Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Topics related to accidents, incidents & over due aircraft should be placed in this forum.

Moderators: sky's the limit, sepia, Sulako, lilfssister, North Shore

Post Reply
FICU
Rank (9)
Rank (9)
Posts: 1291
Joined: Sun Dec 23, 2007 2:37 am

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by FICU »

Heliian wrote: Mon Mar 18, 2019 9:37 amWell, just put a sticky label on the dash and call er good!
Not needed.

As a professional pilot it is your job.
---------- ADS -----------
 
digits_
Top Poster
Top Poster
Posts: 5956
Joined: Mon Feb 14, 2011 2:26 am

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by digits_ »

FICU wrote: Mon Mar 18, 2019 10:03 am
Heliian wrote: Mon Mar 18, 2019 9:37 amWell, just put a sticky label on the dash and call er good!
Not needed.

As a professional pilot it is your job.
Let's look at it from a different perspective. They add the MCAS because Boeing/FAA(via certification requirements) doesn't think pilots can recover from a stall in this airplane. A stall which (almost) never happens. Yet they build a system to deal with this bad stall in such a way that causes more trouble than it prevents in a way that is much harder to correct than an actual stall.

Sounds like a fairly bad design to me.

If your safety system costs more lives than what it tries to prevent, something's off. The pilots probably should have been able to deal with it, but the fact is they weren't. Could have been for multiple reasons, maybe system related, maybe not. Hard to say.
---------- ADS -----------
 
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
FICU
Rank (9)
Rank (9)
Posts: 1291
Joined: Sun Dec 23, 2007 2:37 am

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by FICU »

I'm not disputing a fault in the design. I question why 2 planes crashed. The Ethiopian one especially if it's due to the same problem as Lion Air after Boeing issued a notice to operators about what can happen and how to deal with it.
---------- ADS -----------
 
digits_
Top Poster
Top Poster
Posts: 5956
Joined: Mon Feb 14, 2011 2:26 am

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by digits_ »

FICU wrote: Mon Mar 18, 2019 10:23 am I'm not disputing a fault in the design. I question why 2 planes crashed. The Ethiopian one especially if it's due to the same problem as Lion Air after Boeing issued a notice to operators about what can happen and how to deal with it.
I might have missed it in the previous posts, but have they found out yet after how many seconds the MCAS trim because unrecoverable with just the yoke?
---------- ADS -----------
 
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
FICU
Rank (9)
Rank (9)
Posts: 1291
Joined: Sun Dec 23, 2007 2:37 am

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by FICU »

The MCAS trimming can be stopped by using normal electric trim on the wheel. As long as the pilot is trimming the MCAS is disabled.

There are some good references in this thread as to how MCAS works.
---------- ADS -----------
 
digits_
Top Poster
Top Poster
Posts: 5956
Joined: Mon Feb 14, 2011 2:26 am

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by digits_ »

FICU wrote: Mon Mar 18, 2019 11:23 am The MCAS trimming can be stopped by using normal electric trim on the wheel. As long as the pilot is trimming the MCAS is disabled.

There are some good references in this thread as to how MCAS works.
Yes I read that, but that doesn't answer my question. How many seconds do the pilots have before the MCAS puts the airplane in a state where recovery is impossible with just the yoke? How many seconds before the pilots have to intervene before recovery is extremely unlikely?

If that's 2 seconds, I don't blame the pilots for being unable to do so.
If it's 200 seconds, you could probably expect them to prevent it.

I don't find it unlikely that they won't start trimming right away if the stick shaker goes off. If anything, with a stick shaker, your first instinct would be to trim nose down, not nose up. I could easily see them lose 5 - 10 seconds dealing with that before they end up at a trim runaway conclusion.
---------- ADS -----------
 
As an AvCanada discussion grows longer:
-the probability of 'entitlement' being mentioned, approaches 1
-one will be accused of using bad airmanship
sportingrifle
Rank 5
Rank 5
Posts: 369
Joined: Wed Nov 23, 2005 2:29 am

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by sportingrifle »

Digits....
That is a great question. Since there are no simulators with MCAS programmed in to them, hard to know definitively. But the guess is about 20 seconds...ie 2 cyles of MCAS takes the stab to near full nose down. It depends on how much reverse trimming is done in between.

Originally the system was only going to move the stab a little over 1/2 a degree, but flight testing showed this to be insufficient so the range was increased by over 4 times that.

sportingrifle
---------- ADS -----------
 
C.W.E.
Rank (9)
Rank (9)
Posts: 1262
Joined: Mon Dec 18, 2017 2:22 pm

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by C.W.E. »

Try this for a test of your cognitive abilities.

Look at the seconds hand of a clock for twenty seconds then decide how long that is to observe something for.

