Black box data is the ne plus ultra of aircraft accident investigation. But it is not the only kind of physical evidence. Pieces of debris—in particular, their dents and fractures — can tell a vivid story by themselves.
There are five basic ways that an object can break. The two most important for our present discussion are tension and compression. A tension failure occurs when something is pulled apart—think of pulling the ends of a piece of string until it snaps. Compression is the opposite; it’s what happens when something is crushed by a weight or smashed in an impact.
When a plane crashes, it’s common for all different parts to exhibit different kinds of failure. Imagine a plane whose wingtip hits a tree. The impact would crush the leading edge of the wingtip—compression failure—and then wrench the wing backwards from the body of the plane, causing a tension failure at the forward wing root and compression failure at the aft end.
By collecting many pieces of debris after a crash, investigators can place the mechanical failures in a chronological order to tell a story that makes sense, much as you might arrange magnetic words on a refrigerator. This is how the mystery of TWA 800 was solved. When the fuel tank exploded, the pressure pushed the fuselage skin outward so that it came apart like a balloon popping. The plane broke into two major parts that smashed apart when they hit the ocean. Thus tension failures predominated in the first phase of the catastrophe and compression failures predominated later.
So now let’s turn to the issue at hand. What story do the pieces of MH370 debris tell?
In April of this year the Malaysian government published a “Debris Examination Report” describing the 20 pieces of debris that were deemed either confirmed, highly likely or likely to have come from the plane. For 12 of them, investigators were able to discern the nature of the mechanical failure. Some key excerpts:
Item 6 (right engine fan cowl): “The fracture on the laminate appears to be more likely a tension failure. The honeycomb core was intact and there was no significant crush on the honeycomb core.”
Item 7 (wing-to-body fairing): “The fibres appeared to have been pulled away and there were no visible kink on the fibres. The core was not crushed; it had fractured along the skin fracture line.”
Item 8 (flap support fairing tail cone): “The fracture line on the part showed the fibers to be ‘pulled out’ showing tension failure. Most of the core was intact and there was no sign of excessive crush.”
Item 9 (Upper Fixed Panel forward of the flaperon, left side): “The fracture lines showed that the fibres were pulled but there were no signs they were kinked. The core was intact and had not crushed”
Item 12 (poss. wing or horizontal stabilizer panel): “The carbon fibre laminate had fractured and appeared to have pulled out but there was no crush on the core.”
Item 15 (Upper Fixed Panel forward of the flaperon, right side): “The outboard section had the fasteners torn out with some of the fastener holes still recognizable. The inboard section was observed to have signs of ‘net tension’ failure as it had fractured along the fastener holes.
Item 18 (Right Hand Nose Gear Forward Door): “Close visual examination of the fracture lines showed the fibers were pulled and there was no sign of kink.”
Item 20 (right aft wing to body fairing): “This part was fractured on all sides. Visual examination of the fracture lines indicated that the fibers appeared to have pulled away with no sign of kink on the fibers.”
Item 22 (right vertical stabilizer panel): “The outer skin had slightly buckled and dented but the inner skin was fractured in several places…. The internal laminate seems to be squashed.”
Item 23 (aircraft interior): “The fractured fibres on the item indicated the fibres were pulled out which could indicate tension failure on its structure.”
Item 26 (right aileron): “The fitting on the debris appeared to have suffered a tension overload fracture.”
Item 27 (fixed, forward No. 7 flap support fairing): “One of the frames was completely detached from the skin. It may be due to fasteners pull through as the fasteners’ holes appeared to be torn off with diameters larger than the fasteners.”
Note that all of these but one failed under tension. The exception is item 22, which came from the tail—specifically, from near the leading edge of the vertical stabilizer.
It’s particularly remarkable that Item 18, the nose gear door, failed under tension. (Image at top) If, as the Australian authorities believe, the plane hit the sea surface after a high-speed descent, this part of the plane would have felt the full brunt of impact.
Bill Waldock, a professor at Embry Riddle University who teaches accident-scene investigation, says that if MH370 hit the water in a high-speed dive, you would expect to see a lot of compression, “particularly up toward the front part. The frontal areas on the airplane, like the nose, front fuselage, leading edge of the wings, that’s where you’d find it most.”
