Ethiopian Airlines Crash/ B737MAX grounding

GM228

murphaph wrote: »

plodder wrote: »

The drip feed of groundings certainly creates that impression, but there's 350 of them flying multiple times a day over the last year or two and only two crashes.

I'm just amazed at how this has mushroomed in the space of 24 hours. It's going to be interesting to hear what the additional information received by the Canadian  agency (and the others) was. One has to assume that it is significant enough to justify this.

2 out of 350 is 0.6% of the fleet lost in just 2 years. I think that's very high and if the cause is related the aircraft is definitely very dangerous.

Also remember that 350 have not been flying for 2 years. The Ethiopian aircraft was just 4 months old.

+1

As I posted previously the 737MAX is probably statistically the second deadliest design after Concorde - despite the Concorde flying for years with only one fatal flight it is statistically the most dangerous type, the 737MAX is even worse statistically than the "death trap" DC-10.

RiseToMe

Boeing has recommended that entire global fleet be grounded

GM228

Boeing press release:

https://boeing.mediaroom.com/news-releases-statements?item=130404

I thought there were only 350, but Boeing state 371 though I assume that includes on test/not yet delivered etc.

Roger_007

GM228 wrote: »

Boeing press release:

https://boeing.mediaroom.com/news-releases-statements?item=130404

That's a bizarre statement. They admit to not knowing the cause of the accidents but express full confidence in the safety of the plane.
So are they really saying that whatever the cause, it's no fault of theirs?

Grandeeod

The FAA's hand has been forced by all the other groundings. I'm glad. Now we can figure it all out while the aircraft aren't flying.

Bob24

plodder wrote: »

Ok, but that's the percentage of airframes that have crashed. It doesn't account for the number of flights they have flown successfully.

Sure, but isn’t it still abnormally high for 0.57% of airplanes of a certain type to have a deadly crash within a year or so of entering service? (regardless of how many successfully flights they had)

Tenger

RiseToMe wrote: »

Boeing has recommended that entire global fleet be grounded

Bit behind the curve on this one.
Bad looking PR for them to state this after everyone else has already grounded them

GM228 wrote: »

.........
I thought there were only 350, but Boeing state 371 though I assume that includes on test/not yet delivered etc.

My thoughts as well. Ive seen 370, 387 and 360 on various websites.

wcooba

murphaph wrote:

The FAA position looks very odd now. I suspect Canadian firms are big suppliers to Boeing given the geographic proximity.

Boeing has factory in Winnipeg. It appears quite large chunk of their production is supplying MAX program.

plodder

GM228 wrote: »

+1

As I posted previously the 737MAX is probably statistically the second deadliest design after Concorde - despite the Concorde flying for years with only one fatal flight it is statistically the most dangerous type, the 737MAX is even worse statistically than the "death trap" DC-10.

It could well be, but I don't think the stats support the assertion "If there is a flaw that brought two of them down within months then you have a pretty good chance of it happening to you". People's subjective view of risk (or probabilities generally) isn't always backed up by the evidence.

It's moot anyway, as nobody is going to be flying on one for the forseable future. I just have this nagging question over whether the grounding was based purely on evidence or some kind of snowball effect. It will all come out in the wash eventually one way or another.

From washington post, some more detail about where the new information came from:

Trump’s announcement followed one by Canada’s transportation minister grounding all the jets, saying a review of satellite-tracking data by his country’s experts found similarities between Sunday’s crash of an Ethio­pian Airlines jet and an October Lion Air crash.

Tenger

And on that point let’s park the debate on statistics. The fact is that the MAX is now grounded for at least a week I suspect and aviation will be holding it breath to see the initial results from the FDR

vicwatson

FDR being sent to Paris

murphaph

ED E wrote: »

A liveline caller today was on a previous Ethiopian flight and reported similar nose down behaviour. Do we have a track to validate that?

That claim was posted in the Avherald comments today and a subsequent poster said he or she could not find such a track.

