch), in which respective trajectories conform Inmarsat’s BTO and BFO data. Finally I finalised the first version of the report:
https://www.dropbox.com/s/icoks1iehny2p4x/TN-ATT-Rev1.0.pdf?dl=0
Based on FCOM, the ATT+V/S mode is among a few modes, which remain available in case of ADIRU or FMC failure. In this case navigation data are supplied by SAARU and GPS, but high-level autopilot functions such as LNAV or TRK HOLD become unavailable. I assumed that the main goal of the ATT mode is keeping bank angle, so that respective trajectories are affected by cross-wind and Coriolis.
Interesting features of the suggested trajectories are:
– The terminus area coincides with the high priority area suggested by ATSB in June 2014;
– The terminal locations are close to the potential origin of the acoustic signal detected at HA01 and RCS stations by the Curtin University;
– The locations are consistent with a number of drift studies, particularly the University of Western Australia, including the towelette found near Thirsty Point (WA);
– The trajectories are consistent with the observation of a low flying aircraft by Kate Tee, made from her yacht Aaza Dana;
– Low altitudes at Sumatra’s nortwestern coast explain the lack of Indonesian radar data.
Interestingly, there was another case of the ADIRU failure on B777. Also MAS, Flight 124, 9M-MRD.
Comments and constructive criticism are welcome.
If someone minds inclusion/citing of their results for comparative purposes in this report, please let me know.
@Ge Rijn
Ge Rijn, you’re a jewel!
Pause the video at 00:43, enlarge the image and bingo, there are the three panels, one of which from MH370, subsequently found its way to Mozambique.
RT (as a break, as usual): there is something absurd, as when “Russian envoy to NATO ridicules allegations of plans to invade Poland”, there is something real as when “Putin & FIFA President Infantino launch 2018 World Cup volunteer campaign in Moscow” and there is something from future as new russian MS-21 plane – so yet another useful competition (mentioned in todays press conference of Putin and Netanyahu as joint project too)
https://www.youtube.com/watch?v=SgeCVDeXyKQ
@Rob, Ge Rijn. Please note the purported approximate dimensions of the damaged article at 1.5m X 1m. I take it (dropbox photos 2nd row, 4th in) the 1.5 is the seal edge. Both approximate dimensions would be larger undamaged.
The dimensions mentioned need confirmation of course but if about right it is too big.
@ Jeff
Thank you so much for this transcription, and what a lovely guy Dr Luckhoff is.
Secondly – I’ll just say it – it’s huge. 1.5 metres by 1 metre is a lot larger than I’d imagined from the photographs we’d seen previously.
@ Ge Rijn and Rob – does that still figure with the panels you found? I’m thinking possibly not, if you’re going to fit three along one flaperon, which is only 240cm long.
What a shame after all that.
@ David – sorry! I took too long to read the whole article before posting my comment.
Looks like we noticed the same thing (so I don’t have to worry that I’ve got it wrong, this time)
@Jeff Wise @Rob
Beautifull clear pictures but the dimensions 1m x 1.5m named cann’t possibly be right if those earlier pictures on teh beach are genuine.
The footprint in the sand just below it shows its lenght cann’t hardly be more than 80cm.
Its widht shows larger in those new pictures though but not larger than its lenght.
I wished there was a centimeter gauge beside that panel in the pictures like in some of the other ones…
@Rob
Yes it’s visible isn’t it but with the new dimensions named by Jeff it’s impossible to be one of those compartments.
I’ll await further comment.
But compliments to Jeff anyway. The latest pictures and most insightfull news about MH370 is found here. 🙂
@Guys
Hold your nerve! That panel is one of the three closing panels we have collectively identified as belonging to the flaperon period.
I would bet my pension on it.
Lovely people, just not very good at estimating the sizes of things, in metric.
Jeff, welcome back. For a short while there, I felt we were drifting, rudderless. This blog benefits from a light hand on the tiller.
What has ribs? Like 15 of them? Is that a wing?
Please check out the photo here:
https://www.flickr.com/photos/jeroenakkermans/sets/72157645853477595
#122346 – I can’t find a way to link directly to it.
It’s just over half way down the page. The part is marked Rib 15, it’s got some odd holes and I don’t know about a seal, but the size and shape are correct. Just a further clue perhaps.
Here:
https://www.flickr.com/photos/jeroenakkermans/14530829440/in/album-72157645853477595/
Another explanation for the named dimensions in this mystery with, for some, super natural dimensions could be Big Foot is also walking around in Afrika and pressed his footprint of +50cm under this panel..
@Susie
This is a horizontal stabilizer of MH17.
Good pictures and a good link. Thank you.
