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

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

Post by sportingrifle »

Boeingboy...

You stated that "At the time of the groundings there was no hard evidence of what happened." Not true. What happened the day before China grounded the Max is that the Ethiopians found the stab jackscrew buried in a smoking hole in the ground, and it was in the full nose down position. While they didn't yet have the FCR/FDR data, this was considered worthy enough to initiate the groundings because there would be no plausible reason for the trim to be in this position other than an MCAS failure. And history has proved this cautious pre-emptive grounding to have be correct. Without it it is statistically probable that in the months since the grounding there would have been other MCAS accidents.

Secondly, while the fix will most likely involve the issues you identified, closer investigation has unearthed other issues. The biggest is that the airplane is not trimable in manual trim mode when out of trim and far off its trim speed. This was discovered in the NG testing and EASA questioned it. They eventually signed off on it because Boeing convinced them that the probability of encountering such circumstances was remote. MCAS changed all that. And as I stated months ago, this issue demonstrates that the airplane (and by extension the NG) doesn't meet the FAR25 certification standards for the elevator trim system. It also makes the published Boeing stab trim runaway procedure impossible to accomplish in some flight conditions. The FAA and Boeing might be happy with such a state of affairs but the Chinese and EASA don't owe Boeing any favors and are holding their feet to the fire. And good for them. The other regulator that noticed the deficiencies in MCAS and the trim system prior to either accident was the Brazilians. If a second world country like the Brazilian CAA can figure it out, it doesn't say much for the FAA and TC.

So in addition to the steps that you alluded to, Boeing is going to have to revise their QRH procedures for both an MCAS problem and a stab run away. And to do it without requiring dedicated simulator training is even going to be harder. They are currently inviting management pilots from all the affected airlines to "test drive" the new procedures. It will be interesting to see what they have come up with. When our 737 check pilots gamed it in the sim, quite a few created new simulated aluminum deposits in the ground. That alone tells me that the failure is far more difficult to manage than most armchair quarterbacks understood it to be.

I am going to bet cold beers on a summer 2020 return to line flying after the crews undergo special sim training in the new procedures.

Cheers Sportingrifle.
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Eric Janson
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by Eric Janson »

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Always fly a stable approach - it's the only stability you'll find in this business
C.W.E.
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by C.W.E. »

The aircraft is not unstable. Undesirable - sure...but not unstable.
Sorry for my ignorance on the subject boeingboy, I am always willing to learn as much as possible about aviation and thanks to you I now understand the Max is a stable aircraft with a few undesrable issues that are taking a few days to resolve.
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boeingboy
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by boeingboy »

https://www.msn.com/en-ca/news/world/wh ... li=AAggNb9

One of the best articles I've ever read...
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FlyGy
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by FlyGy »

Here is something else that might be a link, could these incidents have been terrorism related after all?

CNN is reporting on an AA mechanic who admitted that he tampered with a 737 (not Max) in July.

"The defendant also received a news article from an unknown sender referencing the Lion Air crash that had specific references to the plane's Air Data Module system. This is the same system Alani is suspected of dismantling on the American Airlines flight. "


Would similar tampering in the Max cause the system failure that resulted in a crash?


https://www-m.cnn.com/2019/09/18/us/ame ... cnn.com%2F
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boeingboy
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by boeingboy »

As much as I'd like to think it was outside forces and not a plane/aircrew issue - I think that in the cases of the Max It is beyond unlikely. Boeing screwed up, aircrews screwed up and maintenance screwed up.

It is possible that there could one day be an incident where it was a mechanic that sabotaged an aircraft - the current rules are retarded. There are a hundred ways a mechanic could do something to an aircraft and no-one would know.
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pelmet
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by pelmet »

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

Post by FlyGy »

phillyfan wrote: Mon Mar 11, 2019 6:28 am I'm buying Boeing stock this morning. "Buy the Fear" They have orders for 5000 of these things. They are not going anywhere. Shares dropped 12% after the Lion Air crash and bounced back. This is an easy 12 to 15% moneymaker.
Are you rich yet?
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tsgas
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by tsgas »

FlyGy wrote: Thu Mar 12, 2020 8:39 am
phillyfan wrote: Mon Mar 11, 2019 6:28 am I'm buying Boeing stock this morning. "Buy the Fear" They have orders for 5000 of these things. They are not going anywhere. Shares dropped 12% after the Lion Air crash and bounced back. This is an easy 12 to 15% moneymaker.
Are you rich yet?
So in one year his stock went from $391 to $168 . At this rate think of all the $ that he could of make on volume. :lol:
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J31
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by J31 »

Looks like one of the reasons the MAX is still not flying.

https://www.flightglobal.com/safety/sim ... 51.article


Investigators tested various out-of-trim scenarios in July 2019 using CAE-made 737 Max level D flight simulators in Addis Ababa.

They aimed to “assess the control column forces that were present and evaluate the manual trim wheel forces that were required to operate the manual trim wheel,” says the report.

First, the team reconstructed the circumstances of flight 302, setting the simulator’s stabiliser to the 2.3° setting – the same position at which flight 302’s stabiliser was set at the time the pilots struggled to turn the trim wheel.

The Max’s stabiliser swings 17.1°, with lower numbers representing more nose-down trim and higher numbers representing more nose-up trim, according to the Ethiopian and Lion Air accident reports.