Turbulent Bill

Roger_007 wrote: »

That's a bizarre statement. They admit to not knowing the cause of the accidents but express full confidence in the safety of the plane.
So are they really saying that whatever the cause, it's no fault of theirs?

It's the fine PR art of saying everything and nothing.

If it does turn out that Boeing designed a safety-critical system with only one sensor input (no redundancy), that's a huge error and points to bigger development failings. Any engineering failure mode analysis during the MAX's development would have pointed this out almost instantly, so why wasn't it found?

Limpy

Regarding satalite data "The FAA says the data "indicates some similarities"( between Lion Air crash) in its emergency order" from Cnn.

smurfjed

Flight Safety Foundation statement.

“This globally haphazard approach to an important airworthiness issue was most unfortunate, but we understand the need to reassure the traveling public.

“We continue to believe, however, that global aviation safety is best served by timely, harmonized decisions based on facts and evidence, not conjecture, politics, or media pressure.

“Moving forward, we must allow aviation safety professionals — investigators, regulators, engineers, and pilots — to calmly and objectively analyze the data, collaborate, and implement permanent, corrective fixes to ensure a tragedy like this can never happen again.”

smurfjed

in order to get it to bleed off airspeed enough to initiate a stall

You do realise that airliners have stick shakers and if required stick pushers to stop them stalling.

LiamaDelta

tnegun wrote:

Flight radar last has it climbing at 8600ft, flight only lasted 4 minutes.

plodder wrote:

It's moot anyway, as nobody is going to be flying on one for the forseable future. I just have this nagging question over whether the grounding was based purely on evidence or some kind of snowball effect. It will all come out in the wash eventually one way or another.

I'd say mainly snowball but perception is reality. The airline industry relies on the general public having 100% confidence in the aircraft and systems so they can't afford to have that compromised.
It also will help confidence a lot if they're seen to ground the fleet and then have a full 'fix' and relaunch.

smurfjed

Now TRUMP has grounded all MAX aircraft, surely that's the job of the FAA, so WTF.

cml387

In terms of political interference in the operation of the FAA, old timers might remember the dirty deeds around Douglas, airworthiness directives and the DC-10.
That happened under NIxon.

Dante7

smurfjed wrote: »

Now TRUMP has grounded all MAX aircraft, surely that's the job of the FAA, so WTF.

He had earlier tweeted about modern airplanes being too complicated, (despite regularly flying on Airforce 1), so there was a good chance today that he would insist on the grounding so he would be seen as being consistent with his tweet.

L1011

Dante7 wrote: »

He had earlier tweeted about modern airplanes being too complicated, (despite regularly flying on Airforce 1)

SAM28000/29000 are based on 747-200s with little technology from after I started primary school - they aren't modern!

cml387

It's a perfectly good aircraft, but may have a flaw in its software that can be fixed.

The issue for Boeing (and as I mentioned earlier there is a precedent from Douglas) is that the software modification should have been an airworthiness directive.

The Rape of Lucretia

Boeing in an interesting position now - they have to find something wrong whether it is there or not.
If there is a fault, and they do find it, then egg on face and serious loss of confidence.
If its not there, they cant just say <<everything is fine, nothing to see here, everybody back in 737MAX>>. The confidence is gone whatever. So they have to find some figleaf fault to incur a bit of <<mea cult, but at least we found it, and its fixed now>>.

Dante7

The Rape of Lucretia wrote: »

Boeing in an interesting position now - they have to find something wrong whether it is there or not.
If there is a fault, and they do find it, then egg on face and serious loss of confidence.
If its not there, they cant just say <<everything is fine, nothing to see here, everybody back in 737MAX>>. The confidence is gone whatever. So they have to find some figleaf fault to incur a bit of <<mea cult, but at least we found it, and its fixed now>>.

There is an in between option, which is probably close to the truth. There is a slight problem, but it is easy to correct by the pilot, but some pilots haven't trained up on this.

