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Tiredofhumanity
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Tue Mar 16, 2021 5:36 am

Sachmet wrote:
In general the tendency is to optimize economics. Whatever the propaganda - cost is the essential factor in commercial aviation. It is every where else so why the hypocrisy? Sure statistical spoken it has become safer (for the average consumer) but it is also optimized into a pre-planned and boring thing that will easily fail outside of this narrow set of parameters. Take a global crisis (war, financial, economic) and you will find those new planes and the manager-pilot to be lot less safe that the good old ones!. We already are on a path toward this and I prefer four engines and a three man cockpit with pilots that can happily fly the aircraft without any automation.

More automation isn't the answer to compensate for unskilled, untalented, stressed crew or unstable air-planes that need to save a further 5% fuel so that everyone can feel more "ecological" when they go on vacation on the other side of the globe.

Aviation has had a greater share of profiting from the electronic media than many other sectors where when things go south no picture or photo goes around the world even if many more people are dying every year from the reckless use of more and more technology. Commercial aviation is under a heavy pressure to avoid casualties at (almost) any cost. Let the news focus on other forms of dying and I can promise you - no matter the improvement in automation - the accident rate will climb fast if for no other reason.

Lets hope they will find the CVR before this goes under the carpet to all the other "unclear/pilot-error" files. The folks at Boeing are rightly nervous every-time automation comes up in an accident giving the MAX disaster. Not that I have the slightest hope for any profound change in the aviation industry or beyond...


The 737-300 was introduced in 1984 (737-500 predecessor). This was pre-CPU-driven automation by about three years (A320).
 
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SomebodyInTLS
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Tue Mar 16, 2021 2:37 pm

oldJoe wrote:
In general it is to optimize safety nothing else !!!


Ha ha! Good one... you're obviously not an aerospace engineer.

Paraphrasing the professor of my first-year aerospace course: if safety were paramount, passengers would stay stuck inside a motionless block of concrete at the start of the runway.
"As with most things related to aircraft design, it's all about the trade-offs and much more nuanced than A.net likes to make out."
 
oldJoe
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Tue Mar 16, 2021 11:13 pm

SomebodyInTLS wrote:
oldJoe wrote:
In general it is to optimize safety nothing else !!!


Ha ha! Good one... you're obviously not an aerospace engineer.

Paraphrasing the professor of my first-year aerospace course: if safety were paramount, passengers would stay stuck inside a motionless block of concrete at the start of the runway.


Motionless block of concrete ? Your professor in aerospace should look for another job himself, for example in the construction industry !
 
hivue
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed Mar 17, 2021 3:54 am

aklrno wrote:
Automation is your friend if you know how to use it.


A pilot operating in modern airspace designed to meet the flying public's demand who cannot correctly and appropriately use automation is as dangerous as a pilot with poor manual flying skills.
"You're sitting. In a chair. In the SKY!!" ~ Louis C.K.
 
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SomebodyInTLS
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed Mar 17, 2021 5:30 pm

oldJoe wrote:
SomebodyInTLS wrote:
oldJoe wrote:
In general it is to optimize safety nothing else !!!


Ha ha! Good one... you're obviously not an aerospace engineer.

Paraphrasing the professor of my first-year aerospace course: if safety were paramount, passengers would stay stuck inside a motionless block of concrete at the start of the runway.


Motionless block of concrete ? Your professor in aerospace should look for another job himself, for example in the construction industry !


Woosh!

(check my signature)
"As with most things related to aircraft design, it's all about the trade-offs and much more nuanced than A.net likes to make out."
 
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garpd
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed Mar 17, 2021 11:53 pm

Sachmet wrote:
Lets hope they will find the CVR before this goes under the carpet to all the other "unclear/pilot-error" files. The folks at Boeing are rightly nervous every-time automation comes up in an accident giving the MAX disaster. Not that I have the slightest hope for any profound change in the aviation industry or beyond...


Pure hyperbole. The Autopilot on the 737 Classic is simple, tried and tested. Boeing are not nervous about the outcome from this crash.

We know for a fact the plane was having auto throttle issues. We know the engines had a severe asymmetric power setting We have had pilots here post that the crew should have noticed the asymmetric engine thrust and should have acted. But they didn't. They MUST take some blame here. They either let something distract them (Like the AdamAir crew, or the crew of that L1011 that crashed in the Everglades) or they (perish the thought) relied too much on the automation. As a pilot on this thread said: There would have been ample time for an attentive crew to note something was wrong, take the yoke and fly the plane. But for some reason, this crew let it get so far, the AP could no longer handle it and noped out, as it is designed to do, as the crew SHOULD be trained to know and handle.

