Atlas Air 767 down/Texas [Archive]

Carbon Bootprint

23rd Feb 2019, 21:01

According to local witness it weather was good at the time of the accident?

Though it was very foggy this morning with a rather violent front forecast to come through, the fog would have lifted by the time of the crash. I live a few miles NE of IAH on the approach to 26R and the front was never as bad as predicted. It was actually much nicer than expected here, though I acknowledge that weather from one side of the Houston metro area to the other can vary quite considerably. However, the Chambers County Sheriff just gave a press briefing where he stated several witnesses in boats and at a nearby park had stated that the plane basically nose-dived into the bay. He stated surface visibility as good and weather was not reported as an issue.

Aerial pictures of the site show a pretty sizable debris field with not many large pieces visible. The largest piece I've seen was what appeared to be a portion of the vertical stab with the right side of the Amazon logo. The water is murky, five feet deep max with plenty of shallow mud marsh. This is going to take a while to piece together. The sheriff said Chambers County will make their hangar available to NTSB and have offered a building in the park near the scene for use as a command center.

fdgolf

23rd Feb 2019, 21:02

Looks like an in-flight break up.
Condolences to families.
RIP

Longtimer

23rd Feb 2019, 21:13

Debris Field.
https://www.foxnews.com/us/cargo-plane-carrying-at-least-3-people-crashes-in-texas-bay-officials-say (https://www.foxnews.com/us/cargo-plane-carrying-at-least-3-people-crashes-in-texas-bay-officials-say)

RoyHudd

23rd Feb 2019, 21:25

In-flight break-ups are almost unheard of, especially at a relatively low airspeed when level or in a shallow descent. And the 767 is a tough old bird.

Other possibilities exist, but the FDR and CVR should give an explanation. Adverse Wx unlikely to cause such a dive.

wrench1

23rd Feb 2019, 21:33

aircraft's final left turn doesn't seem to follow the standard approach,
Local rumor is the flight was being directed around area of heavy/extreme precipitation prior to lost contact. There is also supposedly a LiveATC tape out of the flight. A bad day for all.

The Bartender

23rd Feb 2019, 21:50

ATC audio on youtube. Accident apparently around 9:00.

https://youtu.be/B790C0IO2kY

Hotel Tango

23rd Feb 2019, 21:52

Looks like an in-flight break up.

I have to say that I find that a very strange statement to make at this point, even coming from a Canadair CL605 pilot.

CorpJetJock

23rd Feb 2019, 21:54

one of last transmissions was a male voice with an accent requesting deviation 'west' (of the cell I assume), and ATC said no, so they said they would deviate East. This is from FlightRadar 24 and shows last radar reply and crash site.

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/1195x657/atlas3591_6eb5d49848fe373924bbf627f7e87ad62ebc1b21.jpg

short bus

23rd Feb 2019, 22:46

Load shift?
Amazon stuff isn't usually too heavy, but maybe a pallet/container broke loose and started a cascade.

fdr

23rd Feb 2019, 22:49

Small package freight debris is going to be dispersed rapidly by wind and current, and a full analysis of their location and time since event would be needed to work out whether they have been liberated in flight. The B767 has had only two in flight events with a rapid descent to impact; Lauda 004 and Egypt Air 990. Lauda was from a structural failure resulting from uncommanded TR deployment on the LH PW4060 engine, resulting in overload of the vertical stab, and a torsional failure of the tail and a rapid overload in negative g of the wings. Egypt Air was.... disconcerting and remains disputed along national lines. The event timeline however is compelling and similar events have occurred far too often in the industry. The B767 has had it's fair share of AD's on the stabiliser and the attachment structure going back more than 20 years. The CF6 engine on the 76 has had it's fair share of uncontained failures. Gust front related overload is raised due to the existing weather that was being avoided/penetrated, but would not by itself have led to an overload of the system, and 18 years after AA587 the industry is more aware of the impact of rudder doublets. The debris trail of large components will be telling.

R.I.P.

EternalNY1

23rd Feb 2019, 22:50

Absolutely no comms, not even a "mayday", so it seems something happened fast and/or they had their hands full.

Wondering about a possible mid-air but it's all speculation at this point.

ironbutt57

23rd Feb 2019, 23:00

Absolutely no comms, not even a "mayday", so it seems something happened fast and/or they had their hands full.

Wondering about a possible mid-air but it's all speculation at this point.

sudden sharp dive could indeed indicate some occurrence with the horizontal stab/elevators, or even a crewmember falling onto the controls.

SliabhLuachra

24th Feb 2019, 00:58

Forgive me, but am I hearing things at 2:33 here? Is there somebody shouting ''pull''?

https://youtu.be/rRirRCh3Xts

patrickal

24th Feb 2019, 01:28

.....
4.It appears something sudden occurred that prevented even a Mayday call.

As opposed to the ridiculous supposition of a possible suicide, a more likely possibility would be a multiple bird-strike through the windscreen. But this is all guessing way ahead of the curve. What we do know for sure is that several families suffered an unimaginable loss today, and they need our thoughts and prayers more than anything else right now.

Machinbird

24th Feb 2019, 01:42

Anyone have an idea what was in the cargo?
Atlas advertises that they can handle outsize cargo. Was it just Amazon cargo or a commercial mix?

peterarmitage

24th Feb 2019, 01:47

if you saw the large numbers, and sizes, of the pelicans that show up in front of my home on Lake Houston, you would easily imagine a bird or two strike on the screen by a couple of those things could incapacitate both front seat occupants.

scallop

24th Feb 2019, 01:48

Is it too high for a drone ?

Technically, no. But unlikely for several reasons.

Vast majority of consumer drones technically capable of that altitude are factory geofenced to 400 ft AGL with some effort required to “jail break.”
Vast majority of consumer drones are 2-3 lbs, compared to an eagle weighing 6-14. Guaranteed to cause damage, but fairly unlikely to cause catastrophic damage.
Most people would not fly a drone around a line of storms, since most of them aren’t rain proof.
Bigger drones are more expensive and more likely owned and operated by licensed pros who could and would likely get a waiver, COA or 333 if they needed to be in that spot, meaning ATC would be in the loop and routing folks around them.

So it’s not impossible for a drone to be up there, but it’s unlikely. And it’s very unlikely for one big enough to cause catastrophic damage to be up there.

tdracer

24th Feb 2019, 01:58

Anyone have an idea what was in the cargo?
Atlas advertises that they can handle outsize cargo. Was it just Amazon cargo or a commercial mix?

Amazon primarily uses their freighters to move relatively large shipments between their distribution centers, then sends the stuff out from their distribution centers via local services do the deliveries.
Amazon sells a lot of personal electronics (think Li batteries) hence my initial thought of maybe a cargo fire - but as I noted that's not likely given how suddenly what ever happened must have happened.

ironbutt57

24th Feb 2019, 02:17

Perhaps the workload during the descent for landing and the intermediate altitude presented the greatest likelihood of non recovery of the dive (by the other pilot) while still being high enough to ensure total destruction of the aircraft on impact.

Its either that or alternatively some never before seen sudden and catastrophic structural failure in an elderly and probably high number of cycles aircraft. Probably the change in pressure from 10,000m to 5,000m was exactly the point at which a failure induced by the change in cabin pressure might take place?

cabin pressure would have been reduced to very little at this stage of the flight..who's to know..everybody only guessing at this point, and there is no "sudden change" normally in the pressurization of the aircraft, the system brings it down at nice comfortable 350-500 feet per minute...wait and see...hope it had a new enough DFDR to give good information...

wjcandee

24th Feb 2019, 02:50

FAA has it listed as registered to Andromeda Leasing LLC

That's an aircraft leasing subsidiary of Atlas. Amazon Air dry-leases the aircraft from an Atlas subsidiary and hires Atlas pursuant to a CMI (crew, maintenance, insurance) agreement to fly, insure and maintain it.

wjcandee

24th Feb 2019, 03:05

Amazon primarily uses their freighters to move relatively large shipments between their distribution centers, then sends the stuff out from their distribution centers via local services do the deliveries.
Amazon sells a lot of personal electronics (think Li batteries) hence my initial thought of maybe a cargo fire - but as I noted that's not likely given how suddenly what ever happened must have happened.

Actually, it works this way: (1) customer places order; (2) algorithm determines which DC(s) are going to contribute product to the order, based on a number of factors; (3) box containing material for a specific customer is prepared at each necessary DC; (4) an algorithm determines, for that day, what the best way to send it to that specific customer is (organic Amazon, FedEx, UPS, Ontract, Lasership, etc.); (5) package leaves DC. If it's going to be riding Amazon Air, it goes to the departure airport, where it is built into a mil-style pallet with a cargo net over it (if the flight is not going through CVG) or put into a can (if the flight is going through CVG, where the cans will be unloaded, the packages sorted, and the packages placed in cans for the flight to the destination airport); this may have changed by now as Amazon cans proliferate. The cans or pallets are loaded on the aircraft. At the destination airport, the packages are trucked to an Amazon "sort center" (formerly called an Amazon "postal sort center", PSC), such as Avenel, NJ. There, the air shipments are run through the center along with ground shipments that have been truck line-hauled by Amazon contractors from closer DCs than this package's DC was. The packages are sorted at the SC for last-mile delivery either by the USPS (biggest provider of last-mile for Amazon-organically-line-hauled packages), by a local carrier like Lasership/Ontrack, or more recently by Amazon-hired local delivery contractors or even by AmazonFresh when those trucks are first moving into an area. If it's going to USPS, Amazon-contracted delivery takes it to the injection point, which is usually the DDU (Destination Delivery Unit, meaning the local post office), and the local mailman takes it from there. The USPS doesn't usually touch it until it is dropped by Amazon at the DDU, although in some places with lighter volume it might get injected at the three-digit-zip destination regional center, called the SCF (sectional center facility), with USPS handling it from there.

So what goes on the planes is thousands of to-the-consumer Amazon packages for which Amazon Air is just one of several potential shipment options. At the other end, they get delivered by USPS or Amazon-contracted delivery.

If I didn't say it earlier, it's Amazon's dry-leased plane. Nobody but Amazon gets to put anything on it. Atlas doesn't get to use it for anything other than Amazon Air flights without express permission from Amazon, which as a practical matter they're not going to receive.

If it's going to go by UPS or FedEx, those guys put it into their own network near the origin DC and keep it on their network all the way until they hand it to the consumer (except to the extent Amazon ever uses FedEx SmartPost (a horrible service that I think they avoid) or UPS Surepost (which is a better service that plans for the package to be delivered by UPS to the local destination post office for last mile, adding a day, but which often ends up with the package staying on the UPS network all the way to the consumer if they're going to be delivering nearby that day).

wjcandee

24th Feb 2019, 03:30

Forgive me, but am I hearing things at 2:33 here? Is there somebody shouting ''pull''?

Sorry but I don't hear it even with the headphones turned up to 11.

FIRESYSOK

24th Feb 2019, 03:37

Sorry but I don't hear it even with the headphones turned up to 11.

Hard to say. At that “okay” transmission there is definitely something. Perhaps a “whoa” or “oh”; perhaps nothing but an artifact on the file- bleed through, etc.- that coincides.

visibility3miles

24th Feb 2019, 03:39

30,000 fpm is 341 mph

wheels_down

24th Feb 2019, 03:39

Can faintly hear something in the background. Pull or oooo sound....something was up.

log0008

24th Feb 2019, 03:44

I can't here anything other than 'ok' however that ok too seems to be in a different tone compared to the other transmissions, very rapid response.

I've had a listen to the original Liveatc audio and can't hear it there either, however this transmission was less than 60 seconds prior to the first "Giant 3591 Houston Approach?"
At 8.35 on the audio file is the ok message, the atc request is at 9.25, the first ELT request at 10.05. Would interesting to know if the first "Giant 3591 Houston Approach?" was because the control had lost the aircraft on radar or because he noticed it was in a dive/descending below assigned alt.
http://archive-server.liveatc.net/kiah/KIAH-App-Feb-23-2019-1830Z.mp3

extreme P

24th Feb 2019, 04:00

As opposed to the ridiculous supposition of a possible suicide, a more likely possibility would be a multiple bird-strike through the windscreen. But this is all guessing way ahead of the curve. What we do know for sure is that several families suffered an unimaginable loss today, and they need our thoughts and prayers more than anything else right now.

Has a Boeing windscreen ever been penetrated by a bird?

wjcandee

24th Feb 2019, 04:03

Running of the FR24 track the aircraft's final left turn doesn't seem to follow the standard approach, which aircraft immediately following it did.

Your altitude graph was interesting. Those blips upward are most likely a function of an FR24 / Flightaware characteristic where the data set records the assigned altitude for a return or two before returning to the reported altitude. Most likely the path is smooth along that plot until the last moments where it falls off a cliff.

