Earlier today, the Australian Transport Safety Board released a document entitled “MH370 — Search and debris examination update.” Perhaps occasioned by the recent completion of the towfish scan of the Indian Ocean seabed search area, the document updates earlier ATSB reports and offers some intriguing insights into what may have happened to the plane. Some thoughts:
— The first section of the report expands upon an assertion that the ATSB made in an earlier report: that the BFO values recorded at 0:19 indicate that the plane was in an increasingly steep dive. Indeed, the newly published calculations indicate that the plane was in an even steeper dive than previously reckoned: between 3,800 and 14,600 feet per minute at 00:19:29, and between 14,200 and 25,000 feet per minute at 00:19:37. On the lower end, this represents an acceleration along the vertical axis from 37.5 knots to 144 knots in eight seconds, or 0.7g. On the higher end, this represents an acceleration along the vertical axis from 140 knots to 247 knots, likewise about 0.7g. If the plane were freefalling in a vacuum, its acceleration would be 1.0g; given that the airframe would be experiencing considerable aerodynamic drag, a downward acceleration of 0.7 would have to represent a near-vertical plunge, which a plane would experience near the end of a highly developed spiral dive.
— The second section describes end-of-flight simulations carried out in a Boeing flight simulator in April of this year. These tests were more detailed than others carried out previously. Evidently, modeled aircraft were allowed to run out of fuel under various configurations of speed, altitude, and so forth, and their subsequent behavior observed. Thus, the exercise modeled what might have happened in a “ghost ship” scenario. Notably, it was found to be possible for the plane to spontaneously enter the kind of extremely steep dive described in the previous section. This being the case, the report states, the plane “generally impacted the water within 15 NM of the arc.” This is not surprising, considering that the plane had already lost altitude and was plummeting straight downward. This offers a tight constraint on where the plane could plausibly be if the 0:19 BFO analysis is correct.
— The third section describes the results of debris drift modeling that has been informed by tests involving replica flaperons “constructed with dimensions and buoyancy approximately equal to that of the recovered flaperon.” An important point not addressed by the report is the fact that the French investigators who tested the buoyancy of the flaperon were unable to reconcile its observed behavior with the observed distribution of the Lepas anatifera barnacles found growing on it. So when the French ran their own drift models, they had to run them twice, one for each buoyancy condition. Apparently the Australians overcame this paradox by discarding one of the states.
— The third section notes that, according to modeling carried out by the CSIRO, debris which entered the ocean in the southern half of the current search area would not likely reach Réunion by the time the flaperon was recovered. Meanwhile, debris that entered the water significantly north of the current search area would reach the shores of Africa much earlier than the time frame in which pieces were actually discovered there. Using this logic, the report concludes that the northern part of the current search area is probably correct. However, this seems dubious reasoning to me: one would expect a gap between the time debris arrives in Africa, and the moment when it is discovered. Also, debris can move quickly across the ocean, only to be trapped in a local gyre and move around randomly before beaching. Therefore I think the argument that the pieces couldn’t have originated further north is flawed.
— The fourth section, describing the damage analysis of the flap and flaperon, is the most interesting and newsworthy of all. In short, it makes a persuasive case that the flaperon and the inboard section of the right-hand outboard flap (which, rather remarkably, turn out to have been directly adjacent) were in the neutral, non-deployed state at the moment of impact. Assuming this is correct, this eliminates the IG’s flutter theory, as well as the widely discussed theory that the flap was deployed and therefore indicative of a pilot attempting to gently ditch the plane. Proponents of these theories will continue to argue on their behalf but in my opinion they were dubious to begin with (given the shredded condition of much of the recovered debris) and are now dead men walking.
— No mention was made of Patrick De Deckker’s exciting work with Lepas shells.