Stop trying to push all the blame on the AP/Boeing, it may be fashionable, but it's not fair.
arpdesign.wordpress.com
 
oldJoe
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Thu Mar 18, 2021 12:15 am

SomebodyInTLS wrote:
oldJoe wrote:
SomebodyInTLS wrote:

Ha ha! Good one... you're obviously not an aerospace engineer.

Paraphrasing the professor of my first-year aerospace course: if safety were paramount, passengers would stay stuck inside a motionless block of concrete at the start of the runway.


Motionless block of concrete ? Your professor in aerospace should look for another job himself, for example in the construction industry !


Woosh!

(check my signature)


Your signurture tells me nothing at all ( fake ) ? And even you are a an engieier at all in France, leave the indunstry bcause they don`t need naysayers at all
 
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VirginFlyer
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Thu Mar 18, 2021 5:27 am

oldJoe wrote:
SomebodyInTLS wrote:
oldJoe wrote:

Motionless block of concrete ? Your professor in aerospace should look for another job himself, for example in the construction industry !


Woosh!

(check my signature)


Your signurture tells me nothing at all ( fake ) ? And even you are a an engieier at all in France, leave the indunstry bcause they don`t need naysayers at all

:redflag:

I’ll step in to bat for him here. His record on these forums over the years is plenty enough proof that he understands what he is talking about. I don’t think there’s any grounds on which to question it.

The point is, safety, while a major consideration, is not the only consideration. There will always be a degree of acceptable risk. For instance, and just using round numbers, you could have a part which has a failure rate of 1 in 100,000,000 flight hours. Now it would be possible to engineer the heck out of it so that it has a failure rate of 1 in 1,000,000,000 flight hours. Safer? Definitely. However, is the penalty of that extra engineering in terms of programme cost, weight, and maintenance expense worth that change in failure rate? And to go to second order considerations, does the improvement in safety by that order of magnitude reduction in failure rate come with a cost such that the number of people travelling by air (which we know to be a very safe method of transportation) reduce in response to pricing signals, increasing the number of people travelling by road (which we know to be a less safe method of transportation); in other words making aviation safer but the overall system of human transportation less safe.

In aircraft design, as in engineering in general, it's all about the trade-offs and much more nuanced than those without direct experience of the process assume.

V/F
It is not for him to pride himself who loveth his own country, but rather for him who loveth the whole world. The earth is but one country, and mankind its citizens. —Bahá'u'lláh
 
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SomebodyInTLS
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Thu Mar 18, 2021 8:07 am

VirginFlyer wrote:
The point is, safety, while a major consideration, is not the only consideration.


Thanks.

I could tell my interaction was rapidly going south so I was going to drop it, but nice to see you got what I was trying to say.

I probably should have spent the time explaining it as well as you did rather than dropping hints and anecdotes.
"As with most things related to aircraft design, it's all about the trade-offs and much more nuanced than A.net likes to make out."
 
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zeke
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Thu Mar 18, 2021 8:38 am

garpd wrote:
The Autopilot on the 737 Classic is simple, tried and tested. Boeing are not nervous about the outcome from this crash.

We know for a fact the plane was having auto throttle issues. We know the engines had a severe asymmetric power setting We have had pilots here post that the crew should have noticed the asymmetric engine thrust and should have acted. But they didn't. They MUSTt take some blame here.


I don’t agree, it’s related to FAR 25.1329.

There is a problem with the autothrust logic, if the aircraft knows of a throttle split and that split is getting larger, the autothrottle should disengage and provide a caution to the crew, I.e. FAR 25.1329(k). When the autopilot disengages it should not produce hazardous transients I.e. FAR 25.1329(g) or excessive loads I.e. FAR 25.1329(g), upon disengagement the autopilot let the controls return to neutral which was not recoverable because of the asymmetric thrust and return of the controls to neutral produced a significant transient.

This is the exact sort of accident the FGSWG changes to FAR 25.1329 was supposed to prevent.

https://www.faa.gov/regulations_policie ... 082897.pdf

If the autothrottle disengagement was earlier (ie at a limit on the maximum throttle split) and gracefully with a caution to the pilots, it would not have driven the pilots to a hazardous situation IMHO.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
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KLMatSJC
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Thu Mar 18, 2021 11:34 am

SomebodyInTLS wrote:
oldJoe wrote:
SomebodyInTLS wrote:

Ha ha! Good one... you're obviously not an aerospace engineer.

