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N72EX (Kobe Bryant) Crash Reconstruction with new ATC Audio

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N72EX (Kobe Bryant) Crash Reconstruction with new ATC Audio

Old 17th Jun 2020, 22:35
  #61 (permalink)  
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It looks like my crash reconstruction is consistent with the NTSB report today: “Calculated apparent angles at this time show that the pilot could have misperceived both pitch and roll angles,” one report stated. "During the final descent the pilot, responding to (air traffic control), stated that they were ‘climbing to four thousand.’”
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Old 18th Jun 2020, 02:25
  #62 (permalink)  
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NTSB Public Docket released 17th June

https://dms.ntsb.gov/pubdms/search/h...BEA33CC33B0675
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Old 18th Jun 2020, 04:04
  #63 (permalink)  
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Amazing how quickly the NTSB can investigate an accident which kills someone important. The average time for a regular fatality is 18 - 24 months for a factual.
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Old 18th Jun 2020, 10:36
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Originally Posted by [email protected] View Post
But we also don't know how many close calls caused by pilots pushing on there continue to be, no-one is going to report that they screwed up and scared themselves but didn't actually crash or break the aircraft.
Very pertinent. Close calls teach you lessons that you hardly get from instructors and will never forget.
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Old 18th Jun 2020, 10:39
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Originally Posted by airplanecrazy View Post
It looks like my crash reconstruction is consistent with the NTSB report today
Bravo to your reconstruction attempt.
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Old 18th Jun 2020, 11:57
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Originally Posted by LRP View Post
Amazing how quickly the NTSB can investigate an accident which kills someone important. The average time for a regular fatality is 18 - 24 months for a factual.
That's not a report - it's the link to the public docket. The press are reporting on what's contained within.
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Old 18th Jun 2020, 14:54
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Originally Posted by LRP View Post
Amazing how quickly the NTSB can investigate an accident which kills someone important. The average time for a regular fatality is 18 - 24 months for a factual.
FYI: the 18-24 month time frame is usually for a Probable Cause report. A Factual report, which has not been released for this accident, is usually released a week to 6 months after the Docket is opened to the public depending on the amount and complexity of the investigative results. Once a Factual is released you can then monitor the "completion" database below for possible Probable Cause report release date:
https://www.ntsb.gov/_layouts/ntsb.a...InvestRel.aspx
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Old 18th Jun 2020, 16:13
  #68 (permalink)  
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Originally Posted by wrench1 View Post
FYI: the 18-24 month time frame is usually for a Probable Cause report. A Factual report, which has not been released for this accident, is usually released a week to 6 months after the Docket is opened to the public depending on the amount and complexity of the investigative results. Once a Factual is released you can then monitor the "completion" database below for possible Probable Cause report release date:
https://www.ntsb.gov/_layouts/ntsb.a...InvestRel.aspx
Not even close my friend. A quick inquiry for the last 18 months in the U.S. shows 32 fatal RW accidents. Among those there are 30 preliminaries, 1 factual (issued 14 months after the accident), and one final (issued 15 months after the accident).
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Old 18th Jun 2020, 16:33
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Question

Originally Posted by [email protected] View Post
If you end up IMC when you weren't expecting to and don't lock straight into an instrument scan, things are going to go wrong quite quickly - if you have the aircraft trimmed straight and level and don't move the controls apart from raising the lever a little to initiate the climb then you might survive to VMC on top.

If you go into cloud already in a turn you are halfway to the crash if you don't lock onto instruments and if this happens while you are moving your head around looking for external references you have a bullet in the chamber and your finger on the trigger.