— Overall, the thrust of this report is that the plane went down very close to the seventh arc in a manner consistent with a “ghost ship” flight to fuel exhaustion, exactly as the ATSB has assumed all along. There is, however, one very large elephant in the room: the fact that Australia has spent two years and $180 million demonstrating that the plane’s wreckage does not lie where it would if this scenario were correct. Therefore it is not correct. The ATSB’s response to this conundrum is rather schizophrenic. On the one hand, it has recently floated the idea of raising another $30 million to search further—presumably the small remaining area where a plane just might conceivably have come to rest in a ghost-ship scenario, as I described in an earlier post. On the other, it has today convened a “First Principles Review” consisting of experts and advisors from Australia and around to world to scrap their previous assumptions and start with a clean sheet of paper. This implies an understanding that they have proven themselves wrong. I wonder how many assumptions they will scrap. Perhaps, as Neil Gordon mused in his interview with me, that the plane wasn’t really traveling south at 18:40? Or perhaps they’ll dare to go even deeper, and contemplate the provenance of the BFO data… ?
— A postscript: Richard Cole recently posted an update of the seabed search (below). I’m intrigued by the fact that the Fugro Equator has deployed its AUV near the northern end of the search zone. When I interviewed him for my last blog post, Fugro’s Rob Luijnenburg told me that the northern end of the search zone was flat enough that it could be scanned by the towfish alone; there was no need for an AUV scan to infill the craggy bits. So why is the AUV looking there now? Especially given that it’s very close to an area just reinspected by Dong Hai Jiu 101’s ROV. Another MH370 mystery.
UPDATE 11-2-16: I emailed Rob Luijnenburg and he immediately responded: “The AUV is scanning in a section in the north part of the priority search area in the very rugged terrain south of Broken Ridge (the east -west mountain range at approximately the 33rd parallel)… Generally the AUV is deployed in spots of extremely rugged seabed to complete the 120,000 sq km priority area survey.” Worth noting is that if the search gets expanded northeastward, it’s going to be into very rough terrain indeed.
@ALSM. A rider on my previous, if I may…
Your chart shows upper and lower limits in red. Does this indicate maximum potential deviation with an operational unit? If so, we have possible non-normal variation up to +/- ~300Hz, not 130?
@ALSM
Yes, I know oscillators are your bag as well, but the figure you are presenting has a vertical scale of 1000Hz per division at L-band. The change in frequency from -10C to 30C is 100Hz+ (at L-band). That is certainly not constant in the context of the BFO changes we are looking at.
I remain stunned by the 142Hz BFO logged at 18:25:27.
@ALSM
Oops! Slippe a decimal point above. 100Hz/div and 10Hz change from -10C to 30C. What’s an order of magnitude among friends?
The rest of the comment stands.
BFO values in the minutes after first logon plotted in the dropbox attachment. Slope depicts more than a passing resemblance to the ATSB’s “decay function”
https://www.dropbox.com/s/u2oy8gwfxvqfhpr/BFO%20vs%20time%20at%20logon%201825.xlsx?dl=0
BFO warm-up artefact or FMT??
@Matt Moriarty
To come back on an earlier post from you yesterday where you say you find it unbelievable that water-pressure could have caused the damage on those trailing edges.
I ask you to take a close look at this picture of the damage on the right wing after the Hudson ditch.
Specifically the aileron. To me it’s the same kind of trailing edge damage:
https://www.dropbox.com/s/2ejuvox43i98rdv/hudson%20aileron%20damage.jpg?dl=0
To clarify…I am only providing factual info and experience based estimates, not theories about what happened. By providing the chart of frequency error vs. ambient temp, I do not intend to imply that I believe the plane was cold or hot. I don’t know what the temperature was. I am simply answering the question: How much error would be incurred if there was a large change in ambient temp, such as might be experienced in a decompression event or air conditioner system failure? The answer is: not much, compared to the warm-up error or vertical Doppler signal. Thus, even if there was a low temp at xx:xx, it would not materially change the end of flight analysis.