FIRESYSOK

24th Feb 2019, 04:17

The accident site seems to be near the RDFSH waypoint which would be flown to in the event of runway 27 transition, however they were given the runway 26L transition by ATC at some point which should have been a more northerly track toward GARRR waypoint.

An altitude constraint of 6000’ would coincide with the RDFSH (RWY27) ‘transition’ at 210 knots published speed. I’d be curious to see a map-position/speed/altitude plot for the last part of the flight. Things could have gotten a little discomposed if the plane flew something unanticipated. The turn could have also been a vector I didn’t hear on the tape, etc., etc.

Godspeed, men. Terrible day indeed.

TRW Plus

24th Feb 2019, 04:37

Weather situation looked challenging and will probably be found to be major contributor. Cold front with sharp wind shift reported at both Houston-Pearland and Galveston around time of incident. Above this low-level wind shift, strong low level jet from SW. Likely some severe turbulence and erratic winds in vicinity of sharp right turn made when left turn denied. Reports of "good weather" in area also credible as these conditions confined to immediate vicinity of the cold front and radar echoes. A few miles either side partly cloudy and warm, not overly windy at surface. Could even be a lightning strike on the fuselage contributing to this unfortunate outcome.

alcan60283

24th Feb 2019, 04:50

I distinctly hear the sound of the word "Pull" from the GPWS system, and I think I hear the stick shaker going off too at 2:33 of the video

I took the snippet and slowed it down quite a bit, and repeated the bits. I have also separated the "OK" from the noise that proceeds it. You can clearly hear the lack of background noise on the OK portion, and then what sounds to me like the gpws "PULL" sound and maybe the stick shaker??!!

https://soundcloud.com/jcamp2112/atlas-air-atc-recording-slowed

Homebrew1

24th Feb 2019, 05:01

I distinctly hear the sound of the word "Pull" from the GPWS system, and I think I hear the stick shaker going off too at 2:33 of the video

Same here, I put the Bose noise cancelling headset on and turned them right up. You can here "pull' very faintly in the background instantly after the crew member says "OK". Could well be from an EGPWS.

lpvapproach

24th Feb 2019, 05:41

I dont hear GPWS also the link arrival there is no way at that point he would be low enough for a GPWS right after he was calmly discussing going east or west with ATC.

Did anyone consider an explosion howsoever caused.

Capvermell

24th Feb 2019, 05:59

Has a Boeing windscreen ever been penetrated by a bird?

I didn't think birds could fly that high but apparently some can all the way up to normal cruising altitude for a commercial jet.

See https://en.wikipedia.org/wiki/List_of_birds_by_flight_heights

Although personally I still feel this aircraft's age may have more to do with the sudden failure in question. I wonder if anyone has yet discovered the number of hours or cycles it had flown and/or any details of any previous accident damage repairs undertaken?

Sqwak7700

24th Feb 2019, 06:10

Would be interesting to see the Flightradar24 tracks of aircraft on that same arrival, right before and right after Atlas’ crash. When all the tracks are overlaid it could possibly rule out weather if the tracks match.

On the the other hand, if Atlas’ track was very different than other aircraft deviating in the area immediately prior and after the crash, that could signal that they encountered quite different flight conditions than those other aircraft.

GordonR_Cape

24th Feb 2019, 06:12

Although personally I still feel this aircraft's age may have more to do with the sudden failure in question. I wonder if anyone has yet discovered the number of hours or cycles it had flown and/or any details of any previous accident damage repairs undertaken?

Yes, its already on Wikipedia: https://en.wikipedia.org/wiki/Atlas_Air_Flight_3591

According to FAA records, the airframe had accumulated more than 90,000 hours over 23,000 flights prior to its hull loss.

Edit: Not sure if this has been discussed/eliminated as a potential issue: Wikipedia and https://www.federalregister.gov/documents/2014/01/27/2014-01433/airworthiness-directives-the-boeing-company-airplanes
In January 2014, the US Federal Aviation Administration issued a directive that ordered inspections of the elevators on more than 400 767s beginning in March 2014; the focus is on fasteners and other parts that can fail and cause the elevators to jam. The issue was first identified in 2000 and has been the subject of several Boeing service bulletins. The inspections and repairs are required to be completed within six years.

ironbutt57

24th Feb 2019, 08:04

I distinctly hear the sound of the word "Pull" from the GPWS system, and I think I hear the stick shaker going off too at 2:33 of the video

I took the snippet and slowed it down quite a bit, and repeated the bits. I have also separated the "OK" from the noise that proceeds it. You can clearly hear the lack of background noise on the OK portion, and then what sounds to me like the gpws "PULL" sound and maybe the clacker??!!

https://soundcloud.com/jcamp2112/atlas-air-atc-recording-slowed

what "clacker", it has an aural alarm..very distinctive

fdgolf

24th Feb 2019, 08:37

I have to say that I find that a very strange statement to make at this point, even coming from a Canadair CL605 pilot.

I guess I went too far and gave the wrong wording. I ment to say something flight control issues. Apologies out there.
At 6000' cabin pressure is no longer an issue.

Livesinafield

24th Feb 2019, 08:40

Can hear something in the background of the "OK" transmission, it sounds like an automated voice, it does sound like PULL but it could just be a bit of confirmation bias

westhawk

24th Feb 2019, 08:55

As usual on the first day following a major crash, the speculation outruns the factual information. There are several more possible failure scenarios not yet mentioned here which could have caused this apparent loss of control. I thought of quite a few myself in the first moments after reading the first couple of news reports. But I see little point in sharing them until there's at least some factual basis, however small, upon which to build theories as to the sequence of events which led to this crash.

I'm not satisfied to simply "wait for the report" either. However these things often take a little time to develop into the basis for informed speculation. When time-synced, the ATC radar and com recordings will provide some early clues. Examination of recovered wreckage may also reveal investigative paths to be further pursued. Finding the CVR and FDR is going to be a high priority in the early stages for obvious reasons.Finding them In the mud beneath 5 feet of water may present some challenges, but it's been done before. (in the Everglades at least twice that I know of)

So fear not, in due course enough facts will emerge to facilitate informed speculation. Until then I have no basis to eliminate either any of my own or anyone else's pet theories. This is a normal circumstance.

Bend alot

24th Feb 2019, 08:56

Boeing have built aircraft for a couple of years now, so I expect they have a clue on how long they last before problems set in.

I expect and the manufacturer that the "average" flight of a B767 to be much greater than 2 hours. So if the manufacture says 50,000 cycles (flights) is the limit, then we are talking way over 100,000 flight hours. But they are not concerned on hours - why are you?

tubby linton

24th Feb 2019, 09:24

Has a Boeing windscreen ever been penetrated by a bird?
I am not aware of one.
The UK CAA put a restriction on maximum speeds at lower altitudes on the Boeing 757 aircraft due to a perceived weakness of the centre windshield pillar though. I do not believe it applied to the B767.

bnt

24th Feb 2019, 10:28

Report from KHOU including eyewitness reports. They say the plane was low and then nosedived. The area where it crashed is shallow and muddy, with police working to ensure nothing is moved before the NTSB arrives today.

qrGwR7aAuUI

Rory166

24th Feb 2019, 10:43

Forgive me, but am I hearing things at 2:33 here? Is there somebody shouting ''pull''?

https://youtu.be/rRirRCh3Xts

It is on the subtitles but all I hear is OK

FIRESYSOK

24th Feb 2019, 10:46

There is something there, no doubt. I think it’s likely some ambient noise/comment rather than any kind of GPWS call-out. But it does, with a good set of cans on, sound quite similar to that played at normal speed.

DaveReidUK

24th Feb 2019, 11:21

The FR24 data, as usual, contains numerous artifacts and synchronisation issues.

That said, once cleaned up it appears to show a slight but unmistakeable climb interrupting the descent just before reaching 6000', starting about 10 seconds before the beginning of the final dive.

It's exaggerated, obviously, in this foreshortened view (apologies for the skewed verticals):

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/464x592/5y3591a_a42ad9ae66c288d28615ee0d9c5146acd45a5f99.jpg

Council Van

24th Feb 2019, 12:00

The UK CAA put a restriction on maximum speeds at lower altitudes on the Boeing 757 aircraft due to a perceived weakness of the centre windshield pillar though.
That restriction no longer applies.

Bobman84

24th Feb 2019, 12:39

First fatal loss of a B767 on US soil since the 2001 NY events and worldwide since 2002.

Very lucky it didn't hit a mile out from the bay where the town is. RIP to the lost souls on board.

DaveReidUK

24th Feb 2019, 12:47

Very little evidence until we have FDR results but the sudden dive following a climb looks suspiciously like a possible stall.

I did warn that the previous plot was foreshortened ...

Here it is in profile:

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/864x362/5y3591b_e290b6503f2a3b1b611bc6e3678921233159755e.jpg

Does that help ?

gulliBell

24th Feb 2019, 12:53

I don't know if this has been mentioned earlier, but I'm curious why there doesn't seem to be much fuel on the water in the vicinity of the crash site.

alcan60283

24th Feb 2019, 13:15

Of course exactly what is heard on that clip is up to interpretation, but I think what is clear to me is something happened right after he said ok, because the cockpit goes from quiet to cacophony right after he finishes the word. I anxiously await the CVR transcript. So sorry to all those involved, crappy day for aviation that's for sure.

Doesn't the 767 have a stick shaker? If I remember right, they are awfully loud, and sound similar to what I hear on the tape there.

b1lanc

24th Feb 2019, 14:11

I don't know if this has been mentioned earlier, but I'm curious why there doesn't seem to be much fuel on the water in the vicinity of the crash site.

Interesting - crossed my mind while looking at the news chopper video.

Comment from Chambers County Sheriff Brian Hawthorne"

"The environmental impact is extremely minimal as very little fuel, if any, spilled on the water, Hawthorne said."

fire wall

24th Feb 2019, 14:25

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 ?

Sailvi767

24th Feb 2019, 14:28

I don't know if this has been mentioned earlier, but I'm curious why there doesn't seem to be much fuel on the water in the vicinity of the crash site.

With the weather in the area you would expect that were arriving with at least 16,000 lbs of fuel. That would put 8000 in each wing with the center empty. That’s only about 1200 gallons a side. Fuel actually dissipates pretty fast in salt water. Most slicks you see are when fuel is leaking from a small rupture. If the tanks were mangled and all the fuel released at once the fuel would be miles away in a hour and dissipate pretty quickly.

icemanalgeria

24th Feb 2019, 15:04

Out of respect for those fine men/women deceased can those of you that have no clue what you are taling 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 (tel: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 signiture doesnt cause that ROD.
Why dont you muppets stop embarrasing yourselves and give the professionals a go....ie the FAA ?

I flew B763 from 1995 till 2018 ( now 789 ) we had restriction on 763 below 8000 313kts ( European Aircraft ).

FIRESYSOK

24th Feb 2019, 15:07

Sailvi, long time since I have flown the twin. 16 k is dfw plus 30 on the 6?

Plus 30 minutes? What regulatory fuel requirement are you referencing here?

Sailvi767

24th Feb 2019, 15:09

Sailvi, long time since I have flown the twin. 16 k is dfw plus 30 on the 6?

Not quite sure what your saying. 16,000 was typical for a arrival with a alternate that was close and suitable. If convective activity in TX was widespread I would personally want a bit more.

FIRESYSOK

24th Feb 2019, 15:12

who said anything about regulatory requirements?
Amateur hr continues.

Please explain what you meant by ‘DFW plus 30’

Tetsuo

24th Feb 2019, 15:18

Please explain what you meant by ‘DFW plus 30’
It seems he means diversion to Dallas Fort Worth plus 30 minutes flight time.

FIRESYSOK

24th Feb 2019, 15:31

It seems he means diversion to Dallas Fort Worth plus 30 minutes flight time.

Thanks. I’m just wondering where his 30-minute fuel supply -after alternate- fits in to this discussion. Maybe someone can enlighten me.

Tetsuo

24th Feb 2019, 15:58

Thanks. I’m just wondering where his 30-minute fuel supply -after alternate- fits in to this discussion. Maybe someone can enlighten me.

If you follow the posts above, at post #65 or so it was brought to attention that there seems to be no (or very little) fuel spillage around the crash site. Following that conversation Sailvi767 mentioned that with that type and the weather around the time of the crash, he would expect the plane to carry about 16000 lbs of fuel at the time of the crash and went on to explain this might not cause a big spill. Fire wall asked whether 16000 lbs on 767 would be enough for a diversion plus 30 minutes. Sailvi767 replied that he would prefer a bit more in those conditions.

Sorry everyone for adding 0 value to discussion by this post.