I spoke to a person who is involved in the MH370 investigation, and was told that officials believe that that observed patterns of debris damage “don’t tell a story… we don’t have any information that suggests how the airplane may have impacted the water.” Asked what kind of impact scenario might cause the nose-gear door to fail under tension, it was suggested that if the gear was deployed at high speed, this could cause the door to be ripped off.
This explanation is problematic, however. According to 777 documentation, the landing gear doors are designed to open safely at speeds as high at Mach 0.82 — a normal cruise speed. The plane would have to have been traveling very fast for the door to have been ripped off. And to be deployed at the end of the flight would require a deliberate act in the cockpit shortly before (or during) the terminal plunge.
The experts I’ve talked to are puzzled by the debris damage and unable to articulate a scenario that explains it. “The evidence is ambiguous,” Waldock says.
In a blog post earlier this month, Ben Sandilands wrote, “Don Thompson, who has taken part in various Independent Group studies of the mystery of the loss of the Malaysia Airlines in 2014, says some of these findings support a mid-air failure of parts of the jet rather than an impact with the surface of the south Indian Ocean.”
A mid-air failure, of course, is inconsistent with the analysis of the Inmarsat data carried out by Australian investigators. So once again, new evidence creates more questions than answers.
UPDATE 5/24/17: Via @ALSM, here’s a diagram of the front landing gear and doors:
UPDATE 5/25/17: In the comments, we discussed the possibility that the front gear door could have come off in the process of a high-speed dive. @ALSM speculated that the loss of engine power upon fuel exhaustion could have led to loss of hydraulic pressure, which could have allowed the gear doors to open spontaneously, and then be ripped off in the high-speed airstream. But he reported that Don Thompson had dug into the documentation and confirmed that following a loss of hydraulic power the gear would remain stowed and locked. Thus it seems unlikely that the gear door could have spontaneously detached in flight, even during a high-speed descent.
UPDATE 5/25/17: There’s been some discussion in the comments about flutter as a potential cause of inflight breakup, so I thought it would be apropos to add a bit more of my conversation with the accident investigator involved in the MH370 inquiry.
Q: Does the MH370 flaperon look like flutter to you?
A: In a classic sense, no, but where you would be looking for flutter would be on the stops, on the mechanical stops that are up on the wing, so the part of that piece that came out. And in looking at that piece, you’ve got different types of failures of the composite skin that don’t appear to be flutter.
Q: What does it look like?
It just looks like kind of an impact-type separation. So it looks like you’ve drug that thing either in the water or on the ground or something. But it’s a little hard with that one because you don’t have any other wreckage, so, one of the keys — you don’t base anything on one small piece, you’re trying to look at kind of the macroscopic view of all the wreckage to make sure that, “Oh, if I think this is flutter do I see the signatures elsewhere on the airplane?” Typically we won’t base it on one piece like the flaperon.
To provide some context, we had earlier talked about the phenomenon of flutter in general:
Q: I can think of a couple of cases where there was flutter, where the plane got into a high speed descent and stuff got ripped off.
A: Yup.
Q: Where would that fall in the bestiary of failures that we talked about earlier?
A: So flutter’s kind of a unique thing, and it’s based on aircraft speed and structural stiffness. So, you know, when those two things meet you get this excitation, an aerodynamic excitation of a control surface which will become dynamically unstable and start going full deflection. So for a flutter case you generally look at the control stops—so there’s mechanical stops on all the flight controls—and you look for a hammering effect on the stops. So repeated impacts on the stop will tell you that, hey, maybe you’ve got a flutter event.
Q: But if you see the piece—there was a China Airlines incident, the elevator was shredded, or part of it was ripped off. What would that look like?
A: Mm-hmm. You know, it’s going to be different for every single case. Sometimes that flutter will generate the load in the attachment points, break the attachment points, and other times it will tear the skin of the control surface, and so you’ll see this tearing of the skin and the separation of rivet lines, and everything. I’ve seen both. I’ve seen a control surface that comes apart at the rivets, and flutters that way, and I’ve seen them where it generates loads to break the attachment points. It depends on the loads that are created and how they’re distributed throughout the structure.
For his part, Bill Waldock told me that the tensional failure of the collected debris implies a shallow-angle impact. Both experts, in other words, believe the debris is most consistent with a more or less horizontal (rather than high-speed vertical) entry into the water.
