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Atlas Air 767 down/Texas

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Atlas Air 767 down/Texas

Old 8th Mar 2019, 09:27
  #361 (permalink)  
 
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Thanks.
And to clarify, its transponder #1 that is wired to the battery. If transponder #2 is operating, you need to switch it to #1 if you loose AC power.
Easy to forget in a high stress situation.
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Old 8th Mar 2019, 14:04
  #362 (permalink)  
 
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The video linked below gives a view of some wreckage that has been moved to a warehouse. In it there can be seen the remains of at least one engine. For what it's worth, there is a good view of the aft end of the engine showing a turbine disk. From the way the blades are broken and bent, it appears that the turbine disk was rotating at impact.

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Old 8th Mar 2019, 15:49
  #363 (permalink)  
 
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From the way the blades are broken and bent, it appears that the turbine disk was rotating at impact.
From a frontal impact which should stop the fan dead?

Lots more evidence is needed
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Old 8th Mar 2019, 15:59
  #364 (permalink)  
 
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Originally Posted by Orestes View Post
The video linked below gives a view of some wreckage that has been moved to a warehouse.
Excellent video quality and professional reporting. I'm sure some trained eyes here will recognize many more of the pieces than the reporter or me.

Here is a follow up report on the KHOU evening news.

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Old 8th Mar 2019, 16:03
  #365 (permalink)  
 
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At 4:31 in the video in post 362 is the item in the background the jack screw for the stab?
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Old 8th Mar 2019, 16:25
  #366 (permalink)  
 
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Originally Posted by tubby linton View Post
At 4:31 in the video in post 362 is the item in the background the jack screw for the stab?





This should be a pic of the jack screw on a 737. I dont know how the 767 one looks, but the screw in this picture and the triangular bracket going to the tail plane is very similar to the screw and bracket in the video at about 4.30. If so, then the jack screw in the video seems to be at about 2/3 nose up position.

But, can this be possible? If the jack screw is almost full nose up, how come the airplane plunged like it did? Even if we suppose the trim was running towards nose up at the time of impact, how many seconds would it need to run to this apparent position from lets say a neutral position? Would it be possible at all in the available 18 to 20 sec to first get the airplane to start plunging where the jack screw obviously cant have been in almost full nose up position, and then at some time before impact start running in the nose up direction and have time to reach the position it seems to have had at impact? And another question, considering the very high indicated airspeed the aircraft had at impact, would an almost full nose up trim position be compatible with wings AoA below a value where generated lift wouldnt tear the wings off of the aircraft?

What would the AoA be for the airspeed the aircraft is assumed to have had at impact and at the same time generating say 3G? I believe somewhere between say 5 to 9 degrees AoA at say 400 knots at low altitude would produce so much lift that the wings would tear off?

So, could it be possible that the tail plane was not in the postion that the screw jack is indicating, ie that the screw jack had broken loose in one end before impact?
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Old 8th Mar 2019, 16:29
  #367 (permalink)  
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Not sure...I don't see threading, but the resolution at this enlargement size isn't clear enough.


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Old 8th Mar 2019, 16:37
  #368 (permalink)  
 
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Maybe this is not the tail plane jack screw.... It seems small? Could it be a gear actuator?

Hope a 767 mechanic can chime in on this.
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Old 8th Mar 2019, 16:39
  #369 (permalink)  
 
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Originally Posted by FCeng84 View Post
I concur with your suggestion that a floating stabilizer would be impacted by the elevators in much that same manner as a tab-driven trailing edge control surface. Airplane nose up elevator deflection puts loads on the stabilizer in the opposite direction and thus would drive a floating stabilizer in the airplane nose down direction. For small motions, elevator has about half as much pitch authority as stabilizer on a degree for degree basis. The story is not quite that simple, however. Below are a few factors to consider:
The elevator is hinged at the leading edge, so the servo tab mounted at the trailing edge has the mechanical advantage or leverage to force the elevator to move up or down.
The stabilizer is hinged at the trailing edge with the actuator at the leading edge, so the position of the elevator mounted at the trailing edge of the stabilizer is going to have little or no effect on the position of a free floating stabilizer.
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Old 8th Mar 2019, 16:42
  #370 (permalink)  
 
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Is that not in really bad taste, inviting a TV reporter to look at the debris ?
cannot see the AAIB doing this.
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Old 8th Mar 2019, 16:54
  #371 (permalink)  
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Image of a B737NG screw-jack - certainly looks similar.

The photograph is taken looking down and slightly rearward from the starboard side of the fuselage. The position of the ball-screw on the jack-screw, (nearer to the base & motor), I believe would be "leading-edge-down", for "nose-up" trim.


Last edited by PJ2; 8th Mar 2019 at 21:07.
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Old 8th Mar 2019, 17:01
  #372 (permalink)  
 
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Originally Posted by Meester proach View Post
Is that not in really bad taste, inviting a TV reporter to look at the debris ?
cannot see the AAIB doing this.
Freedom of Information Act.
Unless its been deemed classified or not suitable to be released.
In this case the wreckage is news and its a local TV station.
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Old 8th Mar 2019, 17:08
  #373 (permalink)  
 
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Originally Posted by Meester proach View Post
Is that not in really bad taste, inviting a TV reporter to look at the debris ?
cannot see the AAIB doing this.
Not too much different from the photos that were displayed post the PanAm 103 crash over Lockerbie. And in that one 270 people died. See https://www.gettyimages.com/photos/p...20flight%20103
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Old 8th Mar 2019, 18:41
  #374 (permalink)  
 
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Originally Posted by Meester proach View Post
Is that not in really bad taste, inviting a TV reporter to look at the debris ?
cannot see the AAIB doing this.
In this widely published iconic picture of the Lockerbie crash the bodies of former colleagues Captain Jim MacQuarrie and First Officer Ray Wagner are under blankets with their flight kits embedded in the soil. Few here seem to call this bad taste or question the media's right to publish photos of the wreckage even years later on the 30th anniversary of the crash. Wasn't the AAIB involved in this investigation?


