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-   -   Atlas Air 767 down/Texas (https://www.pprune.org/rumours-news/618723-atlas-air-767-down-texas.html)

SRM 2nd Mar 2019 09:15


Originally Posted by AtoBsafely (Post 10404572)
I believe he was suggesting that water can freeze up the screw jacks so that the hydraulics can’t turn them.

I experienced that with the flaps stuck up on arrival after a departure in heavy rain. We were just beginning the checklist when things thawed out and in another minute were working normally.

In this case, I would expect that a frozen stab problem would have occurred earlier as the trim changed with IAS during descent.

I experienced this on the 727 many years ago, however Boeing changed the screw jack lubrication system and that seems to thave resolved any further issues.
Never had an issue on the 767 200/300 both as PFE with Ansett and AP with Qantas.
There was and AD issued regarding screw jack lubrication of recent times.

ironbutt57 2nd Mar 2019 10:46


Originally Posted by SRM (Post 10404496)


Could please explain how leaking toilet water can get into Pitot Static system of the 767 Elevator Feel Computer.
Having recently removed and replaced a faulty Feel Computer and carried pitot static checks on this system I don’t think this is possible.



well, that was the result of the investigation, they did whatever they did to the airplane, and it never happened again..Im just passing along what we were told...apparently it got into the mechanical side of it somehow, but like I said, I'm just passing along what we were debriefed on...I don't remember mentioning the pitot static portion of the system..

thabo 2nd Mar 2019 16:31


Originally Posted by ironbutt57 (Post 10404315)
at a previous employer we had the elevator feel system freeze due to leaking toilet moisture, and the crew were unable to move the elevators (both columns) during initial level off arriving at destination, they used the stabilizer, after a short while the system unfroze due to warmer air and the airplane returned to ops normal...happened to only one aircraft, twice..system was repaired, never happened again..

I don't know about the BCF, but on the BDSF the lav system is replaced by a stand-alone unit on in right side of the supernumeraries area which has a large diam pipe running down to a service panel on the fwd right side of the lower fuselage.
There is no way water/waste could get near the jack

I assume the BCF has a similar system

Airbubba 2nd Mar 2019 18:10

The CVR has arrived at the NTSB Vehicle Recorder Lab. NTSB engineers Sean Payne and Joe Gregor open the shipping cooler.


https://cimg9.ibsrv.net/gimg/pprune....0d4c7967d6.jpg
https://cimg2.ibsrv.net/gimg/pprune....2a50c0776e.jpg
https://cimg3.ibsrv.net/gimg/pprune....cfe881f241.jpg
https://cimg1.ibsrv.net/gimg/pprune....97dfc5e363.jpg
https://cimg0.ibsrv.net/gimg/pprune....3e290c1be8.jpg
https://cimg8.ibsrv.net/gimg/pprune....594387f8b1.jpg

Airbubba 2nd Mar 2019 18:14

B-roll video of the CVR unpackaging on arrival at the Recorder Lab:


Rodney Rotorslap 2nd Mar 2019 21:06

The CVR is labelled "Flight Recorder"?
Are both recorders labelled with the same generic name?

DaveReidUK 2nd Mar 2019 21:33


Originally Posted by Rodney Rotorslap (Post 10405222)
The CVR is labelled "Flight Recorder"?
Are both recorders labelled with the same generic name?

Typically the data plate (visible on the end of the unit in photo 2) will identify the part number and a description of whether it's a CVR and/or FDR.

The high-visibility legend FLIGHT DATA RECORDER DO NOT OPEN / ENREGISTREUR DE VOL NE PAS OUVRIR is there purely for ease of identification by a recovery team, to ensure that it is handled appropriately.

gulliBell 2nd Mar 2019 22:01

Why do they always transport these things in an esky of water?

Machinbird 2nd Mar 2019 22:17

No evidence of a pinger on this unit. Some significant distortion of the case in places. Likely the pinger was knocked off of it during the accident.

Considering how violent some of these accidents are, the general pinger attachment method looks pretty sketchy.

Did they just luck into finding this data unit?

Pilot DAR 2nd Mar 2019 22:37


Why do they always transport these things in an esky of water?
If instruments to be preserved are found immersed, it is good practice to transport them in the same water in which they were found, to delay or prevent corrosion. Corrosion will happen faster when the unit is exposed to air, so best immersed until at the facility which is ready to handle it properly.

Airbubba 2nd Mar 2019 22:59


Originally Posted by gulliBell (Post 10405265)
Why do they always transport these things in an esky of water?


