Author Topic: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'  (Read 47286 times)

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Offline floobydust

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1075 on: May 08, 2019, 07:17:23 am »
Turkish Airlines flight 1951 737-800 crash in 2009, 9 killed.
Of two radio altimeters, Boeing's software relied on a single sensor for the autothrottle computer, and during landing it shut engines down to idle prematurely  :palm:

They've learned absolutely nothing. This company is rotten to the core.

Boeing failed to apply safety lesson from deadly 2009 crash
 

Online soldar

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1076 on: May 08, 2019, 08:09:08 am »
They've learned absolutely nothing. This company is rotten to the core.

Boeing failed to apply safety lesson from deadly 2009 crash

That link is blocked in Europe and I had to use a VPN to see it:
Quote
The company said that it knew months before the Lion Air crash that a cockpit alert -- suggesting an angle-of-attack sensor may be malfunctioning -- wasn't working the way the company had told buyers of the jetliner. But it didn't share its findings with airlines or the FAA until after that plane went down off the coast of Indonesia.

Boeing's latest admission raised new questions about the 737 Max's development and testing - and the company's lack of transparency.

One reason for adding multiple sensors to aircraft is they can and do fail.

Pilots have for decades relied on the weather-vane-like angle-of-attack sensors to warn them when they near a dangerous aerodynamic stall.
All my posts are made with 100% recycled electrons and bare traces of grey matter.
 

Offline Homer J Simpson

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1077 on: May 08, 2019, 09:23:21 am »




 

Online MT

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1078 on: May 08, 2019, 11:39:57 am »
Which vid is Blanco referring to? There are at least 3!
 

Online GeorgeOfTheJungle

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1079 on: May 08, 2019, 05:48:03 pm »
Quote from: 60 minutes video#1 @1m33s
That's happening irrespective of anything you're trying to do.
That's just happened whether you like it or not.
MCAS had malfunctioned and allowed the pilots five seconds intervals to regain control.

LOL. Who still watches TV? Who still believes a single word of the mainstream media? Only idiots...

An experienced pilot would have thought: "This damn thing wants to kill me, it's trimming nose down relentlessly again and again" and proceed to do whatever it takes to avoid that happening. There's a plethora of things that could have been done:

1) Grab and stop the trim wheel, by hand, yes, by hand Mr. playstation pilot, use the primitive human mechanical brute force because your life depends on it. 2) Push nose up on the trim button on the yoke (overrides MCAS). 3) Put the flaps in position 1 (disables MCAS). 4) untrim manually. 5) Flip the stabilizer trim power cutout switch. And perhaps some more that IDK because I'm not a pilot.
« Last Edit: May 08, 2019, 06:20:15 pm by GeorgeOfTheJungle »
int main (void) { while (1) fork(); }
 

Online MT

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1080 on: May 09, 2019, 01:15:39 am »
Libertarian Judge Napolitano on the juridical aspects of Boing behavior!

 

Online MT

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1081 on: May 10, 2019, 08:03:30 am »
Wallstreet Journal about Boing and FAA relationship.
 

Offline windsmurf

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1082 on: May 13, 2019, 09:52:58 am »
Boeing Altered Switches that might have saved Ethiopian Air.
https://www.heraldnet.com/business/boeing-altered-key-switches-in-737-max-cockpit/
 
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Offline KL27x

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1083 on: May 14, 2019, 04:56:17 am »
^If Boeing's viewpoint is true, that there is no condition where a pilot should ever flip only one switch, then there could either be a single ganged switch* or there could be a physical bar that connects both switches during flight (which can be removed in case there's any condition where a mechanic/tech might need to flip just one).

*Or in this case, it appears they are both doing the same thing, anyway. So you could just remove one of them.

If the goal is to simplify the pilot's life, giving him two switches that secretly operate like an "and" (or an ior, depending on which direction you define the logic) and telling him that "under condition X, Y or Z flip both switches" is a bit obfuscating. Enough switches in the cockpit already without doing this. And leaving the end-user with these kinds of little loose ends and red herrings can build up into a problem. But in this case there was maybe some red tape in the way of doing the obvious. And deadlines.

Why not leave the ability to switch off just the FCC inputs? Perhaps they did not want to allow the plane to be flown with MCAS disabled, because the aerodynamic issue is pretty serious. So they turned it into an all or nothing, only to be cut in a serious emergency where subsequently accidentally stalling the plane is a relative minor consequence and acceptable risk.