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Old 8th Mar 2019, 18:48
  #375 (permalink)  
 
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Originally Posted by B2N2 View Post
Freedom of Information Act.
Originally Posted by B2N2 View Post
Unless it’s been deemed classified or not suitable to be released.
In this case the wreckage is “news” and it’s a local TV station.


Actually, information about an ongoing investigation is specifically exempted from FOIA requests under NTSB regulations:

FOIA Exemptions

The National Transportation Safety Board embraces administration policy and applies a presumption of openness in responding to FOIA requests. The NTSB has also taken steps over the past two years to make discretionary releases of record as evidenced by the number of dockets posted to the public website.

However, certain records retained by the NTSB may fall under exemptions of the FOIA. The NTSB will deny requests, either in whole or in part, if the request seeks information that falls within one of the exemptions of the FOIA. The NTSB may deny a request based on the following exemptions:

...Exemption 7 : Information from an investigation that is ongoing.


https://www.ntsb.gov/about/foia/Page...xemptions.aspx
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Old 8th Mar 2019, 20:36
  #376 (permalink)  
 
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Sorry, but the people who state the airplane hits at full speed nose down are plain wrong.

1. Yes, camera lenses have distortions. However, distortion is about the same in equal radius from the centre. Meaning that an object in an upper screen would be about equally distorted as an object at the bottom of the screen for the same distance from the image centre.
2. That said, this particular lens seems a normal lens (not wide, not tele). One can draw a fairly straight line over horizon. On top of that, all the visible objects (e.g. huts) don't show any major visible distortions.
3: Given points 2 and 3, lens distortion can be ignored as it plays no role in assessing the flying path of this video.
4. As noted in point 3, the video is at an angle. An observer might get a better perception by rotating the screen to the left.
5. The airplane enters the video at about 6''.
6. Just before 7'' we can clearly see the airplane between the tree branches. It's at an angle we can't determine, but on my screen the fuselage is 26px long (only relative size matters). Wings at the root are 4 pixels long. Engines and other features are easily seen and recognisable.
7. The airplane reaches the centre of the area between upper bound of the screen and the horizon (approx. where the line crosses the central trees) at 8''. Thus, it needed 2'' to travel that distance (in 3d space, and we can't determine how fast it's moving away from us).
8. The airplane hits the ground at 11''. Seconds are not detailed enough to determine the right numbers, frame by frame analysis for which I don't have time would be needed.
9. However, it is my estimation that the plane needs about 2'' to reach the relative centre and it needs 3'' to hit the ground.
10. If the airplane was moving in constant speed on the down axis and away from us, the speed should be constant.
11: Therefore I believe the downwards speed in the lower segment is lower and the speed of moving away from camera is higher, in other words, the airplane seem to be changing the trajectory in its final moments.
12. In the final moments there's no clear view of the airplane, as it's exactly following the path the branch is hiding.
13. The airplane in this segment is much harder to see. Engines are not visible. Wings, which are clearly visible at the beginning are now just blips of interpolations. They measure 2 px.
14: Airplane is creating smaller image on the sensor either because it moved a considerable distance away from camera, or because it's pitch got higher, or combination of both.
15. At this point I would invite the reader to watch the recent video "aircraft lands at Asuncion Airport, Paraguay when staff is performing runway works". Watch closely the airplane which is approaching the camera at the landing speed. For the first 5 seconds of the video it stays virtually the same size. In fact, due to perspective humans often underestimate how fast are fast distant objects approaching.
16. The airplane would need to be moving away from the camera very fast to become that much smaller.
17: Hence, the only conclusion is, the pilots were trying to pull up, but unfortunately they did not have enough height.


Any my non factual speculation if I may: downdraft/windshear caused loss of speed while in the clouds, either pilots or systems pushed the stick forward to regain speed, lost awareness as no visual contact with the ground, once they were out of the clouds it was too late to safely pull up.
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Old 8th Mar 2019, 21:07
  #377 (permalink)  
 
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Amazing

Amazing what one can get from a few seconds of fuzzy video, you should call the NTSB and tell you have the probable cause worked out!
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Old 8th Mar 2019, 21:12
  #378 (permalink)  
 
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Any my non factual speculation if I may: downdraft/windshear caused loss of speed while in the clouds, either pilots or systems pushed the stick forward to regain speed, lost awareness as no visual contact with the ground, once they were out of the clouds it was too late to safely pull up
I can only shake my head.
Pixels and inches moved on a screen and THAT conclusion?
Its eyewatering to read.
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Old 8th Mar 2019, 21:13
  #379 (permalink)  
 
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Originally Posted by Airbubba View Post

Actually, information about an ongoing investigation is specifically exempted from FOIA requests under NTSB regulations:



https://www.ntsb.gov/about/foia/Page...xemptions.aspx
Well...mute point as they did give access to the hangar.
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Old 8th Mar 2019, 21:25
  #380 (permalink)  
 
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Originally Posted by B2N2 View Post
Pixels and inches moved on a screen and THAT conclusion?
The references to 6", etc, are seconds into the video, not inches.

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