This explanation, along with improved training, and with a software upgrade and added redundancy on the questionable sensors would probably be enough to get them back in the air with public confidence. Especially in America. There would be a belief by the American public that their pilots would be better than those third world lads.

sdanseo

This article sums up quite nicely what may have happened (if indeed it is similar to Lion Air)

https://theaircurrent.com/aviation-safety/the-world-pulls-the-andon-cord-on-the-737-max/?fbclid=IwAR1uPL-7n38tXbYsUk7ZioGQlAB0Cp-ipJIZauMGQKU48h_t8Y5_g3xO2QI

tl;dr - redesigning the 73XNG was a no-go, so they found a way to put on new engines that were too big for it's ground clearance. This affected CG and stall potential.
The result is an automated system that re-trims the aircraft according to AOA (angle of attack) sensor data.
But when the AOA data is wrong, problem. An aircraft flying level that thinks it's 20 degrees nose up because of a faulty gyro gets auto trimmed 20 degrees nose down.

How the crews didn't take back manual control if visibility was good is beyond me.
If vis was bad, the story writes itself. Disoriented crew with no horizon don't know which was is up (it can happen very easily and instruments are relied on).

If it has happened twice, it's the most fundamental cardinal sin in aviation. Learn from accidents and use them to ensure the same fault can never recur. Allowing anything less to happen is unconscionable.

Is there still a basic, standby attitude indicator on fully glass cockpits in these yokes?

cnocbui

murphaph wrote: »

Spiegel Online reports that the FDRs will be sent to Germany. Strange that there is so much confusion about this.

vicwatson wrote: »

FDR being sent to Paris

That gels with what I said earlier about the Germanwings FDR's, which were examined by France's Bureau d'Enquete d'Accidents at Le Bourget airport in Paris. Those FDR's were also very badly damaged so they clearly have the requisite expertise.

mickdw

circular flexing wrote: »

Don't forget the Concorde flew with a known serious design flaw for years and this flaw eventually led to a serious crash. At the end of the day airlines and manufacturers are bean counters who do put a value on a human life and make decisions based on that.

I was due to fly 737 MAX 8 later on today from Canada, plane has since been swapped for a 777.

I wouldn't agree 're the Concorde.
Sure it's quoted as being the most dangerous type but that is just statistics due to having lost 1 of such a tiny number.
The reality is that the crash was a result of the operators maintenance errors together with the operator taking off over weight with overfilled tanks which cancelled out the free space at top of fuel tank. A suitably filled tank would not have cracked.
I therefore couldnt agree that it flew with a dangerous defect that resulted in the loss. The alterations made were to ensure such an accident didn't happen again, -
cutting power to wheel area during take off, lining tanks, strengthened tyres etc but you could hardly call these dangerous defects, more belt and braces safety.

If you said it had a rudder defect in early days that could well have taken one down, I might agree but the aircraft wasn't at fault for the accident.

vicwatson

cnocbui wrote: »

That gels with what I said earlier about the Germanwings FDR's, which were examined by France's Bureau d'Enquete d'Accidents at Le Bourget airport in Paris. Those FDR's were also very badly damaged so they clearly have the requisite expertise.

It was confirmed by the BEA that they would handle them

vectorvictor

Shn99 wrote: »

Crazy that people are making statements such as “it’s all over for the MAX” ect. If you think this is the end of the MAX, trust me it’s not

Agree. Be curious to see how FR handle their introduction though. Looking at the various statements that it will take a few months and Germany's three month ban, I think it's clear their introduction will be delayed.

FR have theirs loaded for STN flights from Apr/May (identifiable by 35row seat map)

MOL's statements were fairly relaxed (before the mass grounding) but internally that company is very paranoid. Not quite sure in his position that i'd be taking a punt on their hard earned enviable safety record until the fix has been deployed and proven over hundreds of thousands of flight hours ... by somebody else.

Dante7

Following the revelation that Lion Air hadn't purchased the option that would have alerted the flight crew to the dodgy sensor, I was wondering whether Ryanair had purchased this option. On one hand, Ryanair get lambasted as being a cheap no frills airline, but on the other hand they have a superb safety and maintenance record. I doubt if Ryanair skimped on that option with their order.