Although it should not matter in grief... always a higher chance over here that we lost some friends...
http://lite.cnn.com/en/article/h_2d40d8ba62f5e85130bce6065b117780 <-- text version
http://avherald.com/h?article=4c497c3c
If it's someone of our community it hurts even more. I'm hoping for a sign of life ...
|-|ardy
That's actually what I meant with "over here." Any Atlas drivers here?
Hey guys,
I'm with Atlas and, like most in the community, we are still quite disconcerted.
All we know is that no effort is being spared taking care of the affected families.
Regards,
Mariano
I'm very glad you're still here, Mariano!
What a catastrophy for the families and friends.
|-|ardy
Thank you for your concern, Hardy.
Somber and humbling days ahead.
Best regards,
Mariano
Aviation is a big family, and when a tragic accident happens, we are all very saddened
Do I understand correctly that Jon is on 76's with Atlas also??? Hope all OK.
I'm at K4 on the 767, but this still hits pretty close to home for me. I just got off the phone with an FO I flew with last month and he's pretty disturbed by it too. He has a wife and two young kids. We operate from the same hub as these guys and we all know it could have just as easily been any one of us instead of them.
Jon
Mariano, I'm very sorry that you've had a loss in the family.
Best wishes all around, for anyone affected by this tragedy.
NTSB press conference record at AvHerald.com.
There is surveillance video of the A/C in a nose down, steep dive before impact. Something ugly must have happened not with engines and not asymm. Anybody's guess what.
Patience... difficult.
Hoppie
Quote from: emerydc8 on Sun, 24 Feb 2019 22:25
I'm at K4 on the 767, but this still hits pretty close to home for me. I just got off the phone with an FO I flew with last month and he's pretty disturbed by it too. He has a wife and two young kids. We operate from the same hub as these guys and we all know it could have just as easily been any one of us instead of them.
I do feel the same. However rationally, you or me driving to work still is so much more dangerous (especially down here in Miami) that it should provide a bit of comfort that once in the aircraft, you are in a rather safe environment. Statistics are ugly.
Hoppie
Thanks. You're probably right, especially in MIA. I jumpseat almost every month on Atlas and I haven't been on a flight yet where I wasn't made to feel at home and where I didn't know someone (usually a lot of people) that the crew also knew. Maybe it's because I used to work at Polar in another life, or maybe it's just being in the freight side of the business since 1988, but I've found a certain degree of comradery with the Atlas crews that has made it feel like I'm deadheading on my own company's airplane. We usually end up talking so much that the hours go by quickly. On behalf of the Kalitta pilots, our thoughts are with our Atlas brothers right now.
Thanks, Will and Jon.
Tragedies do help us put things in perspective, as we tend to get wrapped around and consumed by mundane and mostly irrelevant issues during the course of daily life.
Lessons will be learned from this terrible situation, albeit at an extremely steep cost. That's all for which we can hope, at this point.
Best regards,
Mariano
Guys,
My first thoughts go the families of the victims of course.
But Jon and Mariano, by your respective jobs I can understand how you must feel right now and how things have a much more personal feeling for both of you.
I guess I speak for many people here saying that if aviation is a family, this forum is a sub part of it.
Both of you are exceptional contributors to this forum, and even if I am frequently a silent reader, and I don't take the time to say thank you, your excellent contributions are always appreciated. People like you are what make this place special.
I guess Hardy's biggest credit, aside from having developed PSX, is attracting quality people that are passionate about what they do, and willing to share it.
With all my thoughts.
Charles
Very sad news :-(
From that report from the camera, might it have been due to cargo detachement ?
We've seen so many wild theories, it makes no sense to just speculate. Cargo shift is not impossible but unlikely that late into the flight and with Amazon, it's usually voluminous but light. Better wait for the investigation to produce results. Should not be a very long wait. :-(
Hoppie
God Bless & God Speed! Our thoughts and prayers follow.
C
Quote from: Jeroen Hoppenbrouwers on Mon, 25 Feb 2019 08:47
We've seen so many wild theories, it makes no sense to just speculate. Cargo shift is not impossible but unlikely that late into the flight and with Amazon, it's usually voluminous but light.
I don't understand why Amazon freight should be lighter than other average freight. Amazon sells all kinds of products, not just popcorn.
Charles,
Thank you for your very kind words.
I have always been amazed at how professional, cordial and welcoming this forum has remained ever since I joined it back in 1997.
I will never understand how one mortal being could have created such a mind-blowing (and affordable) software, and I will never comprehend how he managed to keep this forum so clean and so different from most other nasty, verbally-abusive and negativity-filled forums and online communities these days.
I don't have Facebook, Instagram, Tweeter or any other form of social media. This is the only forum I frequent and the only way I socialize online (aside from WhatsApp), mostly because of the way people behave when behind the safety of a screen. I do read Av Herald reports regularly and sometimes I make the mistake of straying into and reading a few posts from readers, which only reinforce my decision to stay away from socializing online.