Airbubba

24th Feb 2019, 16:01

Thanks. I’m just wondering where his 30-minute fuel supply -after alternate- fits in to this discussion. Maybe someone can enlighten me.

For a domestic Part 121 flight here are the fuel requirements:

§ 121.639 Fuel supply: All domestic operations.

No person (https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=24a80ca42ed148d527b7ddad982da95a&term_occur=1&term_src=Title:14:Chapter:I:Subchapter:G:Part:121:Subpart:U: 121.639) may dispatch or take off an airplane (https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=ee9803083700896cd85aff74cb4f95ea&term_occur=1&term_src=Title:14:Chapter:I:Subchapter:G:Part:121:Subpart:U: 121.639) unless it has enough fuel -

(a) To fly to the airport (https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=48135f7b500227b0896c0a3bae41467a&term_occur=1&term_src=Title:14:Chapter:I:Subchapter:G:Part:121:Subpart:U: 121.639) to which it is dispatched;

(b) Thereafter, to fly to and land at the most distant alternate airport (https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=39f8362bad2de59a09d5b716b71c2650&term_occur=1&term_src=Title:14:Chapter:I:Subchapter:G:Part:121:Subpart:U: 121.639) (where required) for the airport (https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=48135f7b500227b0896c0a3bae41467a&term_occur=2&term_src=Title:14:Chapter:I:Subchapter:G:Part:121:Subpart:U: 121.639) to which dispatched; and

(c) Thereafter, to fly for 45 minutes at normal cruising fuel consumption or, for certificate holders who are authorized to conduct day VFR (https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=89ef57ffe626edb2df5bf10d8ab4f876&term_occur=1&term_src=Title:14:Chapter:I:Subchapter:G:Part:121:Subpart:U: 121.639) operations in their operations specifications and who are operating nontransport category airplanes (https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=ee9803083700896cd85aff74cb4f95ea&term_occur=2&term_src=Title:14:Chapter:I:Subchapter:G:Part:121:Subpart:U: 121.639) type certificated after December 31, 1964, to fly for 30 minutes at normal cruising fuel consumption for day VFR (https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=89ef57ffe626edb2df5bf10d8ab4f876&term_occur=2&term_src=Title:14:Chapter:I:Subchapter:G:Part:121:Subpart:U: 121.639) operations.

Jeff05

24th Feb 2019, 16:02

Thanks. I’m just wondering where his 30-minute fuel supply -after alternate- fits in to this discussion. Maybe someone can enlighten me.

Refers to 30 minutes final reserve holding at 1500 above alternate (or destination if alternate not required). This must be intact on landing.

May be slightly different in FAA land (I have only flown reciprocating engine aircraft under FAA rules) but those are the ICAO requirements for jets.

Thoughts with the families and friends of the victims at this awful time.

tdracer

24th Feb 2019, 16:45

I am not aware of one.
The UK CAA put a restriction on maximum speeds at lower altitudes on the Boeing 757 aircraft due to a perceived weakness of the centre windshield pillar though. I do not believe it applied to the B767.
The windscreen and surrounding structure is common between the 757, 767, and 777, and I'm not aware of any windscreen penetrations on any of those types.
However there is still a risk with large birds - during the development of the 757-300 and 767-400ER, it was determined there was a vulnerability with the forward bulkhead - a large enough bird could penetrate into the flight deck. I don't know if the requirements changed after the initial 757/767 cert, or it was due to better analysis tools, but the bulkhead had to be beefed up in some areas. I'm reasonably sure it was never retrofit.
90,000 hours is not that old for a 767 - even before I retired I was aware of several passenger 767s that had more than 100,000 hours and were still going strong.

49d

24th Feb 2019, 17:08

odd that the rate of descent increased but airspeed seems to have stayed at 240...

FIRESYSOK

24th Feb 2019, 17:24

Refers to 30 minutes final reserve holding at 1500 above alternate (or destination if alternate not required). This must be intact on landing.

May be slightly different in FAA land (I have only flown reciprocating engine aircraft under FAA rules) but those are the ICAO requirements for jets.

Thoughts with the families and friends of the victims at this awful time.

This is a FAR121-Supplemental operating a flag (domestic) flight. So the 45-minute RSV applies, not 30min.

Why they leveled at ~6000’ for a time and tracked West toward a different transition waypoint than other arrivals is curious to me more than a critical fuel status, but stranger things have happened. That said, those wouldn’t have been causal, but perhaps a significant link. I stand by my ‘amateur-hour’ speculations and don’t feel they detract from the discussion.

RIP, fellas.

Farrell

24th Feb 2019, 17:25

odd that the rate of descent increased but airspeed seems to have stayed at 240...
How do you know this?

Jeff05

24th Feb 2019, 17:36

This is a FAR121-Supplemental operating a flag (domestic) flight. So the 45-minute RSV applies, not 30min.

Why they leveled at ~6000’ for a time and tracked West toward a different transition waypoint than other arrivals is curious to me more than a critical fuel status, but stranger things have happened. That said, those wouldn’t have been causal, but perhaps a significant link. I stand by my ‘amateur-hour’ speculations and don’t feel they detract from the discussion.

RIP, fellas.th

Thanks for the correction/clarification - good to know.

PJ2

24th Feb 2019, 17:40

Thanks. I’m just wondering where his 30-minute fuel supply -after alternate- fits in to this discussion. Maybe someone can enlighten me.
A discussion about fuel load is a sidebar perhaps of technical interest. Even given what is known at this point, I doubt that it figures in terms of cause.

CONSO

24th Feb 2019, 17:43

The windscreen and surrounding structure is common between the 757, 767, and 777, and I'm not aware of any windscreen penetrations on any of those types.
However there is still a risk with large birds - during the development of the 757-300 and 767-400ER, it was determined there was a vulnerability with the forward bulkhead - a large enough bird could penetrate into the flight deck. I don't know if the requirements changed after the initial 757/767 cert, or it was due to better analysis tools, but the bulkhead had to be beefed up in some areas. I'm reasonably sure it was never retrofit.
90,000 hours is not that old for a 767 - even before I retired I was aware of several passenger 767s that had more than 100,000 hours and were still going strong.

FWIW- The initial 767 cockpit was designed for 3 crew- but with the then onset of two crew- additional rerouting of several systems ( eg hydraulics and switches rerouting ) About that time the chicken cannon was brought into play ( firing a frozen chicken from an air cannon into a partial cockpit structure to determine windscreen and ' skull cap ' strengths). Forget the weight and speeds involved ..
The result was that the ' skull cap' above the windscreen and the window framework had to be redesigned mostly with titanium. The skull cap cuz some important switches and valves were located there and damage or loss could cause major flight control issues- but still had to be within reach of pilot and copilot..

While the first one or two flyable 767.s built may not have had the rework, I am sure all the rest had that redesign.

WhatsaLizad?

24th Feb 2019, 17:44

Havingwings4ever

24th Feb 2019, 17:51

Airframetime should't be issue, our 76-3 were the first to exceed 100k worldwide according to our airline and recieved an extension to 150k with an adapted maintenance program. Planes still flew fine:)

DaveReidUK

24th Feb 2019, 17:53

About that time the chicken cannon was brought into play ( firing a frozen chicken from an air cannon into a partial cockpit structure to determine windscreen and ' skull cap ' strengths).

I thought it was only the Air Force that supposedly forgot to defrost the birds before the test ... ?

CONSO

24th Feb 2019, 18:10

tdracer said ..90,000 hours is not that old for a 767 - even before I retired I was aware of several passenger 767s that had more than 100,000 hours and were still going strong.
One subtle reason for the very long fatigue life of the 767 and related was the extensive use of two Boeing devlopd processes. One being a technique called ' coldworking " details of which can be found in manuals, info provided by Fatigue Technology ( http://www.fatiguetech.com/ ) (http://www.fatiguetech.com/) developed in the late 60's by Lou Champoux ( next to my desk ) at the time.. In simple terms, bypushing/pulling a mandrel thru a sleeve inserted in the hole - or a special mandrel without a sleeve, the hole stretches leaving the nearby surrounding material in tension, which then results in major fatigue improvement. This techniques was used on main spars, lower wing panels, parts of wing box and some parts of fuselage, etc.

The second process also ' first ' used on major spar assembly was/is called ElectroMagneticRiveting - which uses magnetic drivers to drive and expand a rivet in ONE blow, which also has a major effect on fatigue life. Although the process had been used on smaller parts/assemblies since early 747 days, the use on major spar assembly was a first on 767. The machine was known as ASAT automatic assembly tool. That also was the founding of a company used around the world as improved and further developed by a company called Electro Impact - whos major facility is next to Boeing Everett. They have branched out since then with major wing composite layup for 777X. And no - I do not and have not worked for ElectroImpact or Fatigue Technolocy but have had many personal contacts/background with those involved in both companies over the years.

CONSO

24th Feb 2019, 18:20

I thought it was only the Air Force that supposedly forgot to defrost the birds before the test ... ?

details- details- A careful check will reveal the particulars- as to just how much frozen the birds, turkeys, etc were at time of launch/firing- I did not fbeleive it was necessary to define/explain the exact test parameters. And birds have been found to impact jets at altitudes well over 15,000 feet.
My point was to SIMPLY explain the test used to detrmine design parameters, I'm sure the FAA an various wildlife protection agencies can explain why chickens and turkeys instead o geese, etc.

see also

https://www.youtube.com/watch?v=sCQ2oZtVNpg

PJ2

24th Feb 2019, 19:02

Birds have penetrated the forward bulkhead in front of the cockpit of a 767-300 at least once before. Medium sized birds blasted through it on one flight, fortunately missing the Captain but sending blood, guts and feathers against the aft left wall of the cockpit.

https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/450x600/i_zn8jxq2_l_13979ce95d78c118d98afcba857a78aae17f7b80.jpg https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/600x450/i_mhgfjzh_m_44f1bdf139c4d0da98fbea45766b49d2b7f0661c.jpg

neilki

24th Feb 2019, 19:03

Refers to 30 minutes final reserve holding at 1500 above alternate (or destination if alternate not required). This must be intact on landing.

May be slightly different in FAA land (I have only flown reciprocating engine aircraft under FAA rules) but those are the ICAO requirements for jets.

Thoughts with the families and friends of the victims at this awful time.

I'm pretty sure the fuel thing is a red herring; but under 14CFR Part 121 there is no requirement to land with a specific amount of fuel.
The aircraft must be dispatched with a planned amount of fuel on landing. If you burn it all without declaring a problem to ATC and your dispatcher that's a violation; but it's a planning requirement only.

Its Atlas. As well as the Amazon 767 s they operate the worlds largest 747 fleet. 400s & -8's. They know what they're doing.

aircarver

24th Feb 2019, 19:06

The Mythbusters admitted their early 'chicken gun' tests on a Cherokee were akin to testing cardboard with a .357 magnum ....

lomapaseo

24th Feb 2019, 19:20

fox niner

24th Feb 2019, 19:22

Instead of speculating, you might want to watch the ntsb press conference at 2200Z.

https://mobile.twitter.com/NTSB_Newsroom

Joejosh999

24th Feb 2019, 19:43

What starts a sudden, rapid nose-over followed by an uncorrected, steep descent in which there were no previous non-normal communications or other indication of trouble on a proven type operated by an experienced carrier?

...jammed stab? Trim runaway?

Agent1966

24th Feb 2019, 19:59

I heard it....very faint.

Old Boeing Driver

24th Feb 2019, 20:04

Remember the B-737 rudder hard-over issues?

Does anyone here know of any similar issues/instances on the B-767?

Marty33

24th Feb 2019, 20:29

My GUESS is that something bent, broke or jammed under weather induced maneuvering loads. RIP Giant.

tvasquez

24th Feb 2019, 20:40

Tim Vasquez, meteorologist in Texas here... weather data analysis is what I do for a living, and some of you may remember me from the Air France 447 study (http://www.weathergraphics.com/tim/af447/) about 10 years ago.

Regarding the 767 crash in Houston, a lot of images seem to be floating around that use default radar mosaics. These are problematic as they're focused on higher intensity levels, they are not very granular, they often carry an ambiguous scan time, and they're often built from composite products which are the result of multiple scans rather than a single scan. This makes it very difficult to use such data except to define the basic environment. In fact, I initially didn't think much of weather being a factor based on the preliminary images I saw. However I went ahead and accessed the raw WSR-88D base data files, which are for a single level and accurate to within about 1 minute, and I found some interesting stuff.

