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Boeing 737 MAX 8 Crashes: Lion Air & Ethiopian Airlines

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Boeing 737 MAX 8 Crashes: Lion Air & Ethiopian Airlines

 
Old 03-21-2019, 09:18 AM
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Boeing to stop charging for safety feature on 737 Max models: report

Pretty unreal each MCAS computer relied on only one AoA sensor and did not cross check and Boeing charged extra for AoA indicator and warning light if the two AoA did not equal readings.

https://thehill.com/policy/transport...-models-report
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Old 03-21-2019, 09:23 AM
  #122  
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You think it’s unreal their cost analysis said this was the better path? Seems almost par for the course of capitalism.
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Old 03-21-2019, 09:29 AM
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Originally Posted by oo7spy View Post
You think it’s unreal their cost analysis said this was the better path? Seems almost par for the course of capitalism.
Their cost and system/safety analysis are definitely wrong. The cost to add indicators (for AoA and AoA not equal/fail) to the pilots was minimal (AFAIK they are on the pilots display so they can be programmed)
Consider the loss of lives, lost of revenue, lost of safety reputation,....Boeing management and engineering trully F'ed up on MCAS.
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Old 03-21-2019, 09:46 AM
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Is Boeing alone in charging for an extra sensor? I doubt it...
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Old 03-21-2019, 09:51 AM
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Originally Posted by nfnsquared View Post
Is Boeing alone in charging for an extra sensor? I doubt it...
They're not adding a extra sensor, just putting the sensor readings on the display's
AFAIK, all of this is just S/W. Cross checking and displaying the AoA data.
The AoA sensors are both on the ARINC-429 buses.
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Old 03-21-2019, 10:21 AM
  #126  
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Originally Posted by Legend2TL View Post
Their cost and system/safety analysis are definitely wrong. The cost to add indicators (for AoA and AoA not equal/fail) to the pilots was minimal (AFAIK they are on the pilots display so they can be programmed)
Consider the loss of lives, lost of revenue, lost of safety reputation,....Boeing management and engineering trully F'ed up on MCAS.
I wasn’t arguing. I was lampooning.
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Old 03-21-2019, 10:59 AM
  #127  
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Originally Posted by oo7spy View Post

I wasn’t arguing. I was lampooning.
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Old 03-21-2019, 03:40 PM
  #128  
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I can't tell you how much I hate Boeing and LM.
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Old 03-21-2019, 03:44 PM
  #129  
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Originally Posted by oo7spy View Post
You think it’s unreal their cost analysis said this was the better path? Seems almost par for the course of capitalism.

Even though their stock took a hit, I'm willing to bet it will rebound and many people are going to get rich off it

Originally Posted by gatrhumpy View Post
I can't tell you how much I hate Boeing and LM.
You just did
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Old 03-21-2019, 05:15 PM
  #130  
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Bitching that they charge for the system....., sad that the airline didn’t pay less than one percentage point of what the aircraft cost to get the safety system. And really fucked us that the Airline owned a simulator for this aircraft, and the pilot NEVER logged any time in it, and was allowed to fly the aircraft, with a Copilot that had less than 200 flying hours period.
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Old 03-21-2019, 05:24 PM
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I didn't tell you HOW much though.
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Old 03-21-2019, 10:34 PM
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Originally Posted by gatrhumpy View Post
I can't tell you how much I hate Boeing and LM.
Originally Posted by Majofo View Post
.....You just did
Nah, I think he can do better. C'mon gatrhumpy, give it your best shot. Put some effort into it.
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Old 03-22-2019, 01:43 AM
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https://www.wsj.com/articles/indones...ts-11553232103

Indonesia Flag Carrier Seeks to Cancel Order for 49 Boeing 737 MAX Jets

March 22, 2019 1:21 a.m. ET

JAKARTA, Indonesia—Flag carrier Garuda Indonesia said it is seeking to cancel an order for 49 Boeing Co. 737 MAX jets, saying passengers have lost confidence in the aircraft following two deadly crashes in recent months.

The move makes Garuda the first airline to publicly confirm plans to cancel a 737 MAX order.

