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Old 05-15-2019, 06:09 AM   #621  
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https://www.cnn.com/2019/05/15/us/bo...ots/index.html

This certainly doesn't help Boeing's case!
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Old 05-15-2019, 06:27 AM   #622  
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https://www.cnn.com/2019/05/15/us/bo...ots/index.html

This certainly doesn't help Boeing's case!
Of course it won't, because some are too ignorant to know that the article is far off base, misleading, and inaccurate.

From the article cited (https://www.cnn.com/2019/05/15/us/bo...s/index.html):

Quote:
Preliminary reports of the crashes implicate the MCAS and faulty sensor readings
No, they didn't. In fact, one who knows what he's talking about and reads the report understands something very different.

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But that computerized stability program, the MCAS, received faulty sensor readings in both the Lion Air and Ethiopian jets, and repeatedly pushed the planes' noses downward, and ultimately into steep dives. The pilots' attempts to overcome it were unsuccessful.
Nothing "pushed the planes noses' downward" and we know that MCAS moved the stab trim at the rate of only 1/3 unit per second, max 2.4 units, and could be stopped at any time with standard procedures, and that keeping speed in check eliminated controllability issues. What happened in each case was the crews failure to fly the airplane.

As the Boeing representative noted, the procedure didn't differ with or without MCAS, and the standard procedure for runaway or unwanted pitch trim should have been applied (and was applied in the case of Ethiopian). Again, the procedure worked, or would have, if only the crew had flown the aircraft instead of allowing it to accelerate to destruction.
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Old 05-15-2019, 07:24 AM   #623  
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Of course it won't, because some are too ignorant to know that the article is far off base, misleading, and inaccurate.

From the article cited (https://www.cnn.com/2019/05/15/us/bo...s/index.html):
You can argue the article is all these things, but you can't argue the audio is "far off base, misleading, and inaccurate".

I think the audio is pretty clear.
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Old 05-15-2019, 07:32 AM   #624  
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Nothing "pushed the planes noses' downward" and we know that MCAS moved the stab trim at the rate of only 1/3 unit per second, max 2.4 units, and could be stopped at any time with standard procedures, and that keeping speed in check eliminated controllability issues. What happened in each case was the crews failure to fly the airplane.

As the Boeing representative noted, the procedure didn't differ with or without MCAS, and the standard procedure for runaway or unwanted pitch trim should have been applied (and was applied in the case of Ethiopian). Again, the procedure worked, or would have, if only the crew had flown the aircraft instead of allowing it to accelerate to destruction.
The repeated erroneous application of nose down trim by the automated system - with automation disconnected - that is the problem.

Several have now flown the profile and have only successfully recovered by using the porpoise technique. This technique has been in the manual but has not been taught for decades. Training. Training. Training. MCAS implications with AOA failure were never considered properly. It didnít auto trim once. In fact the first application was imperceptible. Humans were distracted be erroneous airspeed indications and alarms. MCAS snuck up on them and killed them. Iím sure had they turned the cut off switches back on - retrimmed then turned them off they would have been fine. There wasnít time by the time they gave up on an impossible to move stab. Yes reducing power could have helped but speed at their attitude would have taken a long time to reduce to a level where the stab could be moved manually. A crew, expecting this exact failure and focusing only on it, expecting it, could only recover using the porpoise technique unloading the stab. If the airplane was an NG with the same AOA failure this would not have happened. MCAS killed them. Not inexperience.
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Old 05-15-2019, 12:52 PM   #625  
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Originally Posted by pangolin View Post
The repeated erroneous application of nose down trim by the automated system - with automation disconnected - that is the problem.

Several have now flown the profile and have only successfully recovered by using the porpoise technique. This technique has been in the manual but has not been taught for decades. Training. Training. Training. MCAS implications with AOA failure were never considered properly. It didnít auto trim once. In fact the first application was imperceptible. Humans were distracted be erroneous airspeed indications and alarms. MCAS snuck up on them and killed them. Iím sure had they turned the cut off switches back on - retrimmed then turned them off they would have been fine. There wasnít time by the time they gave up on an impossible to move stab. Yes reducing power could have helped but speed at their attitude would have taken a long time to reduce to a level where the stab could be moved manually. A crew, expecting this exact failure and focusing only on it, expecting it, could only recover using the porpoise technique unloading the stab. If the airplane was an NG with the same AOA failure this would not have happened. MCAS killed them. Not inexperience.
Maybe we should be calling it the "reeling in a big fish" technique instead of the porpoise technique. Just like reeling in a fish, you have to give it some slack to reel in.
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Old 05-15-2019, 01:17 PM   #626  
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The repeated erroneous application of nose down trim by the automated system - with automation disconnected - that is the problem.
It really isn't.

