Boeing 737 Max8 Aircraft Crashes and Investigations [Part 2] 44

[Alistair_Heaton]

This thread is a continuation of:

thread815-445840


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Another 737 max has crashed during departure in Ethiopia.

To note the data in the picture is intally ground 0 then when airborne is GPS altitude above MSL. The airport is extremely high.

The debris is extremely compact and the fuel burned, they reckon it was 400knts plus when it hit the ground.

Here is the radar24 data pulled from there local site.

It's already being discussed if was another AoA issue with the MCAS system for stall protection.

I will let you make your own conclusions.

 

[VEBill]

News:

BBC: UK joins wave of countries grounding the 737 Max

 

[Alistair_Heaton]

It's uk airspace so it's basically blocked them being used transatlantic.

 

[VEBill]

News: "Germany, Ireland and France ban Boeing 737 Max 8 planes from airspace"

 

[waross]

Over 4 months without a fix.
They could have at least pulled a fuse or disconnected a wire.
A simple alarm rather than computer directed flight into terrain.
Instead they delayed until another 157 people died.
Are there any calls yet for criminal charges against Boeing executives.
Unbelievable and shameful.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[TenPenny]

Well, I see now that 'Einstein' shouldn't be flying the planes, so let's all go back to wooden biplanes and sticks!

 

[RVAmeche]

Such an embarrassment...

 

[itsmoked]

Indeed.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[MDEAus]

That map from the guardian is inaccurate, below is the co-ordinates for the crash site.

https://earth.google.com/web/@8.87673473,39.25097948,2397.78746035a,807.17751268d,35y,-0h,0t,0r

lots of speculation on this accident on the airliners forum. 35 pages of mostly speculation and rehashing mis-information on the MCAS system and it's operation, and a lot of back and fourth about if the Type should be grounded. There is a couple of nuggets of info but sorting through it all is a mess.

 

[Sparweb]

There are so few facts to choose from. I can't tell if the European no-fly orders are politically motivated or have technical merit.
I'm still trying to learn the function and purpose of the MCAS system.
This helps:

http://www.b737.org.uk/mcas.htm

It repeats the conditions when MCAS is active (autopilot off, flaps up). The description on that site makes it seem more like a thrust compensation device. Engines are mounted down low, so when the throttles are pushed forward, Boeing chose to "tweak" the elevator trim to compensate for the nose-up pitch. It just doesn't seem like this system can back off, or reverse the compensation when the throttles are eased back. In fact, if you consider that the pilots have manual control over the pitch anyway, giving them full authority over the airspeed, too, this system should be backing off the compensation almost immediately after it activates. If I understand its function right, it works in chunks of 2.5 degrees at a time - pretty big chunks of elevator pitch change to give out all at once.

In 100 years, there have been many aircraft with thrust-lines far off-center from the center of drag. In fact, it's common. It doesn't take much to be noticeable. I was exposed to it in basic training on a Cessna 172 doing go-arounds. When aborting a landing you have to get the flaps up and slam on the throttle, so you have to be ready for both the torque and wicked nose-up motion by doing both of those things at the same time. Pilots who can't deal with pitch changes associated with thrust changes get weeded out of the talent pool long before they are charged with passengers.

No one believes the theory except the one who developed it. Everyone believes the experiment except the one who ran it.
STF

 

[thebard3]

There are so few facts to choose from. I can't tell if the European no-fly orders are politically motivated or have technical merit.

I heard this morning that the Ethiopian authorities are holding the black boxes and can't access the data. I don't know if that's true but if so this seems totally irresponsible and negligent. Otherwise, from what I have been able to find out, anything related to the cause of this crash is simply speculation. The Lion Air crash was apparently caused by a faulty AoA sensor and the MCAS incorrectly trying to compensate for the bad data from it. A contributing primary factor was the pilots inability or lack of knowledge about how to respond to that situation. Also, this condition had existed for several previous flights for this airplane and it should not have been left to fly until the problem was corrected. To attribute the latest crash to airplane design without some empirical evidence to support the claim is just irresponsible. That's the world we live in today, though.

Brad Waybright

It's all okay as long as it's okay.

 

[LionelHutz]

It changes at 0.27 degrees per second. The limit is 2.5 degrees of change which would occur over 9.26 seconds.