This is not consistent with the ATSB’s interpretation of the BFO data unless we posit some kind of end-of-flight struggle, à la Egyptair 990, or last-minute change-of-heart by a suicidal pilot. Either seems like a stretch to me.
@Ge Rijn
What exactly do you mean with ‘manually deployed’? The diagram above shows both forward doors are closed once the landing gear is deployed, they only open for a short amount of time while the gear is being deployed.
@Nederland
As corrected earlier by @ALSM the diagram above is not representing a B777 but a MD11 nose gear assembly.
In a B777 the fwd-doors are not mechanically interconnected with the rwd-doors but opened and closed by an hydraulic actuator.
If there’s no hydraulics left (i.e. after both engines flame out and APU off) the gear can be lowered ‘manually’ by unlocking the electric lockers with a switch in the cockpit.
As I understand it in such a case the fwd-doors will open while the nose gear deployes under gravity but will not close after deployment while there’s no hydraulics to close them.
http://www.askcaptainlim.com/flying-the-plane-flying-90/478-what-happens-when-the-landing-gears-cannot-extend.html
Thanks Russell and G Rijn.
There is some news of a Malaysian airplane hijacking, or attempted hijacking. MH128
Hard to find reports yet:
http://avherald.com/h?article=4a9b58fe&opt=0
@Gecina, Wow, thanks for letting us know. Obviously will want to keep a close eye on this one.
My first thought was that this puts paid to the idea that a plane would have to circle to burn fuel before attempting an emergency landing (obvs this is a different kind of plane from MH370, but not so dissimilar, both large intercontinental airliners)
“Local journalist from SBS News Brianna Roberts reported that a passenger said the man in question was tackled by 11 other passengers. The suspect “ran up to the cockpit”, she tweeted, “holding an electronic frequency device, not a bomb”.”
http://www.channelnewsasia.com/news/world/malaysia-airlines-plane-mh128-forced-to-turn-back-to-melbourne-8900384
Electronic frequency device? Could significant damage be done with something like that?
@gecina:
“…Electronic frequency device? Could significant damage be done with something like that?”
Great find, Malaysia Airlines do seem to have a lot of bad luck. Regarding the device, seems unlikely an electronic device would be able to open an electro-mechanical lock, but could have been a small disguised limpet bomb deigned to blow out the lock and stun the flight crew. Alternatively it could just an innocent item used by the potential hijacker to commandeer the plane; who knows?
@Boris Tabaksplatt
“Malaysia Airlines do seem to have a lot of bad luck”. That’s an interesting way to put it.
Authorities seem to have discounted it as a terrorist incident even though it was an attempted hijacking.
And at the same time another incident:
CNN: “Flight diverted when lithium battery catches fire onboard”
http://cnn.it/2soS0LH
The amount lithium batteries on MH370 was several orders of magnitude higher.
… and the Malaysian’s still refuse to release the full MH370 cargo manifest – might this be a clue?
Kate Tee was overflown by what appeared to be an aircraft venting smoke – might this be a clue also?
This conflicts with Inmarsat data who’s provenance could be suspect though.
Going back to the debris, see resource link below from ATSB. high resolution photos of debris.
https://www.atsb.gov.au/mh370-pages/resources/images/
if you download them, you can actually zoom in.
@Jeff, you touched a soft spot here on the debris.
I may be wrong but some of these appear to be machine cut if you examine closely.
mh370_stabiliser-panel-1.jpg still got the red mark of the pencil on left bottom side of picture. Note also the cut has been badly done and went further than wanted with the 2 cut slot extensions.
mh370_inboard-section-of-flap-1 appear to have the edge grinded by a machine. A physical examination may be necessary to confirm.
I advised you get these photos checked by an expert in honeycomb sandwitch panel failure. Some of the failure edges are odd and probably not expected from a single impact (would require a series of impact as opposed to a single impact to achieve such failures). You could also check with those experts you quoted.
I still wonder what that official detailed forensic study on the debris said.
@HB
.. if you wanted to plant debris (a possibility) then you would plant in locations to reinforce the current Malaysian-driven deep SIO theory – such as the coast of Western Australia – not East Africa (their actual resting place) …. unless of course the planters aren’t the Malays and wanted to show otherwise?