First of all, one caveat with these images: the ones I've posted here are built from 0.5-deg scans, which were underneath the 767 at a beam center altitude of about 2000-2500 ft and a beam width of about 2000 ft. I used these because there are usually a lack of scatterers at the higher tilts, and most of the convective circulations we see above 5000+ ft are initially generated near the surface. So there are indeed some assumptions about what is going on up at 5000 ft, where the problem presumably started. Time stamps are based on the FlightAware track log (https://flightaware.com/live/flight/GTI3591/history/20190223/1608Z/KMIA/KIAH/tracklog), which comes straight from the ASDI feed. My assumption is these times are accurate. Sorry for the watermarks, I got burned back in 2009 by the media reprinting my diagrams commercially without permission.

A couple of conclusions:

* A textbook gust front is clearly shown within 3 nm of the crash site. This correlation is definite and is striking.

* There were no thunderstorms within 5 nm of the crash site. There may have virga or weak showers though.

* It appears some sort of gust surge developed over northern Trinity Bay, lasting about 10 minutes, originating from the storms further west near Baytown, and it reinforced the gust front. This developed ground-relative motion of 50-60 kt along a band 6 nm long oriented NE-SW.

* Velocity product showed a transitory divergent couplet with 65 kt of shear within a 1 nm volume, slightly below and left of the track. This could be a piece of the northern edge of the gust surge. This is probably associated with turbulent motion, as the result of shear & friction along the frontal boundary.

* Velocity at higher levels (4000+ ft) and along the forward edge of the gust front are typically difficult to determine in these situations because a lack of scatterers.

* I don't think a gust front like this is anything that looks particularly dangerous. That said, it's impossible to directly measure turbulence, and in between the turbulence and cloud scales there are often strong circulations that can go undetected. Typically when we see small-scale patterns on radar imagery with strong gradients and circulation, we consider the possibility that strong motions can extrapolate down to the smaller scales. It's certainly possible that this gust surge rolled up into a vortex like I've shown in the cross-section below.. this can certainly be a hazardous area to fly in.

In short I'm skeptical weather caused a direct effect, but I do see enormous potential for a sudden, rough ride here, and that could have been the first event in a chain that led to something like a CG shift or loss of a control surface (from fatigue, improper maintenance, design issue, something like the 737 in Colorado Springs, etc).

It would be interesting to see what the TDWR radars showed, unfortunately as I have to attend to my other work I probably won't have time to look at this.

Anyway this is just an armchair analysis and I'm sure the investigators have more information at this point than we do, but it's nice to have quantitative data to work from.

https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/921x593/r_1835_track_wm_be454b5f9ca2755e26fee69bcac909ed46ca4f92.jpg

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/919x593/r_1838_track_wm_197d280902b162e216484444fd987a8eaf05a485.jpg

https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/917x592/v_1835_track2_wm_ccd570c5648262d795ad49ef75261858831f4826.jp g

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/971x569/v_1838_track_wm_d5c0ad8e327c6f10d32305b7e49d12b0d22176aa.jpg

https://cimg4.ibsrv.net/gimg/pprune.org-vbulletin/720x339/vortex_vertical_2941d7eb3f5f9337be3bf550f3b9f1701b58a3c1.jpg
Conceptual vertical cross section of air flow along a gust front ahead of a microburst.

fox niner

24th Feb 2019, 20:52

https://twitter.com/NTSB_Newsroom/status/1099710245360812038?s=20

What are they measuring here? What are those holes?

gums

24th Feb 2019, 21:07

Salute. Tim!

Good stuff, and it might be relevant if shear or gust had an effect on cargo shift, as some are already discussing.

BTW, I am discounting bird strikes, as we should have heard radio calls like we did with Sully. Something really bad happened, and it happened quickly and crew was BZ trying to save their lives and not talking.

Gums sends...

Carbon Bootprint

24th Feb 2019, 21:27

NTSB presser just finished. There wasn't much new that hasn't already been covered here. One item of mention is that there is a video of the plane going down which was taken from a camera at the Chambers County Jail, a bit more than a mile away.It shows the plane in a nose down attitude for about five seconds. The video has been sent to the NTSB labs. It won't be released to the public until it's made part of the official NTSB docket, probably some months from now. The Chambers County Sheriff did say two bodies have been recovered; they have not yet been identified.

Livesinafield

24th Feb 2019, 21:43

Great post tim, and great data collection nice to see posts with unbiased/ non speculative content

MartinAOA

24th Feb 2019, 21:50

Prayers to the crew and the families.

https://twitter.com/NTSB_Newsroom/status/1099788040506171392?s=20
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/d0m7fi6wkae11x5_dae80b22d0abb496d1ff697755031377a05f99d2.jpg
https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/d0m7ej4xcau4nhw_fcb554d9c76a270dcb2867d1ca8b2799abb500db.jpg

MarkerInbound

24th Feb 2019, 21:56

And from the NTSB the debris field is about 200x100 yards.

log0008

24th Feb 2019, 22:55

Excellent stuff Tim! It looks like a situation to me where it is extraordinary if the gust front didn't have something to do with it, given its proximity to where the accident occured but also extraordinary if i did because of how it seems like just a routine front. As you say its possible it set of a chain of events. This is just pure speculation on my behalf but any airline pilots will know (I'm only an instructor) but is it possible some kind of gust/turbulent/wind shear event could lead to the autopilot disconnecting and thus being miss managed, like forgetting that the auto throttle has also disconnected?

jetpig32

24th Feb 2019, 23:05

BTW, I am discounting bird strikes, as we should have heard radio calls like we did with Sully. Something really bad happened, and it happened quickly and crew was BZ trying to save their lives and not talking.

Anahuac Wildlife Refuge and nearby High Island are some of the largest areas for bird fallouts in the country. Although usually happens in spring just prior to an approaching cold front. I knew nothing about it while living in Houston, then saw a movie called The Big Year about birding enthusiasts.

FIRESYSOK

24th Feb 2019, 23:48

This is just pure speculation on my behalf but any airline pilots will know (I'm only an instructor) but is it possible some kind of gust/turbulent/wind shear event could lead to the autopilot disconnecting and thus being miss managed, like forgetting that the auto throttle has also disconnected?

Irrespective of this accident, yes, this has happened. Two high-profile accidents of 777s that I know of. Not in the circumstances you describe, but relevant to autoflight mismanagement or misunderstanding in general. Again, not saying anything about the accident flight.

45989

25th Feb 2019, 00:18

FIRESYSOK

25th Feb 2019, 00:40

Exactly! Too many flight sim/armchair warriors here as usual

Yet your quote was of someone who stated he flew 767s, and ‘the whale’ for ‘years’, yet simultaneously queried another poster about VFR fuel numbers.

short bus

25th Feb 2019, 00:52

Re: the NTSB photos above.

Does anyone think there is any significance to what ever it is they are measuring and documenting (punctures and imbedded material?)?

The Dominican

25th Feb 2019, 00:53

How about waiting for some facts to surface?

chopper2004

25th Feb 2019, 00:59

Load shift?
Amazon stuff isn't usually too heavy, but maybe a pallet/container broke loose and started a cascade.

Firet and foremost RIP to the crew and condolences to their relatives , friends and colleagues alike.

Think it was last year, one saw an Atlas 767F landed at RAF Lakenheath to drop off cargo etc...one of many as well as their 747 fleet that have dropped into both Mildenhall and Lakenheath over the years.

Speaking of 747, are you thinking along the lines of the National 747 fatal accident out of Kandahar, back in 2013?

ATB

cheers

Sqwak7700

25th Feb 2019, 01:41

If there was some explosive devise on board, it could make sense it detonated after descent if it had some sort of pressure switch. Most suspected bomb on board checklists I’ve seen detail procedures to handle pressure switch devices.

Also, what piece is that? It looks like grey paint, aluminium outside and some sort of thick honeycomb structure below. Could that be the nacelle ie? Almost looks like the puncture marks come from the outside in, opposite from expected if there was some sort of severe damage from an engine failure.

Edit: Looks like the nacelles are white, the only light gray seems to be on the wings and pylons. So maybe the punctures could be an engine throwing parts out.

lomapaseo

25th Feb 2019, 01:45

How about waiting for some facts to surface?

I thought the reported size of the debris field was pretty significant

And from the NTSB the debris field is about 200x100 yards.

JPJP

25th Feb 2019, 02:30

Prayers to the crew and the families.

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/d0m7fi6wkae11x5_dae80b22d0abb496d1ff697755031377a05f99d2.jpg
https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/d0m7ej4xcau4nhw_fcb554d9c76a270dcb2867d1ca8b2799abb500db.jpg

I echo the sentiment. I have close friends at Atlas, and have availed myself of their jumpseat and bunks on a number of occasions. They’re a good bunch, and very professional.

Those photos are very interesting. The gentleman on the left is a GE Rep, but I don’t know if that indicates they we’re looking at a piece of engine or cowling. The damage to the material is quite idiosyncratic.

Where’s an engineer when you finally need one ? David R ? :)

ironbutt57

25th Feb 2019, 02:59

the debris field is possibly large because it apparently dove straight in from around 6000'...and hit the bottom....

xyze

25th Feb 2019, 03:08

I echo the sentiment. I have close friends at Atlas, and have availed myself of their jumpseat and bunks on a number of occasions. They’re a good bunch, and very professional.

Those photos are very interesting. The gentleman on the left is a GE Rep, but I don’t know if that indicates they we’re looking at a piece of engine or cowling. The damage to the material is quite idiosyncratic.

Where’s an engineer when you finally need one ? David R ? :)

Not an engineer but if by idiosyncratic you mean suggestive of ‘shrapnel’-like penetration of the object with paint loss around penetration areas (compare with photos of mh17 debris), mainly from outside in but at least one from inside out, I agree. Likely source, engines, but odd to have caused such rapid loss of control. ?Unlucky replay of catastrophic engine failure a la QF32.

Longtimer

25th Feb 2019, 03:19

Video shows Atlas 767F in ‘steep’ dive prior to crash: NTSB

24 February, 2019
SOURCE: Flight Dashboard
BY: Jon Hemmerdinger
Boston

The National Transportation Safety Board (NTSB) has obtained security video showing Atlas Air flight 3591 in a “steep nose-down attitude” prior to crashing in Trinity Bay near Houston on 23 February.

“The aircraft is in the video… at a steep descent – [a] steep nose-down attitude,” NTSB chair Robert Sumwalt said during a press conference on 24 February. “I saw no evidence of the aircraft trying to turn or pull up at the last moments.”Authorities have confirmed three people were aboard the aircraft. Atlas Air says there were no survivors.

The video shows the aircraft for approximately 5s, says Sumwalt, adding that the NTSB is sending the footage to laboratories in Washington DC for analysis.

He made his comments in Anahuac, Texas, which is near the crash site. The agency’s top priority is to recover the flight data and cockpit voice recorders, a process that may require dredging, divers or wading “through the debris field and feeling for them”, says Sumwalt.

He also confirmed several details about the flight, which took off from Miami at about 11:30 local time. The 767 was approaching Houston George Bush Intercontinental airport on the “standard arrival routes from the south-east”, says Sumwalt.

At about 12:30 Houston time, the aircraft was descending through 18,000ft. Shortly after, Houston air traffic controllers advised the pilots of “light-to-heavy rain ahead, and provided radar vectors around the weather”, Sumwalt says.

Controllers then cleared Atlas flight 3591 to descend to 3,000ft.

At 12:39, while the aircraft was at about 6,000ft and travelling at 240kt, “communication was lost with the aircraft, as was radar contact”, Sumwalt says. “There was no distress call.”

The aircraft had not been logged as carrying hazardous materials, he adds.

The NTSB has recovered “remains of both wings” and landing gear components from a debris field that measures about 183m (600ft) by 91m, Sumwalt says.

“We have conducted aerial surveys and up-close examination of debris fields via airboats,” he adds. The NTSB intends to load debris onto barges for transport to shore and onward to a local hangar.

The Federal Bureau of Investigation has recovered two bodies and is assisting the NTSB with collection of witness statements and documentation of debris, says an FBI spokesperson.

The criminal investigation agency’s involvement in the early stages of NTSB investigations is common practice, he adds.

The Federal Aviation Administration, Boeing, Atlas Air, the National Air Traffic Controllers Association, pilot union International Brotherhood of Teamsters and engine maker General Electric are assisting the NTSB with the inquiry, says Sumwalt.

Boeing manufactured the CF6-80C2-powered 767-300ER, registration N1217A, in 1992 and delivered it new to Canadian International Airlines, according to Cirium Fleets Analyzer.

Atlas Air affiliate Titan Aviation Leasing acquired the aircraft in January 2016, at which time it entered service with Atlas Air, Fleets Analyzer shows.

Parent company Atlas Air Worldwide Holdings owns both Atlas Air and Titan.

