OldB747Driver
Posts: 49
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Thu Mar 14, 2019 2:48 pm

I'm not sure why the NTSB is slow-walking information out like this - I do understand that it is necessary to be factual, but facts are facts, legal arguments notwithstanding. One needs to ponder the motive of the NTSB's specificity of some data while incongruously not stating other critical, but surely known relevant information.

For instance, the NTSB [specifically] stated in their initial update:

"...rapidly pitched nose down to about 49° in response to column input."

...by restating it as:

"...then pitched nose down over the next 18 seconds to about 49° in response to nose-down elevator deflection."

...without any further elaboration. Even the current statement as it stands begs the question of why they chose to phrase it that way yet not feel obligated to explain the strained description. Clearly the first phrasing was - for some reason - inappropriate and required modification. Reality TV shows follow the same method in order to keep viewers tuning in for the next episode, but that motive supposedly doesn't (shouldn't ???) exist, so, Why, NTSB?

Retired NTSB Investigator Feith, while not speaking officially, along with other media-produced information such as potentially critical parts on the warehouse floor clearly not a focus of the investigation - combined with the fact that if there WERE a critical safety issue discovered at ANY TIME, they would be issuing Alert Bulletins to operators of other B767 aircraft - demonstrate they have narrowed the focus on the nature of this accident but have been reluctant to share this additional information, aka, facts.

On that note, the NTSB narrative goes to great pains to describe that the indicated airspeed was a steady 230 prior to "the engines increasing to maximum thrust" - are they implying the engines did this on their own somehow? Or that they don't know why the engines accelerated? I'm guessing they do - why not produce that information as well? They go on to state that the stick shaker did not activate, which together with the "steady 230" implies that wind shear was not the issue, but also displays a dopler wind chart that inidcates that there may have been significant shear in that area? Continuing in this vein, noting that the NTSB has the FDR data in hand, why, after being detailed in their reason for explaining the nose down condition ("elevator deflection"), is there no explanation for why the nose down attitude was reduced by 29 degrees, regardless of the CVR transcripts?

Ultimately we will know all the details in order to hopefully prevent another simlar accident from happening, but this intentional slow-walking process can be maddening.
 
Boof02671
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Thu Mar 14, 2019 3:06 pm

 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Thu Mar 14, 2019 3:29 pm

Boof02671 wrote:


It appears as though this is a reshash of the NTSB March 12 Update that is already being discussed, intermingled with some opinion / interpretation.
 
Moosefire
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Thu Mar 14, 2019 3:31 pm

OldB747Driver wrote:
Boof02671 wrote:


It appears as though this is a reshash of the NTSB March 12 Update that is already being discussed, intermingled with some opinion / interpretation.


Some pretty poor interpretation at that!
MD-11F/C-17A Pilot
 
mrbots
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Thu Mar 14, 2019 3:41 pm

So...not a pilot but I don't recall ever being on a flight that hit turbulence and then the pilots push the throttles to full, or even adjusting the engines any noticeable amount during turbulence. Except that one time we seemed to get hit by a pretty significant cross-wind on final approach where they throttled up and pulled up to circle back around for a second attempt.
 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Thu Mar 14, 2019 5:33 pm

mrbots wrote:
So...not a pilot but I don't recall ever being on a flight that hit turbulence and then the pilots push the throttles to full, or even adjusting the engines any noticeable amount during turbulence. Except that one time we seemed to get hit by a pretty significant cross-wind on final approach where they throttled up and pulled up to circle back around for a second attempt.


Uh, yeah, I kinda' chuckled at that statement too - I think most pilots' first reaction to turbulence is to pull the power back to slow to Vb, turbulence penetration speed, because we're "moving right along". Most flight crews would normally already be slowed (or request to slow if higher airspeeds were required or requested) to Vb in and around weather as was evident in Houston at the arrival time; in the specific case of 3591, they were already well below Vb at 230 KIAS so any power up would, to a pilot's mind, be a result of getting too slow or to maintain airspeed upon leveling out, not turbulence. In any case, without any shear or drastic speed reduction, one would certainly not normally command maximum thrust.

I'm also scratching my head at their declaration of "extreme weather" as the NTSB narrative says the airspeed was stable at 230 with "small" vertical accelerations associated with turbulence. Given the wording of the actual NTSB Update, I wondered whether the author of the article, Tomos Howells, had some "inside information" as to what the NTSB is really thinking? Otherwise, I guess his guess is as good as ours (Your Mileage May Vary).
 
TSS
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Thu Mar 14, 2019 6:12 pm

tjerome wrote:
kaneporta1 wrote:
Could pitot icing have produced false low airspeed (and maybe climb rate) readings? This could have caused the crew to firewall the engines and push the nose down to avoid the perceived oncoming stall? The turbulence just before the loss of control could had been interpreted as stall buffet and added to the confusion.


Accident occurred around 1840Z, here is the last METAR prior:
KIAH 231802Z 32015G24KT 10SM FEW035 SCT060 BKN080 BKN250 22/12 A2992 RMK AO2 T02220117=

KIAH field elevation 97 feet. Using the rule of temperature decreases 2 degrees C per 1,000 feet, it would've been about 8 degrees C at 7,000 feet. 46 degrees F. Sure icing is a possibility, anything is at this point, but I don't think it is likely.