Garuda CEO I Gusti Ngurah Askhara Danadiputra told The Wall Street Journal that the airline sent a letter to Kevin McAllister, head of Boeing’s commercial plane division, “to say that we want to cancel.”

The letter was sent March 14, company spokesman Ikhsan Rosan said, adding that Boeing representatives were planning to meet with Garuda in Jakarta on March 28 “for further discussion.”

Mr. Rosan said the decision to cancel “is in line with the desires of consumers who have lost confidence in the Boeing 737 MAX 8.”

Garuda placed an order for 50 MAX jets in 2014 and has taken delivery of one, the airline said. The remaining 49 were scheduled to be delivered through 2030, it said.

As of January, Boeing had delivered 350 of the 737 MAX planes and received orders for about 5,000 more, making the MAX its most popular plane.
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Old 03-22-2019, 06:26 AM
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Originally Posted by Bearcat94 View Post
Nah, I think he can do better. C'mon gatrhumpy, give it your best shot. Put some effort into it.


I whenever I visit the LM F-35 facilities and I see a huge flag inside their production areas that says "We Never Forget Who We're Working For." Yeah, corporate greed and shareholders you freakin' pricks.
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Old 03-22-2019, 08:20 AM
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Originally Posted by gatrhumpy View Post


I whenever I visit the LM F-35 facilities and I see a huge flag inside their production areas that says "We Never Forget Who We're Working For." Yeah, corporate greed and shareholders you freakin' pricks.
+1
I've heard LM tales from the 59th Test and Evaluation Squadron. The best is not only does LM charge an exorbitant amount of money for the F-35 test pods but they also "own" the data they collect.

I was all for the F-35 in the 2000's before FSD went off the rails in schedule and budget. Very difficult to say who's at fault but I put LM in the majority.

Last edited by Legend2TL; 03-22-2019 at 08:33 AM.
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Old 03-22-2019, 08:48 AM
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Seattle Time Spills the Beans on Boeing’s (Allegedly) Flawed 737 MAX

Glad to see Seattle Times had the guts and perseverance to find out the story and details of the 737 Max
https://www.yahoo.com/finance/news/s...183441335.html .

This is really disturbing
Blame for both disasters currently centers on Boeing's Maneuvering Characteristics Augmentation System, or MCAS, flight control system for the 737 MAX -- a system that was assessed as safe by the Federal Aviation Administration (FAA) when Boeing was getting the 737 MAX certified to fly. But as reported this week by The Seattle Times (ST), there appear to have been "several crucial flaws" in the System Safety Analysis (SSA) review that Boeing conducted on MCAS at the FAA's behest.

Yes, you read that right. The FAA appears to have delegated the job of evaluating MCAS's safety to Boeing, and then approved the company's report. Indeed, in some instances, ST reports, FAA managers, pressed for time, delegated even their review of Boeing's assessment of Boeing's work "back to Boeing" itself!

As one engineer quoted by ST lamented: "There wasn’t a complete and proper review of the documents. ... Review was rushed to reach certain certification dates."

Did this contribute to the 737 MAX's two crashes? Citing engineers "at the FAA and other aviation organizations ... directly involved with the evaluations or familiar with the document," ST further noted that the SSA:

Understated by a factor of four the distance MCAS could automatically swivel the plane's horizontal tail (the stabilizer) in order to direct the plane downwards (to avert a stall). Initially designed to be limited to 0.6 degree of movement, MCAS ultimately was enabled to move the stabilizer 2.5 degrees. As a result, pilots may have been surprised at how difficult it would be to manually correct the automatic flight adjustments dictated by MCAS.
Did not address MCAS's ability to reset itself and repeatedly re-swivel the tail to resume a dive, after pilot attempts to correct the move manually. Just two such swivels could theoretically have pushed the stabilizer its maximum distance, putting the plane into a full dive.
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Old 03-22-2019, 09:01 AM
  #137  
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I've drafted numerous Contract Data Requirements Lists (CDRLs) with LM to know they're a very disgusting, slimy company.

