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]

BBC: Ethiopian Airlines No survivors

 

[LittleInch]

Surely after tge Lion Air crash, 737 max pilots must be aware of the issue and how to solve it?

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

 

[John2025]

That altitude variation at the end looks awfully suspicious. It's hard to believe the pilots wouldn't know what to do, though.

 

[Alistair_Heaton]

Well they put through a software "fix" to the system I believe.... but not sure if it was mandatory or not.

There is still only 1 simulator in the world that actually simulates this MCAS system.

The official Boeing differences training is a 3 hour CBT between the NG and MAX no simulator time is mandated. Just do the CBT and go and fly.


This phase of flight is statistically one of the safer phases and two aircraft of a new type in the space of 6 months crashing in that phase is highly unusual and to be honest extremely worrying.

 

[John2025]

I thought the pilots could easily disengage the new attitude system and surely after the 1st crash they would have been thinking about it all the time, no? Maybe the AoA sensor failed and they couldn't fly the plane without it. How hard is it to maintain the proper AoA on that kind of plane without functioning instruments? I don't usually worry at all about flying, but right now I would have to think hard about flying on the Max.

 

[Alistair_Heaton]

Its pretty easy on any plane you just set an attitude either by looking out the window, looking at the artificial horizon or maintaining the book airspeeds.

This MCAS system takes the AoA reading and then applies forward trim if it thinks the plane is going to stall while manual flying with the flaps up. Full forward trim is 45kg stick force for level flight.

There is an easy trained way of getting rid of the trim system.


But its spotting there is a problem and then realising what the problem is. They were in the air 180 seconds before they crashed.

Memory items for our quickest procedure which is the fire evacuation on the ground take 50 seconds which is quick, the 737 has to put flaps down first so takes 2 mins.



An aircraft type should not be in the air if the pilots have to presume there is going to be a trim runaway as soon as the flaps come up.

 

[NorthCivil]

Wonder if there is going to be a recall? Or will there have to be a crash on a western carrier before Boeing takes action?

 

[Sparweb]

Give it about a week. If Boeing does't escalate its response to this flaw by then, I believe it will require condition "b" to provoke it.

I would like more insight into how the Southwest Airlines' pilots union is reacting to this. They have the most at stake, having the biggest order of these aircraft so far. What can be read of the SWAPA union press releases contains normal griping concern about not being consulted on issues related to the evolution of the 737 to the new Max variant, but little about the MCAS system. I have found nothing written by persons who display an adept understanding of aircraft control systems in the press releases (why should I expect it?).

So if the pilots are not concerned should we be not concerned?

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

 

[IRstuff]

Seems like the plane was pushing its climb a bit in the second attempt:

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

 

[NorthCivil]

the government of china has ordered all 737max8's grounded within their airspace

https://edition.cnn.com/2019/03/10/africa/china-boeing-ethiopian-air-crash-intl/index.html

 

[Alistair_Heaton]

the first section the flap will have been down for takeoff so the MCAS system won't be turned on yet.

1000ft agl is acceleration when the flap would come up.

As the AoA also controls the stick shaker then I would expect one side to be running in phase 2 climb. You can see the level off phase 3. Then decent in phase 4 when the MCAS kicked in when flaps retracted.

4000ft per min is nothing special to be honest at 9000ft MSL clean and 350+ knots. Which is way over the Vmo of the aircraft.

 

[itsmoked]

You mean altitude not acceleration?

Does the MCAS shut off with any flaps or only with full flaps?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Alistair_Heaton]

We call it acceleration altitude which is when we come out of takeoff configuration and speeds which is normally V2 +10 and 1 or 2 stages of flap and into climb mode.

You level accerate to V climb retract the flaps and climb away at that.

With any stage of flap the MCAS system is not required to ensure stability. Flaps move the center of pressure inboard and to rear increasing stability in pitch and decreasing it in roll.

It's required because the center of thrust is lower with leap engines giving an increased nose pitch up with power. So the MCAS is meant to automatically pitch the nose down.

 

[thebard3]

I think this is the best place to get news for all things aviation, and their thread for this accident;

https://www.airliners.net/forum/viewtopic.php?f=3&t=1417519&sid=6893eaae1f8ba3761ebac1c795c93d02

It's all just rumor and speculation at this point.

Brad Waybright

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

 

[charliealphabravo]

I enjoy that site but it is not very well moderated. That thread is mostly quarreling to this point.

 

[TenPenny]

There have been what, 350 of them delivered, and two have crashed in relatively similar ways?

That's a pretty high percentage.

 

[Lou Scannon]

There have been what, 350 of them delivered, and two have crashed in relatively similar ways?

That's a pretty high percentage.

...and I wonder how many white knuckle moments that didn't make the news?

"Schiefgehen wird, was schiefgehen kann" - das Murphygesetz

 

[VEBill]

CBC "Boeing to update software in model of plane involved in Ethiopian crash"

"Boeing confirmed late on Monday it will deploy a software upgrade to the 737 Max 8... ...a few hours after the Federal Aviation Administration said it would mandate 'design changes' in the aircraft by April."

 

[LittleInch]

The missing three minutes are shown on this map. Look like the pilot had made a right turn to try to get back to the airport but from the crater seems to have gone in near vertical at high speed. Hope the FDR and CVR give us some data about what was going on.

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