I was wondering about a similar possibility: Pitot fouling, specifically a bird hitting and getting jammed in the pitot tube during flight. I realize that's highly unlikely, I'm just spitballing here.
Able to kill active threads stone dead with a single post!
 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Thu Mar 14, 2019 8:03 pm

tjerome wrote:
kaneporta1 wrote:
Could pitot icing have produced false low airspeed (and maybe climb rate) readings? This could have caused the crew to firewall the engines and push the nose down to avoid the perceived oncoming stall? The turbulence just before the loss of control could had been interpreted as stall buffet and added to the confusion.

TSS wrote:
I was wondering about a similar possibility: Pitot fouling, specifically a bird hitting and getting jammed in the pitot tube during flight. I realize that's highly unlikely, I'm just spitballing here.


Blockages certainly can occur although I believe someone already showed the math that where flight 3591 was likely not in a potential icing location. With weather in the area, it could still be possible but that location did not show any significant precipitation, i.e. the beginnings of a cell with significant vertical air/moisture movement. Add to this that at 230 KIAS, the air is as is slightly compressed, and therefore warmed, as the aircraft passes through it.

Probably more important than whether the pitot became blocked or not would be how professional crews normally respond to such a malfunction, which in turn has a lot to do with their familiarity with the aircraft and it's automation. Airspeed as we read it off the Airspeed Indicator is only one parameter of flight and if we were to lose that information, Angle of Attack sensor information, if available, is almost just as good, and even better in some situations. In many modes of flight, a collection of other information is available to the pilots that are independent of the pitot tube, such as power setting vs pitch angle, pitch angle vs rate of climb or descent, etc. are available and are, in fact, routinely used to verifty that the airspeed indicator is giving us good information.

An actual change in airspeed would also cause the aircraft to react in a manner that would be unmistakable, so for in this instance, the aircraft leveling out at 6200 and then a slight climb to 6300 while maintaining 230 KIAS could be a confirmation that the aircraft descended into a increasing headwind while descending and maintaining a constant airspeed**. Generally speaking, the more sudden the actual airspeed change, the more rapidly the aircraft's flight path would be altered. In 3591's case, the NTSB seems to have wanted to make sure that everyone knew that the aircraft was stable with only a "small vertical" movement prior to "the 18 seconds" despite the weather graphic they included.


** IF the level off at 6200 occurred while the aircraft was in "vertical speed" mode, this would have sent a signal to the autopilot to push the nose further down in response to the descent rate being reduced to less than the rate originally commanded, however most properly functioning autopilots would almost make this imperceptible, i.e. it wouldn't "wait" for a level off to command nose down, it would do it gradually and immediately with the first small reduction in the rate of descent. The key take away here would be that the autopilot would be giving an increased nose down command just prior to the aircraft rapidly pitching to 49 degrees nose down.
 
trnswrld
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Thu Mar 14, 2019 11:07 pm

So more or less we are all still scratching our heads even after the initial release? I am anyway lol.

Hey quick question for airline pilots or 767 pilots. Correct me if I am wrong, but a relatively lightly loaded 767 cruising along 6,000-7,000 ft at about 230kts.....then quickly increased to max thrust....that would be a pretty intense experience right? I already know a 767 is no slouch by any stretch of the imagination, but I would imagine the engines spooling would be loud, you’d likely be in your seat back pretty heavily, and would the airplane naturally want to start climbing like a rocket?
 
mzlin
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 1:27 am

From https://www.washingtonpost.com/national ... story.html

"Todd Curtis, a former Boeing safety engineer who runs AirSafe.com, said the plane’s slight upward tilt might have been the pilots compensating for a hard down draft. But there would be no reason to suddenly drop the plane’s nose, he said.

The plane’s dive was either caused by a major mechanical or computer malfunction, by a pilot’s error or it was a deliberate act, Curtis said. But this last option is unlikely, he said, as it would have led the FBI to take over the investigation as a criminal probe."
 
GalaxyFlyer
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 1:55 am

trnswrld wrote:
So more or less we are all still scratching our heads even after the initial release? I am anyway lol.

Hey quick question for airline pilots or 767 pilots. Correct me if I am wrong, but a relatively lightly loaded 767 cruising along 6,000-7,000 ft at about 230kts.....then quickly increased to max thrust....that would be a pretty intense experience right? I already know a 767 is no slouch by any stretch of the imagination, but I would imagine the engines spooling would be loud, you’d likely be in your seat back pretty heavily, and would the airplane naturally want to start climbing like a rocket?


Yes, you’d feel rapid acceleration and, if ALT engaged, maintain the altitude as the plane gained speed and notice the trim running to maintain the trim as the speed increased. It would pitch up some, but the autopilot would counter it.


Gf
 
mcdu
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 4:14 am

GalaxyFlyer wrote:
trnswrld wrote:
So more or less we are all still scratching our heads even after the initial release? I am anyway lol.

Hey quick question for airline pilots or 767 pilots. Correct me if I am wrong, but a relatively lightly loaded 767 cruising along 6,000-7,000 ft at about 230kts.....then quickly increased to max thrust....that would be a pretty intense experience right? I already know a 767 is no slouch by any stretch of the imagination, but I would imagine the engines spooling would be loud, you’d likely be in your seat back pretty heavily, and would the airplane naturally want to start climbing like a rocket?