For example, I drafted some contracting language with them for LM to perform a service for the F-35 Joint Program Office (JPO). I listed all the documents by which they have to perform the service we're buying, including official military documents, SAE guiding documents, and Navy-specific documents. I sent this up the chain of command, as per policy, and long story short, LM's lawyers had the CDRLs changed back to language that favored general, non-specific requirements and tasks that have to be done.

I want to know what I'm getting for my money as a tax payer from LM. You all have entrusted me with that responsibility. If I'm not doing my job, I'm failing you all as tax payers.

LM's lawyers basically said, "we're not going to give you language that makes us accountable for specific deliverables we're supposed to provide, so we're just going to make it extremely vague and general.

This was acceptable to them because money.

I left the program after the third time of trying to change the process.
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Old 03-22-2019, 09:29 AM
  #138  
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We were warned in 1961. Some people can see it. Unfortunately most of them have to get really close to it first.
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Old 03-22-2019, 09:46 AM
  #139  
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Brah.. vagueness and ambiguity go two ways..
Gatr only catches
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Old 03-22-2019, 10:06 AM
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First time I've seen anything seeming to confirm what the software update will entail, which is exactly what I would expect:

After the upcoming April software update, the MCAS will be updated to check both sensors and to disable itself if there is “meaningful disagreement” between the two.
https://www.extremetech.com/extreme/...ells-as-extras

Such an easy fix, can't believe it wasn't incorporated from the start...
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Old 03-27-2019, 09:12 AM
  #141  
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Boeing to preview fix for 737 Max jets Wednesday. Here's everything we know

https://www.cnbc.com/2019/03/27/boei...g-we-know.html

Pilots and other people familiar with the work say there are four notable changes.


Limit MCAS corrections

As Boeing and investigators studied the brief flights of the Lion Air plane that plunged into the Java Sea in Indonesia Oct. 29 and the Ethiopian Airlines crash on March 10, the scariest similarity was the way both flights pitched up and down before crashing.

Many believe the automated flight control system — the Maneuvering Characteristics Augmentation System, or MCAS — continually pushed the nose of the plane down despite the pilots repeatedly trying to correct the move. The new software will allow MCAS to push the nose of the plane lower just once and only for 10 seconds at most.



Two sensors, not one

Another factor believed to have played a role in the 737 Max crashes is the possibility that erroneous data was fed to the MCAS software from the plane's two angle-of-attack (AOA) sensors.

Those sensors on the outside of the nose of a plane measure how a plane is positioned. If the nose of the 737 Max is pointed too high relative to its airspeed, it could go into a stall. Boeing originally designed MCAS to receive data from just one AOA sensor on the 737 Max.

That will change in the future with both sensors feeding data into the automated flight control system. And if the readings between the two sensors are substantially different, they will not trigger MCAS.



Cockpit alerts

Since the crashes of the two 737 Max planes, Boeing has faced fierce criticism for not doing more to tell flight crews about the MCAS system or alert them when the automated flight control technology kicks in.

In particular there are two indicators Boeing has offered, but only if airlines paid extra to have them installed on the cockpit. That will be changing in the future. Boeing will now offer to angle of attack indicators in the cockpit free of charge.

It will additionally include another indicator showing if the angle of attack sensors disagree that will now be standard equipment in all 737 Max airplanes.


Updated training

While flight crews around the world are now aware of MCAS and how it can impact the lift off and flight of the 737 Max, that was not the case initially.

Even after Boeing issued an airworthiness directive late last year clarifying procedures pilots should follow to shut off MCAS, there has been steady criticism that Boeing was not going far enough.

As a result, Boeing will be increasing how airlines train flight crews how to handle 737 Max planes when MCAS is enabled and how they can disable the system if it is creating a dangerous situation.