Paraphrasing the professor of my first-year aerospace course: if safety were paramount, passengers would stay stuck inside a motionless block of concrete at the start of the runway.


Motionless block of concrete ? Your professor in aerospace should look for another job himself, for example in the construction industry !


Woosh!

(check my signature)

On behalf of all aerospace engineers on here, we thank you.
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Fri Mar 19, 2021 2:15 pm

Please keep the discussion on the topic of SJ182.
I was raised by a cup of coffee.
 
Sachmet
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Thu Mar 25, 2021 8:24 pm

zeke wrote:
garpd wrote:
The Autopilot on the 737 Classic is simple, tried and tested. Boeing are not nervous about the outcome from this crash.

We know for a fact the plane was having auto throttle issues. We know the engines had a severe asymmetric power setting We have had pilots here post that the crew should have noticed the asymmetric engine thrust and should have acted. But they didn't. They MUSTt take some blame here.


I don’t agree, it’s related to FAR 25.1329.

There is a problem with the autothrust logic, if the aircraft knows of a throttle split and that split is getting larger, the autothrottle should disengage and provide a caution to the crew, I.e. FAR 25.1329(k). When the autopilot disengages it should not produce hazardous transients I.e. FAR 25.1329(g) or excessive loads I.e. FAR 25.1329(g), upon disengagement the autopilot let the controls return to neutral which was not recoverable because of the asymmetric thrust and return of the controls to neutral produced a significant transient.

This is the exact sort of accident the FGSWG changes to FAR 25.1329 was supposed to prevent.

https://www.faa.gov/regulations_policie ... 082897.pdf

If the autothrottle disengagement was earlier (ie at a limit on the maximum throttle split) and gracefully with a caution to the pilots, it would not have driven the pilots to a hazardous situation IMHO.

Very interesting - thanks.

There is no news at least on the net about the CVR - it doesn't really look too promising. Will they at least release the raw FDR data?

I still wonder if the pilots where hesitating taking back the controls? From everything I read so far I doubt that they did ignore the situation until the Autopilot/Autothrust switched off by itself. Could the over reliance and subsequent missing real flight experience lead to the point where pilots have too little self-esteem to "simply fly the plane"?
 
 
FlyingViking
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed Mar 31, 2021 3:01 am

 
wjcandee
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed Mar 31, 2021 3:18 am

Pretty-clear article, just the facts, by Reuters. Let's see where it goes from here.
 
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Aesma
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed Mar 31, 2021 3:26 am

Good news. We probably know the content, the pilots will be confused, not understanding what's happening, but it's good to have the proof.
New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
 
washingtonflyer
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed Mar 31, 2021 4:40 am

Excellent news. Hopefully the memory modules are still serviceable.
 
Paolo18
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed Mar 31, 2021 8:41 am

 
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TWA302
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed Mar 31, 2021 4:22 pm

So the CVR has been underwater for nearly 3 months. I hope that they are still able to get data from it. Good news that they found it.

Was looking at how long some went undiscovered after the crash. Interesting list
https://news.aviation-safety.net/2016/06/19/flight-recorders-under-water-list-of-longest-periods-before-recovery/
 
BEG2IAH
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Fri Apr 02, 2021 4:21 am

Some details of the search below. Fair use excerpt from: https://www.nytimes.com/2021/03/31/worl ... order.html

In a search hampered by rough weather and poor visibility, divers tried for six weeks to locate the unit without success. Officials tried various other methods and then brought in a dredging ship last week to pump up mud and sand from the seafloor.

Officials said they had planned to halt operations with the dredging ship on Wednesday if they had not found the device by then.

“There’s a mud sucker that works like a vacuum cleaner,” said Soerjanto Tjahjono, chief of the National Transportation Safety Committee. “We extracted the mud down to one meter deep. Last night, when it was the last night of the search, we found it.”

Before the dredging operation began, divers spent about two weeks removing as much airplane debris as possible from the site. For the past week, the dredging vessel pumped up sediment containing aircraft parts and workers sifted through it until they found the memory unit.

Nurcahyo Utomo, the committee’s head of air safety investigation, said that investigators would dry out the module overnight and remove salt deposits before connecting it to a cockpit voice recorder and retrieving its data.