Oleksandr:
Since we are discussing sideslip and crab, what you write on page 11 of your ATT paper is not correct:
In a landing approach in crosswind the airplane flies on a heading such that its track angle resulting from the vector sum of its airspeed vector and the windspeed vector is aligned with the extended runway center line. In that situation the airspeed vector lies in the airplane’s plane of symmetry, there is no lateral component or lateral drag, the wings are level, ailerons and rudder are neutral. The angle between heading and track is called the crab angle, hence the term “crabbed landing”.
I don’t know what your textbook intends to show with the figure you modified in your figure 4, so I can merely guess what it could have been. You probably misunderstood and modified it incorrectly. It does show the direction but not the magnitude of wind speed, nor the magnitude and direction of airspeed. The direction shown in blue as “Heading” is probably meant to represent track, and the rudder deflection shown is probably meant to illustrate the use of the rudder in a decrab maneuver, an input applied just before touchdown to align the airplane with the runway, which is one of the considerations that determine the required size of the rudder during the design of the airplane.
Light airplanes, gliders in particular, can fly a side-slip approach. In that situation the airspeed is at an angle to the airplane’s plane of symmetry, causing increased drag (which can be the desired effect of the sideslip). To maintain the airplane on the desired track requires crossed controls, i.e. right aileron and left rudder or vice versa, and the airplane is banked into the wind.
Autoland systems may use a combination of these techniques, starting from a crabbed approach with zero sideslip, gradually reducing the crab angle by increasing sideslip as the airplane nears touchdown.
@Ge Rijn
I salute your ingenuity, but I don’t think that’s it.
Not “bigfoot”, perhaps the ghost of “Lucy”? the female who left her mark in Olduvai Gorge, Tanzania, a long time ago.
Some of you will know what I mean, If you don’t, then please Google it.
@Rob
If the footprint was left by the ‘Ghost of Lucy’ the piece would be probably at least 2m in lenght.. 😉
@Rob
Just kidding. Lucy was a dwarf. It doesn’t look like a little childs footprint which would shorten the dimensions considerably.
And there is a second one on the top.
With a medium adult foot the dimensions of 1.50m x 1m cann’t be right according thos photos.
@Ge Rijn: “This is a horizontal stabilizer of MH17.” Are you sure?
@Suzie: Wing ribs are usually numbered from the fuselage outwards, but the B777 spoilers are numbered from left to right.
@Ge Rijn
Perhaps dwarf is not exactly the right word. We were all smaller in those days 🙂
Thank you guys. I’m happy to wait and see what the consensus is regarding the item’s size and so on. I just thought the shape was familiar.
There’s a nice little PDF here from the folks who make a lot of these components.
Pictures of a couple of 777 parts if you scroll.
https://depts.washington.edu/amtas/events/amtas_04jan/NorthwestComposite.pdf
@Gysbreght
Yes, view the before and after pictures in this Flickr sequence. I saw the whole picture of this stabilizer before and named identified.
@Rob
And still a lot smaller than Big Foot 😉
The more we know, the more we know.
The history of the cowling piece makes a lot more sense now.
@RetiredF4
Hope you don’t think this a silly question, I don’t mean it to be.
Did you used to fly Phantoms? (ie, F4’s?)
@Jeff Wise
Donn’t you mean the object visible in the background on the above-right in that Brak River picture?
I cann’t find a log on the left side..
Nice interview. An example of the importance of first hand information. So the Mossel-bay piece can be renamed in the Klein Brak River piece.. You redefined the finding spot with 10km..
Gysbreght,
This is only semantics problem.
It seems you consider only black and white, that is to say pure crabbed landing or pure sideslip landing. How would you call a combination of, say, 80% crab and 20% sideslip landing?
I agree that a more accurate formulation would be “an example of the combination of the crabbed and sideslip landing techniques”.
@Ge Rijn, You have to remember that it’s in South Africa, so everything is upside-down, and hence “left” really means “right.” It’s related to Coriolis force.
But just in case this might confuse some people, I edited the caption as per your suggestion. Thank you.
Oleksandr:
I think you are trying to retreat by confusing the issue under discussion. Yes, I describe crabbing and sideslipping to explain the difference, but also allow for a mixture of both in the case of a coupled approach with autoland. For more examples see “Runway alignment” in the Continental Airlines B777 Flight Manual Sect.3 page 172 and “Crosswind landing” on pages 228 – 230.
The real issue is that initiating and maintaining sideslip is not a consequence of crosswind but requires specific control inputs that are not present in the trajectories you are construing in your CTS and ATT papers. Without those inputs crosswind will result in a difference between heading and track (the ‘crab’ angle) at zero sideslip.
:-):-) Yes offcourse! Confusing especialy for dutch people who tend to think the other way around anyway..