For those that haven't experienced it, I cannot explain how powerful the illusions of bank can be - the leans - and how easy it is to end up in a spiral descent. If you have the height and awareness to recognise the situation you can recover it with good instrument flying skills and I have had to take control from disorientated students in this configuration many times in cloud. If you don't have the height and awareness you are doomed.
Originally Posted by 212man View Post
i agree - like a lot of things it’s hard to understand without experiencing it. I’ve had full blown leans three times - once in IMC and twice in VMC. The IMC encounter was after a 270 degree turn from ATC vectors, and when I rolled level it felt like I was banking the opposite direction. It required complete fixation on my scan until the felling began to dissipate. The VMC encounters were once in clear visibility above a smooth full cloud layer that had a slope to it, giving a false horizon (I assume a temperature gradient?). Secondly in hazy conditions with no visible horizon, approaching the coast, that was straight but not perpendicular to our approach, giving a false horizon. I had to revert to instruments to overcome the sensation of banking which was almost overwhelming in both cases.
Thank you Crab and 212man, for your vivid accounts of the illusion of banks (the “leans”). From your accounts it sounds as if even recent IMC skills don’t do away with this illusion, but rather give you the ability to ignore/suppress the illusion. Further that recent IMC skills mean that your skills to fly by instruments are not rusty.

At the risk of stating the obvious, let us be reminded that a pilot flying in VMC doesn’t experience the leans. This is important as the standard explanation of the leans is that the illusion is caused by “the stabilisation of the fluid in the semi-circular canals when in actuality the aircraft still is in a banked turn”. Obviously, the same stabilisation of fluid in the semi-circular canals would also happen when the pilot has a clear view of the horizon.

Nonetheless, despite the vestibular system disagreeing with what the eyes see, the brain apparently completely mutes the conflicting information from the vestibular system. Further, any halfway proficient pilot effortlessly manages to fly by visual cues (real horizon, angle of bank = the angle at which the ‘window’ intersects the real horizon, rate of turn = angular velocity of faraway landmarks). All the while, if I may add, we all believe that in VMC we all fly by the seat of our pants, meaning that in all generality we make use of the smallest sensation of acceleration or turn around any axis, and accept such non-visual sensory input in assisting us with smooth VMC flying.

Now, this begs the question: Where does the problem start? When are insufficient visual cues sufficient to make the brain accept the input from the vestibular system with such high associated confidence that – as reported – it is very difficult to ignore or consciously override?

Obviously:
  • A pilot flies well by visual clues in VMC.
  • After some training, pilots don’t struggle (in IFR training under ‘foggles’) to fly by the traditional 6-pack. Arguably, the remaining visual cues that a student pilot gets in the peripheral vision at the corners of the ‘foggles’ are sufficient to convey things such as a constant (or changing) angle of bank and the presence (or absence) of a rate of turn. Student pilots under ‘foggles’ may start feeling nauseous after some time, but in all generality they do not suffers the “leans”.
  • Flight sim pilots fly very well, using ‘synthetic vision’ (i.e., the flight sim view out of the cockpit) and maybe an occasional scan for IAS, ALT and VSI.
  • After some instrument training, most pilots won’t struggle to fly a sim based input from the traditional 6-pack only. Again, not heard of any IMC simmer who suffered the “leans” – of course not, as no real motion involved, hence no fluid in the semi-circular canals are affected.
So where ‘do we lose the plot’? Would a proper EFIS (combining AH, DI, airspeed, VSI and ALT onto one display) make all the difference (in other words: Is the mental work of scanning the 6-pack and mentally putting together the information overpowering us)?

Does screen size matter? Would displaying the AH on a 10-inch display make all the difference in the world, compared to a standard 3.5 inch round gauge? (All questions here asked with regards to avoiding to suffer the “leans” or other overpowering illusions). Would adding highly realistic terrain (i.e., making it “synthetic vision”) help to make the poor brain accept the visual cues provided as ‘real’, and suppress the contradicting information received from the vestibular system?

-> I guess the question is: How does instrument-derived data need to be presented, in order to appear to the brain at least as real as the (very limited) visual cues that a student pilot still gets when under ‘foggles’?
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Old 18th Jun 2020, 17:30
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I found the NTSB interviews very telling and at times difficult to read.