“Our hope is that we will gather a lot of information on what happened and the steps taken in the cockpit during that flight,” he said.
Flying at the cruising altitude is (mostly) boring. I wish all flights were nothing but endless take offs and landings every 10 minutes or so.
 
wjcandee
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Fri Apr 02, 2021 11:56 am

BEG2IAH wrote:
[NYT excerpt...]"...investigators would dry out the module overnight and remove salt deposits before connecting it to a cockpit voice recorder and retrieving its data. [...]


Well, the NYT almost made it to the end of the excerpt without bollixing some aspect of their story.
 
BEG2IAH
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Fri Apr 02, 2021 4:46 pm

wjcandee wrote:
Well, the NYT almost made it to the end of the excerpt without bollixing some aspect of their story.


True. :)
Flying at the cruising altitude is (mostly) boring. I wish all flights were nothing but endless take offs and landings every 10 minutes or so.
 
Boeingphan
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Thu Apr 08, 2021 12:26 pm

Silence a week after finding the cvr? I was thinking we may hear something by now.
 
Western727
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Thu Apr 08, 2021 12:28 pm

Boeingphan wrote:
Silence a week after finding the cvr? I was thinking we may hear something by now.


Likewise.
Jack @ AUS
 
Boeingphan
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Mon Apr 12, 2021 11:40 am

 
SwissCanuck
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Mon Apr 12, 2021 12:28 pm

Boeingphan wrote:


That last line through - I'm pretty sure only a preliminary report is required after 12 months?
 
Blankbarcode
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Tue Apr 13, 2021 9:19 am

CVR has been read out, per AvHerald:

"On Apr 13th 2021 the KNKT announced, that the CVR had been downloaded. Two hours of recordings were retrieved including the accident flight. The KNKT stated: "NTSC managed to download all 4 channels from CVR, but channel 4 on CVR was disrupted. However, !based on the existing records, it has added important data for the investigation which results will be presented in the final report."

Does anyone know what's generally kept on the fourth channel? I wonder to what extent they mean with "disrupted"

Source: http://avherald.com/h?article=4e18553c/0001&opt=0
 
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zeke
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Tue Apr 13, 2021 10:46 am

Blankbarcode wrote:
Does anyone know what's generally kept on the fourth channel? I wonder to what extent they mean with "disrupted"


Channel 4 is really up to the local regulatory requirements, typically channel 1 is the hot cockpit area microphone (CAM), next 2 channels the radio/intercom audio panels at the captain and first officer positions. The forth maybe setup to take cabin communication or the jump seat, or nothing at all. Often it was not required to have anything on that size of aircraft so it is often blank.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
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flyingturtle
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Tue Apr 13, 2021 11:40 am

Boeingphan wrote:
Silence a week after finding the cvr? I was thinking we may hear something by now.


Under ICAO rules, a month after the accident, a preliminary report is due.

12 month after the accident, the final report. If a final report is not possible, then there will be yearly updates on the investigation.

The investigators will probably not release the CVR transcript without a careful interpretation - which would take weeks, or even months. Analyzing noises picked up by the microphones will take even longer.
Reading accident reports is what calms me down
 
Sachmet
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Fri Apr 23, 2021 11:11 am

Lawsuit against Boeing citing the autothrottle malfunction as primary reason for the crash

https://www.seattletimes.com/business/b ... lfunction/
 
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PixelFlight
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Tue Apr 27, 2021 9:02 pm

zeke wrote:
garpd wrote:
The Autopilot on the 737 Classic is simple, tried and tested. Boeing are not nervous about the outcome from this crash.

We know for a fact the plane was having auto throttle issues. We know the engines had a severe asymmetric power setting We have had pilots here post that the crew should have noticed the asymmetric engine thrust and should have acted. But they didn't. They MUSTt take some blame here.


I don’t agree, it’s related to FAR 25.1329.

There is a problem with the autothrust logic, if the aircraft knows of a throttle split and that split is getting larger, the autothrottle should disengage and provide a caution to the crew, I.e. FAR 25.1329(k). When the autopilot disengages it should not produce hazardous transients I.e. FAR 25.1329(g) or excessive loads I.e. FAR 25.1329(g), upon disengagement the autopilot let the controls return to neutral which was not recoverable because of the asymmetric thrust and return of the controls to neutral produced a significant transient.

This is the exact sort of accident the FGSWG changes to FAR 25.1329 was supposed to prevent.

https://www.faa.gov/regulations_policie ... 082897.pdf

If the autothrottle disengagement was earlier (ie at a limit on the maximum throttle split) and gracefully with a caution to the pilots, it would not have driven the pilots to a hazardous situation IMHO.