The attempted hijack has now hit the mainstream press. This extract is from the Malaysian Mail…
“…Earlier today, the Sydney Morning Herald reported that the Victoria Police took 86 minutes before they could storm the Malaysian Airlines flight MH128 that turned back to Melbourne after the bomb scare, because of a bungle among the officers.
Citing an anonymous source, the report said the plane was stranded on the tarmac because of an on-call officer who failed to respond to an emergency message, followed by the response team later unable to locate firearms and body armour.
The report said that the police were poorly briefed and thought for nearly an hour that the man may have been carrying an explosive device, when it was reported later to be just a powerbank.
The source also said that the police were not informed that the man had already been restrained by crew and passengers…”
See more at: http://www.themalaymailonline.com/malaysia/article/australian-cops-defend-delayed-response-on-mh128-video#sthash.GfpLGPq0.dpuf
This is almost as bad as the recent Manchester bombing event, where Fire & Rescue Service units were prevented from attending the scene of the incident, although ambulance crews were on site straight away. Something strange going on – it really does beggar belief.
@Boris Tabaksplatt
Re: MH128. The person responsible for hijack allegedly has a psychiatric history and was recently discharged from a psychiatric hospital.
@Cargo Handler
The West Australian coast is quite tightly monitored and planting there risks detection.
@ Steve Barratt
What knowledge of WA coastal monitoring might you have?
I ask because having lived in WA for +6 years I can assure you it isn’t.
Should plenty of debris have landed on teh WA coast people would have found some of it – but “tightly monitored ” – it is not – and for what reason?
Question: What story would I put out if I wanted to conceal/cover up a vulnerability to electronic hijacking? Exactly that one. (“A psycho with a crazy 3-antenna-device.”)
With regard to the landing gear door:
On http://en.wikipedia.org/wiki/China_Airlines_Flight_006 “the inboard main landing gear lost two actuator doors” in a vertical dive.
Further damage:
@cargo handler
I am not promoting a theory but simply torule in or out scenarios.
The logic goes like this: (a) inmersat data shows that plane is in SIO (b) reunion flaperon is confirmed to be from a b777 (c) french investigators concluded it should be from mh370 despite no traceable ID since it is confirmed by (a) that it is the only missing b777 in indian ocean.
I.e. given than a is true and b is true therefore c should be true. This is the official vetsion.
Then Reverse drift is trying to demonstrate that a is true given c but we know c is already assuming that a is true so that study is irrelevant if a is true in a first place.
Now if b is proven to be consistent with
1) planted debris – plane location will be found in KL
2) deep dive crash – either we were unlucky in the aerial + seabed search or all steps were taken to ensure it will not be found (common cause factor). If unlucky, why stopping the search? It must be there
3) ditch – sat data is inconsistent. follow the inmersat data source and the plane will be found in KL
4) land crash – sat data from inconsistent, same as 3
This deep dive assumption is therefore critical. You could argue that even for scenario 2, the plane could be found in KL. So much data not released.
If those debris were machine cut like the photos show and dismantled, we are in scenario 1
@HB, You wrote, “I advised you get these photos checked by an expert in honeycomb sandwitch panel failure.” Do you know of any such people? More than happy to make such a call, if you have a lead that would cut my workload a lot.
@HB, I see that red mark you’re talking about–it almost looks like someone cut out a notch with a saw or knife.
It’s not at all clear to me why the flap wasn’t included in the Malaysian debris breakage analysis report.
Also: there’s a big difference in the degree of corrosion and overall wear and tear seen between these two pieces, especially in the fastners.
@HB
Well done , great observation. From the underside picture it is very clear also that the cuts are clean i.e. no 45 deg shearing as in the rest of the edges and
very interestingly cut at 90 deg to each other . Did some one take a sample of the material ? but why bother marking it out exactly to 90 deg ?
One thought is that this was part of a stress test ( or flutter test) in a rig and deliberate failure was induced with a V notch cut in the surface. Any way for sure this did not fall from the sky in that state ! So who cut it ?
@HB
Regarding the stabiliser panel, that’s a great find actually, it looks highly suspicious insofar as I can judge. Is there any possible innocent explanation for this? Maybe something had been attached or similar to this part before?