Most, if not all of the pilots attending the briefing at Boeing's Renton facilities Wednesday are aware of the plan to fix the Max. The Federal Aviation Administration will soon be reviewing the software and pilot training changes and is expected to certify them within a week or two, a major hurdle to ultimately having the FAA lift the grounding of the 737 Max.
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Old 03-27-2019, 09:32 AM
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"how they can disable the system if it is creating a dangerous situation"

It amazes me that this sentence can exist.
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Old 03-28-2019, 02:34 PM
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Old 03-28-2019, 03:18 PM
  #144  
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I mean, isn’t there a fuel shut off valve for if the engine catches fire “creating a dangerous situation”?

Seems kind of common place on airplanes, no?
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Old 03-28-2019, 03:23 PM
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Originally Posted by Anachostic View Post
"how they can disable the system if it is creating a dangerous situation"

It amazes me that this sentence can exist.
I'm guessing that line is a poor interpretation by a non-technical, non-pilot author of what was discussed.

Putting the flaps down will disable MCAS. Engaging the autopilot will disable MCAS. Moving the stabilizer trim cutout switches to the cutout position will disable the stab trim (which effectively disables MCAS).

Unless Boeing is also adding a "logic" kill switch to tell the active FCC (flight control computer) to exit the MCAS sub-routine, the above are the only options I know of to disable MCAS.
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Old 03-28-2019, 04:24 PM
  #146  
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Originally Posted by Anachostic View Post
"how they can disable the system if it is creating a dangerous situation"

It amazes me that this sentence can exist.
Originally Posted by gatrhumpy View Post
Originally Posted by oo7spy View Post
I mean, isn’t there a fuel shut off valve for if the engine catches fire “creating a dangerous situation”?

Seems kind of common place on airplanes, no?
This would not be uncommon to have a disable function to avoid a more serious situation. These automated systems rely on a lot of sensor inputs. If the sensors start to malfunction, there is an array of mitigations that are in place to prevent malfunctions from propagating and making things worse, with the final mitigation usually being "the pilot shuts it off and flys the plane".
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Old 03-28-2019, 04:58 PM
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Originally Posted by 1Louder View Post
This would not be uncommon to have a disable function to avoid a more serious situation. These automated systems rely on a lot of sensor inputs. If the sensors start to malfunction, there is an array of mitigations that are in place to prevent malfunctions from propagating and making things worse, with the final mitigation usually being "the pilot shuts it off and flys the plane".
Ironically/tragically, more automation/computer systems that is meant for safety also introduces more possibilities of faults/errors into the flight eco-system that the pilots have to deal with and learn/train on how to shut them off. The MCAS was a perfect example where a simple autopilot dis-engage did not turn it off, as the pilots would have to know how to specifically disable that in addition to the standard auto-pilot disengage.

In the modern era, looks like pilots will need to be rigorously trained on how to deal with more and more computerized systems and sub-systems that can affect flight controls.

Seems like modern piloting of commercial jets is about managing a large array of computer systems that flies a plane rather than actual direct flying of plane...lol
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Old 03-28-2019, 06:29 PM
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Originally Posted by nist7 View Post
In the modern era, looks like pilots will need to be rigorously trained on how to deal with more and more computerized systems and sub-systems that can affect flight controls.

Seems like modern piloting of commercial jets is about managing a large array of computer systems that flies a plane rather than actual direct flying of plane...lol
I can't speak to the specifics of these crashes, but in the general case it's absolutely essential pilots get good training on the ins and outs of the automated features, and even more important that they don't become "system operators" but remaining capable of flying the aircraft even if everything but the compass blanked out. I've read a few things that imply some of these carriers lean too far toward treating them more like system operators.
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Old 03-29-2019, 08:51 AM
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https://www.wsj.com/articles/investi...sh-11553836204

Investigators Believe Boeing 737 MAX Stall-Prevention Feature Activated in Ethiopian Crash

Emerging consensus is the strongest indication yet that the same MCAS system misfired in the fatal Ethiopian and Indonesian flights

March 29, 2019

Officials investigating the fatal crash of a Boeing Co. 737 MAX in Ethiopia have reached a preliminary conclusion that a suspect flight-control feature automatically activated before the plane nose-dived into the ground, according to people briefed on the matter, the first findings based on data retrieved from the flight’s black boxes.

