PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Rumours & News (https://www.pprune.org/rumours-news-13/)
-   -   Atlas Air 767 down/Texas (https://www.pprune.org/rumours-news/618723-atlas-air-767-down-texas.html)

Airbubba 26th Feb 2019 01:34

NTSB listening for the CVR and FDR pingers.


https://cimg5.ibsrv.net/gimg/pprune....1d58e98329.jpg

Airbubba 26th Feb 2019 01:42

NTSB B-Roll video for the media to use for voice-overs in their newscasts.


Volume 26th Feb 2019 06:34


the B767 has dual jacks which are independent
Except for some russian models, most aircraft have single jacks with dual (concentric) spindles and dual drive.
Some have dual nuts in which the spindle (or balls) do run, but even those can wear at the same rate and fail together.

Alaska seems to ba a one off. The stabilizer trim actuator is understood by everybody as a very critical item, and obviously receiving appropriate attention.

However, every second time can happen for the first time... Stabilizer trim failure/runaway is a valid hypothesis for such a spontaneous dive.

Less Hair 26th Feb 2019 08:07

This accident seems to prove again, that aditional floating data recorders are needed that are auto jettisoned before impact. Like some USB stick with some EPIRB bolted on.
Over and over again the recorders hold the key information and cannot be found. Who is blocking these addtional ones to be required by authorities?

DaveReidUK 26th Feb 2019 08:32


Originally Posted by Less Hair (Post 10400717)
This accident seems to prove again, that aditional floating data recorders are needed that are auto jettisoned before impact. Like some USB stick with some EPIRB bolted on.
Over and over again the recorders hold the key information and cannot be found. Who is blocking these addtional ones to be required by authorities?

Sorry, but it doesn't prove that at all.

Aside from the cost and feasibility considerations, discussed previously in these columns on a number of occasions, ejectable recorders in this instance could have ended up being buried as deep in the Trinity Bay mud as they appear to be anyway.

Less Hair 26th Feb 2019 10:43

We have some known area, flat water and a professional, organized search going on but no recorder. That seems to be enough for you?

Ian W 26th Feb 2019 10:53


Originally Posted by Airbubba (Post 10400546)
NTSB listening for the CVR and FDR pingers.

{{Snip Pic}}

Here we go again.
That will be followed IF the CVR is found by groups of 'experts' trying to work out 'what that sound is'.

The entire area of system recording and safeguarding needs a reappraisal. Not starting from minor evolutionary changes to DFDR/CVR, but from a systems analysis of what information is required. ICAO should also look at the arrangements for assigning costs for recovery so an airline/air carrier is also hit for the costs of recovery if they only use the minimum legal system recording capabilities. Similarly misuse of system recordings by airline management and news organizations, should be a criminal offense when those recordings are intended for emergency/post crash analysis use, (it probably is already an offense under some data protection and privacy laws in any case).

InfrequentFlier511 26th Feb 2019 11:36

At one point in the edited atc recording, I heard something about "primary contact only." From the edit, atc started asking other aircraft to look for debris very soon after, so it could be atc losing the ADS-B signal amongst ground clutter. Did the transponder stop broadcasting before impact, and what - if anything - would that mean?

cappt 26th Feb 2019 12:00


Originally Posted by InfrequentFlier511 (Post 10400893)
At one point in the edited atc recording, I heard something about "primary contact only." From the edit, atc started asking other aircraft to look for debris very soon after, so it could be atc losing the ADS-B signal amongst ground clutter. Did the transponder stop broadcasting before impact, and what - if anything - would that mean?

Primary contact means the radar facility is painting a target on radar but they are not receiving the transponder or assigned code. This can also be caused by birds.

GlueBall 26th Feb 2019 12:11


Except for some russian models, most aircraft have single jacks with dual (concentric) spindles and dual drive.
DC-8 comes to mind.

dogsridewith 26th Feb 2019 12:25

767 ballscrew elevator
 

Originally Posted by NSEU (Post 10400504)
Correct. The 767 only has one ballscrew. However, it does use two hydraulic motors which drive the single ballscrew through a differential gearbox.

Will one motor drive the system if the other locks up? Mechanically separates (ie. broken shaft)? Loses hydraulic pressure?
How is a functioning system inspected?

DaveReidUK 26th Feb 2019 13:15


Originally Posted by Less Hair (Post 10400845)
We have some known area, flat water and a professional, organized search going on but no recorder. That seems to be enough for you?