@Ge Rijn
Thanks for that.
The fragmentation of the piece, to me, looks like it didn’t come off as a whole, but it’s good to explore different possibilities.
@JeffW @Nederland @all
I have competed a comment draft report on a Proposal for a 180S “Straight” South Flight Path:
https://docs.google.com/document/d/149krnQCSITLHDS1KPnOr__pZpiaqRL0mq0Ppc7m9oWs/edit?usp=sharing
If one assumes a 180S flight path, a 180S CTH path from just above ISBIX seems to fit the BTO/BFO data from Arc2 to Arc5. Shortly after Arc5, twilight begins and this apparently coincides with a controlled descent at 300 ft/sec, possibly to manage the visual profile of the aircraft in the approaching morning light.
The end point is S33.7.
I agree we should not jump to conclusions.
The other weird issue is the significant presence of scratches on the parts which is not expected on sea crash scenario. For sure the barnacles have been removed and tests could have been done but how could this be a logical explanation for the failed edges shapes (the non cut ones).
This forensic reports on the parts is critical to further understand the scenario.
@Jeff, this expertise will be within part manufacturer and universities.
One relevant paper I found is this one:
http://www.sciencedirect.com/science/article/pii/S0263822398001238
Another one is:
http://www.google.com.hk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0ahUKEwjKkqWKgp7UAhXjlVQKHfTvDRAQFgg8MAM&url=http%3A%2F%2Fwww.gruppofrattura.it%2Focs%2Findex.php%2Fcigf%2Figf17%2Fpaper%2Fdownload%2F270%2F300&usg=AFQjCNFUllXoai8tMyDFCVsFfLkUJ52VlA&sig2=TsV7HnSitS4DDW4lzwEBDA
The authors can be contacted.
@Jeff and HB – the cuts (and overcuts) look like the work of a 4.5″ or 7″ angle grinder with a cutting wheel. These are readily available and very portable. They also cut just about anything in a pretty straight line with a minimum amount of damage. The user doesn’t generally need to know what they’re cutting as long as it’s not granite or glass.
The overcuts are consistent with a circular blade – note the longer one appears to be lighter towards the end as if it was shallower. A reciprocating saw would go full depth the entire cut, and besides the operator would have enough vision to stop in time. The foot of the saw would also mar the surface and leave marks on both sides of the cut.
@HB,
The cut-out is a sampling cut; this has likely been done at the ATSB. Refer to ATSB image 192 and you can see the panel pre sample.
Also the sample has likely been taken using a Dremel or other high speed cutter.
OZ
@OZ
Cannot find 192, could you paste the link?
https://www.atsb.gov.au/media/5769347/img20160228074602.jpg
OZ
@OZ,
You are correct to point for the modification before and after.
Note that looking closer it looks like the entire left edge and part of right edge have been cut by a machine. I cannot see a crack of these type of materials to yield those circular edge shapes, simply not possible mechanically especially on the two sides simultaneously.
The report on the above mentioned forensic study is critical to understand.
And the scratches are certainly not explanable.
All these require proper official explanations.
Note you find similar issues of apparent machine cuts on the photos of the Debris Examination Report on quite a number of items. Particularly apparent on Item 26. Does not look like a sample on those ones.
@HB
Suggest stop hyper-ventilating as a few of the more excitable readers bubbling:
1. WA coastline isn’t “tightly monitored “as you claim (provide evidence).
2. The “debris cuts” are part of the investigation.
Go back to the Grassy Knoll or bring credible data, not speculation.
@Cargo Handler, I think it’s impressive that @HB, with help from others, was able to visually identify a man-made alteration to a piece of debris. The fact that the causes of this alteration–the accident investigation–was then identified is additionally impressive.
As far as the absence of debris on the WA coast, the ATSB has itself recognized it as a limiting factor in where the crash could have occurred.
You are right no need to panic or say more than what the facts are. Some of my observation need further confirmation from a closer look or from a honeycom structure expert. No need to draw conclusions at his stage but at least we have something else to explore. In any case o have no further observations
@Cargo Handler
Apologies for the delay for your query about my comments regarding the surveillance of the Western Australian (WA) coastline. You are correct the the Western Australian coast is sparsely populated and one can travel hundreds of kilometers without seeing anyone. I completely agree there are not customs officers not conducting regular patrols.