The emerging consensus among investigators, one of these people said, was relayed during a high-level briefing at the Federal Aviation Administration on Thursday, and is the strongest indication yet that the same automated system, called MCAS, misfired in both the Ethiopian Airlines flight earlier this month and a Lion Air flight in Indonesia, which crashed less than five months earlier. The two crashes claimed 346 lives.

The preliminary finding from the “black box” recorders of Ethiopian Airlines Flight 302 is subject to revisions, according to the people briefed on the matter. U.S. government air-safety experts have been analyzing details gathered from Ethiopian investigators for the past few days, according to one of the people. A preliminary report from Ethiopian authorities is expected within days.

Investigators have been homing in on the MCAS as a potential cause in both of the recent crashes. Ethiopia’s Transport Minister Dagmawit Moges previously said earlier readings from black-box data showed “clear similarities were noted” between both fatal flights.

Earlier this week, federal transportation officials during hearings defended the government’s response to the two crashes, even as questions grew about how the jet was certified for commercial use. Acting FAA Administrator Daniel Elwell told a Senate panel that there had been no flight tests of the 737 MAX to gauge how pilots would react in the event that a malfunctioning sensor triggered the automated system.

In the Lion Air crash, the new stall-prevention system, based on erroneous sensor information, repeatedly pushed the plane’s nose down and, according to the preliminary report, the pilot battled the flight controls while facing a cacophony of alarms before losing control and plunging into the Java Sea.

Boeing on Wednesday outlined its planned overhaul of the MCAS system to make it less aggressive and more controllable by pilots. The changes include an added layer of protection: Instead of relying on a single sensor indicating the angle of the plane’s nose, MCAS will rely on data from both of the plane’s sensors. As part of the fix, the FAA also will mandate certain cockpit alerts about incorrect sensor data.
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Old 03-29-2019, 09:03 AM
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Boeing 737NG horizontal stabilizer jackscrew cycle

.

I'd imagine the Max version of this jackscrew is the same or very similar.
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Old 04-03-2019, 10:22 AM
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Boeing software under scrutiny as Ethiopia prepares crash report

https://www.yahoo.com/finance/news/b...--finance.html


A preliminary Ethiopian report into the disaster is due to be published within days and may include evidence the software system kicked in as many as four times before the 737 MAX dived into the ground, two people with knowledge of the matter said.

A third person familiar with the findings confirmed the software had fired up again after pilots had initially switched it off, but said there was only one significant episode in which the plane pointed itself lower in the moments before the crash.

The so-called MCAS software is at the center of accident probes in both the crash of Ethiopian flight 302 and a Lion Air accident in Indonesia five months earlier that together killed 346 people.

It was not immediately clear whether the Ethiopian crew chose to re-deploy the system, which pushes the Boeing 737 MAX downwards to avoid stalling. But one of the sources said investigators were studying the possibility that the software started working again without human intervention.

In a statement on media reports about the investigation, Boeing said: "We urge caution against speculating and drawing conclusions on the findings prior to the release of the flight data and the preliminary report."
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Old 04-04-2019, 03:44 PM
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At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and FirstOfficer confirmed stab trim cut-out.

At 05:40:41, approximately five seconds after the end of the ANU stabilizer motion, a third instance of AND automatic trim command occurred without any corresponding motion of the stabilizer, which is consistent with the stabilizer trim cutout switches were in the ‘’cutout’’ position
http://www.ecaa.gov.et/documents/204...8-d7af1ee17f3e

https://www.bbc.com/news/business-47812225

This could be HUGE news.

Preliminary report shows the flight crew did infact tried to use the cut-out switch but seems that was not enough.....looks like Boeing could be in a world of hurt.