It follows that, if there was an event circa 17:21 resulting in a major change in ambient temp, then all the BFO values could be off, but probably not more than ~20 Hz.
The red dotted lines depict the spec., not the expected worst case error.
@JeffW
I went back to harvest comments from Byron’s editorial, and I think it is Byron himself who made the below follow-up comment:
“They (ATSB) were told, as I was by one of them, in middle of 2014, that the FBI had found 6 lat/long geographic points deleted on Shah ‘s home computer setup. These inserted into a FMS computer become defined waypoints and therefor an airway for the FMS controlled autopilot to navigate along deep into the southern Indian Ocean. Also was told that FBI considered Shah responsible for the hijack. Now why wouldn’t the ATSB consider running a search along the track. They really do not seem that motivated to find the wreck!”
The statement new to me is that FBI considered Z as responsible. I certainly feel that is consistent with what I surmise the U.S. gov’t believes, but I’ve never seen it stated so directly.
@Gysbreght
My “drop downwards and away” wording was describing the designed intention
of the behaviour of an aircraft engine, in the general case where it
experienced a frontal impact (of sufficient force to exceed the {designed}
shearing limit of the attaching bolts or shear pins).
In your more specfic case, of a ‘wheels-up’ crash, the impact force on the
engine may well have components that are acting both against the front of
the engine and against the underside of the engine. Although aircraft
‘wheels-up’ landings are somewhat rare, perhaps some guidance can be
taken from the ‘wheels-gone’ crash of the Asiana OZ-214;
http://www.ntsb.gov/investigations/AccidentReports/Reports/AAR1401.pdf
whereat the aircraft left and right Main Landing Gear hit a seawall and
separated from the aircraft, thereafter the aircraft flew on a short
distance and crashed. The accident report states;
The left and right engines separated cleanly from their respective wings
during the impact sequence as per design specifications. The left engine
came to rest about 600 ft north of the main wreckage in the grass on the
opposite side (right) of the runway….The engine exhibited fan blade
airfoil fractures opposite the direction of rotation consistent with
high speed fan rotation at the time of impact.
The right engine came to rest against the right side of the fuselage
near door 2R, lying on its right side…The engine exhibited fan blade
tip bending opposite the direction of rotation and hard object impact
damage on the fan blade airfoil leading edges, consistent with foreign
objects entering the fan when the engine was rotating at high speed.
On page 12 is stated that, at the time of the impact with the seawall;
“the N1 speeds for both engines were increasing through about 92%”,
therefore the engines were developing thrust.
Note that even though both engines were developing thrust and even
though the (engines) impact force had components acting both against
the underside of the engines, and against the front of the engines,
neither engine ‘rotated over and passed above their wings’. Both
separated from the engine support structure and continued forward,
stopping in the positions as noted above. (Of course, the engines in
this case were unable to fall down and away, as there was no ‘down’
to go to – they were already impacting at surface level!)
Cheers
@TBill, That does sound like Bailey. I don’t know what the US believes–it’s not really in a position to have an official stance anyway–but France and Malaysia have both indicated that they consider it terrorism/hijacking/criminal, whatever you want to call it. From the moment it became clear from primary radar that the plane had turned around and made a runner, I think that instantly became the default view. And once you categorize it as hijack, you’ve got two options: one of the pilots, or something very disturbing and weird. So the pilot, specifically Zaharie, was suspect #1 practically from the get-go.
However, Bailey’s logic doesn’t really hold up. As we’ve discussed here at length, the flight sim data points don’t correspond with someone heading south until they run out of fuel. And they don’t match the Inmarsat data. So searching “along the track” doesn’t make any sense.
@Jeff W. Would you like to have a go at asking for the actual data for those test/pre-accident flight decay curves that they reference in their paper? I don’t see any reason why they should be coy about it.
@PaulSmithson, Sorry, are you referring to the warm-up characteristic of the SDU?
yes. sorry i should have been clearer
@PaulSmithson, No problem, I just sent an email to Dan O’Malley at the ATSB.