As for lack of debris on the WA coast I refer the the Amazon Single by Jeff Wise “The Plane that Wasn’t There” Location 439: “Last October, a nonprofit organization called the Tangaroa Blue held its annual West Australian Beach Cleanup. Some 1,500 volunteers combed 130 beaches up and down the western coast collecting plastic rubbish and other debris”. I presume October refers to 2014 but nothing from 9M-MRO has been found in WA from these annual cleanups. I agree there is a small risk of a false negative but there seems to be an acceptance that drift modelling should include a lack of debris from 9M-MRO on the WA and Tasmanian coastlines.
As for surveillance I refer to the Royal Australian Airforce’s website (http://www.dsto.defence.gov.au/innovation/jindalee-operational-radar-network) states that:-
“The JORN network is Australia’s first comprehensive land and air early warning system. It not only provides a 24-hour military surveillance of the northern and western approaches to Australia, but also serves a civilian purpose in assisting in detecting illegal entry, smuggling and unlicensed fishing.” Anything the size of an ocean going fishing boat or larger should be detectable. I’m not sure about a runabout or tinny – I doubt it’s that sensitive. As its a military installation exact specifications are not available.
Of course the reason JORN failed to detect 9M-MRO has been put down to the fact it wasn’t on which as an Australian I find embarrassing. However I’m not sure this is the truth. Anyway JORN and 9M-MRO has had an enormous amount of discussion on Jeff Wise’s blog (amongst others). There is no point in me elaborating further.
@all
I have a new flight-end idea but not sure it is consistent with debris and other things.
I am suggesting the BTO/BFO’s from 2314+ are possibly explained by descent at 300 ft/min starting at twilight (approx. 22:50). The pilot then brings the aircraft to 10,000 ft (FL100) by about 00:00 or so. The FL100 brings the aircraft into the tops of the cloud layer that morning. I am seeing level flight at 00:11 in the cloud layer. As the fuel runs out the pilot glides to 5000ft below the clouds to survey the surroundings. Optional final maneuvers if he had picked a good spot…under clouds or whatever. Then aircraft is brought down.
Jeff,
in his newest blogpost, Victor states in his conclusion that “the aircraft impacts the water at speeds around Mach 1 and with nearly vertical nose-down pitch. The distance of the impact point from the crossing of the 7th arc is less than 5 NM.”
What do you make of that ?
(particularly with regards to the area that has already been searched)
@Peter Norton, Great question. It seems to me that there’s a very significant consequence of Victor’s finding that he fails to state–namely, that it is not consistent with the ATSB’s current (revised) search area, which has already been searched out to this distance.
Another way to put this is that if Victor’s analysis is correct, the plane should have been found by now.
To put it yet another way, the more we understand the data in hand, the less sense we can make of it.
@Jeff
Don’t confuse what constitutes understanding. I have had many disagreements with the IG on issues including 38S, BFO error magnitude, and most recently the 18:25:27 login which they insist is the result of an oven control system error which Holland has misinterpreted.
Of course, the fact that Holland’s paper was peer reviewed and the AES manufacturer is on the SSWG makes little difference to the IG.
I am not saying Vicor is incorrect and i am not familiar with the sat data but as a mechanical engineer, i would say
(1) it virtually impossible to reach Mach 1.1 unless you design the plane to do so and with thrust power. If Mach exceedance occurs accidentally, it would be marginal say Mach ~1.01 as it was experienced in previous cases with thrust powered dives. Mach 1.1 is hardly conceivable and even more difficult to conceive with engines off.
(2) Also, if engine cuts off with auto pilot on, the plane will eventually stall then deep dive, re-accelerates until it reaches terminal velocity (ie 0 vertical acceleration) or 0 altitude which ever comes first. Note the drag increases as the air density increase losing altitude and that terminal velocity would be well below Mach 1.
(3) Debris don’t show such impacts either. And no debris fields were found. Saying that if Mach 1.01 ish is reached, you may find consistency of some debris with plane reaching Mach Critical.
If Victor is correct, the engines would most likely be on and i would be highly suspicious with the sat data trustworthiness.