Yes, you’d feel rapid acceleration and, if ALT engaged, maintain the altitude as the plane gained speed and notice the trim running to maintain the trim as the speed increased. It would pitch up some, but the autopilot would counter it.


Gf


The trim is silent in the 767. How do you “notice “ it running unless you are staring at the trim setting indicator ?
 
LTC8K6
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 6:41 am

Looks like they clarified that the pitch down movement was a relatively slow event, rather than a quick move? It occurred gradually over time, rather than immediately.
 
Endeavor
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 8:00 am

LTC8K6 wrote:
Looks like they clarified that the pitch down movement was a relatively slow event, rather than a quick move? It occurred gradually over time, rather than immediately.


The public updates haven't been handled smoothly. I appreciate the fact that they are providing updates, especially so soon after the incident, however all these followup clarifications,contradictions and statement changes are sloppy.

I wonder how much time elapsed during the nose down movement from start to finish. If it was gradual, does that invalidate control column input by a crew member? I don't see how the crew wouldn't notice a nose down movement that culminated at 49° (gradual or not).

When running the possibilities and potential outcomes in my mind, based on the known series of events, I keep getting back to two different scenarios.

1) Crew falsely thinking plane was in a stall (despite absence of stick shaker)

2) Mechanical failure
 
LTC8K6
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 8:10 am

Endeavor wrote:
LTC8K6 wrote:
Looks like they clarified that the pitch down movement was a relatively slow event, rather than a quick move? It occurred gradually over time, rather than immediately.


The public updates haven't been handled smoothly. I appreciate the fact that they are providing updates, especially so soon after the incident, however all these followup clarifications,contradictions and statement changes are sloppy.

I wonder how much time elapsed during the nose down movement from start to finish. If it was gradual, does that invalidate control column input by a crew member? I don't see how the crew wouldn't notice a nose down movement that culminated at 49° (gradual or not).

When running the possibilities and potential outcomes in my mind, based on the known series of events, I keep getting back to two different scenarios.

1) Crew falsely thinking plane was in a stall (despite absence of stick shaker)

2) Mechanical failure

The airplane then pitched nose down over the next 18 seconds to about 49° in response to nose-down elevator deflection.


FDR data indicated that the airplane gradually pitched up to about 20 degrees nose down during the descent.


Sounds a bit like the yoke was gradually moved forward and then there was a gradual move back. As if under control.

Maybe an incapacitated pilot fell forward?

Either the speed, or someone trying to recover, pulled the nose back up some.
Last edited by LTC8K6 on Fri Mar 15, 2019 8:11 am, edited 1 time in total.
 
Endeavor
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 8:10 am

mzlin wrote:
The plane’s dive was either caused by a major mechanical or computer malfunction, by a pilot’s error or it was a deliberate act, Curtis said.


He covered every possible scenario. :spin:
 
wjcandee
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 9:22 am

I'm pretty sure that many of our posters will be shocked by the straightforwardness of how all the elements in the report will be tied together into an accident sequence -- and it's going to leave them dumbfounded that what happened could have happened like that. No mechanical failure. No shifting cargo. Nobody falling forward on the controls. No self-harm. Just mishandling and less-than-optimal CRM. I think that almost everything one needs to construct a viable scenario is right there in the NTSB reports, if one thinks about the significance of each item mentioned and what each means, independently and collectively.
 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 1:57 pm

wjcandee wrote:
I'm pretty sure that many of our posters will be shocked by the straightforwardness of how all the elements in the report will be tied together into an accident sequence -- and it's going to leave them dumbfounded that what happened could have happened like that. No mechanical failure. No shifting cargo. Nobody falling forward on the controls. No self-harm. Just mishandling and less-than-optimal CRM. I think that almost everything one needs to construct a viable scenario is right there in the NTSB reports, if one thinks about the significance of each item mentioned and what each means, independently and collectively.


Could this really be the result of a shear induced near stall and mishandled recovery?? But if Greg Feith's statement is to be taken at face value "The automation was still coupled, the pilots didn’t hand fly the airplane when they lost control and even through the recovery they were fighting the automation", it could fit that scenario. The word 'recovery' is generally used with regard to a stalled condition, although lack of stick shaker or pusher is an intriguing twist. It would make sense for the NTSB to not make accusatory statements or any that would implicate the human factors until they could positively elliminate the aircraft component. It's painful to say, but it fits.
Last edited by OldB747Driver on Fri Mar 15, 2019 2:10 pm, edited 2 times in total.
 
SteinarN
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 1:59 pm

Endeavor wrote:
mzlin wrote:
The plane’s dive was either caused by a major mechanical or computer malfunction, by a pilot’s error or it was a deliberate act, Curtis said.


He covered every possible scenario. :spin:


Yes, pretty much everything.