@DennisW
I”ll just note that MEKAR to NILAM is actually 297°.
(I find, if you are clicking on waypoints, that mouse
accuracy is not sufficient to correctly designate a
point. Selecting the waypoint name, or inputting the
name into the SkyVector input box and clicking ‘Go’,
however, will cause SkyVector to use the correct,
promulgated position for a waypoint, and correctly
calculate bearings, etc., between waypoints.)
Cheers
@airlandseaman:
“Warm-up drift at 18:25 = ~100-130 Hz (cold start +1 min)
Warm-up drift at 18:28 = ~30-50 Hz (cold start + 4 min)
Warm-up drift at 18:39 = ~0-10 Hz (cold start +15 min)
Warm-up drift from 19:41 to 00:11 = ~0 Hz
Warm-up drift at 00:19 = ~0-10 Hz (warm start +1 min after power off for 1 min)
The jump between the first two values circa 1825 is still odd, but after the warm up bias is taken into account, all except the first value appear to make more sense now.”
During the first minutes, more power are applied to preheat the oven faster, otherwise it may take too long time for the OCXO to reach the desired temperature (usually about 70°C, or 158°F) :
Power consumption and Heat dissipation:
•Nominal 55 W (OCXO at nominal current draw)
•Maximum 100 W (OCXO at maximum current draw)
The HSU draws an additional 20 W during the first 10 minutes (maximum) of operation at 77 °F (25 °C) because of the OCXO. The OCXO continuously dissipates this additional 20 W at -67 °F (-55 °C).
@DennisW
“I remain stunned by the 142Hz BFO logged at 18:25:27.”
Could you please explain in a way that everyone understands?
@ALSM
Well having done tests like you describe a few thousand times, there are issues with your graph. Tests like that are performed in large commercial grade ovens which have a huge thermal inertial i.e. the temperature changes slowly and the oven containing the oscillator can easily chase it. In the real world such as an aircraft cabin, temps can change quickly and dramatically, and the results will be very very different.
Even the temp change shown in your graph does not support the notion that a 142Hz BFO could have occurred after a turn on event.
If you want me to believe the 142Hz BFO could have occurred in conjunction with a decompression event you are smoking dope.
@ALSM
Thanks for stating one theory, but as your graph shows very cold temperature doesn’t seem to be enough to account for that.
@DennisW
I just did a quick sensitivity test of the rate of climb at 18:25
If we assume the BFO measured is “valid”
If we subtract 130Hz as per ATSB’s paper
To get 12Hz BFO, the airplane has to be between -3000fpm rate of climb (track 180) and -7000fpm rate of climb (track 0)
To be noted as well is the aircraft is lost by radar not long before that.
At this stage, if the assumptions are correct, it seems to me that the aircraft was still under active control.
Now is it possible to level off from such a rate of descent in only 6 seconds?
@buyerninety:
I note that neither engine passed below its wing either. Where did you get the impact force components against the engine?
@Trond
In simple terms the 18:25:27 BFO is too perfect. At that time we have very good reasons to believe that the aircraft was flying along the airway between Mekar and Nilam.
If one plugs in the track, speed, location, and BFO bias derived on the tarmac in KL, you get exactly 142Hz (rounded to a whole number). How weird is that? Given the data on BFO variation statistics provided by the DSTG it is truly remarkable.
Now toss in an SDU reboot just prior to that event, and it becomes incredibly serendipitous. Certainly a cabin decompression event did not occur, and I am extremely doubtful about an SDU reboot as well.
It would be like a dropped coin coming to rest on its edge. Physically possible, but no one I know has ever seen it happen.
@DennisW, @Trond:
Sounds like maybe the data or flight path is being engineered to appear that mh370 flew that route. Far too “weird”..
@MH
Yeah, well we are out of fresh ideas now as evidenced by recent posts. Time for the guys with thick necks and Glocks to start waterboarding people in KL.