Jeff Wise said: “Another way to put this is that if Victor’s analysis is correct, the plane should have been found by now. “
In the Microsoft Flight Simulator FSX 4.5 units of control wheel displacement are needed to let the airplane roll at 3.6 degree per second, so that it is inverted in about 50 seconds. With 9 units of control wheel deflection the airplane would roll twice as fast and would complete a roll through 360n degegrees in the same time.
4.5 degrees of control wheel deflection is apparently needed to achieve descent rates that would produce the BFO values at 00:19. In the simulation the airplane crashed before the APU would come online to power the SDU that sent a log-on request message to the satallite.
@HB, Thanks for pointing out the impossibility of 9M-MRO achieving Mach 1.1. One would not expect a computer game to have particularly realistic flight modeling, especially beyond the aircraft’s envelope. One would not even expect a top-of-the-line professional simulator to be realistic beyond the envelope. Then again, I don’t think it really matters–I think the key take-home remains valid, namely that a plane accelerating downward at a high rate is going to hit the ocean very close to the seventh arc.
@Gysbreght, You wrote, “In the simulation the airplane crashed before the APU would come online to power the SDU that sent a log-on request message to the satallite.” In other words, Victor’s simulation couldn’t possibly be accurate.
To me, the real achievement of Victor’s latest post is the finding that the deployment of the RAT will itself cause the plane to roll if the autopilot is disconnected.
Jeff Wise said: “To me, the real achievement of Victor’s latest post is the finding that the deployment of the RAT will itself cause the plane to roll if the autopilot is disconnected.”
Yes, the ATSB, in their 3rd Dec 2015 update to the MH370 – Definition of Underwater Search Areas, did include this comment on end-of-flight simulations:
“The aircraft behaviour after the engine flame-out(s) was tested in the Boeing engineering simulator. In each test case, the aircraft began turning to the left and remained in a banked turn.“
P.S. The above reply was copy-pasted from Don Thompson’s comment on Victor’s blog.
Victor banned me from his blog because he does not tolerate critical comments.
@Gysbreght, I vaguely remember that bit about the turn to the left but without an explanation for why it occurred, it was hard to credit. This helps a lot, thanks.
Sorry about the banning!
If MH370 impacted within 10 nm distance from the seventh arc, then it can not be south of 32.8S (see below, p. 18)
It is therefore a real possibility that MH370 came down at 31.1S as I argue in my revised proposal. The proposed route works exclusively with waypoints and is the only route that does so. I argue that MH370 went around Sumatra, at the boundary of Indonesian airspace and outside of Sabang radar range, then continued to ISBIX and onto BEBIM before flying onto Wilkins Runway (YWKS) before running out of fuel.
http://docdro.id/GvlrLaV
(Apologies this is a long read, but it is enough to have a look at p. 11-12)
Anyone can spot a flaw in this proposal?
@TBill
Can the speed reduction you propose for your final segment be explained simply with reduction in altitude or is additional change of speed required?
Also, if MH370 was flying at ~10,000 ft at the sixth arc, then it would have crashed within the 10 nm range from either side of the arc already searched (or the BFOs are wrong or wrongly interpreted).
@Gysbrecht:
Honesty apparently got the better of you, eventually.
Big smile and cheers. Long time no see.
Should have been: @Gysbreght. Sorry.
@Gysbreght
The 2 november 2016 update shows that not in all cases the plane turned to the left.
In two cases the plane turned to the right and stayed in a right banked turn. Why?
The report doesn’t tell.
See page 13 figure 6:
https://www.atsb.gov.au/media/5771773/ae-2014-054_debris-update_2nov2016.pdf
@Jeff Wise @Gysbreght
Jeff Wise said: “To me, the real achievement of Victor’s latest post is the finding that the deployment of the RAT will itself cause the plane to roll if the autopilot is disconnected.”
To me it is not logical how the RAT could cause the plane to roll to the left.
The RAT sticks out on the right side of the fuselage causing drag forces on the ride side with a momentum which I think would push the plane slightly to the right not to the left, causing the right wing losing some lift.
The not actuated left flaperon which moves upwards in such a case (under RAT power only) would be a more logical cause of letting the plane roll to left.
Maybe this two opposite forces level eachother out to some degree and maybe this is a reason why the RAT was placed on the right side of the fuselage and not on the left?