After PSX was introduced, I feared that our small community would be flooded by hordes of arrogants and "experts". Somehow, this never materialized and we remain a rare, yet exemplary online family, for which I couldn't be more pleased.
Best regards,
Mariano
As a frequent customer I can attest that their packing is normally unrpoportionally large for the ordered item. I have seen small but fragile items in a huge box with lots of air cushions. Even non-fragile items are delivered in normally oversized boxes.
No complaints, but I do see where this could be much lighter than standard industrial bulk or boxed
shipments or a single generator etc.
C
Regarding Amazon cargo.
Sometimes we fly containers filled with boxes being shipped to homes/business (lighter cargo) and sometimes we also fly heavier pallets loaded with inventory of all sizes and weights being moved between warehouses for logistics positioning. Most of the time, it's a combination of both.
Best regards,
Mariano
And sometimes it's hard to tell who you're flying for.
And that, yes. 😂
Mariano
Quote from: Hardy Heinlin on Mon, 25 Feb 2019 13:00
I don't understand why Amazon freight should be lighter than other average freight. Amazon sells all kinds of products, not just popcorn.
My (personal) reasoning is that Amazon packages are not average freight. A large amount of stuff Amazon ships is a small item in an oversize box. It's a lot of air, compared to shipments that are prepared for airlift. Assuming, of course, that there are actual end-addressee packages in those containers -- and here I may make a crucial mistake. If Amazon merely ships between warehouses, they probably pack their containers as tightly as anybody else.
Hoppie
We're regularly leaving the DHL hub (night sort) with 110,000 - 120,000 pounds of freight, which puts us very close to our 326,000 pound landing weight limit. With only 24 positions (ULDs), they must be packing them pretty tight.
Yet another theory down the drain. With most/all cargo in containers, cargo shift isn't likely anyway.
Well, that flight was not coming from the hub and it wasn't a DHL flight, so I can't speak for the kind of loads they're carrying between MIA and IAH.
So with that theory thoroughly washed down the drain can we respectfully now stop the speculation.
Only the remains of two of the crew have been recovered from the debris field, I doubt whether they have yet to be released to the families - it is only then than the processing of grief can begin - this is a process that never ends for the next-of-kin & wider families of the lost crew.
For the family of the still missing crew member - the search continues.
We are privileged to have amongst our number Jon & Mario who fly this aircraft type as professionals, just for a second before you feel like a little more 'Monday Morning Quarterbacking' put yourselves in their shoes.
We will find out what happened, when it happened, how it happened & why it happened & what will be put in place to ever prevent it from happening again in due course as the investigation reaches the fullness of its outcome. If you want to speculate then go & do that on one of the myriad of other 'aviation' related websites out there.
Sorry for being blunt.
Best Regards
Steve
QuoteWe are privileged to have amongst our number Jon & Mario who fly this aircraft type as professionals, just for a second before you feel like a little more 'Monday Morning Quarterbacking' put yourselves in their shoes.
Personally, I don't fault anyone for asking what happened. We're all wondering -- probably we pilots who fly the airplane more than others. If it turns out to be something that could be prevented by getting information out to the flight crews, I suspect that information will filter down from our FAA Certificate Management Teams well before the final report.
When the news first broke my thoughts turned immediately to a friend who has flown *that* 767. :( Thankfully they are OK.
Hearing it was in a "steep nose-down attitude" makes me think something catastrophic occurred.
I understand there was weather right where they were and aircraft were vectoring around it, but I'm not sure how bad it was (CB?).
I'm not going to join the speculation, but whatever happened I think was pretty sudden as after they received a weather report and started descent, nothing was heard from them again.
My condolences to their families.
I hope they can determine the cause - as SR111 showed - an aircraft crashing in that situation leaves a massive jigsaw puzzle that takes years to re-build. :( :( :(
From what I understand their routes are fairly random. They seem to fly all over the place, not just between Amazon hubs. I think it is where they best fit the goals of Amazon rather than because of any particular routing.
I think they're packed in tight - Amazon didn't start this operation without ruthless efficiency in mind.
Flight recorder found.
https://www.pprune.org/10405959-post259.html
Good. We have both now. Let's see what happened. Usually some prelim facts-only stuff appears in a few days.
Hoppie
http://avherald.com/h?article=4c497c3c&opt=0
QuoteOn Mar 5th 2019 the NTSB reported the download of the CVR was successfully completed, the last portion of the accident flight is available on the 2 hours' recording, the quality of the recording however is poor and it was difficult to determine what was being said, occasionally required advanced filter techniques. The aircraft was being vectored for an approach to Houston Intercontinental's airport's runway 26L. The NTSB stated: "Crew communications consistent with a loss control of the aircraft began approximately 18 seconds prior to the end of the recording." The FDR was also successfully read out, 54 hours of flight data spanning 17 flights were downloaded. The recorder stores about 350 parameters. The investigators are currently verifying and validating the FDR data. A transcript of the CVR is estimated to be compiled during the next week (Mar 11th and following).