Since April 2017, Atlas Air has operated the 767 for online retailer Amazon under the Prime Air brand, Fleets Analyzer shows.

tdracer

25th Feb 2019, 03:43

Those pieces do not look to me like parts of the engine nacelle - the honeycomb is too thick. Best guess is a moveable aerodynamic surface (e.g. flaps or part of the tail)

ThreeThreeMike

25th Feb 2019, 03:59

Instead of all these what-if combinations I would prefer to parse the discussions down to the supporting facts at this time with no more than one leap of speculation beyond what is known.

Question. Do we know the length and spread of the debris trail ?

does that give us a hint of the attitude of the plane during break-up?

For those unfamiliar with Texas geology, I'll provide a brief description of the soil in and around Trinity Bay, hoping it makes understanding the conditions which exist at the impact site easier to visualize.

Basically it's a very deep layer of dark, stiff clay, with little else except some loam around creek beds and occasional fractured blue clay. There is very little sand on the coastal beaches of the bay area, and the impact area consists of marsh grasses and the dark clay already described, with the surrounding water levels between one and three meters.

Recovery of recording devices and airframe debris may be extremely difficult, especially if specific parts suspected of failure are to be located. I was a bit surprised that the bodies of two crew members have already been recovered, I hope this provides a degree of comfort to loved ones.

tdracer

25th Feb 2019, 04:19

the debris field is possibly large because it apparently dove straight in from around 6000'...and hit the bottom....
I wouldn't consider 100m x 200m large at all - in fact for an aircraft the size of a 767 that's on the small side. It would also rule out any in-flight breakup (unless of course they find bits at another location).
I also would consider an uncontained engine failure to be rather unlikely since they'd have been at a relatively low engine power setting - most engine breakups at takeoff power sets, or at high altitudes where the physical rotor speeds tend to high. I suppose a major bird strike might cause enough damage and a large enough imbalance that perhaps the engine could start coming apart, but again the probability would be low at relatively low rotor speeds.
But, one of more big birds through the forward bulkhead that took out some flight controls (remember, the 767 is basically a cable controlled aircraft)? Even if it didn't incapacitate the crew they'd have precious little time to react...

Ripper3785

25th Feb 2019, 05:09

I don't intend to be suggesting anything because I'm not an investigator. Is it possible they are they measuring and photographing the smallish dents on whatever surface that ends up being?

lpvapproach

25th Feb 2019, 05:21

The accident site seems to be near the RDFSH waypoint which would be flown to in the event of runway 27 transition,

I am looking at the linkk1 star. What is the "runway 27 transition" - there is no such literally named transition on the plate. I also heard this mentioned listening to the ATC, I have not heard this previously but dont fly in the area. Thank you.

wiggy

25th Feb 2019, 05:35

I am looking at the linkk1 star. What is the "runway 27 transition" - there is no such literally named transition on the plate. I also heard this mentioned listening to the ATC, .

It’s the transition from the terminating waypoint of the STAR onto the published approach - take a look at the 27 ILS plate, you should find it there.

fdr

25th Feb 2019, 05:45

I wouldn't consider 100m x 200m large at all - in fact for an aircraft the size of a 767 that's on the small side. It would also rule out any in-flight breakup (unless of course they find bits at another location).
I also would consider an uncontained engine failure to be rather unlikely since they'd have been at a relatively low engine power setting - most engine breakups at takeoff power sets, or at high altitudes where the physical rotor speeds tend to high. I suppose a major bird strike might cause enough damage and a large enough imbalance that perhaps the engine could start coming apart, but again the probability would be low at relatively low rotor speeds.
But, one of more big birds through the forward bulkhead that took out some flight controls (remember, the 767 is basically a cable controlled aircraft)? Even if it didn't incapacitate the crew they'd have precious little time to react...

The debris field of the airframe is commented on, and is not particularly large as reported so far, but the point of interest will be any debris in the 3-4nm to the east of the aircrafts impact point. At idle, the engine still has around 20-25% of the kinetic energy of the full thrust uncontained failure case, enough to cause further damage. As far as I recall, there has only been one incident on the 767 GE where an uncontained failure damaged the second engine, and that was a liberated disk fragment bouncing off the ground and impacting the other engine.

PuraVidaTransport

25th Feb 2019, 05:46

For those of you who are talking about diversion fuel and don't have a good idea of airports in Texas, just an FYI post. There are a LOT alternates (runway length ~8000ft or longer) as close or closer than DFW. Three in Houston (Bush, Hobby and Ellington Field (NASA/military)), four airports in the DFW area (DFW, Love Field, Alliance and the Naval Air station in Ft Worth), San Antonio, Austin, Waco, New Orleans (La), Tyler, Longview, Shreveport (La), Corpus Christi, Victoria, and Laredo plus a LOT of others with shorter runways they could use in an emergency like the two in Conroe, College Station airport (Easterwood), Army airbase at Killeen, Stinson Municipal in San Antonio, Austin Executive, Beaumont, Baton Rouge (La) and Lufkin. This is also not a complete list just ones off the top of my head.

CONSO

25th Feb 2019, 05:57

Those pieces do not look to me like parts of the engine nacelle - the honeycomb is too thick. Best guess is a moveable aerodynamic surface (e.g. flaps or part of the tail)

Looks to me more like NON structural fairing or possibly interior panel which used a light blue adhesive - perhaps a cargo liner ? nearest top edge of grey painted ( aluminum ?) in photo is not torn but simply folded over some semi circular object eg a manufactured ' cutout '

thabo

25th Feb 2019, 06:12

Those photos are very interesting. The gentleman on the left is a GE Rep, but I don’t know if that indicates they we’re looking at a piece of engine or cowling. The damage to the material is quite idiosyncratic.

Where’s an engineer when you finally need one ? David R ? :)

Looks like a part of the 9G rigid barrier at the front of the cargo deck
can't think of any other item off-hand which is made from aluminium honeycomb and is that thick

Air Profit

25th Feb 2019, 07:16

CargoMatatu

25th Feb 2019, 07:32

This brings back memories from my earlier days in my aviation career, remembering the Dan-Air 707 crash on approach to Lusaka in 1977 where the starboard horizontal stabiliser detached on approach.
Lost some good friends and colleagues in that one, and in more recent times I am ex Atlas!

Not suggesting there is any link here, just an unpleasant similarity.

R.I.P. brothers.

Homebrew1

25th Feb 2019, 08:12

Not speculating on cause, more a question: would it be possible for a sudden negative-g load to break free a cargo pallet and force it upwards into elevator control cables (assuming that is where the cables are located on a 767)?

Wouldn't have though so. Would need to be significant and in that case would also be exceeding A/C structural limitations.

B2N2

25th Feb 2019, 08:17

I heard it....very faint.

1. I don’t hear anything on that tape
2. Any perceived noises or sounds out of context don’t mean anything.
Even if “pull” was said and picked up by any of the microphones it could be dozens of things.
A comment about seat adjustment, seat belts, folding table tops, crew bags, door handles anything.

”Hey could you grab me the sunshade?”
”Go ahead just pull”

Not trying to be facetious but if you’re trying to hear “Pull” then consider the Youtube videos of cats sounding like they say hello.

Zeffy

25th Feb 2019, 10:58

NTSB briefing by Chairman Sumwalt:
https://youtu.be/Me7zDd-YN7Y

https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/1277x718/screen_shot_2019_02_25_at_6_55_06_am_c9b2002f5a4cafe5330f2fa 2db4cb4f7a80b3a5f.png

Carbon Bootprint

25th Feb 2019, 11:37

The crew members have been identified in today's Houston Chronicle (https://www.chron.com/news/houston-texas/article/FAA-Cargo-plane-crashed-in-Trinity-By-in-13639542.php?cmpid=trend). According to the paper, one was a Mesa captain and new father who was jumpseating to Houston to begin his "dream job" with United Airlines this week.

Very tragic all around.

Mike Park

25th Feb 2019, 12:48

Thanks Tim Vasquez, very good information.
Mike, 30,000 hrs B-737

lomapaseo

25th Feb 2019, 13:28

Assuming it's factual doesn't, a steep dive into the ground with a tight debris pattern have to fit an aerodynamic principle of flight ?

derjodel

25th Feb 2019, 13:56

SeenItAll

25th Feb 2019, 14:46

So Fly Dubai, Lion Air and now Atlas all share:
- Boeing airplane
- Nosedive

Lion Air is probably an outlier, but then again, what if all 3 have trim management in common? Because at least Lion and FlyDubai do.

In Addition Fly Dubai and Atlas both share low visibility and approach/final, right? And somebody mentioned constant speed. It seems Atlas air was actually slowing down and FlyDubai was just slightly accelerating, both despite nose down, if FR data is to be trusted (can't post links, sorry).

Seems like some kind of a pattern, doesn't it?

Not at all. Statistics is about accepting or rejecting hypotheses that are made in advance of knowing the data. Claimed confirmation of a hypothesis that was generated after seeing the data is just cherry-picking. Given there are so many parameters to cherry-pick from, it is sure that you can find some that will all align between the incidents -- but this has no probative value as statistical inference. Indeed, each of these crashes is so different from one another in terms of the stage of flight, that I doubt any similarity will be found. And note that trim problems generally don't cause an immediate nosedive into the ground. You generally see the flight crew struggling with the imbalances for some minutes (or at least multiple seconds) before control is finally lost. That doesn't seem to be the case with the altitude profile shown here.

EDML

25th Feb 2019, 14:50

physicus

25th Feb 2019, 14:51

It looks like the airplane followed a parabola, maintaining forward velocity while building up vertical velocity, as evidenced by the near constant GPS (=ground) speed in the FR24 data. As Sumwalt stated in the briefing, the aircraft flew wings level but in a steep nose down attitude. Lack of elevator effectiveness springs to mind. In the presumed absence of intent (i.e. suicide) it remains to be seen whether that's a runaway trim, complete loss of elevator control, or loss of elevator/tail surfaces. In level flight, the tail surface provides a net down force, lose some of that surface, and an up moment of the tail ensues resulting in a nose down moment on the pitch axis.

derjodel

25th Feb 2019, 14:58

I know, and indeed LionAir FDR data indicates acceleration. For the other two there's only ADS-B data available at the moment I believe? FlyDubai did accelerate in the last moments, but only from about 180-230 while it was in steep dive.

derjodel

25th Feb 2019, 15:08

Not at all. Statistics is about accepting or rejecting hypotheses that are made in advance of knowing the data. Claimed confirmation of a hypothesis that was generated after seeing the data is just cherry-picking. Given there are so many parameters to cherry-pick from, it is sure that you can find some that will all align between the incidents -- but this has no probative value as statistical inference. Indeed, each of these crashes is so different from one another in terms of the stage of flight, that I doubt any similarity will be found. And note that trim problems generally don't cause an immediate nosedive into the ground. You generally see the flight crew struggling with the imbalances for some minutes (or at least multiple seconds) before control is finally lost. That doesn't seem to be the case with the altitude profile shown here.

Not at all. Indeed the p value (if one is to use the dreaded p value in order to accept hypothesis) should be adjusted and fairly small. In essence, we could go in blind over all data available, but adjust the p value according to degrees of freedom available to avoid false positives.

Now given that the flight data sample is huge (say, all flights in the past 3 years), the probability of false positive is actually small anyway. So is there a statistically significant difference between # of flights that did/didn't crash in the group of flights which are Boeing in low visibility on final/approach?

And btw, picking a hypothesis up front makes no difference. Imagine 20 different statisticians would decide to test a hypothesis over flight data, each unbeknown and independent of each other. Each would choose a different parameter, but p of only 0.05. Those results would not be different, but there would indeed likely be at least 1 false positive due to stupidly large p value (0.05 is really astronomical when you think about it).

physicus

25th Feb 2019, 15:31

ADS-B data from FR24 gives GPS derived speed, which is the ground speed, i.e. the speed of the aircraft in the horizontal plane only as seen from straight above. If you're tossing a stone off a tower by throwing it away from the tower, it will retain most of the forward velocity but vertical velocity will continue to increase until it hits the ground, thus creating parabolic flight path. An aircraft without (sufficient) elevator authority will do the same. The impact velocity is far greater than the horizontal velocity would indicate, it's the vector product of both the horizontal and vertical speed components.

Lion Air was a very different case. Fly Dubai and this Atlas crash look a lot more similar in the end phase - which bears absolutely no meaning on the root cause. All it says is: elevator authority was impaired. Period.

AnyOldPilot

25th Feb 2019, 15:48

Going to be lots of human factors focus here. Interactions between pilots, between controllers, between pilots and controllers.