This switch change is further evidence of where Boeing's main concerns were. They gave MCAS a huge authority/response. They changed the switches to prevent disabling of MCAS. Preempting/avoiding an aerodynamic stall was evidently the major concern. They made the change, because they thought it made the plane safer. And perhaps they were correct. If a 737 pilot can't even bring himself to press the trim up button for more than a few seconds when the plane is drying to nose into the dirt, I find it unlikely a pilot is going to immediately trim down for 9+ seconds if and when he/she were to ever get the plane into a severely high AOA. This is like expecting the captain of the Titanic to be able to slalom through traffic cones by making decisive and extreme course corrections that manifest in the proper behavior 2 minutes into the future.
« Last Edit: May 14, 2019, 06:21:46 am by KL27x »
 

Offline Brumby

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1084 on: May 14, 2019, 12:27:20 pm »
Why not leave the ability to switch off just the FCC inputs?

While I do understand your point (and it would seem like a good idea) this is where you would enter into the "new type" situation.  The cutoff switches were meant to kill the stabilser trim motor for any and all reasons.  There was no intent to define WHAT conditions caused the unwanted stabliser trim action - just that, if it happened (for whatever reason) the pilots had a means to halt it.

Change the functionality of these switches and you add a whole new chapter in the operation of the aircraft.  Just because you think such a change is a minor one, does not mean you are right.  For example, say you did change these switches to disconnect from computerised control - and then there was a short in the driver circuitry for the stabliser trim motor.  Your "cut out" switches don't cut power any more ... the stabilser goes full travel and the only thing you can do is put your head between your legs and kiss your arse goodbye.

Such differences in operation are the sort of thing that lead to a new type rating requirement if there's enough of them.  This can happen if there are a sufficient number of "almost negligible" changes, which is why the passenger "No smoking" sign switch still exists in the cockpit of the 737, even though it's not been needed for decades.
 

Online BradC

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1085 on: May 14, 2019, 12:38:51 pm »
While I do understand your point (and it would seem like a good idea) this is where you would enter into the "new type" situation.  The cutoff switches were meant to kill the stabilser trim motor for any and all reasons.  There was no intent to define WHAT conditions caused the unwanted stabliser trim action - just that, if it happened (for whatever reason) the pilots had a means to halt it.

But if the article is correct, that is exactly what Boeing *did*.

Quote
But as Boeing was transitioning from its 737 NG model to the 737 MAX, the company altered the labeling and the purpose of those two switches. The functionality of the switches became more restrictive on the MAX than on previous models, closing out an option that could conceivably have helped the pilots in the Ethiopian Airlines flight regain control.

Prior to the Max the two switches had different roles :

Quote
The Seattle Times found that the left switch on the 737 NG model is capable of deactivating the buttons on the yoke that pilots regularly press with their thumb to control the horizontal stabilizer. The right switch on the 737 NG was labeled “AUTO PILOT” and is capable of deactivating just the automated controls of the stabilizer.

Which is explains the quote you quoted :
 
Why not leave the ability to switch off just the FCC inputs?
 

Offline floobydust

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1086 on: May 14, 2019, 12:58:27 pm »
The cutout switches, electric trim operating differently between 737 models is another Boeing design flaw.
They must have contracted Clown Co. to do the design. The basics of user-interface design: keep it simple, keep it consistent.
This is anything but a "blame the pilots" for yet another unnecessary complicated memory item.

"uncommanded movement of the {737} aircraft's rudder". It was the same actuator valve as the elevator... so much for hydraulics being reliable.

"Testing revealed that under certain circumstances, the PCU's dual servo valve could jam and deflect the rudder in the opposite direction of the pilots' input. Thermal shock testing revealed that the uncommanded rudder movement could be replicated by injecting a cold PCU with hot hydraulic fluid. Thermal shock resulted in the servo's secondary slide becoming jammed against the servo housing, and that when the secondary slide was jammed the primary slide could move to a position that resulted in rudder movement opposite of the pilot's commands."

I wonder if other systems (elevator) flight control design was changed as a result of these incidents.
Too bad Boeing fired all the senior engineers that remembered this stuff.
 