 

[Spartan5]

I heard this morning that the Ethiopian authorities are holding the black boxes and can't access the data. I don't know if that's true but if so this seems totally irresponsible and negligent. Otherwise, from what I have been able to find out, anything related to the cause of this crash is simply speculation. The Lion Air crash was apparently caused by a faulty AoA sensor and the MCAS incorrectly trying to compensate for the bad data from it. A contributing primary factor was the pilots inability or lack of knowledge about how to respond to that situation. Also, this condition had existed for several previous flights for this airplane and it should not have been left to fly until the problem was corrected. To attribute the latest crash to airplane design without some empirical evidence to support the claim is just irresponsible. That's the world we live in today, though.

https://www.washingtonpost.com/worl...6d711e-4574-11e9-90f0-0ccfeec87a61_story.html

Ethio­pian Airlines announced Wednesday that it would send the voice and data recorders from its ill-fated Flight 302 to be analyzed abroad, as more countries said they were banning planes of the same type from operating in their airspace.
...
Ethio­pian Airlines Chief Executive Tewolde Gebremariam told CNN on Tuesday that the pilot reported “flight control problems” and asked to return to the airport.
...
Tewolde told CNN that the boxes would be sent abroad “because we don’t have the equipment here” to analyze their data. He said the boxes could possibly go to the United States or to a European country closer to Ethi­o­pia “in the interest of proximity and speed.” The decision will be made by the team investigating the crash.
...
In both the Lion Air and Ethio­pian Airlines crashes, the airplane immediately showed signs of trouble, with an erratic flight path that ascended and then descended before the airliner crashed minutes later.

 

[VEBill]

I heard this morning that the Ethiopian authorities are holding the black boxes and can't access the data. I don't know if that's true but if so this seems totally irresponsible and negligent.

Perhaps you're misinterpreting.

"Ethiopian authorities are holding the black boxes..." ...perhaps while they're making arrangements to have them sent to a suitable facility for reading out the data. They'd be holding them in a secure location, as evidence. It's the sort of secure transportation arrangements that could quite reasonably require a couple of days.

"...and can't access the data." There are probably a hand-full of suitable facilities in the world that can read the data from the boxes (which may be heavily damaged). So it's perfectly reasonable that the Ethiopian authorities can't access the data themselves. Even if they could try, it would be safer to let the experts (such as the OEM) do it.

So I don't see anything that's remotely irresponsible and negligent.

Hopefully I'm not misinterpreting what you've posted.

Did you want to clarify?

 

[thebard3]

Perhaps you're misinterpreting.

I sometimes exhibit poor choice of words. This crashed happened Sunday and the data recorders were found quickly. It just seems to me an unreasonable delay to have not made a decision on where to have them analyzed still on Wednesday.

BTW- A pilot reporting 'flight control problems' means just about anything could be wrong. Immediately assuming this has any similarities to the Lion Air crash is just pure speculation, IMHO. The recorder data will quickly clear things up and identify a need (or unnecessary step) to ground the fleet.

Brad Waybright

It's all okay as long as it's okay.

 

[VEBill]

Canada has now grounded the 737 Max 8 and 9.

CBC: "This safety notice restricts commercial passenger flights from any air operator, both domestic and foreign, of the Boeing 737 MAX 8 and 9 aircraft from arriving, departing, or overflying Canadian airspace," Transport Minister Marc Garneau said Wednesday. Garneau said the decision was made after his department received new information.

 

[thebard3]

Garneau said the decision was made after his department received new information.

Can't wait until someone shares that with us.

Brad Waybright

It's all okay as long as it's okay.

 

[VEBill]

"...happened Sunday and the data recorders were found quickly."

Reportedly, the data recorders were found on Monday.

 

[VEBill]

And now the USA...

CBC News: "U.S. President Donald Trump issued an 'emergency order' grounding all Boeing 737 Max 8 and Max 9 a few hours after Canada's decision."

 

[dgallup]

Because tRump is such a recognized aviation safety authority ...

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[charliealphabravo]

the Ethiopian authorities are holding the black boxes and can't access the data. I don't know if that's true but if so this seems totally irresponsible and negligent. Otherwise, from what I have been able to find out, anything related to the cause of this crash is simply speculation. The Lion Air crash was apparently caused by a faulty AoA sensor and the MCAS incorrectly trying to compensate for the bad data from it. A contributing primary factor was the pilots inability or lack of knowledge about how to respond to that situation. Also, this condition had existed for several previous flights for this airplane and it should not have been left to fly until the problem was corrected. To attribute the latest crash to airplane design without some empirical evidence to support the claim is just irresponsible.

Just a friendly comment. They've been spatting about just these questions for 30+ pages on airliners.net and I hope to be civil here with you guys as always.

Anyway, doesn't this kind of beg the question to say it is irresponsible on both fronts? I can see how urgency on both would be warranted. Some of the groundings may be motivated by political or corporate interests, and these are not necessarily irresponsible, they are just different than technical grounds. It forces Boeing to resolve this with more urgency than they seem to have shown. It looks bad for them to be talking about a software patch the day after these two incidents.

At any rate, I think a simple risk matrix can be used to support a grounding, even with as little as we know. Two brand new Max 8 apparently fly themselves into the terrain on a clear day with experienced pilots reporting control issues, killing all souls on board. That weighs heavy on the consequence side of the equation even if the probability is low or non-existent for most of the 300+ planes in the fleet.