Originally Posted by Pilot DAR (Post 10405290)
If instruments to be preserved are found immersed, it is good practice to transport them in the same water in which they were found, to delay or prevent corrosion. Corrosion will happen faster when the unit is exposed to air, so best immersed until at the facility which is ready to handle it properly.

From the NTSB CVR Handbook:


4.5. If the CVR is recovered in water, it shall immediately be packed in water (fresh, if possible) and not be allowed to dry out. Packaging may be accomplished by sealing the recorder (in water) inside a plastic beverage container with silicon [sic] adhesive or a similar sealant.

Originally Posted by Machinbird (Post 10405276)
No evidence of a pinger on this unit. Some significant distortion of the case in places. Likely the pinger was knocked off of it during the accident.

The pinger is normally removed prior to shipment according to NTSB CVR guidelines:


4.7. The IIC [Investigator-in-Charge] should attempt to ensure that the underwater locator beacon (ULB) is removed and properly disposed of or returned to the operator prior to shipping. If the ULB cannot be disposed of or returned, contact the chief of the Vehicle Recorder Division (RE-40) for guidance.
https://www.ntsb.gov/investigations/...R_Handbook.pdf

Machinbird 3rd Mar 2019 01:24


The pinger is normally removed prior to shipment according to NTSB CVR guidelines
Thanks Airbubba. That was a useful reference.
Guess I've seen pictures of too many CVRs being recovered from other countrys' waters.:(

Chu Chu 3rd Mar 2019 10:43

Presumably, the more rigidly the pinger is attached, the more likely it is to sustain damage -- or to damage the crash-protected part of the recorder itself. A detached pinger would still help locate the wreckage in general (not that they seem to have been too effective in open-ocean crashes recently . . .). So I guess there's a trade off.

GlueBall 3rd Mar 2019 12:17

Conceivably, the ULB (pinger) is removed to preclude activation during shipment of the recovered FDR/CVR.

DaveReidUK 3rd Mar 2019 13:06


Originally Posted by Chu Chu (Post 10405630)
Presumably, the more rigidly the pinger is attached, the more likely it is to sustain damage -- or to damage the crash-protected part of the recorder itself. A detached pinger would still help locate the wreckage in general (not that they seem to have been too effective in open-ocean crashes recently . . .). So I guess there's a trade off.

No trade-off required.

It's perfectly possible for a pinger to be both securely attached, so that it won't separate from the recorder in an impact, and also readily removable once its job is done and the unit has been recovered (note the 4 Allen screws):

https://cimg9.ibsrv.net/gimg/pprune....67a50bf509.jpg
The pinger is, of course, externally mounted so that its batteries can be changed without having to open up the recorder itself.

Airbubba 3rd Mar 2019 15:58

Remains of all three crewmembers have now been officially identified.

From the CCSO Facebook page:


Sheriff Brian Hawthorne reports that at 6:05 p.m. today he received notification confirming the identity of Captain Ricky Blakely, 60, recovered in Trinity Bay from the crash of flight 3591.

Chambers County Sheriff’s Office extends their heartfelt condolences to his family, friends and coworkers.

Machinbird 3rd Mar 2019 16:30


The pinger is, of course, externally mounted so that its batteries can be changed without having to open up the recorder itself.
That is one of the advantages of course.
Ultimately, whatever mount used has to allow the pinger/ULD to couple acoustic energy effectively into the water.

I suppose that the CVR/FDR recorder manufacturers have tested the mounting technique under dynamic conditions, however the use of what visually appears to be 1/4 inch or 5-6 mm Allen head screws seems weak should the mount receives a blow in the direction of the pinger axis.
I have sheared plenty of 1/4 inch hardware in my life, and going up at least one hardware size would significantly improve strength of the mounting.

One of the AF447 pingers was knocked off its mounts. Neither was detected. That was not a very high energy impact as crash energies go.
Lessons learned from the AF447 search

What we discovered is that you are dealing with a lot of uncertain information in such a search operation. You cannot count on the pingers: after a crash it is always unclear if they are going to work. They towed the pinger locators right over the wreck shortly after the crash, and they didn’t hear anything. When the black boxes were found, only one pinger was still attached. The other one was never found.

tubby linton 3rd Mar 2019 18:18

FDR now found according to NTSB.

Airbubba 3rd Mar 2019 18:23

From @NTSB_Newsroom:


https://cimg7.ibsrv.net/gimg/pprune....bf116c2a8c.jpg
https://cimg6.ibsrv.net/gimg/pprune....f9c1e13d26.jpg

Machinbird 3rd Mar 2019 18:50

Pinger ?
 
Fresh from the accident scene, muddy, without a pinger attached.
Somehow, I don't think they were keeping an Allen wrench handy to immediately remove the pinger as soon as the unit was discovered.


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