Why the CA/PF was on the radio descending through 17,800' when Approach cleared them for the 26L transition (they were actually told that they "can" fly the 26L, pilot appeared to say "91" but did not read back the transition change).
What was the FO/PM working on.
Why they were approaching RDFSH at 6000' and not GARRR at 7000' (sure, Approach thought 3591 was deviating for weather, although they hadn't cleared them for it, and Approach didn't ding them for being at 6000' instead of 7000' for GARRR).
Why the constant 240KTS in the descent with the parabolic drop-off at the end, were they in speed mode, what altitude was set.
Did they have a high rate of descent result from pulling power while trying to decelerate, did the 30,000 FPM final rate of descent result from a departure from controlled flight-- maybe with parts coming off-- in the effort required ("PULL!") to bring the nose up from 18,000 FPM through 11,000 FPM, which is where the bottom fell out.

Not throwing stones here. I live in a glass house of my own making. Just looking for the most obvious/likely causal factors. Occam's Razor. Whatever you do, don't ask how I can envision this scenario happening.

I've worked through it a number of times and have a more lengthy write-up, that is, if you want some more conjecture as to what happened. Guys just out trying to make an honest living, and the whole thing went to hell on them. Whole thing makes me want to puke.

FIRESYSOK

25th Feb 2019, 16:24

The 240 ground speed would roughly equal 210 KCAS at 6000’, which is the published speed and altitude at RDFSH point (if in fact that was being navigated to and autothrottle managing speed).

At that speed, clean wing in light to moderate chop (as reported by another arrival), that could be approaching a critical AOA. Of course nothing is known here- conditions, config, etc.; nothing.

DaveReidUK

25th Feb 2019, 16:31

ADS-B data from FR24 gives GPS derived speed, which is the ground speed, i.e. the speed of the aircraft in the horizontal plane only as seen from straight above. If you're tossing a stone off a tower by throwing it away from the tower, it will retain most of the forward velocity but vertical velocity will continue to increase until it hits the ground, thus creating parabolic flight path.

Yes, although the aircraft's trajectory, with at least some thrust being generated, would differ slightly from the purely ballistic trajectory of a thrown stone.

The last few points of the ADS-B data would suggest a flightpath angle approaching -50° and a resolved velocity approaching 400 kts at the last recorded point. That's consistent with the relatively small debris field.

derjodel

25th Feb 2019, 17:10

ADS-B data from FR24 gives GPS derived speed, which is the ground speed

:ugh: Of course! How could I have missed that. Sorry!

SeenItAll

25th Feb 2019, 17:50

Not at all. Indeed the p value (if one is to use the dreaded p value in order to accept hypothesis) should be adjusted and fairly small. In essence, we could go in blind over all data available, but adjust the p value according to degrees of freedom available to avoid false positives.

Now given that the flight data sample is huge (say, all flights in the past 3 years), the probability of false positive is actually small anyway. So is there a statistically significant difference between # of flights that did/didn't crash in the group of flights which are Boeing in low visibility on final/approach?

And btw, picking a hypothesis up front makes no difference. Imagine 20 different statisticians would decide to test a hypothesis over flight data, each unbeknown and independent of each other. Each would choose a different parameter, but p of only 0.05. Those results would not be different, but there would indeed likely be at least 1 false positive due to stupidly large p value (0.05 is really astronomical when you think about it).

I really don't want to argue with you, but using a tighter p-value is no cure for improper statistical design. You have no model for the distribution of the errors because you chose a hypothesis to fit your limited choice of data. Indeed, the hypothesis you chose fit the data exactly -- so you have a degenerate error distribution. Further, you seem to have a very limited view as to what the relevant data are. For example, the XL Air crash at Perpignan was also a nose-over -- but that was a A320. Your "model" cannot explain that at all. https://en.wikipedia.org/wiki/XL_Airways_Germany_Flight_888T

Livesinafield

25th Feb 2019, 17:53

Why the CA/PF was on the radio descending through 17,800'

There a loads of reasons for this, PM could have been on the other radio talking to Ground services/company or updating the new weather, or anything, how many times in a flight do you end up saying "can you just take "one" a second while i do XXXX"

AnyOldPilot

25th Feb 2019, 18:53

There a loads of reasons for this, PM could have been on the other radio talking to Ground services/company or updating the new weather, or anything, how many times in a flight do you end up saying "can you just take "one" a second while i do XXXX"
Not disagreeing with you on this. Of course we all do it. Just saying it’s going to be part of the board’s figuring out what happened and why the jet was where it was.

Airbubba

25th Feb 2019, 19:09

And from the NTSB the debris field is about 200x100 yards.

Actually, what Chairman Sumwalt said is that the main wreckage is approximately 200 yards long by about 100 yards wide. Perhaps he implies that the packages and aircraft parts are scattered over a wider area.

See his comments at 4:46 in the NTSB media conference video:

https://www.youtube.com/watch?v=Me7zDd-YN7Y

Here's cellphone video of the debris field on the Chambers County Sheriff's Office Facebook page:

https://www.facebook.com/watch/?v=2305590612836823

Chiefttp

25th Feb 2019, 19:17

I’ve flown into IAH many times, but as a Night Cargo Pilot, it’s much less busy and relatively easy. My Son, however, absolutely hates IAH. He flies for a passenger airline and he says the controllers constantly change the arrivals and runways on them during the arrival phase of flight. He’s come close to being violated there a few times and tries to avoid IAH if possible. Perhaps this is why some posters mentioned the crew at an incorrect altitude. I know my airline has just issued a bulletin about changing STARS and Runways while on an arrival.

Old Boeing Driver

25th Feb 2019, 19:20

tubby linton

25th Feb 2019, 19:29

Airbubba the link to the facebook page led to a rather meaningless video.

fdr

25th Feb 2019, 19:51

So Fly Dubai, Lion Air and now Atlas all share:
- Boeing airplane
- Nosedive

Lion Air is probably an outlier, but then again, what if all 3 have trim management in common? Because at least Lion and FlyDubai do.

In Addition Fly Dubai and Atlas both share low visibility and approach/final, right? And somebody mentioned constant speed. It seems Atlas air was actually slowing down and FlyDubai was just slightly accelerating, both despite nose down, if FR data is to be trusted (can't post links, sorry).

Seems like some kind of a pattern, doesn't it?

your examples also share other characteristics:

1. built after Dec 17, 1903
2. had paint on the outside
3. had people and stuff on the inside
4. took off
5. had wings
6. had engines

yep, theres a definite pattern there.

FZ981 was a disorientation event following a GA in wind shear.
Lion Air 610 has indications of sensor failure leading to loss of control for unknown reasons at this time.

FZ approach was not low viz, with an GA due wind shear according to the interim report. Fedex was at 6000', starting the approach, and the weather at the field itself was clear, the line of weather on the approach that the aircraft entered was well away from the airport.

Agent1966

25th Feb 2019, 19:54

1. I don’t hear anything on that tape
2. Any perceived noises or sounds out of context don’t mean anything.
Even if “pull” was said and picked up by any of the microphones it could be dozens of things.
A comment about seat adjustment, seat belts, folding table tops, crew bags, door handles anything.

”Hey could you grab me the sunshade?”
”Go ahead just pull”

Not trying to be facetious but if you’re trying to hear “Pull” then consider the Youtube videos of cats sounding like they say hello.

I did hear it. You are right about the possible context......but given the timing of the crash relative to that word heard, I'd be comfortable making a $20 bet, it wasn't anything to do with a seat belt.

fdr

25th Feb 2019, 19:55

I know nothing about the 767 stabilizer and elevator system, and I realize this is a completely different type of airplane, but does anyone remember what happened with Alaska Airlines Flight 261 and the jack screw assembly?

https://en.wikipedia.org/wiki/Alaska_Airlines_Flight_261

AZ261 MD80 aircraft had a single screw jack, the B767 has dual jacks which are independent, except that they share structure at the fuselage attachment, which was the subject of AD's in the past related to cracking.

Old Boeing Driver

25th Feb 2019, 19:57

@ FDR Thanks for your response.

Here is the "proposed AD

" ....in 2000"On January 31, 2000, there was an accident involving a McDonnell Douglas Model DC-9-83 (MD-83) airplane. The National Transportation Safety Board (NTSB) determined that the probable cause of this accident was a loss of airplane pitch control resulting from the in-flight failure of the acme nut threads of the jackscrew assembly of the horizontal stabilizer trim system.
The NTSB concluded that the thread failure was caused by excessive wear, resulting from insufficient lubrication of the jackscrew assembly.Start Printed Page 58621The drive mechanism of the horizontal stabilizer on McDonnell Douglas Model DC-9-83 (MD-83) airplanes has a jackscrew assembly with an acme screw.
The drive mechanism of the horizontal stabilizer on Boeing Model 767 airplanes uses a ballscrew. Acme screws and ballscrews have some differences in design, but perform similar functions and have the same airplane level effect following failure. The manufacturer's safety analysis of the 767 drive mechanism found no safety problems with the configuration of the drive mechanism, but showed that changes to the maintenance procedures and maintenance intervals are required to keep the drive mechanism properly maintained and operating as designed.
We have received a report indicating that the ballscrew in the drive mechanism of the horizontal stabilizer on a Boeing Model 757 series airplane showed extensive corrosion, which could lead to excessive wear. The ballscrew on Boeing Model 757 airplanes is similar to that on Boeing Model 767 airplanes that are the subject of this proposed AD. Therefore, both of these airplane models could have the same unsafe condition.
We are considering separate action for the Boeing Model 757 series airplanes and other similar Boeing airplanes.Extensive corrosion of the ballscrew in the drive mechanism of the horizontal stabilizer, if not corrected, could cause an undetected failure of the primary load path for the ballscrew and subsequent wear and failure of the secondary load path, which could lead to loss of control of the horizontal stabilizer and consequent loss of control of the airplane."

Zlinguy

25th Feb 2019, 21:34

AZ261 MD80 aircraft had a single screw jack, the B767 has dual jacks which are independent, except that they share structure at the fuselage attachment, which was the subject of AD's in the past related to cracking.

Are you positive about the 767 having dual jacks? I'm pretty sure there's only one screwjack ( although there might be concentric load path redundancy in the event of a failure) with dual hydraulic motors/brakes. It's been a few years since I've flown it, though...

NSEU

25th Feb 2019, 23:19

Are you positive about the 767 having dual jacks? I'm pretty sure there's only one screwjack ( although there might be concentric load path redundancy in the event of a failure) with dual hydraulic motors/brakes. It's been a few years since I've flown it, though...

Correct. The 767 only has one ballscrew. However, it does use two hydraulic motors which drive the single ballscrew through a differential gearbox.

B2N2

26th Feb 2019, 01:26

Even if you personally don’t feel the need to contribute please forward the link.
It has been verified as legitimate.

https://www.gofundme.com/f/atlas-air-crash-3591-victims-family-fund

Thank you

Airbubba

26th Feb 2019, 01:34

NTSB listening for the CVR and FDR pingers.

https://cimg5.ibsrv.net/gimg/pprune.org-vbulletin/2000x1333/d0shn84w0aawlro_65661d606b641364162ddc755a1c7f1d58e98329.jpg

Airbubba

26th Feb 2019, 01:42

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

https://youtu.be/hfa4S7Heal0

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

DaveReidUK

26th Feb 2019, 08:32

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

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

cappt

26th Feb 2019, 12:00

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

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

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

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 (https://www.legislation.gov.au/Details/F2005L00096) and the according bulkhead (https://www.federalregister.gov/documents/2004/12/01/04-26494/airworthiness-directives-boeing-model-767-200--300-and--300f-series-airplanes)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

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/agencies/federal-aviation-administration

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

EuroNato100

26th Feb 2019, 14:37

B2N2

26th Feb 2019, 14:38

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/press-releases/en/2017/06/airbus-launches-new-fixed-and-deployable-flight-recorders-for-it.html

DaveReidUK

26th Feb 2019, 16:05

Something like this:
https://www.airbus.com/newsroom/press-releases/en/2017/06/airbus-launches-new-fixed-and-deployable-flight-recorders-for-it.html

That article is more than 18 months ago. It doesn't offer any evidence for your assertion that Qatar Airways, or indeed any operator, is actually taking delivery of aircraft with ejectable flight recorders.

Note that Airbus calls them "deployable", which doesn't sound quite so bad when they eject by accident in the hangar. :O

Interestingly (and perhaps confusingly) QR is the launch customer for Global Beacon, which provides Iridium satellite-based ADS-B tracking coverage worldwide, though it's not clear whether that is yet in operation.

lomapaseo

26th Feb 2019, 16:22

Tell me another widebody crash where they weren't eventually found?

ElAl B747 freighter, AMS

Machinbird

26th Feb 2019, 16:45

Used to be on some aircraft, that the trim could wind nose down until the A/P could not hold it.
Then the crew got handed a nasty surprise.
What kind of warnings and protections does the 76 have for this situation?