However, some causes seems to be ruled out, for example the idea I put forward of a broken jack screw making the tail plane free float.
If the cause is not a deliberate act then it might seems like the cause is either on a systems failure at a higher level, like the autopilot. NTSB also say that it was the elevator and not the stabilizer which was the control surface which deflected causing the dive. What causes this deflection might be less clear, if it could be the autopilot, the crew or another electrical or mechanical fault. But at the same time the engines spool up, again could the autopilot/autothrottle be at fault? It seems not likely at all that the crew could be so confused that they both applied significant nose down and set high power on the engines. Very confusing to say the least.
 
GalaxyFlyer
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 2:12 pm

mcdu wrote:
GalaxyFlyer wrote:
trnswrld wrote:
So more or less we are all still scratching our heads even after the initial release? I am anyway lol.

Hey quick question for airline pilots or 767 pilots. Correct me if I am wrong, but a relatively lightly loaded 767 cruising along 6,000-7,000 ft at about 230kts.....then quickly increased to max thrust....that would be a pretty intense experience right? I already know a 767 is no slouch by any stretch of the imagination, but I would imagine the engines spooling would be loud, you’d likely be in your seat back pretty heavily, and would the airplane naturally want to start climbing like a rocket?


Yes, you’d feel rapid acceleration and, if ALT engaged, maintain the altitude as the plane gained speed and notice the trim running to maintain the trim as the speed increased. It would pitch up some, but the autopilot would counter it.


Gf


There’s not “trim in motion” aural tone?

GF

The trim is silent in the 767. How do you “notice “ it running unless you are staring at the trim setting indicator ?
 
GalaxyFlyer
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 2:13 pm

mcdu wrote:
GalaxyFlyer wrote:
trnswrld wrote:
So more or less we are all still scratching our heads even after the initial release? I am anyway lol.

Hey quick question for airline pilots or 767 pilots. Correct me if I am wrong, but a relatively lightly loaded 767 cruising along 6,000-7,000 ft at about 230kts.....then quickly increased to max thrust....that would be a pretty intense experience right? I already know a 767 is no slouch by any stretch of the imagination, but I would imagine the engines spooling would be loud, you’d likely be in your seat back pretty heavily, and would the airplane naturally want to start climbing like a rocket?


Yes, you’d feel rapid acceleration and, if ALT engaged, maintain the altitude as the plane gained speed and notice the trim running to maintain the trim as the speed increased. It would pitch up some, but the autopilot would counter it.


Gf


The trim is silent in the 767. How do you “notice “ it running unless you are staring at the trim setting indicator ?


There’s no “trim in motion “ aural tone?

Gf
 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 2:33 pm

SteinarN wrote:
NTSB also say that it was the elevator and not the stabilizer which was the control surface which deflected causing the dive. What causes this deflection might be less clear, if it could be the autopilot, the crew or another electrical or mechanical fault. But at the same time the engines spool up, again could the autopilot/autothrottle be at fault? It seems not likely at all that the crew could be so confused that they both applied significant nose down and set high power on the engines. Very confusing to say the least.


Stall recovery procedures mandate that, in or near a stall:
* Lower the nose (reduce the AOA)
* Set Max thrust
* Verify spoilers down

It is interesting that, given other accidents/incidents that have involved stalled aircraft, the FAA mandated a changed mentality on stall recovery for Air Carriers. The emphasis on recovery used to be to minimize altitude lost, thus any stall recovery began with, essentially, a slight reduction of pressure on the yolk comensurate with max thrust and the airplane would claw its way back to a flying airspeed with very little altitude lost. When pilots started stalling airplanes at higher altitude and prolonging the recovery by trying to minimize altitude lost (which resulted in actually MORE altitude lost than necessary) the FAA put new emphasis on getting that nose over and not worrying about the altitude lost until flying airspeed was recovered.

I still can't figure out how the automation may have contributed, however, or hindered their recovery if, in fact, that is what happened, as equipment I've operated was designed to deactivate the autopilot in a stalled condition... however, if this was actually a 'near stall', that deactivation may not have occurred?
 
Yakflyer
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 3:05 pm

OldB747Driver wrote:
Stall recovery procedures mandate that, in or near a stall:
* Lower the nose (reduce the AOA)
* Set Max thrust
* Verify spoilers down

It is interesting that, given other accidents/incidents that have involved stalled aircraft, the FAA mandated a changed mentality on stall recovery for Air Carriers. The emphasis on recovery used to be to minimize altitude lost, thus any stall recovery began with, essentially, a slight reduction of pressure on the yolk comensurate with max thrust and the airplane would claw its way back to a flying airspeed with very little altitude lost. When pilots started stalling airplanes at higher altitude and prolonging the recovery by trying to minimize altitude lost (which resulted in actually MORE altitude lost than necessary) the FAA put new emphasis on getting that nose over and not worrying about the altitude lost until flying airspeed was recovered.

I still can't figure out how the automation may have contributed, however, or hindered their recovery if, in fact, that is what happened, as equipment I've operated was designed to deactivate the autopilot in a stalled condition... however, if this was actually a 'near stall', that deactivation may not have occurred?