Like flight 302’s pilots, the simulator pilots initially countered the 2.3° nose-down stabiliser trim by pulling back on the control column. Pulling together, the simulator pilots managed to climb, though “forces needed from both pilots to achieve this were considered significantly very high and unbearable for the duration held”, says the report.

Then, a simulator “pilot attempted to control the aircraft and return for landing with elevator authority only”, it adds, but states: “The attempt was unsuccessful.”

Investigators used the simulator to examine pilots’ ability to turn the trim wheel at varying nose-down stabiliser settings and differing speeds. Again, electric trim was cut off and one pilot was hauling back on the column.

At 220kt and the stabiliser set at 2.5° (slightly less nose-down trim than flight 302’s pilots faced) the simulator pilots found the trim wheel to be “barely moveable”, meaning they could not complete one turn. At 2.5° and 250kt airspeed, the wheel was “not movable”, says the report.

“For all speeds higher than 220kt and trim set at a value of 2.5 units, the difficulty level of turning the manual trim wheel was… trim wheel not movable,” it says.

Investigators say pilots must turn the trim wheel 15 times to adjust the stabiliser 1°, meaning the Ethiopian pilots would have needed to turn the wheel 40 times to return their Max’s stabiliser to a neutral position.
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L39Guy
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by L39Guy »

Ethiopian investigators no doubt.

So how is it that the Lion Air incident crew was able to fly their MCAS airplane for an hour and a half using the manual trim wheel after the Stab Trim shut-off switches were used to turn off all electrical trim.

There can be no doubt that the control forces (manual trim wheel) forces increase as the airspeed increases. Similarly, control forces decrease as the IAS decreases too, like when one is flying around at 180 kts rather than 250+.

The skeptic in me thinks this is a case of having a predetermined conclusion then finding justification for that conclusion.
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mbav8r
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by mbav8r »

L39Guy wrote: Sat Apr 04, 2020 2:10 pm Ethiopian investigators no doubt.

So how is it that the Lion Air incident crew was able to fly their MCAS airplane for an hour and a half using the manual trim wheel after the Stab Trim shut-off switches were used to turn off all electrical trim.

There can be no doubt that the control forces (manual trim wheel) forces increase as the airspeed increases. Similarly, control forces decrease as the IAS decreases too, like when one is flying around at 180 kts rather than 250+.

The skeptic in me thinks this is a case of having a predetermined conclusion then finding justification for that conclusion.
For the crew that flew it manually, what was the maximum trim that was reached prior to disabling the MCAS?
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L39Guy
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by L39Guy »

The preliminary and final reports are both online and have that information.
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Gear Jerker
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by Gear Jerker »

What's everyone figuring for a timeline on max recertification at this point? Summer 2020?
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by 7ECA »

Gear Jerker wrote: Wed Apr 15, 2020 12:13 pm What's everyone figuring for a timeline on max recertification at this point? Summer 2020?
Seems unlikely, what with a pandemic ongoing.
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Heliian
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by Heliian »

Boeing will be fully govt stimulus'd up and cranking out more planes in no time.

Too bad that airlines don't need them right now.
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iflyforpie
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by iflyforpie »

Heliian wrote: Thu Apr 16, 2020 5:39 am Boeing will be fully govt stimulus'd up and cranking out more planes in no time.

Too bad that airlines don't need them right now.
The problem with capitalism is that you eventually run out of other people’s money.
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goldeneagle
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by goldeneagle »

Heliian wrote: Thu Apr 16, 2020 5:39 am Boeing will be fully govt stimulus'd up and cranking out more planes in no time.

Too bad that airlines don't need them right now.
The claim to fame for the Max, it burns about 10% or so less fuel than earlier models.

I thought oil futures were looking awful last friday at 18 dollars. This morning at 11 dollars I figured they cant go any lower. 7.83 is the quote for WTI as I type this.

Today it's cheaper to haul a -200 out of storage and pour fuel into it than it is to pay interest on loans to buy a max.

We will see how long the oil collapse runs for, but, airlines wont need the capacity for a couple more years at a minimum, and if they do need some short term capacity in the interim, lots of gas guzzlers in the desert that will look pretty economical to run this summer.
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Re: Ethiopian Airlines: 'No survivors' on crashed Boeing 737 max

Post by goldeneagle »

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

Post by telex »

goldeneagle wrote: Mon Apr 20, 2020 9:54 am
Heliian wrote: Thu Apr 16, 2020 5:39 am Boeing will be fully govt stimulus'd up and cranking out more planes in no time.

Too bad that airlines don't need them right now.
The claim to fame for the Max, it burns about 10% or so less fuel than earlier models.

I thought oil futures were looking awful last friday at 18 dollars. This morning at 11 dollars I figured they cant go any lower. 7.83 is the quote for WTI as I type this.

Today it's cheaper to haul a -200 out of storage and pour fuel into it than it is to pay interest on loans to buy a max.

We will see how long the oil collapse runs for, but, airlines wont need the capacity for a couple more years at a minimum, and if they do need some short term capacity in the interim, lots of gas guzzlers in the desert that will look pretty economical to run this summer.
Available airframes? Spare parts?
Qualified engineers?
Qualified pilots?
Available training facilities?
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