Thanks you for those information and document link. I was able to find into it the cost evaluation for new development without manufacturing, development with "cut-in" in ongoing production, and modification of existing airplanes. This shows that that issue was serious and that all airplanes should be modified to fix it. But I failed to find when this proposal eventually enter in force, and what delay was eventually set to comply to it.
:stirthepot: 737-8 MAX: "For all speeds higher than 220 Kts and trim set at a value of 2.5 units, the difficulity level of turning the manual trim wheel was level A (trim wheel not movable)." :stirthepot:
 
Sachmet
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Sun May 02, 2021 12:29 pm

Some new detail about the CVR and EGP WS readings:

https://translate.google.com/translate? ... ch&pto=aue
 
Elkadad313
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Mon May 03, 2021 5:11 pm

Sachmet wrote:
Some new detail about the CVR and EGP WS readings:

https://translate.google.com/translate? ... ch&pto=aue

Is this the 30-day interim report?
 
Sachmet
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 05, 2021 7:18 pm

Elkadad313 wrote:
Sachmet wrote:
Some new detail about the CVR and EGP WS readings:

https://translate.google.com/translate? ... ch&pto=aue

Is this the 30-day interim report?

No

I hope we will get a partial transcript but it doesn't seem to be a very transparent investigation. I also suspect that some pressure is applied to withhold the detailed info. Boeing isn't in a position to ground another fleet and no one s eager to ask the question: "could this happen again?".

FAR 25.1329 should really be applied to improve the older classic A/P A/T systems. I know they worked well so far but the issue is that newer generations are used to more automation and they will easily overestimate the abilities of those old systems. I don't say this easily because I like simplicity and I would rather see pilots who don't rely too much on those systems.
 
LTEN11
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 05, 2021 8:32 pm

Sachmet wrote:
Elkadad313 wrote:
Sachmet wrote:
Some new detail about the CVR and EGP WS readings:

https://translate.google.com/translate? ... ch&pto=aue

Is this the 30-day interim report?

No

I hope we will get a partial transcript but it doesn't seem to be a very transparent investigation. I also suspect that some pressure is applied to withhold the detailed info. Boeing isn't in a position to ground another fleet and no one s eager to ask the question: "could this happen again?".

FAR 25.1329 should really be applied to improve the older classic A/P A/T systems. I know they worked well so far but the issue is that newer generations are used to more automation and they will easily overestimate the abilities of those old systems. I don't say this easily because I like simplicity and I would rather see pilots who don't rely too much on those systems.


Just what exactly are you implying ? Are you suggesting that Boeing, the airline, or government agencies, or all together, are deliberately withholding information, just to enable some older aircraft to keep flying ?

The generation of the flight crew is totally irrelevant, they have been trained to fly this type of 737. It's not like they fly the MAX or the NEO and are then suddenly thrown onto a 737 classic and told, there you go boys, this is yours for the day. They are trained for this particular type of cockpit, it's layout, it's systems, older/newer generation of pilot is irrelevant, you're flying what you've learnt and are rated to fly.
 
Sachmet
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Thu May 06, 2021 7:34 pm

LTEN11 wrote:
Just what exactly are you implying ? Are you suggesting that Boeing, the airline, or government agencies, or all together, are deliberately withholding information, just to enable some older aircraft to keep flying ?

If past behaviour gives any clue for present action than at least one can have doubts and suspicions. It needed two MAX to come down and not even that made Boeing, the airlines and the government agencies to take immediate action to assure safety of the whole fleet. I have my strongest doubts that the culture at Boeing and the others has so deeply changed. That said automation dependency and overuse is of course not just Boeing's problem. The irony is that it was exactly Boeing's conservative approach that brought them the trouble with the MAX.

The issue isn't really one company against the other but a general tendency in society that spells trouble. I am also for better training and most of all better practice (not only in simulators but flying the Aircraft without or with a minimum amount of automation). The reality is that the use of manual flying is discouraged and then 1000ths hours flying practice mean very little if almost all if it is with A/P, A/T systems on.

LTEN11 wrote:
The generation of the flight crew is totally irrelevant, they have been trained to fly this type of 737. It's not like they fly the MAX or the NEO and are then suddenly thrown onto a 737 classic and told, there you go boys, this is yours for the day. They are trained for this particular type of cockpit, it's layout, it's systems, older/newer generation of pilot is irrelevant, you're flying what you've learnt and are rated to fly.

This is of course the theory. Its not just what you are trained for but the whole level of automation that surrounds you. I am not comfortable with it but many others are and so they rely more and more on electronic devices to do their work everywhere in life. Yes it is a generational question and that makes using those old systems more dangerous with each new generation.