That may give you a better grasp of time.
---------- ADS -----------
 
sportingrifle
Rank 5
Rank 5
Posts: 369
Joined: Wed Nov 23, 2005 2:29 am

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by sportingrifle »

.....
Now try looking at the clock while flying a simulator close to the ground with a stick shaker activated, aural warnings of "stall," "too low", don't sink," differing indicated airspeeds, some warning messages on the EICAS, and the mis-trimming happening intermittantly. Time flies when you are having fun! And if you don't catch it in the first 10 seconds, you will have serious difficulties manually trimming the airplane after you do get the stab cutout switches selected.

There are no simulators set up to replicate this fault but a well known 737 operator tried to mimic this scenario with a number of their crews. It did not end well for many. These were experienced North American line pilots who had some idea what to do after Lion Air.

Cheers sportingrifle.
---------- ADS -----------
 
C.W.E.
Rank (9)
Rank (9)
Posts: 1262
Joined: Mon Dec 18, 2017 2:22 pm

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by C.W.E. »

For sure it would be challenging sportingrifle , and for sure Boeing has a problem on their hands.
---------- ADS -----------
 
User avatar
BTD
Rank (9)
Rank (9)
Posts: 1506
Joined: Wed Mar 23, 2005 8:53 pm

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by BTD »

sportingrifle wrote: Mon Mar 18, 2019 4:31 pm .....
Now try looking at the clock while flying a simulator close to the ground with a stick shaker activated, aural warnings of "stall," "too low", don't sink," differing indicated airspeeds, some warning messages on the EICAS, and the mis-trimming happening intermittantly. Time flies when you are having fun! And if you don't catch it in the first 10 seconds, you will have serious difficulties manually trimming the airplane after you do get the stab cutout switches selected.

There are no simulators set up to replicate this fault but a well known 737 operator tried to mimic this scenario with a number of their crews. It did not end well for many. These were experienced North American line pilots who had some idea what to do after Lion Air.

Cheers sportingrifle.
This is indeed the crux of the issue I think. It is to identify that it is in fact a runaway. Once that is known the solution is straightforward. Any basic human factors/crm courses will discuss the limitations to human multitasking. Throw in the sticker shaker, egpws warnings etc, and life just got more challenging. 2 10 second bursts of trim or more smaller ones if you interrupt them and it’s full nose down. Throw in that sts trim is running often at this time anyway and it is easy to see how it gets missed.

The first Lionair flight that made it back had an IAS disagree that could have helped lead the crew to the problem. Do we know if the same message appeared in the accident flight? I don’t recall reading that in the report. Maybe I missed it. And we don’t know if it was there or not in the Ethiopian accident.

Keep in mind to, when the Lionair preliminary report was issued, they still didn’t have the CVR. Who knows the distraction in the flight deck from all the noise at this point.
---------- ADS -----------
 
sportingrifle
Rank 5
Rank 5
Posts: 369
Joined: Wed Nov 23, 2005 2:29 am

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by sportingrifle »

.....

I think that this is going to be way bigger than the 737, definitely way bigger than the sub-system in the airplane that caused the problem. First of all, it calls into question Boeing's competence and approach to aircraft certification in general.

A quick read of the Far.25 certification standards shows that the MCAS system isn't even close to meeting it. As it originally was designed, it may have been. But as installed, not even close. Many engineers in Boeing would have raised a red flag on this and yet were overruled by higher ups. The problem is that this corporate culture is probably more pervasive than just in the 737 flight control division. This is not the first time that Boeing have rushed an airplane thru certification only to have the fleets grounded.

But the bigger problem, is that the FAA couldn't work as fast as Boeing wanted them to. So Boeing convinced very senior people in the FAA to delegate certification review work back to Boeing. Work that is normally done by the FAA. It takes a very robust safety and QA culture to allow somebody to wear an FAA hat but cash a Boeing paycheck. Obviously it didn't work here.

So the first problem Boeing has is to devise a fix that will satisfy the FAA. A band aid, for a band aid, for an airplane with bad aerodynamics. But the world has already pretty much lost faith in the FAA certification office in Renton. So Boeing is going to have to convince TC, the European JAA, and everybody else, one at a time. This has already started to happen as of about an hour ago. This will add weeks to getting the airplanes back in the air.

The second problem that hasn't happened yet, is that some certification authorities may decide that they want to look at the whole airplane again. If the FAA got the trim system wrong, what else in the airplane doesn't meet FAR25. If this happens, expect the airplanes to be grounded for a year.

But the biggest problem for Boeing going forward is the erosion of trust. Every airplane they build going forward will be getting the fine tooth comb going over at certification. Especially the growth of airplanes under previous grandfathered type certificates. The 787-10, 777X, everything. Boeing better get used to the process taking a long time, and having lots of suits with slide rules looking over their shoulders. And as this drags on, the Airbus sales team will be filling the order books with NEO's and A350's.