Icelanta

26th Feb 2019, 17:01

ElAl B747 freighter, AMS

That is only because Mosad found them before the Dutch.

my condolences to all involved.

jugofpropwash

26th Feb 2019, 18:45

The following was posted earlier:

"In January 2014, the US Federal Aviation Administration issued a directive that ordered inspections of the elevators on more than 400 767s beginning in March 2014; the focus is on fasteners and other parts that can fail and cause the elevators to jam. The issue was first identified in 2000 and has been the subject of several Boeing service bulletins. The inspections and repairs are required to be completed within six years."

Six years would be 2020, so the time isn't up yet. Would this apply to the aircraft in question, and if so, is there any way to know if the inspections and repairs were completed?

filejw

26th Feb 2019, 19:04

Livesinafield

26th Feb 2019, 19:40

https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/2000x1124/inkedprime_stab_li_e6d6a537f260b0660ea89d2db9cdc2561c1703f9. jpg

What are them marks by the Stab?? like dents? im sure its nothing but i don't see it on other pictures

Old Boeing Driver

26th Feb 2019, 19:40

Atlas took delivery from CIT Leasing in Jan 2016
The freighter conversion was done in April 2017. Presumably, the AD would have been done then.
7 Jan. 2016 N258CT Atlas Air
5 April 2016 N631GT Atlas Air
8 Dec 2016 N1217A Atlas Air
April 2017 N1217A Atlas AirBCF (cargo) conversion
30 Apr 2017 N1217A Amazon Prime Air operated by Atlas

B2N2

26th Feb 2019, 19:48

CONSO

26th Feb 2019, 20:22

re propwash re AD yes !-detailed records are SOP !

jugofpropwash

26th Feb 2019, 20:23

I’m pretty sure most of these Atlas A/C came to TLV for some type retrofit and update. You would hope something like this would be addressed

One would hope - but, technically, the date wasn't up. And there's always the chance something could be missed in an inspection. Could a failure have resulted in this sort of crash?

B2N2

26th Feb 2019, 21:25

Maybe.
AFAIK this is how the NTSB goes to work:

Engine team
Airframe/Flight control team
MX team
Human factors/ Crew team

Engine team will include reps from GE
Airframe team will include reps from Boeing
MX team will include reps from Boeing
Human factors/ Crew team will be looking for training records, rest/duty times and interview colleagues, friends and family.
The Union will have several representatives from the pilot group on scene to monitor and assist.
These union reps have received special training.

Multi prong approach is the strategy.
I may have the phraseology wrong but that’s basically what’s going to happen.

Based on the accident site a basic working theory will be formed and any evidence discovered by the various teams will be used to either support or discredit the initial theory.

Up to that point we can only guess.

tdracer

26th Feb 2019, 21:28

One would hope - but, technically, the date wasn't up. And there's always the chance something could be missed in an inspection. Could a failure have resulted in this sort of crash?

While I'm not familiar with the AD in question, it's pretty common for the AD compliance times in question to be staggered based on risk (for structural issues it's typically age related - hours and/or cycles). So you might have something where aircraft with more than xxxxx cycles must comply within 3 years, those with less have 6 years.

That being said, it would extraordinarily sloppy for an aircraft to come out of a major structural mod with an outstanding AD not complied with.
I was in this business long enough to know you 'never say never', but I think the likelihood is quite small that whatever happened is related to that AD.

thabo

27th Feb 2019, 02:57

I’m pretty sure most of these Atlas A/C came to TLV for some type retrofit and update. You would hope something like this would be addressed

Atlas has split their conversion orders between Boeing and Iai.
N1217A was converted to freighter by Boeing in Singapore.

noske

27th Feb 2019, 08:04

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?

Asiana Cargo 747 near Jeju in 2011. Major parts of the wreckage were found and recovered, but not the flight recorders, apparently due to strong currents over a muddy seabed. https://flightsafety.org/asw-article/in-flight-inferno/

But I have no doubt that these recorders will be found, within a week or two.

Carbon Bootprint

27th Feb 2019, 11:38

Asiana Cargo 747 near Jeju in 2011. Major parts of the wreckage were found and recovered, but not the flight recorders, apparently due to strong currents over a muddy seabed. https://flightsafety.org/asw-article/in-flight-inferno/

But I have no doubt that these recorders will be found, within a week or two.I agree. The NTSB has already acknowledged they will dredge the bay if they can't find them by divers, pingers, or mud sloggers.

Bobman84

27th Feb 2019, 13:42

Tell me another widebody crash where they weren't eventually found?

Have no doubt these will be found and agree in principle.

However here's a list for you:

SAA 295 B747 (FDR not found)
Iran Air 655 A300 (neither found)
El Al 1862 B747 (CVR not found)
American 11 B767 (obvious reasons not found)
United 175 B767 (obvious reasons not found)
Asiana 991 B747 (neither found)
Malaysia 370 B777 (neither found)

So, seems a few missing CVR/FDR from wide bodies in the last three decades and quite a lot more from narrow body jets.

capngrog

27th Feb 2019, 14:02

[QUOTE=noske;10401664]

I also agree that the recorders will be found eventually. It looks like most of the wreckage array is in a marshy area with varying water depths. This is a most difficult type of terrain in which to work: too deep to walk (slog through the mud), too shallow to swim. The Atlas Air B-767 crash site looks very similar to the ValuJet 592 crash site, which was in the Florida Everglades, west of Miami.

I've not previously posted on this Forum because I'm neither a currently rated pilot nor much of an expert on anything that really matters; however, I was extensively involved in the recovery efforts and investigation of the ValuJet Flt. 592 crash (May 11, 1996). The two major difficulties that were encountered were having to slog through the mud, crud and debris and the unsuitability of a standard airboat to support such an operation. It may be different now, but back then, the average airboat could only transport three people and was relatively unstable, making it difficult to get on and off the boat. We were lucky in one major respect, because an airboat tour operator (Everglades Holiday Park as I recall) volunteered the use of one of their 40 passenger airboats and operator. This really helped out a lot, since we could transport the guys from the levee to the site safely, and the boat was stable when folks were going into the water and getting back onto the boat. It was also extremely important that no other airboats operate in the recovery area, since their propwash would blow heavily contaminated (mostly biological) water onto other boats and onto the guys in the water.

As I recall (after the first day, things seemed to all run together in my memory), the first data recorder was not recovered until almost a week after the crash. I also recall that no pinging from the recorders was ever detected. Anyway, I have a great deal of respect for the job that the NTSB does and understand that while they seem to slow in issuing their findings, they are extremely effective in finding the causes of accidents. The unsung "heroes" in aircraft crash investigations are the folks (both law enforcement and civilian) who are actively involved in recovery efforts, and who, depending on circumstances, are totally unprepared (both physically and psychologically) for what they must do. Insofar as the ValuJet crash was concerned, it started the day of the crash with our MIA Terminal Operations folks who counseled bereaved relatives friends etc. all the way to the guys on the levee decontaminating recovered debris, to the Medical Examiner's Staff who did a remarkable job of identifying remains (so that loved ones could have closure).

I apologize for this somewhat rambling account, and I could go on and on, but I won't.

Cheers,
Grog

Almostfamous

27th Feb 2019, 15:36

Have no doubt these will be found and agree in principle.

However here's a list for you:

SAA 295 B747 (FDR not found)
Iran Air 655 A300 (neither found)
El Al 1862 B747 (CVR not found)
American 11 B767 (obvious reasons not found)
United 175 B767 (obvious reasons not found)
Asiana 991 B747 (neither found)
Malaysia 370 B777 (neither found)

So, seems a few missing CVR/FDR from wide bodies in the last three decades and quite a lot more from narrow body jets.

However, with the exception of MH 370, the cause(s) of the crashes were determined.

Carbon Bootprint

27th Feb 2019, 22:06

A Houston TV channel has released security camera video (https://www.click2houston.com/news/video-shows-cargo-plane-moments-before-crash-at-trinity-bay) from a school in Anahuac which shows a brief glimpse of 5Y 3591 descending. It was taken from quite a distance away and it's not particularly good quality video, but enough to show the speed and angle with which it came down.

Capn Bloggs

27th Feb 2019, 22:17

Gives me the shivers...

JH_CAMO

27th Feb 2019, 23:34

Long time lurker of the forum, but this particular thread has struck a sad chord.

Just to alleviate the discussion on ADs, this aircraft was in full compliance as are all of the Atlas Air / Amazon aircraft.

I’ve been involved with this project for 3 years and have compiled the AD records for most of the Amazon aircraft, including this airframe.

Reference the splitting of the conversions between the Boeing BCF and the IAI SF, this occurred as IAI did not have approval for winglet aircraft.

A sad day and my heart goes out to the families, and the many good people at Atlas, RIP.

Airbubba

28th Feb 2019, 00:25

From the Chambers County Sheriff's Office Facebook page:

Chambers County Sheriff Brian Hawthorne and Lt. Erik Kvarme had the honor this evening of transporting family members of the 3 pilots that were involved in the crash of flight 3591 to the crash site via the Sheriff’s Office airboats. Each family placed a wreath and flowers in the water in honor of their loved ones. Our thoughts and prayers are with families.

https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1280x1712/52830934_2099423980145785_8767119688225259520_o_19cff95a54d3 e9a2cf93e9cc4e1a329fa8ee852a.jpg

aterpster

28th Feb 2019, 00:46

thabo

28th Feb 2019, 02:58

Reference the splitting of the conversions between the Boeing BCF and the IAI SF, this occurred as IAI did not have approval for winglet aircraft.

I mentioned this because originally this aircraft was reported as having been a BDSF (Bedek Special Freighter) but it was in fact a BCF (Boeing Converted Freighter).

Iai only received their STC for 767-300 aircraft with winglets a couple years ago - about 7 years after receiving their regular 763 STC.

A sad day and my heart goes out to the families, and the many good people at Atlas, RIP.

A sad day indeed

RIP

fdr

28th Feb 2019, 06:20

Are you positive about the 767 having dual jacks? I'm pretty sure there's only one screwjack ( although there might be concentric load path redundancy in the event of a failure) with dual hydraulic motors/brakes. It's been a few years since I've flown it, though...
Correction:

Zlinguy, you are correct; I was wrong, the B767 has a single shaft with dual motors, controllers, and brakes. there is a single ballscrew actuator assembly, per Ch 27 IPC and AMM.

VGCM66

28th Feb 2019, 19:20

Maybe a sudden load shift forward changing the center of gravity but already too low to compensate or counteract. Maybe...:sad:

thabo

28th Feb 2019, 19:41

Maybe a sudden load shift forward changing the center of gravity but already too low to compensate or counteract. Maybe...:sad:

I wouldn't think that very likely unless it was carrying outsized cargo such as vehicles or engines. (Unlikely on 763 flying Amazon cargo).
In normal cargo operation there would be several pallets/containers and even severe turbulence should not be sufficient to rip out enough cargo locks to enable one of the pallets to move forward and affect the cg.
the w&b manual allows for operation with missing cargo locks and in such instances limitations on cargo loads will still ensure that pallets can not tear free under normal operating conditions.

The 747 crash a few years ago which was caused by military equipment moving used a layout where there were no pallets/containers in front or behind the vehicles to prevent then moving if they tore free.

@JH-CAMO - does atlas use pallets or containers on the 763?

seagull967

28th Feb 2019, 22:02

I wouldn't think that very likely unless it was carrying outsized cargo such as vehicles or engines. (Unlikely on 763 flying Amazon cargo).
In normal cargo operation there would be several pallets/containers and even severe turbulence should not be sufficient to rip out enough cargo locks to enable one of the pallets to move forward and affect the cg.
the w&b manual allows for operation with missing cargo locks and in such instances limitations on cargo loads will still ensure that pallets can not tear free under normal operating conditions.

The 747 crash a few years ago which was caused by military equipment moving used a layout where there were no pallets/containers in front or behind the vehicles to prevent then moving if they tore free.

@JH-CAMO - does atlas use pallets or containers on the 763?

While I agree in principle, the scenario would not be ripping out locks but rather not engaging locks to begin with. If there are a lot of empty positions the pallet can slide fairly easily It has occurred many times in the past.

Hotel Tango

28th Feb 2019, 22:18

While I agree in principle, the scenario would not be ripping out locks but rather not engaging locks to begin with.

In that case they would already have had a serious problem on take-off!

seagull967

28th Feb 2019, 23:04

In that case they would already have had a serious problem on take-off!

Not necessarily. Depends on where the cans are, etc. Seen that one too!

DaveReidUK

28th Feb 2019, 23:06

In that case they would already have had a serious problem on take-off!

Not necessarily.

If, for example, the forwardmost ULD hadn't been securely locked down, but those behind had, then the problem wouldn't have been apparent on take-off, but on descent.

