Ethiopian Airlines Crash/ B737MAX grounding

Damien360

Steve wrote: »

Sorry if already posted, the preliminary report makes for some interesting reading.

http://www.ecaa.gov.et/documents/20435/0/Preliminary+Report+B737-800MAX+%2C%28ET-AVJ%29.pdf/4c65422d-5e4f-4689-9c58-d7af1ee17f3e

Notable imo are the stabilizer trim adjustments and whether they were manual or from the AND after it was disabled.

Read this and page 18 stands out. Stab trim switch in override position allows electric trim to still be active and I assume regardless of switch being in cutout or not. So they confirmed it was off according to conversation but what position was that switch in and did it still engage nose down.

No aviation experience so can someone correct me if I read wrong.

Jeff2

Right I'll try again for picture of inside of trim mechanism.

GM228

Panrich wrote: »

Sky reporting that the pilots followed Boeing process to deal with the MCAS error and that they eventually turned off MCAS but that it turned itself back on. This is from the report by the Ethiopian authorities.

Is that accurate though?

Surely the system can't, or at least should not be able to turn itself on after specifically being disabled, sounds like a sci-fi TV show where AI has evolved and gone rogue.

GM228

Hotblack Desiato wrote: »

Airbus's order book for the 320 family is full for years, so they won't directly benefit.

Their book is full with build and delivery time estimates most likely based (at the time) on the assumption the A380 production and assembly lines could be still open, I wonder with that line closing in two years or so will they be able to ramp up production and assembly of other airframes, after all there are a lot of staff and facilities solely dedicated to the A380. Surely the recent announcement on the A380s requires a re-estimated timeframe for the other products and allows for more/quicker orders and a bit of scope to potentially take what otherwise could have been Boeing orders.

GM228

Hotblack Desiato wrote: »

Costs of changing your fleet from one to the other are huge, running a mixed fleet is inefficient and operationally inflexible

That very much depends on the airline and the scale of their operations, look at AA, yes they are huge compared to the average airline, but up to a few years ago they were near 100% Boeing, in the last number of years they have become 51% Boeing and 43% Airbus (the rest being Embraer and MD).

Muahahaha

There were reports in some media yesterday that the pilots turned off the MCAS but somehow it turned itself back on which sounds bizarre. Did the report bear this out and if it did happen does it make this crash unique, i.e. a software system crashing a plane not because of failure to operate but instead operating when it had been commanded not to

ZiabR

Turbulent Bill wrote: »

Agreed, Boeing and Airbus form a duopoly and it's in both of their interests to keep this going. Airbus took a financial hit on the A380, same for Boeing on the MAX, but overall I wouldn't see either being seriously damaged long term.

I don't see it that way. the A380 is the best aircraft I have flown on hands down. It is a very safe and very comfortable flight. The issue was that is was to big and not economical to run with its 4 engines.

That is a considerable difference when compared to the MAX that has already had 2 catastrophic failures resulting in loss of life. The MAX is Boeing's best selling aircraft in the history of the company. It has over 5000 on order.

There is a big difference between an aircraft that is to big and surplus to requirements and an aircraft that falls out of the sky due to design oversights. Remember the only reason Boeing had to design the MCAS system in the first place is because they tried to save money, by not redesigning the 737 and instead bolt bigger engines onto the MAX and moving them forward. We already know that due to these 2 changes, the MAX had the tendency to go nose up.

Stimpyone

jasper100 wrote: »

= manufacturer at fault. Which contradicts your earlier "guess" that it leaves manufacturer off the hook to some degree.

It won't

Hmm. I'm not sure but I think you've misunderstood me.

If you read my comment again I was having a go at the reporting in the media more so than anything else.

Hence the "keep my powder dry" comment. That usually indicates that you reserve judgement until you have all the facts.

At no point did I put it forward as my "guess" as you put it and in fact I was responding to a previous posters point.

But hey ho....

ChikiChiki

The only solution to reinstill passenger confidence for this is to redesign the aircraft so that it flys straight and level without the need for software input. But Boeing wont take that option as it would come at heavy costs. Personally knowing what I know about MCAS I would not be confident getting on one with the software fix in place.