I would not be surprised if this 27-year old airframe never got a recorder upgrade.
/-/
I hope that they can still track the required info to get some light over what really happened with that aircraft, and the souls in it.
As mentioned on PPRuNe.org, here's what looks like the stabilizer ballsscrew...
https://youtu.be/qOa4V4JF4t4?t=268
Atlas part comparison (http://www.members.iinet.net.au/~b744er@ozemail.com.au/744er/767HSTJackScrew.jpg)
It looks ok, in the sense that the screw itself doesn't look shredded (as in the Alaskan Airlines accident) and the gimbal hasn't parted from the ballscrew.
The Atlas was a 767-300
The stabilizer mechanical limits are 0~14.2 units (approx 1 deg/unit)
Column switch limits are between 0.25 and 12.8 units
Neutral position is at 2 units.
Note dimension "A" in the diagram above.
767-300 AIRPLANES;
for all stabilizer trim modes, except alternate trim mode, the
stabilizer leading edge DOWN limit is -11.00 degree stabilizer
angle, or 12.8 units of trim on the position indicators, or
Dimension A is 22.43 inches (569.7 mm). The flaps retracted/not
retracted position determines the leading edge UP limit.
When the flaps are UP (retracted), the leading edge UP limit is 0.50 degree
stabilizer angle, or 1.5 units of trim, or Dimension A is 3.00
inches (76.2 mm).
When the flaps are DOWN (not retracted), the leading edge UP limit is 1.75 degree
stabilizer angle, or 0.25 unit of trim, or Dimension A is 0.92 inch
So with flaps extended to 5 units, the jackscrew range is 21.51 inches. With flaps not extended, the jackscrew range is is only 19.43 inches.
Without a clearer photograph, and without knowing the diameter of the jackscrew, it would be hard to say what the stab trim setting was (but I'd say a few degrees nose up).
On Mar 12th 2019 the NTSB provided an update stating:
QuoteThe wreckage was situated in a shallow muddy swamp area, and the main debris field was oriented east to west and about 350 yards long by about 200 yards wide (figure 1). One engine and some landing gear components were found beyond the main debris field to the west. Less dense components and a large portion of the cargo floated southward and were recovered up to 20 miles away.
The NTSB reported:
Air traffic control communications and radar data indicated the flight was normal from Miami to the Houston terminal area. About 12:30 pm the pilots contacted the Houston terminal radar approach control (TRACON) arrival controller and reported descending for runway 26L; the airplane was at 17,800 ft with a ground speed 320 knots.
At 12:34, the airplane was descending through 13,800 ft, and the controller advised of an area of light to heavy precipitation along the flight route and that they could expect vectors around the weather.
About 12:35, the flight was transferred to the Houston TRACON final controller, and the pilot reported they had received the Houston Automatic Terminal Information System weather broadcast. The controller told the pilots to expect vectors to runway 26L and asked if they wanted to go to the west or north of the weather.
Radar data indicated the airplane continued the descent through 12,000 ft with a ground speed of 290 knots, consistent with the arrival procedure. The pilots responded that they wanted to go to the west of the area of precipitation. The controller advised that to do so, they would need to descend to 3,000 ft expeditiously.
About 12:37, the controller instructed the pilots to turn to a heading of 270°. Radar data indicated the airplane turned, and the automatic dependent surveillance-broadcast (ADS-B) data indicated a selected heading of 270°. The airplane was descending through 8,500 ft at this time.
About 12:38, the controller informed the pilots that they would be past the area of weather in about 18 miles, that they could expect a turn to the north for a base leg to the approach to runway 26L, and that weather was clear west of the precipitation area. The pilots responded, "sounds good" and "ok." At this time, radar and ADS-B returns indicated the airplane levelled briefly at 6,200 ft and then began a slight climb to 6,300 ft.
Also, about this time, the FDR data indicated that some small vertical accelerations consistent with the airplane entering turbulence. Shortly after, when the airplane's indicated airspeed was steady about 230 knots, the engines increased to maximum thrust, and the airplane pitch increased to about 4° nose up and then rapidly pitched nose down to about 49° in response to column input. The stall warning (stick shaker) did not activate.
FDR, radar, and ADS-B data indicated that the airplane entered a rapid descent on a heading of 270°, reaching an airspeed of about 430 knots. A security camera video captured the airplane in a steep, generally wings-level attitude until impact with the swamp. FDR data indicated that the airplane gradually pitched up to about 20 degrees nose down during the descent.
Gregory Allen "Greg" Feith is an American
former Senior Air Safety Investigator with the National Transportation Safety Board (NTSB). Today on Denver News Channel 9, while commenting on the 737 Max crashes, Greg Feith said this, verbatim:
Quote...and a lot of carriers overseas, they are so automation dependent that they don't know, based on their training, when to intervene, and if there is a problem they continue to try to use the automation. We've seen that now in three accidents. Lion Air, Ethiopian, and in fact, Atlas Air, the one that crashed in Houston. The automation was still coupled, the pilots didn't hand fly the airplane when they lost control and even through the recovery they were fighting the automation.