Read the previous posts: "electronics do everything faster that humans" - frightening quote. Our whole environment is turning into a autopiloted world - of course a generation that is so much used on all the automated systems around it is hesitating to turn them off and do manual. Maybe just hesitating for ten seconds - enough to enter a critical situation like we had here (We have still to wait for the CVR so I will only speak in general terms). I am open to hear what you tell me why else do perfectly flyable planes fall off the sky and it becomes a major problem?
 
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PixelFlight
Posts: 1033
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Fri May 14, 2021 11:22 pm

Sachmet wrote:
LTEN11 wrote:
Just what exactly are you implying ? Are you suggesting that Boeing, the airline, or government agencies, or all together, are deliberately withholding information, just to enable some older aircraft to keep flying ?

If past behaviour gives any clue for present action than at least one can have doubts and suspicions. It needed two MAX to come down and not even that made Boeing, the airlines and the government agencies to take immediate action to assure safety of the whole fleet. I have my strongest doubts that the culture at Boeing and the others has so deeply changed. That said automation dependency and overuse is of course not just Boeing's problem. The irony is that it was exactly Boeing's conservative approach that brought them the trouble with the MAX.

The issue isn't really one company against the other but a general tendency in society that spells trouble. I am also for better training and most of all better practice (not only in simulators but flying the Aircraft without or with a minimum amount of automation). The reality is that the use of manual flying is discouraged and then 1000ths hours flying practice mean very little if almost all if it is with A/P, A/T systems on.

LTEN11 wrote:
The generation of the flight crew is totally irrelevant, they have been trained to fly this type of 737. It's not like they fly the MAX or the NEO and are then suddenly thrown onto a 737 classic and told, there you go boys, this is yours for the day. They are trained for this particular type of cockpit, it's layout, it's systems, older/newer generation of pilot is irrelevant, you're flying what you've learnt and are rated to fly.

This is of course the theory. Its not just what you are trained for but the whole level of automation that surrounds you. I am not comfortable with it but many others are and so they rely more and more on electronic devices to do their work everywhere in life. Yes it is a generational question and that makes using those old systems more dangerous with each new generation.

Read the previous posts: "electronics do everything faster that humans" - frightening quote. Our whole environment is turning into a autopiloted world - of course a generation that is so much used on all the automated systems around it is hesitating to turn them off and do manual. Maybe just hesitating for ten seconds - enough to enter a critical situation like we had here (We have still to wait for the CVR so I will only speak in general terms). I am open to hear what you tell me why else do perfectly flyable planes fall off the sky and it becomes a major problem?

:thumbsup: Good analysis !
The generation evolution is directly driven by the automation evolution. Not only electronics will do everything faster than humans, but the reliability will be very high (when redundancy is done the right way), and the level of expertise will be incredibly large. Many peoples underestimate the last point because it's a relatively new aspect of automation, but it's now possible to design automation systems that embed more data set that any human. My point of view is that this is the critical part that need to evolve to precisely help the pilots in case of unexpected scenarios, a part not well covered by the current automation. Pilots will still be there to manage high levels decisions, but every workloads that can be automated will be, even in non normal situation, like TCAS already do.
:stirthepot: 737-8 MAX: "For all speeds higher than 220 Kts and trim set at a value of 2.5 units, the difficulity level of turning the manual trim wheel was level A (trim wheel not movable)." :stirthepot:
 
Tiredofhumanity
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Sat May 15, 2021 1:12 am

Sachmet wrote:
Elkadad313 wrote:
Sachmet wrote:
Some new detail about the CVR and EGP WS readings:

https://translate.google.com/translate? ... ch&pto=aue

Is this the 30-day interim report?

No

I hope we will get a partial transcript but it doesn't seem to be a very transparent investigation. I also suspect that some pressure is applied to withhold the detailed info. Boeing isn't in a position to ground another fleet and no one s eager to ask the question: "could this happen again?".

FAR 25.1329 should really be applied to improve the older classic A/P A/T systems. I know they worked well so far but the issue is that newer generations are used to more automation and they will easily overestimate the abilities of those old systems. I don't say this easily because I like simplicity and I would rather see pilots who don't rely too much on those systems.


Are there any other types in operation that (A320's, 744's, etc) that may not have fallen under this FAR?

EDIT - too lazy to look though all the TCDS's, but it looks like this FAR only goes back to 2004:

https://www.law.cornell.edu/cfr/text/14/25.1329

Could any NG or A320 drivers chime in?

