Atlas NTSB 3/12 investigative update

JeppUpdater

Well-Known Member
Not to step on @MikeD ’s toes here for the locked thread, just figured this was worth sharing.

NTSB released an investigative update today. Emphasis mine.

Also, about this time, the FDR data indicated that some small vertical accelerations consistent with the airplane entering turbulence. Shortly after, when the airplane’s indicated airspeed was steady about 230 knots, the engines increased to maximum thrust, and the airplane pitch increased to about 4° nose up and then rapidly pitched nose down to about 49° in response to column input. The stall warning (stick shaker) did not activate.
Full update:


47341
 
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Ajax

¯\_(ツ)_/¯
Hit 430 knots airspeed, and the descent gradually pulled back to 20 degrees nose down from 49.

Very odd
 

ian

Well-Known Member
so either intentional (can't fathom) or a bad attempted recovery from something that couldn't be recovered from the recovery?
 

NovemberEcho

Dergs favorite member
Accidental autopilot disconnect a possibility? I know in the Russian crash where he let his kids fly the yoke was moved just enough to disconnect the ap.

(If yoke is wrong term, well, tarmac.)
 

ian

Well-Known Member
What would he be trying to recover from? I have to believe 230 knots isn't anywhere near the clean stall speed of a 767...
depends on the G load, which it appears in this case was pretty close to 1.0 so unless some crazy turbulence I agree. Someone else said maybe inadvertently hit GA and a correction from it? Still quite a mystery.
 

obx

Well-Known Member
How much forward stick is needed to pitch down nearly 50 degrees, and what in the world would they have been attempting to recover from at 230 knots in light turbulence?
 
Not to step on @MikeD ’s toes here for the locked thread, just figured this was worth sharing.

NTSB released an investigative update today. Emphasis mine.



Full update:


View attachment 47341
I stand by my earlier question... the eff?? Assuming "column input" means hand on yoke, that would have to be a helluva push. I'm mean, you'd almost have to fall on the thing... and hold it there. Assuming nothing was broken, if the aircraft were trimmed for level at 230, it would aerodynamically want to recover to something approximating level at 230 all by itself if that column input was released.
 

ian

Well-Known Member
I stand by my earlier question... the eff?? Assuming "column input" means hand on yoke, that would have to be a helluva push. I'm mean, you'd almost have to fall on the thing... and hold it there. I mean, if the aircraft were trimmed for level at 230, it would aerodynamically want to recover to something approximating level at 230 all by itself if that column input was released.
its easily doable with one hand, but it certainly has to be intentional if its not someone keeling over incapacitated on it....but yes if you push hard over to it and let go it tries to recover...just not enough altitude to do it.
 

tomokc

Well-Known Member
The CVR transcript hasn’t been released yet, but after a quick analysis the FBI stepped out of the investigation.
 
its easily doable with one hand, but it certainly has to be intentional if its not someone keeling over incapacitated on it....but yes if you push hard over to it and let go it tries to recover...just not enough altitude to do it.
Well, here's the problem... At 230 knots, to get the airplane to 49° nose down would take awhile. That's not going to happen instantaneously without breaking something or negatively stalling the plane. So why the sustained nose push?? We'll find out in the report of course, but as of now, it does not appear there was even an attempt at recovering from the nose down attitude, aerodynamically or otherwise.
 
Did you not read the part where they said the attitude increased to -20 at the bottom of the dive?
I did not. That would certainly make more sense. Going to the link now. Thanks for pointing that out. But still, to get to 49, that's something... and would take a fairly sustained input.
 

ian

Well-Known Member
While their limp hand simultaneously pushes the thrust levers to max.
not if the GA button is pushed
Well, here's the problem... At 230 knots, to get the airplane to 49° nose down would take awhile. That's not going to happen instantaneously without breaking something or negatively stalling the plane. So why the sustained nose push?? We'll find out in the report of course, but as of now, it does not appear there was even an attempt at recovering from the nose down attitude, aerodynamically or otherwise.
it takes about 5-6 seconds to get from level flight to -50 with a moderate push.
 
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