Offline KL27x

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1087 on: May 14, 2019, 03:58:52 pm »
^Scary. The plane doing the opposite of what is required and in a way that leaves the plane to nose dive, plus this happens for a control that is mostly used when landing!!! There were quite a lot of fatal accidents and close calls attributed to that. I guess the timing of these MAX accidents and the perceived 'shadiness' is what makes it such a bigger deal?

Quote
The Seattle Times found that the left switch on the 737 NG model is capable of deactivating the buttons on the yoke that pilots regularly press with their thumb to control the horizontal stabilizer. The right switch on the 737 NG was labeled “AUTO PILOT” and is capable of deactivating just the automated controls of the stabilizer.
Yep. I wonder if they got this right. I think the "master" (left) switch should probably kill the motor, completely. But I suppose it might just disconnect the pilots' controls, in case of a button/switch fault, so that the autopilot can still be used? And the other switch USED to enable/disable just the FCC/autopilot control over the motor. If I understand the article, correctly, both switches now cut all motorized trim movement. 00, 01, 10 all mean the motor is disabled. 11 = motors enabled and accessible to pilot manual trim button, autopilot, and MCAS. It's funny that they can't remove a switch due to red tape, but they can apparently rename it?

In any emergency, it seems you never do anything but cut both switches, so it shouldn't have any immediate effect on an emergency. But it means that after stabilization, a fault of any of these 3 controls means you can't re-enable any of the others after, say, further troubleshooting and/or call with maintenance crew. But I agree with the Times that if the pilots had the ability to flip off just MCAS/autopilot control and leave the manual trim buttons intact, and they knew this was available, that ET302 esp might have been ok. I think I posted something to that effect a week ago. These pilots apparently knew what they were doing when flipping stab trim back on, but maybe weren't prepared for the immediacy/scale of the MCAS response or the enormity of how much manual trim they really needed to apply, in addition to allowing the plane get too fast for the condition and not knowing or anticipating the effect that had on trim and elevator control of the plane. It sure seems like they were trying to fix the trim with the wheel and would surely have enabled only the manual trim control buttons if they had and were aware of that option. They had at that point realized there was a left alpha vane malfunction.

One thing that seems obvious in hindsight is some sort of notification when MCAS is activated. It might have just gotten lost in the other noise, stick shakers, clacker alerts, ground proximity warnings. But it is evident that when a plane is crashing, pilots don't necessarily look straight down between the seats. I imagine if they even heard/noticed the trim moving, they both thought the other pilot was trimming UP. If they had been aware, I bet even GoJ's "Playstation pilot" takes some corrective action, hopefully in time.

Quote
"uncommanded movement of the {737} aircraft's rudder". It was the same actuator valve as the elevator... so much for hydraulics being reliable.
Wonder if the extreme control surface forces/pressures in these accidents might be revealing some new, still unknown fault in the hydraulics?

Totally unrelated one of the strangest accidents I have come across. The ghost flight.
5 seconds too late, maintenance guy, "oh, yeah. Hey, can you check that switch I might have forgotten to flip back?"
Everyone in the plane puts on an oxygen mask except the pilots?
Autopilot continues doing its thing, ascending to 40,000 feet, even when the cabin has no pressure?
Flight attendant wakes up and is actually a pilot. But the fuel runs out 10 seconds, later?
« Last Edit: May 14, 2019, 05:19:05 pm by KL27x »
 

Offline Homer J Simpson

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1088 on: May 15, 2019, 11:43:47 am »
 

Offline langwadt

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1089 on: May 15, 2019, 06:35:44 pm »
Totally unrelated one of the strangest accidents I have come across. The ghost flight.
5 seconds too late, maintenance guy, "oh, yeah. Hey, can you check that switch I might have forgotten to flip back?"
Everyone in the plane puts on an oxygen mask except the pilots?
Autopilot continues doing its thing, ascending to 40,000 feet, even when the cabin has no pressure?
Flight attendant wakes up and is actually a pilot. But the fuel runs out 10 seconds, later?

afair the outcome of the investigation was to change the checklist for missing cabin pressure, putting "Put on oxygen masks!" as the first item so the pilots don't pass out while debugging the problem
 

Online BravoV

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1090 on: May 16, 2019, 01:02:36 pm »
It’s sad to see some congressmen and the FAA chief himself are in Boeing payroll after watching this part of video.

Its no secret for decades, the collusion & corruption level in there at the whole either country/legislative/executive, is comparable to those less developed world like in Africa or South America.