I doubt the airplane stalled, but if it did I can't believe the PF felt the need to pitch down 49 degrees to recover. With max thrust, a light airplane and almost no induced drag (i.e. zero or negative angle of attack) it's tough for me to get my head around anybody feeling the need to push further. Also when we consider the possibility of a stall recovery gone bad we need to remember there was no stick shaker so I have serious doubts there was any other indication of a stall. I just can't believe this might be a stall recovery gone bad.
 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 3:27 pm

As far as the 49 degrees nose down goes, I wouldn't classify it as intent as much as the inadvertent result, so I would agree. The actions described by the NTSB (the increase to max thrust and elevator commanding nose down) fit a 'recovery' profile despite the actual flight path. I am somewhat suspicious of the way the NTSB's statement states that the "The stall warning (stick shaker) did not activate" as this may have been stated to assert that the automation did not push the nose over, but yet leave unanswered whether the 'warbler' was audible (which might contribute to "the quality of the audio is poor") or what indications were evident inside the aircraft.
 
mcdu
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 3:30 pm

GalaxyFlyer wrote:
mcdu wrote:
GalaxyFlyer wrote:

Yes, you’d feel rapid acceleration and, if ALT engaged, maintain the altitude as the plane gained speed and notice the trim running to maintain the trim as the speed increased. It would pitch up some, but the autopilot would counter it.


Gf


The trim is silent in the 767. How do you “notice “ it running unless you are staring at the trim setting indicator ?


There’s no “trim in motion “ aural tone?

Gf


No there is no trim in motion aural
 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 4:23 pm

NTSB 3/5/19 wrote:
• There are times during the recording when the content of crew discussion is difficult to determine, at other times the content can be determined using advanced audio filtering.
...
• Crew communications consistent with a loss control of the aircraft began approximately 18 seconds prior to the end of the recording.


• "Poor quality" probably means a LOT of sound intermingled, including aircraft warnings (warbler?), warning annunciations (whoop, whoop, pull up?), increasing background noise due to increasing airspeed not to mention the likely intense and elevated verbal discussion as well as the actions being taken by the crew.

• "Advanced audio filtering" probably means recording the aircraft's audible alarms and 'wind noise' and then 'subtracting' them from the audio to hear what remains.

Its sobering to reflect on the statement that essentially 18 seconds of audio recording "will be a time-consuming process to complete the transcript."
Last edited by OldB747Driver on Fri Mar 15, 2019 4:29 pm, edited 1 time in total.
 
mcdu
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 4:27 pm

wjcandee wrote:
I'm pretty sure that many of our posters will be shocked by the straightforwardness of how all the elements in the report will be tied together into an accident sequence -- and it's going to leave them dumbfounded that what happened could have happened like that. No mechanical failure. No shifting cargo. Nobody falling forward on the controls. No self-harm. Just mishandling and less-than-optimal CRM. I think that almost everything one needs to construct a viable scenario is right there in the NTSB reports, if one thinks about the significance of each item mentioned and what each means, independently and collectively.


I think this is going to be very true. The CRM issues may prove key. The audio reveals a transfer of control of some type just prior to the crash. What as being said between the pilots to cause that to take place?
 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 4:31 pm

Where are you getting the information regarding the audio?
 
freakyrat
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 4:33 pm

Here is my take after reading the preliminary NTSB report.

Plane is making a normal descent in IMC conditions and being vectored around weather.
Aircraft is already slowed to 230kts. Aircraft hits turbulence, how severe we do not know yet.
Crew increases throttles or autothrottles go to full power, that we do not know yet.
Aircraft hits severe downdraft while still in IMC pitching the nose down while aircraft is at full power.
Pitch down angle increases, aircraft comes out of IMC but is still pitched down at full power.
Crew has mere seconds to react with basic unusual attitude recovery that is taught in a basic private pilot schooling.
That is pull off power and level the aircraft. Crew doesn't react in time and aircraft hits the water.

Again this is all Pure speculation on my part at this time. I trust that the NTSB will figure it out. The other problem I see is that today we rely to much on automation and do not practice basic hand flying skills enough. This crew was possibly fighting the automation instead of using good CRM and basic hand flying skills to recover from an unusual attitude situation.
 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 5:16 pm

mcdu wrote:
The audio reveals a transfer of control of some type just prior to the crash. What [w]as being said between the pilots to cause that to take place?


In practice, a transfer of the controls is always initiated by the Captain and would be expected due to the Captain's experience and judgement regarding the conditions; it is verbally commanded by the Captain to avoid both pilots grabbing the controls and attempting conflicting actions with each other.

But again, what audio?
 
asdf
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 6:15 pm

LTC8K6 wrote:
Looks like they clarified that the pitch down movement was a relatively slow event, rather than a quick move? It occurred gradually over time, rather than immediately.


slow movement leaves both possibilities
- manual imput by the crew
- automatic input by the flight automation

fast movement could be nailed down to the crew ...
 
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SheikhDjibouti
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 6:50 pm

asdf wrote:
LTC8K6 wrote:
Looks like they clarified that the pitch down movement was a relatively slow event, rather than a quick move? It occurred gradually over time, rather than immediately.


slow movement leaves both possibilities
- manual imput by the crew
- automatic input by the flight automation

fast movement could be nailed down to the crew ...

Or option #3; Sir Isaac Newton's favorite pet slowly exerting control, whilst both options 1 & 2 battled against it, hampered by some factor we don't yet know about (e.g. frozen control surfaces)

(Much like a tree falling; that also starts very slowly.....)

*frozen in the mechanical sense, not a reference to icing.
Nothing to see here; move along please.
 