Interesting that the NTSB has since revised the following passage from:
Quote... rapidly pitched nose down to about 49° in response to column input
to
QuoteThe airplane then pitched nose down over the next 18 seconds to about 49° in response to nose-down elevator deflection.
https://www.ntsb.gov/investigations/Pages/DCA19MA086.aspx
The way it was initially worded could have definitely led to certain conclusions being drawn. The new wording, not as much.
Quote...when the airplane's indicated airspeed was steady about 230 knots...
...engines increased to maximum thrust...
...rapidly pitched nose down to about 49°...
...The stall warning (stick shaker) did not activate...
Hmm.
Quotein response to column input
They said it, then apparently redacted it. I would doubt they would write it if they didn't mean it.
Given everything else written, and the video, it's not looking good.
QuoteGregory Allen "Greg" Feith
He's talking rubbish. The 737 MAX crashes and incidences have nothing to do with pilot reliance on automation. There is TOO MUCH AUTOMATION working against the pilot.
In the 737 MAX problem, the MCAS is sensing bad data, not checking it, not faulting, and instead pushing the nose over, suddenly, during critical phases of flight where the aircraft is low to the ground.
He's blaming pilots far too readily - he's not unbiased (or even accurate).
QuoteThey said it, then apparently redacted it. I would doubt they would write it if they didn't mean it.
There have been other suggestions like a crew member heart attack (and subsequent slumping on the control column). Would all crew members be securely belted in at this point?
Although column position is fed into the DFDR, I'm not certain if that data is necessarily recorded. The DFDR may only have had a record of elevator position. (Something may have been lost in translation .. between the guy reading the DFDR data and the guy who issued the statement).
The column sometimes kicks when hydraulics are applied. Might a hydraulic problem have caused a hard nose down input? Have there been incidences of mechanical or A/P failures resulting in large elevator deflections? It's happened on A330s, but they are different beasts.
Another interesting analysis:
https://www.satcom.guru/2019/02/more-questions-raised-for-atlas-5y3591.html
Do they know whether the A/P was engaged during the dive?
I read "column" and "elevator" -- did I miss something?
Quote...and a lot of carriers overseas, they are so automation dependent that they don't know, based on their training, when to intervene, and if there is a problem they continue to try to use the automation. We've seen that now in three accidents. Lion Air, Ethiopian, and in fact, Atlas Air, the one that crashed in Houston. The automation was still coupled, the pilots didn't hand fly the airplane when they lost control and even through the recovery they were fighting the automation.
While riding in the observer seat of a flight this evening we were at FL370 in moderate TB. The captain decided to climb to FL390 to get over the tops. During the climb, it went into SPD|VNAV PTH and the A/T came right back to about 75% N1 as we leveled at FL390. It stayed there as the airspeed bled off towards M.70 and headed lower. We have no idea why it happened but intervention was definitely required to prevent a stall. The automation is definitely not foolproof and this was no programming error by the crew.
I so hope this was an automation dependency-related crash so that at least something good could come out of it.
Was there any turbulence while the A/T was staying at 75%?
Yes. And IMC conditions, but too cold for ice (-56 SAT). The ECON SPD was .79 and I saw .70 when I said something. It took firewall power to get it back and even then it took about a minute. The throttles were not moving at all by themselves. They eventually disengaged the A/T and then pressed SPD to reconnect. After re-engaging VNAV they seemed to work okay, but we were already out of the TB by then.
Was a report filed?
This isn't United.
Is there any turbulence mode on the 767 that freezes the A/T to avoid chaotic thrust adjustments?
Not that I'm aware of. But there is something to the effect that operation in moderate to severe icing conditions could result in erratic or unreliable autothrottle operation. I just can't seem to find it now. They train this in the sim on a LOFT during climbout. If you don't intervene quickly, you'll blow right through the barberpole when you level off at an intermediate altitude.
Found it. We were on top/in this "bomb cyclone" over the midwest https://www.zerohedge.com/news/2019-03-12/bomb-cyclone-back-and-its-ready-explode-hurricane, so it could have been ice crystal icing that caused the A/T issue, even at the colder SAT. It was pretty unusual weather.
(http://www.hoppie.nl/forum/var/ad20111602(1).jpg)
Just asking out of curiosity. The autothrottle cannot maintain the desired airspeed, but the engines can, right?
Many control systems are based on two items:
1. A model, using mathematics, to predict what the controlled system will do,
2. A feedback loop, using sensors, to tell the controller what the controlled system actually does.
If the A/T cannot maintain the desired airspeed, this must mean that something goes completely upside down in the feedback loop. Apparently there are elements other than airspeed (which is obvious) that tell the A/T that it is doing fine. Is the A/T model so much based on physics and expectations that, say, a frozen over OAT/TAT sensor will upset the controller enough so that it does not push the throttle forward, even while it physically can? In other words, is the A/T controller always flying blind by the numbers it uses to estimate the required throttle position, and does not cross-check itself with the desired airspeed, but only with the thrust it wants?