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Several have now flown the profile and have only successfully recovered by using the porpoise technique. This technique has been in the manual but has not been taught for decades.
You're a regional pilot, are you not? What's your experience training in (and flying) Boeing aircraft. From your commentary, zero.

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The repeated erroneous application of nose down trim by the automated system - with automation disconnected - that is the problem.

In fact the first application was imperceptible. Humans were distracted be erroneous airspeed indications and alarms. MCAS snuck up on them and killed them.
No, it wasn't imperceptible. Clearly you've never been in a Boeing cockpit, let alone a 737.

There are two big wheels, right by each pilot's knee, with a big white stripe across them. Their motion is unmistakable. It's visual. It's tactile. It's audible. It can't be missed. If it's moving when you're not moving it, and the autopilot is disengaged, then it's unwanted trim, and this is an immediate indication that something is amiss.

Trim motion doesn't "sneak up" in any way, shape, or form. It was designed this way, for a reason.

In most platforms, with stabilizer trim, opposing motion will stop the trim; this is the first step. Opposing it with control wheel switch trim (thumb switches) on the control yoke will also stop the trim action. Finally, the cutoff switches. It's stoppable, immediately, and once it's stopped, there's no sneaking.

We train for realistic distractions from day one; the first moment the student gets to the airplane, before he ever opens the door, we use distractions and we never stop using them. Distractions in flying are a fact of life, and part of wearing big boy pants in the cockpit means we do our job, handle the distractions and fly the airplane.

What we don't do is allow the airplane to accelerate beyond it's maximum operating speed and re-engage pitch trim motors after it's clear (and we've recognized and verbalized) that the pitch trim is the problem.

Whereas we're talking about the Ethiopian mishap here, we're talking about a crew that had full information regarding MCAS (the reference is in the report, if you bothered to read it), and who stated, verbally, the problem, and the solution, and then did it. Then reactivated the pitch trim and accelerated to their deaths...neither of those two actions, the combination of which (in concert with their failure to fly the airplane) lead to their deaths and the deaths of all aboard. The aircraft WAS flyable and WAS controllable, and it WAS a VFR morning and they WERE at 7,000' when the evolution began. You really can't ask for more ideal conditions than that.

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Iím sure had they turned the cut off switches back on - retrimmed then turned them off they would have been fine.
You have failed to read the report.

They DID turn the switches back on. This is a violation of the procedure. Once the switches are moved to the cutoff position, at no time is trim motor function to be restored: that's the point of the procedure. Don't apply power to the trim motors again. Ever. Don't. Just don't.

They did.

They did just what you say they should do. It enabled the trim to continue to move to a nose down position.

That, in concert with their increasing speed, well beyond the limitations of the airplane, led to their deaths. Not a little nose-down trim. It was flyable and controllable up until they let the speed run away instead of flying the airplane, and the trim wouldn't have moved nose down any more, had they not re-engaged the stab trim. They did the two things that the procedure forbids to do...and not surprisingly, it's just what you recommend: the exact opposite of what should be done.

You have an excuse. You have no idea what you're talking about. They were type rated in the airplane and have no excuse.

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Yes reducing power could have helped but speed at their attitude would have taken a long time to reduce to a level where the stab could be moved manually.
Moving the stab trim is irrelevant.

I R R E L E V A N T.

Fly the damn airplane. Nose is trimmed down a bit? Fly the damn airplane. Keep it at the speed where the trim became a problem, and fly the damn airplane.

Because you have no idea what you're talking about, you keep focusing on re-trimming the airplane. Perhaps you're so close to your primary flight training due to your level of experience that you can't let go of this idea, and you think that everything should focus on retrimming the airplane.

Fly the damn airplane. Whether you ever get it back in trim or not is irrelevant. I R R E L E V A N T. Fly the damn airplane.

You get the point? Obviously not.

It's not about reducing speed, though they should have. It's about keeping the speed where it is; eventually speed need to be reduced, but they're at a safe maneuvering altitude, they have time; all they need to do is keep it under control. Sit on their hands, count to ten, think about it. Breathe. Focus. Fly the damn airplane.

The F/O was inexperienced. A wet commercial and a few hours in the airplane, and his thinking was probably about on par with yours. Dangerous. Immature. Uninformed. Inexperienced. A little learning is a dangerous thing.

