Boeing 737 (500, not a Max) crashed in Indonesia 1

[IRstuff]

https://www.bbc.com/news/world-asia-55601909

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[dik]

and more news from CTV...
"Indonesian navy divers searching the ocean floor on Tuesday recovered the flight data recorder from a Sriwijaya Air jet that crashed into the Java Sea with 62 people on board.

The device is expected to help investigators determine what caused the Boeing 737-500 to nosedive into the ocean in heavy rain shortly after taking off from Jakarta on Saturday.

The 26-year-old jet had been out of service for almost nine months because of flight cutbacks caused by the coronavirus pandemic, officials said. It resumed commercial flights last month."

A sign of more things to come?

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik

 

[RVAmeche]

Wonder if some sort of maintenance item got overlooked during the cutbacks?

 

[MacGyverS2000]

All else being equal, I would lean towards a de-mothballing step was missed or carried out poorly (e.g., anti-freeze not completely removed from a fuel/hydraulic line, etc.).

Dan - Owner

http://www.Hi-TecDesigns.com

 

[IRstuff]

https://www.businessinsider.com/sriwijaya-air-has-a-history-of-boeing-737-plane-crashes-2021-1

This airline accounts for 5 of the 58 total crashes reported for the entire 737 Classic production series.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[LittleInch]

Either the tail fell off or the elevators fell off. Or something broke. The plane seems to have been more or less in one piece when it hit the water so a bomb seems unlikely and no one has claimed responsibility yet.

This just suddenly went into a near vertical dive. Had been flying for about a month. Need to wait for the FDR if it's published.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[davefitz]

it may be a good time to be placed on the "no fly list"


"...when logic, and proportion, have fallen, sloppy dead..." Grace Slick

 

[SnTMan]

Like was said in the Max thread, "If it's Boeing, I ain't going"

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[thebard3]

Despite the number of crashes involving 737s over it's very long period of service, and including the 2 very high profile crashes of the 737 MAX, the type is overall one of the safest airplanes ever made. If I were to make a list of airplanes that I wouldn't fly on, the 737 would not be on it.

Brad Waybright

The more you know, the more you know you don't know.

 

[waross]

It's not so much about safety Brad.
As an example, there is a local farmer who has a very long history of bad dealing.
He advertised a piece of machinery for sale at a good price.
A buyer drove a couple of hundred miles to buy it.
When the buyer arrived, e increased the price.
The buyer went home empty handed.
He was selling hay by weight.
He declared the weight of the bales and refused to accept the weight from a trade-legal scale.
He baled hay wet and when a buyer came to check the quality, he would show him good hay from a different batch and then deliver the bad hay.
When farmers get together and talk about scams, the stories about this guy go on for a long time.
His character is well known over a wide area.
Few people will deal with him.
Even if it is a good deal, why take a chance on finding out a new way to be cheated?
He has shown his character and is not the type of person that a lot of people want to deal with.

Boeing has shown their corporate character and they are not the sort of company that a lot of us want to trust.
By the way, have they addressed the manual trim issue or is it still unusable when the plane is grossly out of trim, just when you need it the most?

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[LittleInch]

The manual trim issue was not addressed, mainly because it would mean too many changes and the FAA also discovered that there was no requirement for it and / or no maximum force required or number of turns required per degree change in the trim in the regulations, therefore they couldn't enforce a requirement where none existed(!!).

This was their excuse for a couple of other things that people had brought up when it came to recertification - no defined requirement therefore although it might be a good idea, they couldn't force Boeing to do it if the regulations didn't specify it.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[waross]

I am aware of that IR.
Thank you for clarifying that the issue has not been addressed.
It helps make my point.
No trust for Boeing and don't depend too much on the FAA.
The agency that sets and changes the rules has chosen to ignore this loophole?
Had the political pressure been different the rules would have been changed.