EDIT II: Disregard the 2004 comment - I need to do more research :oops:
 
Sachmet
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Tue May 18, 2021 10:41 pm

Latest info:

While the FAA has said there is as yet no evidence to suggest that the autothrottle problem could be replicated in other aircraft, it has now informed operators of over 1,041 737-300, -400, and -500 Classic series aircraft to inspect the wiring of their own systems.

The FAA will soon also be issuing an airworthiness directive to the same effect.


https://australianaviation.com.au/2021/ ... ic-wiring/
 
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zeke
Posts: 16104
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 12:15 am

Sachmet wrote:
Latest info:

While the FAA has said there is as yet no evidence to suggest that the autothrottle problem could be replicated in other aircraft, it has now informed operators of over 1,041 737-300, -400, and -500 Classic series aircraft to inspect the wiring of their own systems.

The FAA will soon also be issuing an airworthiness directive to the same effect.


https://australianaviation.com.au/2021/ ... ic-wiring/


As far as I am aware the AD has nothing to do with the particular accident.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
wjcandee
Posts: 10464
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 3:39 am

zeke wrote:
Sachmet wrote:
Latest info:

While the FAA has said there is as yet no evidence to suggest that the autothrottle problem could be replicated in other aircraft, it has now informed operators of over 1,041 737-300, -400, and -500 Classic series aircraft to inspect the wiring of their own systems.

The FAA will soon also be issuing an airworthiness directive to the same effect.


https://australianaviation.com.au/2021/ ... ic-wiring/


As far as I am aware the AD has nothing to do with the particular accident.


I'm also not sure that the explanation in the article, that "investigators have determined that the accident was caused in part by a malfunctioning autothrottle lever system", is particularly-accurate. I don't think anybody has conclusively-shown that the autothrottle "malfunctioned" as opposed to the lever stuck and the autopilot system being one that monitors total thrust ended up advancing the non-stuck throttle to maintain total thrust. In other words, it may be that the autothrottle functioned exactly as designed and taught. But maybe there's an update that I missed.
 
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zeke
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 8:41 am

wjcandee wrote:
I don't think anybody has conclusively-shown that the autothrottle "malfunctioned" as opposed to the lever stuck and the autopilot system being one that monitors total thrust ended up advancing the non-stuck throttle to maintain total thrust.


The autothrottle on the side that was moving was not advanced, it was reduced, this reduction required aileron inputs up to to the limit of the roll control counter the asymmetric thrust to a point where the autopilot dropped out. When the autopilot or autothrottle fails it should fail gracefully (ie no extraordinary pilot inputs required, no excessive loads) with a warning. That did not happen with this event.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
orlandocfi
Posts: 132
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 12:54 pm

zeke wrote:
wjcandee wrote:
I don't think anybody has conclusively-shown that the autothrottle "malfunctioned" as opposed to the lever stuck and the autopilot system being one that monitors total thrust ended up advancing the non-stuck throttle to maintain total thrust.


The autothrottle on the side that was moving was not advanced, it was reduced, this reduction required aileron inputs up to to the limit of the roll control counter the asymmetric thrust to a point where the autopilot dropped out. When the autopilot or autothrottle fails it should fail gracefully (ie no extraordinary pilot inputs required, no excessive loads) with a warning. That did not happen with this event.


When the 737 autothrottles aren’t behaving as desired...which is often tbh...the pilots normally intervene by overpowering the servos or disconnecting the a/t. The thrust levers work great manually.
If the pilots departed into an area of known storms (which they shouldn’t have), the automation should have been disengaged as soon as they entered adverse weather.
 
Sachmet
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 1:02 pm

wjcandee wrote:
zeke wrote:
As far as I am aware the AD has nothing to do with the particular accident.

I'm also not sure that the explanation in the article, that "investigators have determined that the accident was caused in part by a malfunctioning autothrottle lever system", is particularly-accurate. I don't think anybody has conclusively-shown that the autothrottle "malfunctioned" as opposed to the lever stuck and the autopilot system being one that monitors total thrust ended up advancing the non-stuck throttle to maintain total thrust. In other words, it may be that the autothrottle functioned exactly as designed and taught. But maybe there's an update that I missed.


Maybe we missed an interim report (I tried to find it but only got this from aero.de):

Indonesian aircraft accident investigators now attribute the crash of flight SJ182 to a technical malfunction in the aircraft's automatic thrust control. However, the actual cause of the error has not yet been officially established.