Offline floobydust

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1091 on: May 16, 2019, 02:15:31 pm »
The engineering profession is continuing to get worse due to corporation's priority #1 being profit with the ensuing corruption  :(
The former 737 max engineers basically confirming they laid off the experienced/management-bucking engineers, and flogged the remaining ones to meet cost and time targets.

“It was pretty intense low morale because of all the layoffs—constant, grinding layoffs, year after year".
"Boeing has reshaped its workforce in an all-consuming focus on shareholder value."

'The relentless message: Shareholders would henceforth come first at Boeing. The important thing was not to get “overly focused on the box,” [CFO] Hopkins said in a 2000 interview with Bloomberg. “The box”—the plane itself—“is obviously important, but customers are assuming the box is of great quality.” This was heresy to engineers, to whom the box was everything. The strike that year was formally over wages and benefits, but workers described it as a referendum on management.'

"Adam Dickson, a manager of fuel systems engineering for the 737 Max, retired in November after almost 30 years at Boeing—in part, he says, because of dismay over performance targets that risked sacrificing safety for profits. “It was engineering that would have to bend,” he says. The company’s priorities were expressed in annual performance reviews in which engineers were measured in part on how much their designs had cost."

Former Boeing Engineers Say Relentless Cost-Cutting Sacrificed Safety
 

Online BravoV

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1092 on: May 16, 2019, 02:34:47 pm »
The engineering profession is continuing to get worse due to corporation's priority #1 being profit with the ensuing corruption  :(

This investigation video was made in 2014 ... 5 years ago.

Its produced by Al Jazeera, yes, I know & aware, some people here I believe will not trust this news agency.

And yes, in that video already pointed out that FAA already "delegated" it's authority to approve safety matter to Boeing for it's own certification, long ... long time ago.

PS : If you're bored, suggest to jump to about 42:00 and watch for just 5 minutes, to see some funny stunts by their top executive, which was a VP + GM grade executive, and he was trashed and bullied publicly by "higher" authority, in front of the news crews and few Boeing staffs, and its recorded.  :-DD  >:D

« Last Edit: May 16, 2019, 06:28:52 pm by BravoV »
 

Offline Homer J Simpson

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1093 on: May 17, 2019, 12:17:02 pm »


 

Online Gyro

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1094 on: May 17, 2019, 06:21:53 pm »
A reasonable summary for people wanting to catch up...

https://www.bbc.co.uk/news/resources/idt-sh/boeing_two_deadly_crashes
Chris

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Offline KL27x

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1095 on: May 18, 2019, 03:43:51 pm »
Quote
The engineering profession is continuing to get worse due to corporation's priority #1 being profit with the ensuing corruption  :(
The former 737 max engineers basically confirming they laid off the experienced/management-bucking engineers, and flogged the remaining ones to meet cost and time targets.

IME, modern management seems to enjoy repeating buzzwords as if they have magical powers. They view successful exertion of their will as a success, regardless of the wisdom or result of the outcome. They like to take credit when they get lucky and ignore the failures they created despite engineers knowing (not guessing, not hedging) that they are making an irrefutable mistake. When an engineer attempts to explain reality to management, all that happens is their eyes glaze over. I've watched people set fire to millions of dollars despite being explained exactly how they were setting fire to millions of dollars.

It seems like people can't believe it when someone who makes less $$ than them actually understands things that they don't. When you're not able to understand something, I guess it's hard to figure out who to believe, and maybe this person sometimes just plug their ears and closes their eyes and... chooses to believe the outcome that will make them the most profit will somehow become reality.

I would not be surprised if Boeing engineers knew there were flaws and voiced their concerns/protests and were simply ignored.
« Last Edit: May 18, 2019, 03:52:43 pm by KL27x »
 
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Offline windsmurf

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1096 on: May 21, 2019, 11:08:56 am »
Boeing admits 737 Max sims didn't accurately reproduce what flying without MCAS was like
https://www.theregister.co.uk/2019/05/20/737_max_flight_simulators_not_accurate_report/
 

Offline windsmurf

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Re: Lion Air crash: Jakarta Boeing 737 'had prior instrument error'
« Reply #1097 on: Yesterday at 03:07:53 am »
Boeing Official Played Down Scenario That May Have Doomed Ethiopian Jet - WSJ
 


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