Does anybody understand the end-of-flight scenario Byron Bailey is suggesting? (see JeffW post page 1). He is suggesting upon loss of fuel, Z could still be flying, and may have intentionally took a steep dive to get more power from the RAT turbine. What happens next? Could the pilot then level out (without flap power) and get further than we thought off the 7th arc? The ditch would be fatal with no flaps to slow down, I gather that much.
Inmarsat writes in an article in the Journal of Navigation:
ATSB in its new report essentially says that the Inmarsat statement cannot be correct because the Logon Request message is transmitted one minute after power-up, and at that time the SDU OCXO is still in its warming-up drift phase:
That apparent contradiction must be resolved between ATSB and Inmarsat.
No need to start waterboarding in KL.
@DennisW – line them up !! To save time begin with H2O and Razak…
@Gysbreght
–“I note that neither engine passed below its wing either.”
You are aware that directly beneath the Asiana wing was the runway, right?
–“That is not at all ABSOLUTELY certain. If the engine separated (there are several cases where an engine did not separate), then it quite possible, indeed more likely, that it would pass over the wing, as it is designed to do.”
Ok, the word “absolutely” is an exaggeration. And I’m well aware of engines making thrust detaching forward and up. But I’d challenge you to find an instance where a wing-mounted and windmilling turbofan ever detached above the wing in a ditching scenario.
I’d further challenge you to use some common sense when it comes to the physics of two enormous, windmilling, draggy, scoop-shaped engines being the lowest – and first – objects on a 777 to hit the water. Even if you hit tail-first, the next objects to slam into the water have their openings at an arm of about nine feet below the vertical center of the wing root and about 5-6′ below the bottom of the hull. If weight times arm equals moment, that’s a whole lot of torque going in one very apparent direction.
To be honest, I’m not that interested in debating above or below detachment. What I’m saying is the wing area near the engine would be the site of tremendous damage and because of that, I find it hard to believe a flaperon with a near-pristine leading edge could ever be the product of a water impact.
–“AF447…more than 60 deg angle of attack on impact.”
Page 24 of the final report reads “…The last recorded values were a vertical speed of -10,912 ft/min, a ground speed of 107 kt…” 10,912 is 108 kt.
A groundspeed that equals the vertical speed is, by definition, a 45 degree angle of attack.
@Ge Rijn
I’m not saying that water “couldn’t” have caused that damage. I’m saying it “didn’t” because of everything I just wrote above.
Look at the left wing of Cactus1549 directly behind the engine that detached. There are no flaps whatsoever. And that’s on an A320 with comparatively tiny fans.
@Matt Moriarty
Have a look at this final AoA graphic for AF447.
https://www.dropbox.com/s/psp5wflmvyyhkbv/af447-final-aoa.png?dl=0
Barry Carlson
@Gysbreght said;
“Where did you get the impact force components against the engine?”
As a previous poster has implied to you, the aircraft engines
impacted the surface underneath the aircraft. This was while moving
in a downwards direction, which provides the force component acting
against the underside of the engine. The aircraft was concurrently
moving in a forward direction, which provides the force component
acting against the engine from the front.
You said “I note that neither engine passed below its wing”. Also
as that post at 8:05PM noted, there was a surface under the engine
which prevented it moving down.
I have said previously, as we were discussing about an aircraft
crashing, that the design of the engine mount allowed the engine to
“drop downwards and away“.
Evidence for such a design intention by Boeing is this statement;
http://articles.latimes.com/1985-04-17/local/me-14658_1_engine
by Tom Cole, a spokesman for Boeing Commercial Airplane Co.,
“Cole added that many aircraft, including Boeing’s older 707s,
incorporate “shear bolts” in their engine mounts, to allow the
engine to drop off.”