Hoppie
On the 744 (and probably on other jets too) the A/T disconnects when a relevant probe heat fails. The control loop is very sensitive. It's not only the pitot probe that provides fractions of a knot to the sensor loop; the airspeed trend too adds nuances to the sensor loop. The system would oscillate if there wasn't any trend data in the sensor loop that feeds the control loop. Without any anticipation function it would chase the target point back and forth. So the data filters need to be fine-tuned very much; any slight sensor error would have a big effect. I guess disabling the control loop in such a case is better than keeping it enabled, driven by wrong sensor data.
Got it. But I keep thinking, if the single sensor that gives you a final good/no-good of the control loop, the KIAS pitot tube, is telling you you're not at all even close -- what do you do? *BING* A/T disconnect, I'd think. Better than the sneaky slowly decreasing airspeed somewhere up near the coffin corner. Apparently this KIAS sensor is not in the loop at all, or so overwhelmed by all the other air data sensors that it has nearly no vote?
The 767 and 747 A/T computers in the FMC may actually be of the same generation, so they may share this "interesting" feature? Has any of our resident 747 drivers ever seen such a hideous thing?
Hoppie
Quote from: Jeroen Hoppenbrouwers on Wed, 13 Mar 2019 23:52
Apparently this KIAS sensor is not in the loop at all, or so overwhelmed by all the other air data sensors that it has nearly no vote?
I would say the latter is true. The KIAS sensor is even the primary one. No airspeed control without airspeed data. The (744) FMC has a cruise-airspeed-thrust database though. You can see the database thrust data on the VNAV CRZ page, and on the EICAS (magenta line) when the A/T is disengaged and VNAV is engaged. However, this feature is not designed for permanent, exact airspeed control; and not at all for climb/descent or transition phases. It's rather useful for manual flight in turbulence, or when the A/T fails. In level flight.
|-|ardy
NTSB Intial Report review...
https://www.washingtonpost.com/national/cargo-plane-appears-to-have-hit-turbulence-before-crash/2019/03/12/c2737674-44e1-11e9-94ab-d2dda3c0df52_story.html?noredirect=on&utm_term=.bc09e1f4bfa3
This coincides with what the friend of a person on the investigative committee told to me last night. He said they are probably going to be looking hard at Atlas's training department and the experience level of pilots they are hiring. With the labor strife over there, and the pilot shortage, it sounds like they are scraping the bottom of the barrel to keep up with the massive attrition.
Quote
Pilot Error Suspected in Fatal Atlas Air Cargo Crash
Investigators exploring likelihood that crew accidentally increased thrust on approach to Houston airport, sources say
Andy Pasztor
March 15, 2019 4:06 p.m. ET
National Transportation Safety Board experts, these people said, are focusing on a likely sequence of events that started with the crew of the Boeing Co. 767 approaching Houston's George Bush Intercontinental Airport on Feb. 23 inadvertently commanding dramatically increased engine thrust. Turbulent air could have jostled the arm of one of the pilots, causing the engines to rev up to takeoff power, one of these people said.
The sudden surge in thrust, which the safety board disclosed in an earlier factual update, forced the nose of the plane to pitch upward and startled the cockpit crew, according to these people. Almost immediately, according to the preliminary data released by the safety board, the crew responded by sharply pushing down the nose of the aircraft.
The board previously said the nose was pointed downward at a 49-degree angle with the plane still about 30 miles from the airport, creating a much steeper descent than a normal landing approach.
The seemingly disoriented crew failed to regain control—despite commands to pull up from the jet's high-speed dive—and the wide-body plane plowed into a marshy area.
The safety board said the crew had the required training and medical certificates.
The safety board hasn't issued any final conclusions, and the leading theory currently pursued by investigators could change as more information is developed. A spokesman for the board said it had no comment beyond the factual update released earlier. Boeing had no immediate comment.
Atlas Air Worldwide Holdings Inc. and the union representing its pilots both declined to comment, citing the ongoing investigation.
But at this point, such cockpit slipups are considered the most likely cause of the crash. The plane was skirting around some storm cells before the plunge, but people familiar with the details said the turbulence didn't cause any structural damage or lead any system to malfunction.
In its update, the safety board said the "engines increased to maximum thrust" as the plane was flying at roughly 6,000 feet. After a brief nose-up movement, according to the update, the Boeing 767 entered a steep descent in a "generally wings-level attitude until impact with the swamp."
Many airline and aerospace industry officials have watched the probe closely because the 767 model is widely used as a passenger jet around the globe.
The Atlas Air flight, en route to Houston from Miami, was flying cargo for Amazon.com Inc.
The last fatal U.S. airliner crash also was a cargo flight. In 2013, a United Parcel Service Inc. Airbus A300 slammed into hill while approaching to land in Birmingham, Ala., killing both pilots. The safety board determined that a series of pilot errors and violations of safety procedures caused that accident. The aircraft descended too quickly toward a runway shrouded by clouds, and the pilots waited until the last seconds to try to initiate a go-around.