And Coriolis forces seem to be a lot stronger in our area too, affecting our orientation even more..
Maybe that’s two reasons those dutch on their Fugro vessels still cann’t find anything.
ROB
Posted June 7, 2016 at 2:38 PM
@RetiredF4
Hope you don’t think this a silly question, I don’t mean it to be.
Did you used to fly Phantoms? (ie, F4’s?)
@Rob
3.225 enjoyable hours, F-4E, F-4F, RF-4C, RF-4E
@Oleksandr
I do not grasp your problem. In an adrodynamic point of view correction for wind enroute does not produce sideslip, a coordinated flight assumed. The same applies for a crab landing. When using the low wing method for landing or when decrabbing prior touchdown a sideslip is intentionally produced. But I see no relevance to any part of the MH370 discussion.
Gysbreght,
You are playing with words. I am aware of the difference between crabbed and sideslip landing. But as you noted the problem is not about it.
You wrote “The real issue is that initiating and maintaining sideslip is not a consequence of crosswind but requires specific control inputs that are not present in the trajectories you are construing in your CTS and ATT papers.”
Nonsense. You again show your misunderstanding of both the papers and basic aerodynamic principles. And you again confuse static and dynamic cases. Cross-wind is indeed the primary cause of the slip: you confuse this with sideslip landing, which really requires specific input to achieve specific goal.
So, in your opinion cross-wind does not cause any impact on an aircraft? Also, where did you get “maintaining of sideslip”?
@Oleksandr:
You wrote: “Nonsense. You again show your misunderstanding of both the papers and basic aerodynamic principles.”
That does it for me. End of discussion.
RetiredF4,
The problem is as follows: does cross-wind induce force and how does an aircraft compensate its impact during flight? Can cross-wind initiate sideslip, which then gradually vanishes as aircraft’s velocity changes (both heading and speed)?
Gysbreght,
If there is cross-wind, there will be the lateral drag force. If you think there is no cross wind, you need to explain how this is possible in varying wind conditions. If you think there is cross-wind, but no force, you need to explain how the lateral drag is compensated. You may explain or not – up to you. Your problem is that you always think about static picture.
Oleksandr: Nonsense.
Gysbreght,
Perhaps your confusion is caused by the term “cross-wind”, under which I implied instantaneous relative air velocity component perpendicular to the fuselage. Not cross-wind perpendicular to runway etc.
@Oleksandr
you ever drove with a ballon? It is a nice expierience. Although the wind is blowing with 10 knots, you feel nothing about it in the open gondola. You know the reason, the ballon got accelerated to the same speed and direction as the wind when leaving ground, and thus the wind is no longer felt as long as you are in the air.
The same applies for an aircraft in flight, it becomes part of the surrounding atmosphere, although it is pushing through this atmosphere by use of its thrust. You feel the force when on takeoff the aircraft veers into the wind and upon landing the aircraft steaightend out upon touchdown from the previous crab. There is a force induced on the aircraft when the aircraft penetrates airmasses with different airspeeds and directions. The effect is called turbulence and can be felt nicely in the cabin.
Gysbreght,
I am done. Thanks for very valuable feedback.
@Oleksandr:
In common aeronautical language, cross-wind is the wind commponent perpendicular to the intended track. The wind component in the direction of the intended track is called headwind or tailwind, depending on its sign. Inventing new definitions is an infallible way to confuse discussions.
Transport airplane operating limitations include a maximum crosswind component for landing, and everybody cognizant of airplane operations knows how to interpret that number.
RetiredF4,
“the ballon got accelerated to the same speed and direction as the wind when leaving ground”.
Try to convey this to Gysbreght. This is exactly what both my CTS and ATT models do, but Gysbreght calls it nonsense. As a baloon gains speed, relative air velocity tends to zero; so does drag force. Now I’m leaving your example to him to explain.
@Gysbreght, Oleksandr, RetiredF4,
I sense a bit of a disconnect between you in your discussion.
From where I sit, Oleksandr discusses the transient from one stable state of affairs in terms of wind and aircraft velocity to a new state of different wind and aircraft velocity, while Gysbreght discusses the resulting new stable state of wind and aircraft velocities.
For arguments sake, imagine a sudden step change in cross wind from zero to something, the plane changing track to a new direction and velocity. Here both, the initial and final stable states have zero sideslip, while the transition period has a step change from zero side slip to a maximum (due to inertia of the plane), the plane being accelerated sideways by the sideways drag, until it again reaches zero sideslip in the final stable state.
In the real world you wouldn’t necessarily see step changes in crosswind, but the principle of “transition from one to the other state still applies. In that sense, a flight path model, which models these transitions, would be superior to one that ommits such modelling, would it not?