Bill
--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[IRstuff]

The fallacy is presuming that the only other major competitor isn't just as bad; they likely just haven't gotten caught at it yet. Let's not forget that VW, a European company purposely programmed their cars to pass emission tests, and that Airbus hadn't been exact proactive about their air speed sensors freezing up. While we humans have lofty goals and aspirations, we're still hardscrabble walking apes with personal foibles and vested interests that often collide with morality and good acts.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[LionelHutz]

LOL, from what I can see every big publicly traded corporation is about the same as Boeing. They all portray as being responsible caring companies, but it's just a facade. They all do whatever is needed to maximize their reported profits.

 

[Alistair_Heaton]

If your interested the word on the street is that it was an Auto throttle clutch issue on one side which put the aircraft into an asymmetric power situation.

Which it is presumed the crew didn't spot or react to correctly. Apparently its hard to spot unless you have a habit of keeping you hands on the power levers below 10 000 ft. There are various systems which mask the symptoms with the automatics engaged until they run out of authority and then it all goes pair shaped very quickly. If the engine fails there is a master caution alert but in this case it doesn't trigger because there is still oil pressure but the engine isn't providing the commanded thrust.

If it is a AT clutching going this has occurred many times before and is part of the 3 year sim cycle exercises.

This will be mostly a human factors accident.

Just been informed that the oil pressure isn't in the master caution matrix on the 500.. Which seems a bit strange, don't have a clue if it is or isn't on the NG and MAX.

 

[LittleInch]

OK, I can see how this wouldn't be good, but how does it result in the airplane diving into the sea?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Alistair_Heaton]

Failure to apply corrective control inputs in a timely manner after the systems dump a very out of trim aircraft onto the pilot.

Apparently its a mandatory exercise during type rating. Which I have never done. But those that have tell me its quite aerobatic. And even when your expecting it in the sim pre briefed you will get 60 deg plus bank angles. If you are doing a normal line flight and the aircraft is clean and automatics are in you tend to drop down your monitoring and control covering so if you add in the startle and surprise human factors the reaction times increase dramatically which will vastly increase the deviation from controlled flight path.

The Jetstream AP used to do it to us when coupling to a ILS localiser. But that was with relatively low power settings with both engine symmetric. And we were expecting it to do it on every approach so it didn't come as a surprise.

We will have to wait for the pre report. The Indonesian accident investigation unit are extremely 737 knowledgeable and extremely experienced. I expect it wont take long for it to appear.

 

[Comcokid]

If your interested the word on the street is that it was an Auto throttle clutch issue on one side which put the aircraft into an asymmetric power situation.

OK, I can see how this wouldn't be good, but how does it result in the airplane diving into the sea?

Failure to apply corrective control inputs in a timely manner after the systems dump a very out of trim aircraft onto the pilot... But those that have tell me its quite aerobatic.

This exchange brought to mind a new video I just saw and is a week old. This well known incident was not a 737 but a 747-SP, asymmetric thrust, and it wasn't the auto throttle clutch but a sluggish fuel control valve, made worse by crew errors. Autopilot was at maximums when the pilot took over not realizing the trim state the autopilot had the aircraft in.

I've never experienced 4.8 G. "Quite aerobatic" indeed!

First part is intro, commercial, and history of the 747-SP. Incident description begins at 6:20, ends 15:40

https://www.youtube.com/watch?v=1gotTJlXMQc

 

[Alistair_Heaton]

To be honest its not definitely the clutch, there is engine bleed check valve issues as well which there has been an AD issued for. But a surging engine is relatively easy to diagnose and shut down without loosing control.

But that video describes the situation that they may have been in if the clutch issue did occur.

 

[LittleInch]

Ah, ok so the plane gets to a point where it suddenly flips on its back and dives upside down into the sea?

There is a fair bit of chatter out there on this based on a report form the investigators by the sound of it.

Some of the data from that china air flight mentioned sounds very similar in the it fell over 10000 ft in less than a minute.
The damage on that plane was really quite something.

for my information does the A/P only control the ailerons and the stab trim / elevator and not the rudder??

So how are you supposed to fly a twin engined plane with only one engine? With a fair bit of Yaw?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.