Campo
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 8:01 pm

My last post was rejected because I speculated wind shear. Now the NTSB is saying turbulence. The findings that the throttles were pushed to full power lead me to speculate a deliberate act. Someone may have fought for control that's why impact was at 20 degrees not 49.
 
VC10DC10
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 8:28 pm

Let me begin by saying that I am in no way an aviation safety expert, and this is rank speculation--but I am curious if the precipitating event wasn't turbulence, but a mistaken belief that collision with another aircraft was imminent--a belief caused by some sort of optical phenomenon giving the crew the impression that urgent action was necessary.

If this is ludicrous or wrong, I'm happy to reject the speculation.
 
Indy
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 9:36 pm

PlanesNTrains wrote:
but:

5. Pilot Suicide seems like the lazy guess more and more of late.
6. It really seems disrespectful for it to be repeatedly suggested in crashes before we have anything more official from investigators.
7. The investigators would certainly have an indication by now of a possible suicide just from listening to the cvr and reading the FDR.
8. The overriding cause for most crashes - perhaps the vast majority - is some mix of mechanical/systems issues and/or pilot/people error.


Do you realize how that all sounds? Suggesting pilot suicide is no lazier than suggesting a rudder failure or anything else. Just because YOU don't like it doesn't make it lazy. And if people can take a minute stop feeling self-righteous for a moment, you realize there is zero difference between suggesting someone had an undisclosed mental illness resulting in suicide and someone who screwed up at the workplace and got himself and coworkers killed. Suggesting someone was a screw up resulting in deaths is disrespectful as well. And if the CVR and FDR were conclusive, foul play or suicide would have been ruled out. Which it has not been.

Do I think it was a suicide or foul play? I have no idea. Statistically it is possible. But to rule it out before investigators do is... well... you know.
Indy = Indianapolis and not Independence Air
 
PlanesNTrains
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 10:18 pm

Indy wrote:
PlanesNTrains wrote:
but:

5. Pilot Suicide seems like the lazy guess more and more of late.
6. It really seems disrespectful for it to be repeatedly suggested in crashes before we have anything more official from investigators.
7. The investigators would certainly have an indication by now of a possible suicide just from listening to the cvr and reading the FDR.
8. The overriding cause for most crashes - perhaps the vast majority - is some mix of mechanical/systems issues and/or pilot/people error.


Do you realize how that all sounds? Suggesting pilot suicide is no lazier than suggesting a rudder failure or anything else. Just because YOU don't like it doesn't make it lazy. And if people can take a minute stop feeling self-righteous for a moment, you realize there is zero difference between suggesting someone had an undisclosed mental illness resulting in suicide and someone who screwed up at the workplace and got himself and coworkers killed. Suggesting someone was a screw up resulting in deaths is disrespectful as well. And if the CVR and FDR were conclusive, foul play or suicide would have been ruled out. Which it has not been.

Do I think it was a suicide or foul play? I have no idea. Statistically it is possible. But to rule it out before investigators do is... well... you know.


The larger context is not trying to rule it out, it’s understanding that just saying “What about pilot suicide?” and pointing to random things as some sort of analysis is pointless (lazy) without some shred of evidence to go on. I think that the crews deserve better than that in the days following a crash - they’ve already paid with their lives.

But I respect that you disagree.
-Dave


MAX’d out on MAX threads. If you are starting a thread, and it’s about the MAX - stop. There’s already a thread that covers it.
 
Max Q
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 10:38 pm

All speculation still but a bizarre chain of events

One possibility that hasn’t been mentioned is a drone strike

In the blurred still picture I’ve seen the left side of the horizontal stabilizer looks damaged
The best contribution to safety is a competent Pilot.


Guns and the love of them by a loud minority are a malignant and deadly cancer inflicted on American society
 
Indy
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 11:37 pm

PlanesNTrains wrote:
larger context is not trying to rule it out, it’s understanding that just saying “What about pilot suicide?” and pointing to random things as some sort of analysis is pointless (lazy) without some shred of evidence to go on. I think that the crews deserve better than that in the days following a crash - they’ve already paid with their lives.

But I respect that you disagree.


Whatever happened it is a shame that it resulted in the loss of life. Whether it was mechanical, error ot mental health issues, it is still sad. I cannot imaging living those final seconds. Only blessing in this is that there was no suffering involved.
Indy = Indianapolis and not Independence Air
 
1989worstyear
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Fri Mar 15, 2019 11:44 pm

Indy wrote:
PlanesNTrains wrote:
but:

5. Pilot Suicide seems like the lazy guess more and more of late.
6. It really seems disrespectful for it to be repeatedly suggested in crashes before we have anything more official from investigators.
7. The investigators would certainly have an indication by now of a possible suicide just from listening to the cvr and reading the FDR.
8. The overriding cause for most crashes - perhaps the vast majority - is some mix of mechanical/systems issues and/or pilot/people error.


Do you realize how that all sounds? Suggesting pilot suicide is no lazier than suggesting a rudder failure or anything else. Just because YOU don't like it doesn't make it lazy. And if people can take a minute stop feeling self-righteous for a moment, you realize there is zero difference between suggesting someone had an undisclosed mental illness resulting in suicide and someone who screwed up at the workplace and got himself and coworkers killed. Suggesting someone was a screw up resulting in deaths is disrespectful as well. And if the CVR and FDR were conclusive, foul play or suicide would have been ruled out. Which it has not been.