And to top it all off, the Justice Dept. criminal division has started taking an interest in the whole affair. This is going to get waaay worse for Boeing before it get better. And so it should, 349 people died. Getting the Max back in the air is the easy part.
---------- ADS -----------
 
Last edited by sportingrifle on Mon Mar 18, 2019 6:00 pm, edited 1 time in total.
User avatar
BTD
Rank (9)
Rank (9)
Posts: 1506
Joined: Wed Mar 23, 2005 8:53 pm

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by BTD »

I have a feeling a few years down the road, with perspective, this entire debacle will share numerous similarities to the Challenger and Columbia shuttle accidents.
---------- ADS -----------
 
goingmach_1
Rank 3
Rank 3
Posts: 104
Joined: Wed Jan 18, 2006 3:54 pm

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by goingmach_1 »

I have reached out to a good friend of mine who is very much in the know, believe me, and he has let me know there is no stick shaker or pusher on this machine.

It has stall strips on the inboard wings. "it really causes the column to shake at high angles of attack."

Three electric systems help with stall of high AOA in addition to the MCAS.

1. Yaw damp reduces rudder movement
2. More hydraulic pressure is sent to the actuator to double pitch control feel in the cockpit, so as the the AOA builds the stick is harder to pull back.
3. Further, the "Speed trim system", (not the MCAS) trims the nose down to further increase control stick pressure to make it even harder to pull back. This system also helps the other way when accelerating to help offset trim requirements.

Forth system is MCAS.

If the MCAS senses a high angle of attack and as a precaution IN FLIGHT MANUAL ONLY trims nose down for 10 seconds then waits for 5 seconds and if the problem is still there trims another 10 seconds nose down the waits 5 seconds and the system just keeps repeating until the high AOA is reduced.

The only way to stop this nonsense is to shut off the trim system completely. Then use the manual trim wheel thereafter.

Seems like such a simple solution to a otherwise complicated add on. Is it just me, or are 737's stalling all over the skies?

Thinking you might get into fight with the thing before you would react to shutting the whole thing off. Cannot imagine the shenanigans in cockpit as the wrestle begins. Damn thing thinks your stalling, pilot goes WTF, and hits the electric trim on the yoke to stop the MCAS (problem solved?). Sensor says high AOA, and it trims nose down again. Pilot trims from the yoke again. and on and on. I can just see them wrestling this demon by fighting now with the control column till you have no strength to overcome the forces on the elevator.

Its not intuitive what to do thats for sure.
---------- ADS -----------
 
User avatar
Daniel Cooper
Rank 5
Rank 5
Posts: 336
Joined: Thu Dec 20, 2018 6:38 am
Location: Unknown

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by Daniel Cooper »

goingmach_1 wrote: Mon Mar 18, 2019 6:42 pm If the MCAS senses a high angle of attack and as a precaution IN FLIGHT MANUAL ONLY trims nose down for 10 seconds then waits for 5 seconds and if the problem is still there trims another 10 seconds nose down the waits 5 seconds and the system just keeps repeating until the high AOA is reduced.

That sounds like an absolute nightmare and it makes me wonder if they kept it out of the flight manual on purpose because any pilot reading that should be very concerned.
---------- ADS -----------
 
User avatar
BTD
Rank (9)
Rank (9)
Posts: 1506
Joined: Wed Mar 23, 2005 8:53 pm

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by BTD »

goingmach_1 wrote: Mon Mar 18, 2019 6:42 pm I have reached out to a good friend of mine who is very much in the know, believe me, and he has let me know there is no stick shaker or pusher on this machine.

It has stall strips on the inboard wings. "it really causes the column to shake at high angles of attack."
I am afraid your friend is mistaken. There is indeed 2 separate shakers one on each control column. They can and are tested on the ground prior to flight.

Neither my AOM nor the FCTM make reference to stall strips. I have been flying only the MAX for the last 15 months or so.

The rest of your info looks accurate.
---------- ADS -----------
 
linecrew
Rank (9)
Rank (9)
Posts: 1887
Joined: Fri Feb 20, 2004 6:53 am
Location: On final so get off the damn runway!

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by linecrew »

Wow, this is a whole new level of stupid right here. Worried because the aircraft are parked at their airport. How do these idiots rise to a position of power?!

https://windsor.ctvnews.ca/concerns-ove ... -1.4341177
Concerns over Boeing 737 Max fleet aircraft parked at Windsor International Airport

CTV Windsor
Published Monday, March 18, 2019 4:38PM EDT
Last Updated Monday, March 18, 2019 5:15PM EDT

Windsor West New Democrat MP Brian Masse is concerned about the Boeing 737 Max fleet aircraft at the Windsor International Airport.