We're not talking about an accident like Bagram where the cargo moved aft.

Hotel Tango

28th Feb 2019, 23:15

Yep, fair enough. But in that case, wouldn't the problem manifest itself earlier in the descent?

seagull967

1st Mar 2019, 00:22

Yep, fair enough. But in that case, wouldn't the problem manifest itself earlier in the descent?

Again, too many assumptions here. And again, the answer is "not necessarily". I should add that I view this as an EXTREMELY improbable factor in this accident!

tdracer

1st Mar 2019, 01:21

Again, too many assumptions here. And again, the answer is "not necessarily". I should add that I view this as an EXTREMELY improbable factor in this accident!

Given the hull loss rate of the 767 (~1 in 10 million departures), pretty much any cause is going to be in the 'very' to 'extremely' improbable range. That's why we never rule anything out until it's shown to be not relevant.

FIRESYSOK

1st Mar 2019, 01:58

Given the hull loss rate of the 767 (~1 in 10 million departures), pretty much any cause is going to be in the 'very' to 'extremely' improbable range. That's why we never rule anything out until it's shown to be not relevant.

I don’t think the ‘extremely unlikely’ loss rate equates an improbable cause. Modern airliners rarely invent new ways to crash. Unlikely to happen, yes. An improbable cause, probably not.

Machinbird

1st Mar 2019, 05:53

There was an accident in 1981 involving a military EC-135 that bears some resemblance to this B763 accident.
EC-135 loss of control (https://aviation-safety.net/database/record.php?id=19810506-0)

Jackw106

1st Mar 2019, 06:55

Condolences to the families

https://www.youtube.com/watch?v=Qwki7Qutoas

Raffles S.A.

1st Mar 2019, 17:32

He forgot Lauda Air Flight 004.

henra

1st Mar 2019, 18:39

There was an accident in 1981 involving a military EC-135 that bears some resemblance to this B763 accident.
EC-135 loss of control (https://aviation-safety.net/database/record.php?id=19810506-0)

Indeed there are some similarities. Other flights reported IMC conditions, so the onset and what is going on exactly might not immediately have been transparent to the Crew and some ensuing confusion could have delayed possible corrective actions.
That would definitely be one of the somewhat less alien scenarios in this otherwise rather mysterious accident. Although there would still be the question why the Trim ran away. Let's hope they find the boxes soon. Something like this would be rather easy to determine from FDR data.

DDG-37

1st Mar 2019, 18:53

Not necessarily.

If, for example, the forwardmost ULD hadn't been securely locked down, but those behind had, then the problem wouldn't have been apparent on take-off, but on descent.

We're not talking about an accident like Bagram where the cargo moved aft.

Impossible. Not enough moment arm for an attitude such as that.

IcePack

1st Mar 2019, 18:59

Sudden significant negative G onset would certainly cause confusion if not expected.
Can anyone estimate the neg G that could be experienced from the traces posted in this thread.

Airbubba

1st Mar 2019, 19:26

From the NTSB Twitter feed:

NTSB has recovered the cockpit voice recorder from the cargo jet that crashed in Trinity Bay in Anahuac, TX. CVR being transported to NTSB labs in DC and will be evaluated when it arrives.

https://twitter.com/NTSB_Newsroom/status/1101575071699750912

GordonR_Cape

1st Mar 2019, 19:46

Sudden significant negative G onset would certainly cause confusion if not expected.
Can anyone estimate the neg G that could be experienced from the traces posted in this thread.

I tried to guesstimate the negative g forces, but that would require the exact time interval from the traces, which is not entirely clear:
1g would take the aircraft from 6000ft to ground in 19 seconds (sqrt(6000/16))
2g would take the aircraft from 6000ft to ground in 14 seconds (sqrt(6000/32))

172_driver

1st Mar 2019, 19:48

SteinarN

1st Mar 2019, 20:29

There is also the CRJ200 in Sweden that plunged into the ground in a similar fashion. One of the IRUs malfunctioned but instead of removing the attitude all together it displayed incorrect attitude information.

This accident happened in the dark in the middle of the night, starting at about 33,000 feet. No moon either if I recall. The crew was preparing decent or some other task so they had some lights on in the cockpit. The result was that they had very little to no outside visuals.

When the erreonous high pitch attitude showed up on the fligth display of the PF he didnt cross check with the PM's display, instead he almost instantly pushed control column forward reaching negative G as high as -1G.
VMO at 315 knot was exceeded 17 sec after onset. At 30 sec after onset IA was passing 400 knots and altitude was 24,000 feet. Crashed at near supersonic speed at around -80 degrees pitch and got completely pulverized. It took about 120 sec from onset at 33,000 feet until crash.

Tjosan

1st Mar 2019, 20:33

DaveReidUK

1st Mar 2019, 20:34

I tried to guesstimate the negative g forces, but that would require the exact time interval from the traces, which is not entirely clear:

Correct. While you can plot a reasonably accurate profile (altitude vs horizontal position) from the FR24 data, you can't reliably derive anything that's time-dependent as the timestamps (added to the ADS-B data by FR24) are all over the place.

Anyone who doubts that is invited to try to calculate groundspeed by dividing the distance between two successive plots by the interval between the associated timestamps.

172_driver

1st Mar 2019, 20:47

On the captains ADI, yes. Not on the other two.

It was enough to cause the end result.

I don't know if 3591 was in visual conditions or not. The only camera footage I have seen show a rather hazy atmosphere.

It was just one idea of many possible.

gums

1st Mar 2019, 20:56

Salute!
Seems someone elsewhere mentioned that the two recorders were within 10-15 feet of each other vertically and maybe 20 feet horizontally.
So finding the FDR now seems imminent.
Gums.......

Ripper3785

1st Mar 2019, 21:10

Here's some discussion of 767 stab trim from pprune 15 yrs ago - pprune.org/tech-log/145022-unschedule-stab-trim-b767.html (I can't post links)

ironbutt57

1st Mar 2019, 22:19

Gipsy Queen

1st Mar 2019, 23:00

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

Frankly, I'm surprised the former is not a fundamental requirement of forum participation. I'm afraid the latter would exclude me!

Airbubba

2nd Mar 2019, 00:36

An update from the Chambers County Sheriff's Office Facebook page.

Today the Houston Police Department Dive Team continued to be a critical part of the recovery efforts of flight 3591 in Trinity Bay. They have been instrumental in this operation to help try and recover Captain Ricky Blakely of Indiana.

The cockpit voice recorder was recovered this afternoon and was transported by the Chambers County Sheriff’s Office to Houston Intercontinental Airport to be flown to Washington, DC, for immediate analysis.

Sheriff Hawthorne would like to thank everyone that has worked tirelessly on this recovery operation.

https://cimg6.ibsrv.net/gimg/pprune.org-vbulletin/1500x2000/53379759_2102149019873281_5397844932595548160_o_af6995845a74 aa56c2252db388e6842c29924b77.jpg

N1EPR

2nd Mar 2019, 03:12

I think KAL had two crashes that were caused by following bad attitude displays. B747 and an MD11.

Fokkerwokker

2nd Mar 2019, 04:09

I think KAL had two crashes that were caused by following bad attitude displays. B747 and an MD11.

i think Air India as well late 70s in departure from BOM

filejw

2nd Mar 2019, 05:24

I think KAL had two crashes that were caused by following bad attitude displays. B747 and an MD11.

Just one the 744F, the MD11 you speak of the CA was 1500’ high and pushed nose over to sharply and drove A/C into ground from 4500’

fdr

2nd Mar 2019, 05:26

KAL lost the B747-200F at EGSS on 22 Dec 1999 by memory. It had a Capt's ADI failure in roll axis only. The only person who knew what was happening was the Flt Eng, and he resigned to his fate on the way down. The CVR is sobering, as was how close it got to the village. The other ADI and standby were fine until they got mussed up by England's green and pleasant land.

The mega death 2.0 was not caused by any attitude indication failure. The accident report by the state of incident is nonsense, and did not make any sense to the CVR or the radar data which is all that survived. The DFDR was taken out by the APU... The FO was aware of the event as it developed. The underlying causal factor is common on many other aircraft, however, the 2.0 at modest weights can have a wild ride in certain circumstances. Paradoxically, having good performance can result in not having any performance... on 15 Apr 99, the crew got caught out by the interplay of the AP and ATS in high rate events. The logic of the system has been changed since then, but the same sort of interplay still occurs on Boeings to this day. Airbus, this is one event that would not occur in your airplanes, you have other matters to deal with, like full thrust TOGA which adds so much fun to the event. HL7373 was more or less wings level from the event to impact. It did stall twice in the event, once at TOC, and once in the recovery. The last high speed stall probably would have made no difference, the attitude required to meet the available data made a prompt recovery necessary before the pitch attitude had decreased to that in the mid stages of the descent. From approximately 4500' AGL, the aircraft hit the ground in just a little over 16 seconds, from a low speed as recorded by both the radar plot and by the spectral analysis of cockpit wind noise. The behaviour of the autothrottle was identifiable by spectral analysis of the CVR, which showed that where the engine signal was lost due to ambient noise, the 400Hz lines and their harmonics showed the response of the CSD which has a slight delay to the changes in engine RPM; increasing N2 gives an initial overspeed of the CSD which shows as a shift of the 400Hz line, and vice versa for the thrust reduction case. The cockpit broadband noise also provided an SPL solution for speed, which made the modelling of a reasonable flightpath possible in conjunction with the calls of speeds, and the radar data which was pretty sketchy itself. When you are flying your non Bus aircraft, pay some attention to high rate altitude captures with AP and ATR engaged, as during the altitude capture the aircraft is pitching to a rate to achieve the level, which may or may not be within the energy capability of the aircraft. Opposite occurs in a high rate descent capture of an altitude, if you have the boards out, then retracting them once the altitude has been captured will result in a speed excursion dependent on the sink rate and speed at the time of alt cap.

Capturing an altitude from a zoom climb, where you happen to have traded speed for increased vertical rate needs to be carefully monitored, as you may not have enough thrust left to fly the path that is now commanded by the APFD, and you could end up with a reducing airspeed if not intervened.

Filejw: I assure you from hundreds of hours of reviewing 16 seconds of audio, that the crew did not dive the aircraft into the ground, it stalled at TOC. The CAAC report was and is nonsense, and did not match the CVR or radar data. The FO was rather insistent in the last seconds of his life about raising the attitude that the aircraft had achieved in the post stall, and which had a hesitation mid way down from the secondary stall which was evident on the CVR. The hypothesis of a simple push forward from the speed of 240KIAS (by memory that was assumed) but did not match the radar data) was not borne out by kinematic reconstruction or by simulator trials; simply put, you cannot get the plane from Point A to the known Point B in the required attitude at impact, time or distance, which I was also involved in. FYI, the simulator was odd in its own right, we demonstrated 6000FPM + rate of climb in full stall conditions which didn't appear to match either the QTG or the plane itself. The MD11 was an acquired taste; it had more than it's share of issues on landing, from a high approach speed as a freighter, coupled with it's relaxed longitudinal stability which LSAS assisted to some extent. The 10 was a very nicely harmonised plane,

The EGSS aircraft was a -2B5F, (MSN448, HL7451 KAL8509) not a -400. Both of these were messes to clean up.

SRM

2nd Mar 2019, 06:34

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..

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.

AtoBsafely

2nd Mar 2019, 08:19

SRM

2nd Mar 2019, 09:15

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

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

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.org-vbulletin/1620x1080/img_0181_1_47205924232_o_large__bd45fbb92ec4f3974e65fb286d25 ef0d4c7967d6.jpg
https://cimg2.ibsrv.net/gimg/pprune.org-vbulletin/1620x1080/img_0197_3_46343235515_o_large__e85f3433f962b7f7600dd2e6d16a cb2a50c0776e.jpg
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/1620x1080/img_0192_2_40292987013_o_large__33787a4354fedef13698654e9802 d1cfe881f241.jpg
https://cimg1.ibsrv.net/gimg/pprune.org-vbulletin/1620x1080/img_0212_5_46343479315_o_large__b177f5182fd9363395f2402462d7 ea97dfc5e363.jpg
https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/1620x1080/img_0214_6_47206174912_o_large__e4a0dc60d851b6af2ce1a89465d9 5a3e290c1be8.jpg
https://cimg8.ibsrv.net/gimg/pprune.org-vbulletin/1620x1080/img_0209_4_47206174892_o_large__4d83fca800309342c6397937beab 37594387f8b1.jpg

Airbubba

2nd Mar 2019, 18:14

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

https://youtu.be/fU9D-1Ij40Q

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

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

Airbubba

2nd Mar 2019, 22:59

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.

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.

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/process/Documents/CVR_Handbook.pdf