We were told, not that long ago, that the Lion Air CVR wouldn't be found in the mud because the seabed conditions were so inhospitable. It was.

Ejectable recorders (in civil aircraft) aren't going to happen, no doubt much to Murphy's disappoinment.

double_barrel 26th Feb 2019 13:22


Originally Posted by DaveReidUK (Post 10400961)
We were told, not that long ago, that the Lion Air CVR wouldn't be found in the mud because the seabed conditions were so inhospitable. It was.

Ejectable recorders (in civil aircraft) aren't going to happen, no doubt much to Murphy's disappoinment.

What happened to the push for real-time telemetry ? This would require modest bandwidth for FDR data, CVR would be much more data, not sure how practical that would be today.

Volume 26th Feb 2019 13:51


What happened to the push for real-time telemetry ?
What happens to a satcom connection if you do not fly straight & level...
Such systems would produce zetabytes of data every day documenting fine flights, and fail exactly when it is needed.


Will one motor drive the system if the other locks up?
Yes it will, if both motors run, the speed of the spindle is nominal, if one fails it is just half of it.
Works similar to the differential gearbox in your car, just the other way round (not one engine driving two wheels but two motors driving one spindle).


Mechanically separates (ie. broken shaft)?
Concentric shafts should prevent this. Worst case you are stuck with your stabilizer position.


How is a functioning system inspected?
By a series of different tests/checks/inspections. Additionally it is regularly lubricated and from time to time overhauled.
Nevertheless, there can always be some unexpected failure, for example induced by overload in severe turbulence.
Although all attachments are dual loadpath, there can always be structural failure if you seriously overload the system. This also applies to the pivot fittings and the according bulkhead which had issues previously.

Additional to the black boxes, the debris will be very interesting to look at once it has all been retrieved any laid out in a hangar.
The tail section should be fairly intact, although nothing looking alike has been present in any of the pictures.

Less Hair 26th Feb 2019 14:00


Ejectable recorders (in civil aircraft) aren't going to happen, no doubt much to Murphy's disappoinment.
You are aware that they are optional equipment as we speak? IIRC Qatar Airways has some of their latest A350 fitted with them.

mryan75 26th Feb 2019 14:06


Originally Posted by Less Hair (Post 10400845)
We have some known area, flat water and a professional, organized search going on but no recorder. That seems to be enough for you?

Give me a break. They found AAF447's after two years at the bottom of the damn ocean. It's been two days and we need some sort of all out remedy? Tell me another widebody crash where they weren't eventually found?

God i wish this forum required a pilot certificate number for registration. Or an IQ test.

Zaphod Beblebrox 26th Feb 2019 14:14

I don’t want to further muddy the waters but there is an elevator AD on the 767 relating to some shear pins, that are designed to break if the elevators become jammed. This action allows the others actuators to work and control the elevator. It is stated in the AD that some of the same shear pins were found broken and disconnected from the system, so an AD was issued mandating inspections.

https://www.federalregister.gov/agen...administration

The loss of three shear pins renders the aircraft uncontrollable in pitch.

EuroNato100 26th Feb 2019 14:37


Originally Posted by fire wall (Post 10399254)
Out of respect for those fine men/women deceased can those of you that have no clue what you are talking about please shut up.

Having flown the 767 for 11 yrs there was NEVER a speed restriction on the windows. That restriction belonged to the 757 and was 313 kts below 8000 ft.
That is negated by the FAA restriction of 250/10000' so anyone of you fly by night self appointed rocket scientists should know that....including you morons at CNN who couldn't tell the difference between the two.
As for WX, BS. I've been going into IAH for close on the last 12 years in the whale and that minor convective signature doesn't cause that ROD.
Why don't you muppets stop embarrassing yourselves and give the professionals a go....ie the NTSB ?

BRAVO... at last someone speaks up in order to STOP the crap !!!!!

B2N2 26th Feb 2019 14:38


Originally Posted by mryan75 (Post 10401005)


God i wish this forum required a pilot certificate number for registration. Or an IQ test.

Amen ^^^
Asking legitimate intelligent questions is ok but if you’re not an industry professional please stay the hell away from commenting on this thread or any other crash.

Less Hair 26th Feb 2019 14:42

Something like this:
https://www.airbus.com/newsroom/pres...rs-for-it.html


All times are GMT. The time now is 11:41.


Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.