As CTV Windsor reported last week, the Boeing 737 Max 8 and 9 planes arrived at the airport to be parked at AAR Aircraft Services.

“We’ll have between six and 10 on the ground,” said Dave Robertson, the vice president of operations manager of AAR.

As of Monday at 3 p.m., there are 12 Max aircraft at the Windsor airport.

The first planes arrived on Wednesday after both Canada and the U.S. announced the planes would be temporarily grounded, citing concerns stemming from a deadly plane crash in Ethiopia on March 10 that killed 157 people, including 18 Canadians.

Masse has written a letter to Transport Minister Marc Garneau , requesting information to address safety concerns.

“We know that these planes can take off and land in our community. We also know that the incidents with these planes is happening right after take-off,” stated Masse. “I believe that our community deserves answers about the public safety of these planes taking off over our neighbourhoods and what plans are in place to protect our residents.”

Robertson told CTV Windsor the planes were asked to be parked at the Windsor airport.

“We service several of the Canadian operators so, they reached out to us to see if we had places for them to park the aircraft and, of course, we help out our customers just like everybody else does,” said Robertson.

But Masse still wants answers.

“Who will be responsible should something happen, what is expected of our community during this process, and ultimately, are we safe?” wrote Masse. “Those are answers we all deserve and I hope the Minister finds them as important as we do in Windsor.”
---------- ADS -----------
 
tsgas
Rank 7
Rank 7
Posts: 598
Joined: Sun Feb 29, 2004 12:53 pm

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by tsgas »

linecrew wrote: Tue Mar 19, 2019 6:33 am Wow, this is a whole new level of stupid right here. Worried because the aircraft are parked at their airport. How do these idiots rise to a position of power?!

Socialists rise to power by making promises to the gullible, about free stuff ,and an Utopian society. :roll:
---------- ADS -----------
 
boeingboy
Rank (9)
Rank (9)
Posts: 1513
Joined: Wed Mar 03, 2004 2:57 pm
Location: West coast

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by boeingboy »

Everybody keeps thinking everything happened all at once and the crew was overwhelmed….that is not the case. The airspeed disagree and stick shaker came on at rotation. They were known, actioned and dealt with. It wasn't until about 2000 feet when the flaps came up that they got the nose down input....That's 1 problem to deal with. The flaps were selected back out and the trim stopped. So they climbed out normal. When the flaps were selected back up - the trim issue started again. then they maintained altitude and counteracted the nose down trim for 10 min. Im sure they only had one issue front and center - The repeated nose down input. Simple - cut out the trim.

One thing that is being overlooked is I have to ask what are these crews thinking in these parts of the world. the previous Lion air crew after they cutout the trim - continued their flight all the way to destination with the left stick shaker wailing away....why? Because their QRH didn't say to land at the nearest airport. I don't know about you - but I wouldn't need a QRH to tell me that before I was turning around. It seems like more and more of these places outside North America and Europe are getting to the point where their pilots cannot fly airplanes if the smallest thing goes wrong. Look at Air asia and the 777 in SFO were the pilots couldn't hand fly a visual approach on a beautiful sunny day. I think we need to look more at pilot skill and training than the machine.
---------- ADS -----------
 
User avatar
telex
Rank 7
Rank 7
Posts: 634
Joined: Sun Feb 07, 2016 9:05 pm

Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by telex »

boeingboy wrote: Tue Mar 19, 2019 12:41 pm Everybody keeps thinking everything happened all at once and the crew was overwhelmed….that is not the case. The airspeed disagree and stick shaker came on at rotation. They were known, actioned and dealt with. It wasn't until about 2000 feet when the flaps came up that they got the nose down input....That's 1 problem to deal with. The flaps were selected back out and the trim stopped. So they climbed out normal. When the flaps were selected back up - the trim issue started again. then they maintained altitude and counteracted the nose down trim for 10 min. Im sure they only had one issue front and center - The repeated nose down input. Simple - cut out the trim.

One thing that is being overlooked is I have to ask what are these crews thinking in these parts of the world. the previous Lion air crew after they cutout the trim - continued their flight all the way to destination with the left stick shaker wailing away....why? Because their QRH didn't say to land at the nearest airport. I don't know about you - but I wouldn't need a QRH to tell me that before I was turning around. It seems like more and more of these places outside North America and Europe are getting to the point where their pilots cannot fly airplanes if the smallest thing goes wrong. Look at Air asia and the 777 in SFO were the pilots couldn't hand fly a visual approach on a beautiful sunny day. I think we need to look more at pilot skill and training than the machine.
How do you explain that Air Canada 777 tailstrike in Hong Kong again?
---------- ADS -----------
 
Liberalism itself as a religion where its tenets cannot be proven, but provides a sense of moral rectitude at no real cost.
Post Reply

Return to “Accidents, Incidents & Overdue Aircraft”