Also this statement;
http://www.nytimes.com/1990/01/05/us/jet-lands-after-an-engine-drops-off.html
by Craig Martin, a Boeing spokesman,
“The engines on the 727 are designed to break away from the
plane under extreme stress”…”The engine is designed to separate
cleanly, without damaging the airplane.”
Your assertion (in your exact words) is “If the engine separated”
…”then it quite possible, indeed more likely, that it would pass
over the wing, as it is designed to do.”
While I am willing to consider any citation or reference that you
can provide that clearly supports your above assertion, at present
I hope you can understand that for myself (and perhaps other readers),
until you provide such evidence, we must regard your assertion as
unproven.
Cordially, buyerninety
@Barry Carlson, @Gysbreght
Mea culpa. I forgot to add the deck angle of 16deg to the flight path.
Gys 1, MM 0 on AF447 AOA
@DennisW, I am curious why you state that a decompression event did not occur. Is it not possible that after a “loiter” scenario, ZS perhaps abandoned the idea of a Cocos landing? Set the coordinates/waypoint in the FMS before FMT, decompressed and let AP take over? Is that not possible?
Tuesday’s broadcast’s enthusiasms for a new search may be unsustained. There was to have been an interview with Greg Hood and the Australain Minister for Transport. Yesterday’s (Thursday’s) program continued with some coverag after announcing that the two had withdrawn without explanation. This was mid-Review.
Click on Thursday’s program, 14 1/2 mins in if that is still ‘today’s’. No fast forward if not.
http://www.abc.net.au/pm/
@Keffertje
The significant temperature drop associated with a decompression event is not reflected in the accuracy of the BFO logged at 18:25.
RE: Engine Separation
The following article gives some useful insight into the fuse design on Boeing aircraft.
https://www.flightglobal.com/FlightPDFArchive/1993/1993%20-%201655.PDF
Refer to the diagram and you get where Gysbreght is coming from; the forward and aft fuse pins fail at a lower value than the fuse pins at the mid spar fitting. In a ground impact with the engines contacting terra firma (crash), the forward and aft fuses fail allowing the engine to rotate about the mid fittings and over the wing.
Does this mean it will do the same in a ditching scenario? Well that will depend on the angle it hits the water.
In the case of Ethiopian 961 the answer was no. In this accident the right engine hits a reef near head on detaching the right wing; the right engine separates in the ensuing breakup. The left engine on the other hand remains attached.
If you look at the Asiana cartwheel footage you can make out that the right engine is still attached during the roll over.
OZ
@Keffertje
Sorry, did not read your post carefully enough. I suppose it is possible for the event to have happened after 18:25. My comments related to a decompression event being the cause of the diversion i.e. occurring before 18:25.
Reason for Hood, Chester withdrawal from the PM interview now apparent.
https://www.atsb.gov.au/newsroom/correcting-records/first-principles-review-into-the-search-for-mh370/
@Oz
They’ll shear in accordance with whatever force vector the crash applies.
You have your right and left backward when it comes to Ethiopian961 but, regardless, watching in slo-mo you can see the left engine disappear under the wing – sheared off in accordance with the flow of the water into it. The effect is made doubly clear by the left bank which puts the nacelle much lower than the bottom of the fuselage.
Of all the video I’ve seen of it, the slo-mo section of this one seems to show the wing riding over the engine best:
https://m.youtube.com/watch?v=SqKdVo_IcGs
@Matt Moriarty,
An excerpt from the Ethiopian crash report below.
“The center section and the tail section, including the right and left wings, with the left engine still attached to the wing, were found in an area of 400 meters in radius, at the edge of the reef.”
OZ
@OXY
We should be grateful to you, as rather than another 3 or 4 posts without
any evidence presented as to the assertion, now we have your 1 post with
evidence, that it is possible to act as Gysbreght believes. Although it
is not clear that this ‘over the wing’ behaviour is the designed intention
of the manufacturer, (as that is not stated), I do understand why Gysbreght
has come to that conclusion.