This seems to downplay the inadequate/inappropriate flight crew management of the plane.
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Old 04-04-2019, 04:15 PM
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Not really....Cutting out the trim stopped the electronic movement, but if they didn't manually spin the trim back to normal (those big black wheels on either side of the center pedestal), they'd have a tough time controlling the aircraft with yoke force alone.
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Old 04-04-2019, 05:10 PM
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Originally Posted by nfnsquared View Post
Not really....Cutting out the trim stopped the electronic movement, but if they didn't manually spin the trim back to normal (those big black wheels on either side of the center pedestal), they'd have a tough time controlling the aircraft with yoke force alone.
I see. I'm not the most technical in terms of part naming, but here's what the report says just prior to them cutting out the trim switch:

From 05:40:23 to 05:40:31, three Ground Proximity Warning System (GPWS) “DON’T SINK” alerts occurred.

At 05:40:27, the Captain advised the First-Officer to trim up with him.

At 05:40:28 Manual electric trim in the ANU direction was recorded and the stabilizer reversed moving in the ANU direction and then the trim reached 2.3 units.

At 05:40:35, the First-Officer called out “stab trim cut-out” two times. Captain agreed and FirstOfficer confirmed stab trim cut-out.

At 05:40:41, approximately five seconds after the end of the ANU stabilizer motion, a third instance of AND automatic trim command occurred without any corresponding motion of the stabilizer, which is consistent with the stabilizer trim cutout switches were in the ‘’cutout’’ position
So in the two bolded parts above. Since I'm not as familiar with the lingo, what would the Captain have meant when he said to his FO to "trim up with him" ? Is this the same thing as manually adjusting the trim wheel or simply yoke force?

Also "Manual electric trim in the ANU direction was recorded" - is this in reference to the trim wheels adjustment? ANU = Aircraft Nose Up

Again using my limited aircraft knowledge, with yoke force alone it should still have been able to put the trim away from the nose down tendency....just that the pilots would've had to kept pressure on the yoke to keep the stabilizers that way...with the trim wheel, if used manually, as a way to adjust it so you don't have to keep pulling force on the yoke, as far as I understand.

But this clearly to me still shows they were aware of the trim cut-out switch function, which was one of the things we discussed here could've been something they missed. AND the report seems to indicate automated inputs being fed to the trim even with the trim cut out switch....
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Old 04-05-2019, 12:45 PM
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https://www.businessinsider.com/ethi...-crater-2019-4

i overheard on the news this AM that at those speeds even with MCAS disabled it would’ve been difficult to get the plane back up.
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Old 04-05-2019, 01:04 PM
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Link to initial report. The six minute timeline is terrible. Something was seriously fucked up with that plane.

https://games-cdn.washingtonpost.com...72ba3cfebe.pdf
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Old 04-05-2019, 01:32 PM
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Originally Posted by oo7spy View Post
Link to initial report. The six minute timeline is terrible. Something was seriously fucked up with that plane.

https://games-cdn.washingtonpost.com...72ba3cfebe.pdf
Yeah I linked it to my other post.

And looking into it, it seems the pilots DID use the auto trim cut-out switch and from what it appears they tried to manually trim the airplane nose up repeatedly....but the report seems to suggest the data recorders saw computerized trim input to nose down even AFTER the trim cut out switch was already switched off and the pilots were trying to fly the plane manually.

Very very scary.
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Old 04-05-2019, 02:12 PM
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Page 26 shows the data on a timeline. You can see pitch trim adjustments immediately after each manual and automatic trim command until 5:40:45 when it the automatic trim is ignored after the cut out switch acknowledged by the First Officer at 5:40:35. There isn't another trim command until two manual "pitch up" commands which show no effect on the pitch trim. That is immediately followed by a long automatic "pitch down" command which does take and shoved the nose down to 40 degrees.

So, if I'm reading that right, the plane ignored 3 manual "pitch up commands" and executed an automatic "pitch down" which subsequently causes the rapid acceleration and loss of altitude.


Last edited by oo7spy; 04-05-2019 at 03:06 PM.
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Old 04-05-2019, 02:14 PM
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Am I reading the bottom line correctly that they were experiencing nearly 2 G's before impact?
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Old 04-05-2019, 02:37 PM
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Yeah seems like it. Interesting graph....so scary.

I wonder: what would/could have a US trained pilot done under similar circumstances? Seems like the crew did the best they could and somehow the MCAS was still overriding manual trim control/yoke force even after the cut out switch activated....
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