@RetiredF4
Fantastic. I’m not a pilot, as you’ve probably guessed, but I could tell that the Phantom was a truly special flying machine.
Thanks
Rob
Ok, missed the last few posts, while typing mine.
It appears, that I used the wrong terminology (cross wind, where I meant the normal to fuselage component of the wind, as per Oleksandr).
Anyhow, we shouldn’t discard a point of discussion on the basis of anyone using the wrong terminology (admittedly, it can confuse the situation). I guess, if Gysbreght can accept Oleksandr’s “slip” in terms of terminology used, and review O’s paper in the light of normal to fuselage wind component, we may progress the discussion and merit of O’leksandr’s papers.
@jeff,
OT, did you ask the Dr, whether he touched the RR piece or not? If he didn’t, then something is fishy. His photo clearly shows tracks in the sand from the piece having moved across the surface, which shouldn’t be there.
He said or implied (in your transcript), that he was the first on the beach, and the panel having been deposited by the water. Any small tracks would have been washed away by the water lapping around the piece after depositing it.
A bird picking off barnacles and moving it would not seem likely either, given the dimensions and implied weight.
I also remember noticing the sand on top of the piece, which did not quite look like wind blown. I’d expect a more even distribution if merely wind blown. It looked a bit “hand sown”, but could have been the result of someone lifting the piece on one side to have a closer look (or arranging it for a better light angle for a photo) and the wind blown sand cosequently shifting. The latter could then also explain the tracks in the sand.
@ MuOne:
Thanks for entering into a stalled discussion, but your interpretation of physics calls for correction.
A sudden stepchange in crosswind (assuming it is physically possible) would cause an equally sudden change in airplane heading while the airplane maintains its track and zero sideslip. The vertical tail, like a wind vane, will always align the airplane longitudinal axis with the relative air velocity. To change the track requires a horizontal force that can be obtained by banking the airplane.
@Susie, Ge Rijn,Gysbreght. Confirm Ge Rijn, right stabiliser.
http://www.onderzoeksraad.nl/uploads/phase-docs/1006/debcd724fe7breport-mh17-crash.pdf
pages 69, 71, item 15. Left wing tip can be seen nearby in Akkerman’s 125426.
Just practising. Hope I’m not wrong Susie. Did make a mistake once. 1953 I think.
Gysbreght,
I am now pretty sure you are correct about the windvane effect, and it would also be the primary reason that a plane turns when it banks. (Explanations of what actually happens in a banked turn are often incomplete and confusing, which is why I was having trouble.)
@Gysbreght,
“Thanks for entering into a stalled discussion, but your interpretation of physics calls for correction”
A correction is required on your interpretation of my Gedanken Experiment of a non-realistic but idealized (for arguments sake) instantaneous step change in normal to fuselage wind component (not cross-wind, as I originally erroneously termed it).
There is no instantaneous velocity change in physics or the real world (It would require infinite energy or force to be applied). You may get a near instantaneous acceleration step (e.g. when hit by a shock wave), but the velocity will only increase over time.
In my gedanken experiment, the aircraft will accelerate sideways, and possibly also yaw as per your wind vane analogy (but that as well is not instantaneous and rather transient). But, until its sideways to original track velocity has caught up to the wind speed change, there is an ever diminishing sideways component until is again in a stable, no side slip, state, where the sideways (yaw-ways) acceleration drops to zero. All that takes time (transient period).
I believe, it is this transient period, from start of wind change to the plane having caught up to that wind change, which Oleksandr is alluding to, and which you don’t seem to accept exists.
@Jeff: thanks for digging.
This suggests to me a span of 8 weeks between Neels Kruger’s find going viral (reported March 22, 2016 – causing, I’d imagine, something of a stir among the locals…?) and Schalk Lückhoff – one of those locals – finally telling someone (on May 17, 2016) that he’d photographed the exact same piece on the exact same beach.
It is hard to imagine living in that community, yet avoiding seeing any image of the clean piece for those eight weeks. When you asked him about it, how did Dr. Lückhoff explain the delay?
I’m expecting that this linked article is accurate. Very tough for the NOK.
http://www.news.com.au/travel/travel-updates/mh370-lawsuit-brings-ridiculous-questions-heartache-for-families/news-story/c7a120746eea266863cdfa619c33bc88
MuOne,
Yes, you are correct. Gysbreght is wrong.
——-
Gysbreght,
You said “A sudden stepchange in crosswind (assuming it is physically possible) would cause an equally sudden change in airplane heading”
So you decided to argue with Sir Isaac Newton? Why would it be so? While I appreciate your corrections with regard to the terminology I used in papers, we still seem to disagree about fundamental aerodynamics. I only suspect that under “heading” you understand here heading with respect to a coordinate system linked to moving air, which is not the case in my papers.