(And to anticipate a complaint by Matt, we should recognize that in the
case of MH370, where the engines are believed to be in an (unfueled)
windmilling state, there is no engine thrust that would cause them to go
‘over the wing’ during a nose high aircraft impact – for a nose down impact
of MH370 at certain angles, however, I believe Matt has implied he would
not take a contrary viewpoint.)
Incidently, OXY, you may have missed my questions in a previous topic post
– given myself (& perhaps Oleksandr’s) interest in this area, could you
look at it your convenience, thanks…
https://jeffwise.net/2016/10/25/towfish-scan-of-mh370-search-zone-completed/comment-page-6/#comment-192503
Cheers
@Oz
Ok…is the video backwards? When you watch the video, you see the left wing dipped and the left engine slide out underneath it. The right wing goes vertical with the engine still attached.
Flipped or not, again…you clearly see the engine slide back underneath the wing.
Please tell me what you see with your own eyes watching the video.
Thx very much
@OXY, Re Ethiopian Airlines Flight 961
As per above, I agree you may have got the left and right
information, reversed to the actual happening. Both the
Wiki and the video (there are longer versions that appear
to be from the same video tape, and in the longer version,
the word “STAFF” is seen on the jacket of a person – the
conclusion therefore is that the video tape we see has not
been reversed, i.e. there is no reversed writing, so ‘left’
wing touching first on video is the actual ‘left’ wing).
@OZ, correction, my above post was meant for you, OZ.
(Sorry OXY I have you on the brain, while I wait for your
reply regarding the AIMS Left and AIMS Right).
@airlandseaman
On the difference in oscillator-temperature you stated the following:
‘The answer is: not much, compared to the warm-up error or vertical Doppler signal. Thus, even if there was a low temp at xx:xx, it would not materially change the end of flight analysis.
It follows that, if there was an event circa 17:21 resulting in a major change in ambient temp, then all the BFO values could be off, but probably not more than ~20 Hz.’
Now the report says the difference between hot and cold could be 130Hz in BFO values.
If this was the case (130Hz cold) circa 18:21 the cabin (and cockpit) must have been around -50C allready before ~18:21.
If so there could not have been a pilot consious/alive at ~18:21 and after IMO.
Since everyone assumes the plane was actively piloted till performing at least the FMT you have to rule out the possibility the SDU was ‘cold’ in such a case IMO.
It would matter a lot to the flight after ~18:21 and the end flight if the SDU was ‘cold’ at that time for it would mean there was no consious pilot allready at ~18:21 IMO.
@Gysbreght
Maybe to your interest regarding engines seperating:
https://sma.nasa.gov/docs/default-source/safety-messages/safetymessage-2012-04-02-turkishairlinesflight1951.pdf?sfvrsn=4
In the examples you and others mention and the one above, the engines seperated while under full power propelling them forward by their on thrust after seperation.
Another example is ElAl flight 1862.
In case of MH370 we assume the engines had flamed out before crashing. So it is just impossible one of those engines past over the wing during the crash IMO.
Unless there was no flame out and the pilot gave full power just before crashing.
@Barry Carlson:
Thank you, you beat me to it.
Here is another graph showing (for a DC-10) that the part of the engine that hits the water first is forward of its attachment points on the wing:
https://www.dropbox.com/s/xp2pgu4txjwgo8l/360px-DC-10_engine-pylon.svg.png?dl=0
@Matty Moriarty:
That’s just silly. What would you say if I challenged you to find an instance where a detached turbofan damaged a flaperon in a ditching scenario? Then there is also the outboard flap. Was it also hit by a turbofan?
@Gysbreght, @DennisW
What if the SDU remained “on” the whole time. And was only rebooted prior to the 18:25 logon.
The OCXO would have remained quite stable.
The internal logic would have allowed the SDU to communicate without delay.
But what about the oven? Does it come on automatically at boot time? Is it possible that the oven started even if the OCXO was already stable enough too transmit?
That could explain the first BFO without needing a dive.