—Alison Sider contributed to this article.
Write to Andy Pasztor at andy.pasztor@wsj.com
QuoteTurbulent air could have jostled the arm of one of the pilots, causing the engines to rev up to takeoff power, one of these people said.
Do they mean someone hit the GA switch?
That thought came to mind. I can't find any data in my manuals regarding whether or not the A/P would even disconnect if you manully moved the controls while it's engaged. I have tried several times in the real plane to override the ailerons (45 degrees on the yoke) with the A/P engaged to see if it would disengage but I couldn't get it to do it.
From a JAL accident report.
Quote(3) Manual Override of Autopilot
"Manual override" means that when the autopilot is engaged, a force applied by the pilot to the control column makes the control surface angle different from that of the autopilot command. The term "manual override" is used with this meaning in the remainder of this report.
With the Boeing 747-400D airplane, when only one autopilot is engaged, the pilot can manually override the autopilot by applying a force on the control column. The autopilot does not disengage due to the manual override.
This is pure speculation, but what would have happened if both pilots were pushing forward with the A/P engaged and TOGA thrust being applied and at some point the A/P became disengaged? Nose dive?
Max thrust and 49-degree pitch down -- to me that sounds like suicide rather than lack of pilot training.
That's what a bunch of us first thought too, but apparently (according to my source) that has been ruled out. I think we'll know soon enough.
TOGA will not work at that altitude, right?
Nightshifts have crazy effects one's brain... Never understood the flighttime regulations in the USA for freighter pilots. If this is true, this is a solid case to start reviewing this.
TO/GA arms with glide slope capture or flaps out of up.
UPS and its law firm, Jones Day, used the FAA Assistant Chief Counsel, Rebecca MacPherson, to sign off on the cargo carveout just before she left the FAA to take up a job as "Of Counsel" with Jones Day. When I called her out on it, she blamed the OMB's economic analysis. It's a revolving door between government and industry.
http://www.lawyerdb.org/Lawyer/Rebecca-MacPherson/
https://www.faa.gov/regulations_policies/rulemaking/recently_published/media/2120-AJ58-FinalRule.pdf
QuoteAll-cargo carriers may choose to comply with the new part 117 but are not required to do so. Since the carrier would decide voluntarily to comply with the new requirements, those costs are not attributed to the costs of this rule.
Actually, I truly hope fatigue is a causal factor in the Atlas crash. It wouldn't surprise me at all. I fell asleep at the controls last week due to a ridiculous (but legal) schedule.
Yes my mind has trouble understanding it now. Accidental full thrust and accordingly a pitch-up -- ok. But then a startled pilot would PULL the yoke to keep the airspeed in check?!
Or would everybody on the deck think they were already climbing steeply, due to somatogravic illusion (accelleration feels like climbing) and having missed the engine oops due to for example noise of, say, thunder or rattling kit due to turbulence, no outside horizon, etc.?
http://aviationknowledge.wikidot.com/aviation:somatogravic-illusion
Need more info. It will come.
Hoppie
Quote from: Jeroen Hoppenbrouwers on Sat, 16 Mar 2019 11:20
Yes my mind has trouble understanding it now. Accidental full thrust and accordingly a pitch-up -- ok. But then a startled pilot would PULL the yoke to keep the airspeed in check?!
Or would everybody on the deck think they were already climbing steeply, due to somatogravic illusion
That was my initial thought and what is implied (at least to my reading) by the WSJ report (with phrases like "the seemingly disoriented crew"). Although it does seem strange given that the videos etc seem to suggest that it was largely day VMC at the time -- normally one would expect such sensory illusions to be more of an issue with no visible horizon.
Interestingly, the full-flight sims do just that: Lateral acceleration is simulated by pitching the platform nose-up.
767 drivers. Assume flight test. You fly 230 knots level at 6000 ft and intentionally firewall the throttles, count to five, and then agressively pitch down until 50 degrees nose down. How long would this take? Where are you at that moment? Speed and altitude?
Hoppie
If they were looking outside when they pitched up and did not refer to the instruments, the pitch down at night can be killer. There are "visual" cases where you might not really be able to see when you "cross" the horizon or clouds might give you a completely wrong visual impression. You will not be able to tell when to stop pitch down. The pitch down value really makes me feel they had the impression they weren't going down yet. You really have to push long and hard to get that low pitch.
If you then look at the EADI, there will be a few moments where you are completely lost. That's when the famous IFR phrase "trust your instruments" should come into play. People tend to trust what they "believe" in those cases. This wouldn't be the first time somebody freezes up on this situation.
Weren't there daylight VFR conditions?
Quote from: Jeroen Hoppenbrouwers on Sat, 16 Mar 2019 19:33
767 drivers. Assume flight test. You fly 230 knots level at 6000 ft and intentionally firewall the throttles, count to five, and then agressively pitch down until 50 degrees nose down. How long would this take? Where are you at that moment? Speed and altitude?