Oh, and the Company's Training Manual changes dated 03-06-20 are very curious.

Last edited by JimEli; 18th Jun 2020 at 17:39. Reason: added TM inference
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Old 18th Jun 2020, 18:17
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Originally Posted by LRP View Post
Not even close my friend. A quick inquiry for the last 18 months in the U.S. shows 32 fatal RW accidents. Among those there are 30 preliminaries, 1 factual (issued 14 months after the accident), and one final (issued 15 months after the accident).
I guess I missed your point then. We're at 5 months with this one and still only have a Preliminary report. No Factual report has been released as you noted in your previous post. I've seen dockets opened to the public in as little as a month or two after the accident. So I guess I don't see any difference in this investigation as compared to others I've been around at this point except for the media coverage.
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Old 18th Jun 2020, 18:17
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Originally Posted by Hot and Hi View Post
At the risk of stating the obvious, let us be reminded that a pilot flying in VMC doesn’t experience the leans?
Oh yes they do. But as you observe, the visual system usually makes it natural to ignore the phenomenon. When visual clues are reduced, say in hazy weather or at night, it becomes more obvious.

[Edited] Although the leans can be a powerful illusion, it applies only to a single axis. Further up [the previous] thread you will find my, and others', descriptions of the coriolis illusion, which is in three axes. This is not caused by a sustained turn, but by rotating the head while in a turn. The rotation is most likely looking up or down or looking left or right quite quickly. As crab suggests above, getting into a position where this might happen is like putting a loaded pistol to your head.

Last edited by HissingSyd; 18th Jun 2020 at 20:53.
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Old 18th Jun 2020, 18:38
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Really well done on the sim, 4 stars.

... maybe just me (and my own tension!) but I sensed tension in the pilot’s last transmission. A pause, a breath. Dunno.
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Old 18th Jun 2020, 19:27
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Originally Posted by Hot and Hi View Post
...
-> I guess the question is: How does instrument-derived data need to be presented, in order to appear to the brain at least as real as the (very limited) visual cues that a student pilot still gets when under ‘foggles’?
I believe you are missing the point. The vestibular illusions are so overpowering, the pilot disregards the visual clues. The contradictions between the senses leads to additional confusion. Obviously, some types of presentations may be better than others, and what is digitally capable today may be an improvement on previous methods. But in the end, they are all just representations of the real world, and therefore fall short. The breadth of study and experiment in this field is very expansive.
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Old 18th Jun 2020, 20:47
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Originally Posted by Hot and Hi View Post
a pilot flying in VMC doesn’t experience the leans.
I have experienced "the leans" lying in bed asleep.

I opened my eyes and the room was oscillating about 45 degrees each way at say 0.5 - 0.25Hz.

I had to crawl along the floor to go to the bathroom for about 24h.

The systems that tell us which way is up are not simple and straightforward. It appears to me that the brain combines available cues to create an impression of which way is up. It is easily fooled.
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Old 18th Jun 2020, 22:20
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Originally Posted by jimjim1 View Post
I have experienced "the leans" lying in bed asleep.

I opened my eyes and the room was oscillating about 45 degrees each way at say 0.5 - 0.25Hz.

I had to crawl along the floor to go to the bathroom.
Me too once, but I sobered up in the morning.... Sorry....it had to be done, after all we do have a reputation to uphold.....

Back to serious discussion.
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Old 19th Jun 2020, 02:12
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A local 737 captain was inbound when he had the sensory perception of doing back flips while sat in his seat (his description). Co-pilot completed the trip and captain commented on the passengers take when they saw him with four stripes and hat being wheeled off the aircraft in a wheel chair. NASA invited him to travel to the US for study of what prompted the issue, but he declined. Lost his medical, a pity (always is), because he was one of the best you could meet, took up ground instructor duties so his inestimable gifts were not completely lost. Vestibular disorders are many and not necessarily a case of what we call the "leans".

https://vestibular.org/understanding...ular-disorders
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Old 19th Jun 2020, 02:23
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Originally Posted by jimjim1 View Post
I have experienced "the leans" lying in bed asleep.