@Ge Rijn , 2 points
1.) Are you certain that the aircraft was -40°C (freezing), or merely ‘cold’?
Assume that the aircraft was depressurized by a circumstance that
allowed inside air to leak out, not in an all at once ‘bang’ and not
in a tiny slow leak – consider an inbetween scenario, where the
aircraft pressurization equipment simply may not be able to keep up
with the rate of air leaving the hull – but this does not mean the
aircraft heating and pressurization equipment ceased working.
Therefore the pressure is insufficient to maintain human consciousness
(and possibly life), but still sufficient to maintain a (slight) pressure
differential so the air being provided by the pressurization equipment
still flows and carries heated air with it (but because pressure
inside the aircraft is still very low, that {very ‘thin’} heated air
does not transfer its heat so easily to its environment {the aircraft
interior} – some heat transference does still occur however, so that
the very low -40°C figure does not occur, but rather a much higher
relative temperature, albeit, still very cold).
2.) Even if you reject the above possibility, consider this – if you
accept the cell phone tower ping by the FO’s mobile, then it follows
you must consider that MH370 had descended (less than ~5000 feet) as
it approached Penang and then possibly ascended as it joined N571
(minimum flight level 28500 feet). In this scenario, due to the time
spent at low level as MH370 went to swing about Penang island, the
aircraft may have in fact repressurized (too late for the humans,
unfortunately) sufficiently that by the time it arrived circa MEKAR,
MH370 was just finishing depressurizing down to low pressure again,
and was just getting to ‘low’ temperature again, after having been
reheated during the low level swing about Penang Island.
Food for thought.
Some info on the engine mounts of the 777.
http://www.icas.org/ICAS_ARCHIVE/ICAS1994/ICAS-94-6.4.4.pdf
What should be noted in the discussion is the position of the engine in relation to the wing. The mounted engine is positioned in front of the wing, not below it.
I would chip in a laywers answer: It depends………
@Matt Moriarty/Buyerninety,
I agree, there is an anomaly between the video and the official report. I didn’t write the report, merely quoted it.
And I do know left and right by the way.
OZ
@buyerninety
I don’t know what the cabin temp. was.
I only suggested that IF there was a maximum OCXO drift value of 130Hz at ~18:21 before starting the re log-on sequence after a long power interuption (probably one hour from 17:19 till ~18:21) the lowest SDU temp must have been the case.
Suggesting the cabin (and cockpit) temperature must have been ~-50C before 18:21.
On the contrary after the re log-on and warming-up of the SDU at 18:25 and the assumed flame-out of the second engine and re-start of the APU a short power interuption would have been the case of only ~2 minutes.
Resulting in a minimum OCXO drift value with descend rates of 3.800ft/m at 19:29 and 14.600ft/m at 19:37.
IMO the latter only gives a descend rate at a certain altitude (I suggest at ~15.000ft) not necessarily an indication of an impact speed or attitude of how the plane hit the water surface.
@DennisW / @ALSM:
To your knowledge — regarding the peculiar BFO value at 18:25:27 — there is no (reasonable) environmental condition/circumstance that could explain the 142Hz?
I was thinking heat (rather than cold) or cooldown process, or some temporary material issue (due to extreme heat?) that apparently normalised by itself (water (by all means ice) or foam from extinguishing a fire that dried up or vaporized?), voltage drop, static, vibration (gun-shot?, dull object, the old slap on the vending machine?)
I am not asking in relation to the bigger picture (likelihood, perp. etc.) but more for the possible material conditions to explain it.
Also, computers do spit out funny figures at times, don’t they, and here the plane had flewn without major electrical systems working in a -40-50 degree or so air for quite a while. And then there is the reboot. What is the “cable guy’s” take on the funny output value in one instance? It is a glitch, let’s move on?
What would you say from experience produced a single off-the-charts value? What does Inmarsat say?
Or am I approaching this from the wrong end?