Will you find anyone who has tested it in the sim?
I guess from 6500 ft on it would take less than 30 seconds at a sinkrate way higher than 10000 fpm, at over 300 KIAS.
Can this be recovered at 4000 ft?
For some odd reason my mind thought they crashed just past midnight... (which was why I referenced to flighttime limitations at night)
In IMC, or at night with no horizon, I could imagine a pitch-over to -49 degrees in an inexperienced crew. But in visual conditions? The whole windshield would have been full of farms, lakes, roads and cars.
I just happened to read this on pprune. I'm not making any assertion about it's veracity or accuracy, but it raises a few interesting questions. One is whether TO/GA will activate if pressed first and then the flaps are moved out of up a split second later. The other is whether the break-out box for the elevator will command a split elevator or if there is a "prevailing" side that would cause both elevators to work in unison. I'm thinking the elevators are bussed together with a torque tube. Later in the post someone also mentions that the speed brakes were out when this happened and the autopilot was engaged.
https://www.pprune.org/rumours-news/...l#post10425322
Quote"The initial bobble is from turbulence at 6200'. When the FO called for flaps 1, the captain accidentally hit the toga button. Toga didn't engage until after flaps were set to 1, which then brought engine power to full, and started the initial pitch of 10 degrees nose up. The FO was startled, and shoved the nose forward... The CVR is startling, and baffling. The CA was pulling so hard against the FO that he sheared the pins on the stick and at that point had no control. They were IMC at the time. When they broke out into VMC, the FO said oh schit and started to pull. That was the round out you see. I won't get into anything more until everything comes out. The records, the CVR, and what happened in the flight deck is truly shocking. They hit a negative 4 G dive initialy on the FOs push. All you hear is stuff hitting the ceiling and at one point a loud thud. They think the thud may have been the JS hitting the ceiling and maybe not wearing the shoulder harness. Like I said, I won't get into anything more about the background of how it all happened. This is the accident in a nutshell. The facts that will come out are shocking."
QuoteThe other is whether the break-out box for the elevator will command a split elevator or if there is a "prevailing" side that would cause both elevators to work in unison. I'm thinking the elevators are bussed together with a torque tube.
There is a torque tube in the tail, but there is an override mechanism on this torque tube which allows independent left/right side movement
up to a 20° split. The column force required to override is 25 lb at breakout, increasing to 41 lb at 20° of elevator movement.
QuoteThe CA was pulling so hard against the FO that he sheared the pins on the stick and at that point had no control.
My notes don't say what happens if the crew are opposing each other. It only says that 25lbs breakout force between the pilots (at the control column end) will decouple the independent cable system (via the "control columns override system" on the torque tube
between the columns). There is no mention of shear pins in any of my manuals.
QuoteToga didn't engage until after flaps were set to 1
Bizarre.
For info:
With no air load, the elevator can move a maximum of 28.5° up and 20.5° down with a full forward and aft movement of the control column. The maximum movement of the elevator in autopilot mode depends upon the number of flight control computers engaged. In single autopilot, the maximum authority is 8.3° up and down. In multiple autopilot, the maximum authority is 28° up and 20° down.
QuoteThe maximum movement of the elevator in autopilot mode depends upon the number of flight control computers engaged. In single autopilot, the maximum authority is 8.3° up and down. In multiple autopilot, the maximum authority is 28° up and 20° down.
That's the max the servos will move it, right? If the A/P was engaged and a pilot manually pushed forward as hard as he could, would it still go to the normal limit (20.5)?
QuoteIf the A/P was engaged and a pilot manually pushed forward as hard as he could, would it still go to the normal limit (20.5)?
Correct. There is a "30lb force
per channel" mentioned for servo "camout". I'm not 100% sure if this corresponds to pilot input. 90lbs force to override triple engage seems a little excessive.
Just noticed that the cutout switches which inhibit trimming when the columns are moved in the opposite direction to the column trimming on the 767 are activated at 2.2~2.7 degrees (for nose up trimming) and 2.0 ~ 2.5 degrees for nose down trimming.
The wiring schematics, however, just say (a tiny) 1.5 degrees for both directions.
Interestingly, to get this trimming inhibit system to work, the columns have to be moved in the same direction.
You can still trim the aircraft in either direction if the columns are split (at least on later model -300's)
Thanks, John.
Quote
Interestingly, to get this trimming inhibit system to work, the columns have to be moved in the same direction.
Do you think this is a typo?
It's shown in the wiring diagrams.
The trimming signal from the active SAM (Stab Trim/Aileron Lockout Module) goes via both cutout switches (at the bases of the columns) to the tail. The switches are in parallel. You can have one switch in the cutout position (open circuit), but the trimming signal can still go via the other one (closed circuit) if the stick is in neutral or in the opposite direction.
I assume that if the pilots were trimming in opposite directions, the SAM would see this as a fault and not give a command to the stabilizer.