I opened my eyes and the room was oscillating about 45 degrees each way at say 0.5 - 0.25Hz.

I had to crawl along the floor to go to the bathroom for about 24h.

The systems that tell us which way is up are not simple and straightforward. It appears to me that the brain combines available cues to create an impression of which way is up. It is easily fooled.
So, about those unusual mushrooms you ate with dinner....
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Old 19th Jun 2020, 06:25
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The leans can happen to anyone and by that I mean those without underlying vestibular conditions.

It can happen in VMC when your visual reference of the horizon is removed or altered. An example of this is a cloud layer that isn't horizontal but obscures the actual horizon and can cause the pilot to adopt a 'wing down' attitude.

In mountains, where you have high ground all around and rock strata lying at odd angles, the illusion can be powerful enough that when you see something that is actually horizontal, the brain struggles to compute - there is a lake in Snowdonia known as the sloping lake for this reason, you fly up a valley with several turns in it and then come round the corner to see what you thought was level actually isn't. We always taught that mountain flying is a visual/instrument balance to try to keep orientation.

In the Bryant crash you have two of the possible illusions that I have described - low lying cloud, probably in layers, and hilly terrain - the combination is dangerous to start with but if you then enter cloud and are not practised on instruments, it is no surprise that disorientation occurs.

If you remove the brain's horizon reference (or alter it ) and don't replace it with a learned procedure - transferring to instruments and believing them - then things are going to get tricky very quickly.
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Old 19th Jun 2020, 18:44
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Question

Originally Posted by [email protected] View Post
The leans can happen to anyone and by that I mean those without underlying vestibular conditions.

It can happen in VMC when your visual reference of the horizon is removed or altered. An example of this is a cloud layer that isn't horizontal but obscures the actual horizon and can cause the pilot to adopt a 'wing down' attitude.

In mountains, where you have high ground all around and rock strata lying at odd angles, the illusion can be powerful enough that when you see something that is actually horizontal, the brain struggles to compute - there is a lake in Snowdonia known as the sloping lake for this reason, you fly up a valley with several turns in it and then come round the corner to see what you thought was level actually isn't. We always taught that mountain flying is a visual/instrument balance to try to keep orientation.

In the Bryant crash you have two of the possible illusions that I have described - low lying cloud, probably in layers, and hilly terrain - the combination is dangerous to start with but if you then enter cloud and are not practised on instruments, it is no surprise that disorientation occurs.

If you remove the brain's horizon reference (or alter it ) and don't replace it with a learned procedure - transferring to instruments and believing them - then things are going to get tricky very quickly.
Crab, Hissing and JiimEli, all very well noted. So what instrument support would *you* deem sufficient to push back the various overpowering illusions? Clearly the standard 6-pack isn't: The illusions remain strong and convincing, and only "being practised on [those 6-pack] instruments" help you to avoid disorientation.

On the other hand, equally clearly, replacing all windscreens with computer screens that display exactly what you'd see in fine weather conditions through the windscreen, would be perfectly alright. (We'd call this an immersive flight sim.) To say that there would be a (principal) difference between the so-called "reality" perceived through our senses on one side, and any representation of reality perceived by our senses on the other side, is of course humbug.

Would you therefore argue that - if not the classic 6-pack - maybe a 12-inch highly realistic synthetic vision screen on the dash would be sufficient to push back the evil spirit of illusions? OK, 12 inch is not the same as the entire windscreen around you. But given that we seem to agree that already the limited visual cues a student pilot gets while flying with 'foggles' are enough to push back those illusions, a nice TV screen infront of the pilot might just do the trick...
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