The flight data recorder recorded an error message from the automatic thrust control shortly after take-off. Instead of shutting down the system, according to Indonesian investigators, the pilots first tried to fix the problem. "Differences in performance" between the engines could then have led to the crash, according to a first report.


https://translate.google.com/translate? ... ch&pto=aue
 
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zeke
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 2:09 pm

orlandocfi wrote:
When the 737 autothrottles aren’t behaving as desired...which is often tbh...the pilots normally intervene by overpowering the servos or disconnecting the a/t.


What is required under FAR 25 is when the autopiltot or autothrottle misbehaves it disconnects gracefully and generates a warning, if you are saying the system does not do this, that is a design flaw. I posted the relevant FAR 25 certification regulation above that states this.

orlandocfi wrote:
If the pilots departed into an area of known storms (which they shouldn’t have), the automation should have been disengaged as soon as they entered adverse weather.


Jakarta would have CBs almost every day of the year, the weather was not unremarkable for an airport so close to the equator. As as far as I am aware, there is no AFM or FCOM limit stating that autopilot or autothrottle should bot be used in such conditions, if anything its encouraged.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
FLYBY72
Posts: 36
Joined: Mon Feb 08, 2021 4:16 am

Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 2:09 pm

zeke wrote:
wjcandee wrote:
I don't think anybody has conclusively-shown that the autothrottle "malfunctioned" as opposed to the lever stuck and the autopilot system being one that monitors total thrust ended up advancing the non-stuck throttle to maintain total thrust.


The autothrottle on the side that was moving was not advanced, it was reduced, this reduction required aileron inputs up to to the limit of the roll control counter the asymmetric thrust to a point where the autopilot dropped out. When the autopilot or autothrottle fails it should fail gracefully (ie no extraordinary pilot inputs required, no excessive loads) with a warning. That did not happen with this event.


Except it did happen in this event. In the initial report they purposely left out a lot of the FDR data on throttle position and pilot inputs. Imagine if the truth is that when the AP disengaged the airplane only slightly rolled. The pilots, being in the weather, misinterpreted that slight roll and made a huge input that cause the plane to roll over. What if they also did not bring the stuck throttle to idle until very late in the recovery.

That part of the data was not released but everyone likes to infer that the autopilot disengagement caused the snap roll. If they released all of the data we would know for sure.
 
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zeke
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 2:26 pm

FLYBY72 wrote:
Except it did happen in this event.


It did, the autopilot only disengages when the maximum authority is reached and it is exceeded, and when it is reached the control inputs go back from the maximum deflection to neutral, ie equivalate to a full opposite input while at the same time have idle thrust on one side and climb thrust on the other. For the pilots to save it they would have had to immediately recognize and understand what was happening, simultaneously lowered the nose, reduced thrust on both engines, and opposed the roll. No pilot is that good.

As far as the pilots were concerned the autopilot was doing as commanded, as they had commanded it to a right heading and level off at 11000 ft and they saw the right turn on the yoke and the aircraft leveling at 11000.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
Exeiowa
Posts: 384
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Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 2:38 pm

So where we are now and been for a while is why the autothrotle behaved in the way it did and why the pilots did not intervene at that point.
 
orlandocfi
Posts: 132
Joined: Mon Nov 23, 2020 12:53 am

Re: Sriwijaya Air 737-500 (SJ182 CGK-PNK) crashes shortly after takeoff

Wed May 19, 2021 2:43 pm

zeke wrote:
orlandocfi wrote:
When the 737 autothrottles aren’t behaving as desired...which is often tbh...the pilots normally intervene by overpowering the servos or disconnecting the a/t.


What is required under FAR 25 is when the autopiltot or autothrottle misbehaves it disconnects gracefully and generates a warning, if you are saying the system does not do this, that is a design flaw. I posted the relevant FAR 25 certification regulation above that states this.

orlandocfi wrote:
If the pilots departed into an area of known storms (which they shouldn’t have), the automation should have been disengaged as soon as they entered adverse weather.


Jakarta would have CBs almost every day of the year, the weather was not unremarkable for an airport so close to the equator. As as far as I am aware, there is no AFM or FCOM limit stating that autopilot or autothrottle should bot be used in such conditions, if anything its encouraged.


Isnt it amazing that there are thunderstorms every day around the globe and professional pilots manage to not fly into them?
Use of autopilot in extreme weather is actually not recommended as it can impose excessive loads on the aircraft structure. Does that have to be stated in the AFM?
It appears that Indonesia would like to obscure the human factors involved in this accident rather than address them.

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