Do I think it was a suicide or foul play? I have no idea. Statistically it is possible. But to rule it out before investigators do is... well... you know.


What if the Boeing elevator bellcrank designers back in 1978-9 were screwups who caused this tragedy 40 years later?

Same with their autoflight system and SW engineers back then.
Stuck at age 15 thanks to the certification date of the A320-200 and my parents' decision to postpone having a kid by 3 years. At least there's Dignitas...
 
mxaxai
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 12:18 am

SheikhDjibouti wrote:
(Much like a tree falling; that also starts very slowly.....)

Although a tree rarely slows down again prior to impact.

If you let go of the controls, trim neutral, would the 767 be able to reduce its dive angle as quickly as this one did? Or does this require an elevator deflection (by autopilot or crew)?
The GA planes I know would attempt to return to a normal attitude but not as quickly. Maybe 1 - 2 degrees per second. In fact, I'd be quite worried about an over speed in such a steep dive. (Not to mention that the ground would take up a worryingly large part of your view in VMC, a luxury this crew did not have until it was too late).
 
jetmatt777
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 1:09 am

A few questions:

A) Does the artificial horizon on the primary flight display get its pitch information straight from the AoA on the nose of the airplane. Or is the artificial horizon developed from a gyro?

B) is this information from A) fed to both displays or are they independent of each other?

(My question is sparked by the thought of an erroneous increasingly nose high indication on the PFD (and not looking at the backup) giving the crew justification to push forward. By the time the exited IMC they were at -49 pitch and had little time to correct)

Just a thought, looking for feedback.
Lighten up while you still can, don't even try to understand, just find a place to make your stand and take it easy
 
GalaxyFlyer
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 1:27 am

jetmatt777 wrote:
A few questions:

A) Does the artificial horizon on the primary flight display get its pitch information straight from the AoA on the nose of the airplane. Or is the artificial horizon developed from a gyro?

B) is this information from A) fed to both displays or are they independent of each other?

(My question is sparked by the thought of an erroneous increasingly nose high indication on the PFD (and not looking at the backup) giving the crew justification to push forward. By the time the exited IMC they were at -49 pitch and had little time to correct)

Just a thought, looking for feedback.


Each pilot gets attitude and heading information from their IRS with a third as back up. It’s displayed independently on each side.

This from WSJ,

Investigators exploring likelihood that crew accidentally increased thrust on approach to Houston airport, sources say

Andy Pasztor
March 15, 2019 4:06 p.m. ET

National Transportation Safety Board experts, these people said, are focusing on a likely sequence of events that started with the crew of the Boeing Co. 767 approaching Houston’s George Bush Intercontinental Airport on Feb. 23 inadvertently commanding dramatically increased engine thrust. Turbulent air could have jostled the arm of one of the pilots, causing the engines to rev up to takeoff power, one of these people said.

The sudden surge in thrust, which the safety board disclosed in an earlier factual update, forced the nose of the plane to pitch upward and startled the cockpit crew, according to these people. Almost immediately, according to the preliminary data released by the safety board, the crew responded by sharply pushing down the nose of the aircraft.

The board previously said the nose was pointed downward at a 49-degree angle with the plane still about 30 miles from the airport, creating a much steeper descent than a normal landing approach.

The seemingly disoriented crew failed to regain control—despite commands to pull up from the jet’s high-speed dive—and the wide-body plane plowed into a marshy area.

The safety board said the crew had the required training and medical certificates.

The safety board hasn’t issued any final conclusions, and the leading theory currently pursued by investigators could change as more information is developed. A spokesman for the board said it had no comment beyond the factual update released earlier. Boeing had no immediate comment.

Atlas Air Worldwide Holdings Inc. and the union representing its pilots both declined to comment, citing the ongoing investigation.

But at this point, such cockpit slipups are considered the most likely cause of the crash. The plane was skirting around some storm cells before the plunge, but people familiar with the details said the turbulence didn’t cause any structural damage or lead any system to malfunction.

In its update, the safety board said the “engines increased to maximum thrust” as the plane was flying at roughly 6,000 feet. After a brief nose-up movement, according to the update, the Boeing 767 entered a steep descent in a “generally wings-level attitude until impact with the swamp.”

Many airline and aerospace industry officials have watched the probe closely because the 767 model is widely used as a passenger jet around the globe.

The Atlas Air flight, en route to Houston from Miami, was flying cargo for Amazon.com Inc.

The last fatal U.S. airliner crash also was a cargo flight. In 2013, a United Parcel Service Inc. Airbus A300 slammed into hill while approaching to land in Birmingham, Ala., killing both pilots. The safety board determined that a series of pilot errors and violations of safety procedures caused that accident. The aircraft descended too quickly toward a runway shrouded by clouds, and the pilots waited until the last seconds to try to initiate a go-around.

—Alison Sider contributed to this article.