The captain, on the other hand, he didn't have nearly the excuse. You'll notice, if you ever actually read the report, that he didn't have a lot of experience, but he did have time in type, and all his experience was with the company. He did something telling, though; immediately engaged the autopilot, and he focused on repeatedly trying to engage the autopilot. This is also a dangerous line of thought; if one can't get away from the trivial and focus on flying the damn airplane, then one paints one's self into a corner. For you, it's an obsession with retrimming. For him, while he did suffer from that same misfocus, he kept returning to wanting the autopilot to handle the airplane for him.

Certainly in an emergency, sometimes using the autopilot can free you up to bring more attention to bear on the problem, but when the problem is a flight control issue with a trim issue, and the autopilot won't engage, the immediate concern is flying the airplane, not handing it off, and he focused on engaging autopilot immediately after takeoff, and during the course of the flight.

Recently we see an Atlas pilot who gets stuck in a confirmation bias loop and keeps pushing the nose down for what he perceives as a problem with the airplane trying to pitch up, and here we see a pilot who allows the airpalne to accelerate when he should have been focusing on the opposite.

The problem with the speed was NOT that it made the airplane harder to trim. You don't seem to understand this concept. The problem with increasing speed was that it exacerbated the existing trim force. The trim at 200 knots might be a nuisance. Do nothing but increase airspeed, and at 300 knots it could be a real problem, and at 500 knots, beyond control. The solution: keep the airplane flying at the speed where the problem occurred, but they didn't do that. They accelerated through 500 knots to a point where they ensured the airplane couldn't be controlled.

Forget "porpoising." You're stuck on this idea that they crew had to re-trim. It's good if one is able to retrim, but that is NOT the immediate problem, nor the immediate solution. Flying the damn airplane is the immediate problem. For you millennials, who love acronyms and cell phone speak, FTDA. Fly the damn airplane. FTDA. FTDA. FTDA.

By keeping control of the airplane, which includes roll, pitch, yaw, and airspeed and altitude, the crew would have had a flyable airplane. They did have a flyable airplane until they accelerated to an airspeed that made the airplane uncontrollable. This is the point you really don't seem to be able to grasp, and until you do, you'll go in circles ignorantly fixated on the wrong thing...just like the crew. It was that ignorant fixation, not MCAS or AoA vanes, that killed them, their crew, and all their passengers.
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Old 05-15-2019, 06:10 PM   #627  
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This has been going downhill since Boeing removed the dog from the cockpit. The one that was there to bite the pilot if he tried to touch anything.
Are you the FO that accepts my comfort animal porcupine I bring on board, but then gets upset by my seeing eye lion?
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Old 05-15-2019, 06:25 PM   #628  
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Are you not familiar with the concept of the set of car keys, the brick, the duck, the cat, and the dog in the cockpit?

In the event of disorientation, open a window (for those who can remember aircraft in which one could open the window), and toss out the car keys. Follow them. They will lead you to earth. In the event you lose the keys (and who doesn't?), then toss out the brick. It will head in the same general direction. In wet weather, the duck shines. Toss it out. Reduce airspeed. Stay in formation. If unable to open a window or you ingest the duck, toss the cat in the air. It lands on its feet. That is down. It only works with declawed cats. The others stick to the ceiling.

The dog is there to bite the pilot if he tries to touch anything.
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Old 05-15-2019, 06:36 PM   #629  
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...[The porpoise] technique has been in the manual but has not been taught for decades...
I want to know more about this technique. 40 years in the business (four decades) and I have never seen it in any manual, general airmanship or type specific, much less "the manual." To what "the manual" do you refer?

I get unloading the stab to reduce aerodynamic loads thereby allowing manual trim, but does it involve, as the name implies, alternately and repeatedly sticking everything to the ceiling then slamming everything to the floor at low altitude and high speed?

Pangolin: I am specifically asking you, who brought it up, to explain this technique and to refer us all to "the manual" in which it is published. Thank you in advance for your specific reply.
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Old 05-15-2019, 06:58 PM   #630  
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Hold the trim thumb switch while releasing the yoke pressure; when the stab starts moving hold the yoke still watching for correct stab movement. Itís NOT porpoising, itís merely unloading the pressure the elevators are putting pitch trim actuator.

I learned it 40+ years ago reading Handling The Big Jets by D.P. Davies. BAcked up by an old timer on the 727 at EAL.

GF
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