On the classic, after every engine start we would trim the stab aft and push the yoke forward to verify that the stab trim cutout was working. Then do the same in the opposite direction and check it again.
If you have an unscheduled stab trim, you turn both stab cutout switches off, observe the unscheduled stab stopped moving and then turn one switch back on (center) and see if the runaway continues. If it doesn't (I guess you have a 50/50 chance), then you would leave it like it is and use the center stab trim system to bring it back into trim.
So, in the situation below, you would want stab trim movement in the direction of the yoke.
For example, you get an unscheduled stab trim aft and you override with full forward yoke and move both cutout switches off. The stab stops. Then you move the center system cutout switch back on and check for further unscheduled stab movement. If no movement, you would leave the other switch (left) off and bring it back into trim using the center system. So the stab would be moving forward in the direction of the full forward elevator. You wouldn't want the stab trim to move opposite (aft).
Does that make sense?
QuoteToga didn't engage until after flaps were set to 1
Does the 767 include the same 2-second delay logic that is included in the 744 for the time from TOGA push to THR REF engagement on the ground? If so, maybe the delay is used for some parameter validations, like the flaps-out condition etc. If the system detects any flaps-out status before the timeout is passed, the TOGA command might be executed. Perhaps! I don't know.
|-|ardy
Either that or the captain could have hit the TO/GA switch after selecting flaps 1.
QuoteInterestingly, to get this trimming inhibit system to work, the columns have to be moved in the same direction.
Just to clarify... I meant that both columns have to be moved in the same direction
as each other (in the opposite direction to the column switch trimming) to stop the trimming.
I was talking about having one pilot pushing and other pilot pulling (i.e. split elevator operation) with one pilot trimmng.
Sorry, I misunderstood what you were saying there. But with regard to the example of the runaway stab trim, I don't know how else the system and the QRH would work. I never tried the stab cutout check by trimming in the same direction as elevator movement -- only in the opposite direction. But if the cutout system inhibited the stab from moving when trimming in the same direction (yoke full forward and trimming nose down at the same time), then how would you ever get the stab to move in this case? The cutout feature wouldn't allow it. I guess you could release the forward pressure on the yoke and try to get the trim moved forward, but the QRH doesn't mention this technique. Maybe this is just another mystery system of Boeing's.
I still think I'm not explaining myself properly.
If, say, the captain was pushing the nose down, but trimming nose up, and the F/O wasn't doing anything, the stabiliser would not run. Both column cutout switches would be open circuit. If the F/O then pushed hard in the wrong direction, the captain's wrong trim input would then activate, assisting the F/O's column input.
This scenario wouldn't happen in real life because you would need both pilots to do silly things. The 4 column cutout switches are only there for redundancy.
Quote from: John H Watson on Sun, 24 Mar 2019 14:37
This scenario wouldn't happen in real life because you would need both pilots to do silly things.
Sadly John, as attested to by many accident and incident reports, this happens far more than we like to see...
Rod
There seems to be some confusion on PPRuNe regarding GA arming.
Someone stated a Radio Altitude input.
I just have glideslope capture and flaps out of up. After a little fishing, it seems to be trailing edge flaps. i.e. flap lever >1 unit.
An "or" gate is also shown in the A/T computer logic.
I've never heard about the RA. Nothing in any manual I have.
QuoteAfter a little fishing, it seems to be trailing edge flaps. i.e. flap lever >1 unit.
Strange. Only one manual has this ">1 unit". The others seem to go on flaps in general.
This YouTube video seems to show G/A at flaps 1, prior to G/S capture:
https://www.youtube.com/watch?v=O3ZKv6-0MQc
The RA kept popping in and out (so the video starts around 2500')'
No new material, but all of it...
http://avherald.com/h?article=4c497c3c/0000
https://youtu.be/GR4xhTF-13g
I find this guy's style and content fascinating - this is his commentary on the preliminary report.
There is too much misinformation in this guy's comments. He corrected himself with the alternate EFIS selection, but he talks about the speedbrakes auto-retracting during go-around.
The F/O's instrumentation failure doesn't seem to be stressed enough. Did he actually see the instruments telling him he was stalling and responded accordingly?
Final report is out.
https://avherald.com/h?article=4c497c3c/0002
QuoteThe NTSB determines that the probable cause of this accident was the inappropriate response by the first officer as the pilot flying to an inadvertent activation of the go-around mode, which led to his spatial disorientation and nose-down control inputs that placed the airplane in a steep descent from which the crew did not recover. Contributing to the accident was the captain's failure to adequately monitor the airplane's flightpath and assume positive control of the airplane to effectively intervene. Also contributing were systemic deficiencies in the aviation industry's selection and performance measurement practices, which failed to address the first officer's aptitude-related deficiencies and maladaptive stress response. Also contributing to the accident was the Federal Aviation Administration's failure to implement the pilot records database in a sufficiently robust and timely manner.
The F/O was a total liability and shouldn't have even been sat in that seat at the time of the accident. A sad day for all concerned. :(