Write to Andy Pasztor at [email protected]
 
N243NW
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 2:44 am

Figured I'd throw this out there...(it's been several years since my 767 ground school)

From where does the autopilot get its airspeed information? And from where does the stall warning computer get its airspeed information? I know that SOP at some airlines is for the FO to use the right autopilot when flying, and the CA to use the left autopilot when flying. Suppose that perhaps some sort of partial or full blockage in only one of the pitot tubes/probes (even due to FOD like a bird) resulted in a decrease in airspeed on the pilot flying's instruments, while also fooling the aircraft into thinking that it was flying much slower than the commanded airspeed. This could not only cause the thrust levers to respond, but it could also result in the PF glancing down at his airspeed indicator and noticing a startlingly low reading, prompting him to push to regain airspeed without realizing that a malfunction and airspeed disagree was occurring. And depending on the inputs that the aircraft uses for its stick shaker and stick nudger, I suppose it's possible that neither received the necessary inputs required to activate...?
B-52s don't take off. They scare the ground away.
 
Indy
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 2:52 am

Are pitot tubes heated automatically or can the heaters be turned off and on?
Indy = Indianapolis and not Independence Air
 
GalaxyFlyer
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 2:54 am

Depends on the plane, I’ve seen both.
 
WPvsMW
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 2:58 am

N243NW wrote:
Figured I'd throw this out there...(it's been several years since my 767 ground school)

From where does the autopilot get its airspeed information? And from where does the stall warning computer get its airspeed information? I know that SOP at some airlines is for the FO to use the right autopilot when flying, and the CA to use the left autopilot when flying. Suppose that perhaps some sort of partial or full blockage in only one of the pitot tubes/probes (even due to FOD like a bird) resulted in a decrease in airspeed on the pilot flying's instruments, while also fooling the aircraft into thinking that it was flying much slower than the commanded airspeed. This could not only cause the thrust levers to respond, but it could also result in the PF glancing down at his airspeed indicator and noticing a startlingly low reading, prompting him to push to regain airspeed without realizing that a malfunction and airspeed disagree was occurring. And depending on the inputs that the aircraft uses for its stick shaker and stick nudger, I suppose it's possible that neither received the necessary inputs required to activate...?


As you speculate, I, too, think that bird flak was the root cause, rather than WX. Damage to one or more sensors, and/or to control surfaces. Spring migrations over wetlands.
 
wjcandee
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 3:13 am

So the WSJ is out with an article containing leaks from the investigation. As we surmised, some want people to know that they're thinking it's straight-up pilot error, with no issues with the airframe or its systems, given how widely-used the 767 is in pax operations.

But the leaker's take on the initiating event is positively-bizarre, and has to do with a "pilot's arm being jostled in turbulence", thus thrusting the throttle to max. On the one hand, we're talking about the rarest of events, a fatal crash from altitude in a transport-category aircraft operated by a First World carrier, so I guess anything is fair game. But to me that seems just too weird. And then nobody just pulled it back? Why would anybody's hand be gripping the throttle anyway when 2/3 of the way through an automation-controlled flight-level-change? Lightly on it to sense position, yeah. Holding it so an arm jerk would push to max? And then to leave it there so the engines actually developed a high thrust level? Weird.

But now I guess we all just wait and see how NTSB lines it all up. Unless they find something else that explains it. If that's the best they've got, then I really do think we can stop speculating until they get deeper into the data analysis.
 
OldB747Driver
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 4:00 am

All Transport category aircraft must have multiple sources of data, and multiple ways of displaying it. Even if the flying pilot's instruments were erroneous, there are two pilots, both of whose responsibility is to monitor their seperately sourced / powered instruments and then utilize their training which requires verbalizing deviations from the common plan of action that is determined (or implicitly understood from the flight plan, SOP, rules and regulations, etc.) throughout a flight.

Using the NTSB narrative, the crew had discussions consistent with a loss of control while they were IMC, so the instrumentation must have allowed that recognition to occur. Now, the ability to recover an aircraft from an undesired state is a different matter - experience with an aircraft's peculiarities and normal indications can definitely affect the rate of successful recoveries. So, again from the information given by the official source, regardless of the cause of the departure from intended flight path, the pilots either:

    * Did not correctly identify the problem, thus making the possibility of a proper response unlikely, OR
    * Correctly identified the problem but did not execute the proper recovery in a timely manner, OR
    * Recognition of the problem was inconsequential as it was not a recoverable condition.

    The possibilities are, of course, not limited to just these distinctions, but the vast number of accidents tend to fall into one of these descriptions.

Because both pilots seemed to have enough experience to understand their dilemma (they discussed it), the focus then centers around what was required to correct it and whether that was accomplished or possible, not whether their instruments had failed or mislead them.

...and I agree that the WSJ article was wishy-washy at best.
 
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SaveFerris
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 4:04 am

Indy wrote:
Are pitot tubes heated automatically or can the heaters be turned off and on?


On the 767 it is automatic, the pitot tubes are heated whenever an engine is running. There is no physical switch to turn the pitot heat on or off.
 
ALERT
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Re: Atlas Air 3591 Down in Trinity Bay, Texas

Sat Mar 16, 2019 4:14 am

I still cant figure out why the official update had/has the specific details they let out but nothing else. Why dont they talk at all about what control inputs were being made? Especially for the final seconds. Why leave it vague when they could easily state if there were attempts to recover or not?

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