Muilenburgs statement certainly didnt help either. Its a huge mess.

Hotblack Desiato

GM228 wrote: »

Their book is full with build and delivery time estimates most likely based (at the time) on the assumption the A380 production and assembly lines could be still open

They were only producing 380s at a slow rate anyway, so I wouldn't expect large gains there. Suits them actually to not speed up delivieries too much, a full order book for years to come is money in the bank.

GM228 wrote: »

That very much depends on the airline and the scale of their operations, look at AA, yes they are huge compared to the average airline, but up to a few years ago they were near 100% Boeing, in the last number of years they have become 51% Boeing and 43% Airbus (the rest being Embraer and MD).

They'd still save money running one of 737/320 instead of both. Interesting though that Ryanair are now kind of running a mixed fleet (Laudamotion) so they now have first hand experience of the economics of a 320 operation. More ammunition for them to drive hard bargains with Boeing...

GM228

Hotblack Desiato wrote: »

They were only producing 380s at a slow rate anyway, so I wouldn't expect large gains there. Suits them actually to not speed up delivieries too much, a full order book for years to come is money in the bank.

That may be the case, but, it's an airframe which is a lot slower to build and assemble than say an A320neo, and there is a massive workforce and facilities solely dedicated to it which will become available in time and no doubt speed up production of other airframes, but as you say it probably suits to stick with current production rates.

Hotblack Desiato wrote: »

Interesting though that Ryanair are now kind of running a mixed fleet (Laudamotion) so they now have first hand experience of the economics of a 320 operation. More ammunition for them to drive hard bargains with Boeing...

I don't think Lauda (as it's called now) counts as Ryanair running a mixed fleet, Lauda is still a separate airline with Ryanair Holdings as the parent company.

The Ryanair we know (as in the airline company Ryanair DAC) is not the parent company of Lauda, rather it's Ryanair Holdings (Ryanair PLC), who are also the holding company for Ryanair.

Muahahaha

Muahahaha wrote: »

There were reports in some media yesterday that the pilots turned off the MCAS but somehow it turned itself back on which sounds bizarre. Did the report bear this out and if it did happen does it make this crash unique, i.e. a software system crashing a plane not because of failure to operate but instead operating when it had been commanded not to

Anyone know the answer to this? The NY Times are reporting that the pilots followed all the correct emergency procedures and ended up switching off the power to the MCAS entirely but even then it still continued on forcing the nose down. Like how could that even happen? They also reported that at the last minute the pilots switched the MCAS back on and it was at that point the nose did one final massive tilt downwards and from there there was no way of saving it.

If the above is true and the pilots did everything right and disabled the MCAS then are we now into unchartered territory? It is one thing for only one AoA sensor to be connected to MCAS, another thing for the sensor to be giving faulty data but on an entirely different level when software that was over ruled by a human continues to operate despite being switched off and that software literally goes on to crash the plane. Astounding stuff if true, we seem to be into the realm of robots killing humans.

Humans killing humans. Heads should roll for how that was implemented.

Imagine a Tesla ignoring driver attempts at overriding its self-driving system.

GM228

Boeing CEO Dennis A Muilenburg saying sorry on behalf of Boeing:-

With the release of the preliminary report.....it's apparent that in both flights the MCAS activated in response to erroneous AOT information

Whilst well suspected and pretty much confirmed at this stage, is this the first official acknowledgement by Boeing themselves that the apparent issue was MCAS?

https://twitter.com/BoeingCEO/status/1113880952575549441?s=19

Royale with Cheese

Relentlessly focused on safety... yet were desperate to keep these things from being grounded when the Ethiopian flight went down, and this is after they'd been working on a fix for months for the known MCAS issue since the Lion air crash.

This whole debacle makes my blood boil. A cut and dry case of profit above all else, in an industry where that just can't be allowed to happen.

cnocbui

GM228 wrote: »

Boeing CEO Dennis A Muilenburg saying sorry on behalf of Boeing:-



Whilst well suspected and pretty much confirmed at this stage, is this the first official acknowledgement by Boeing themselves that the apparent issue was MCAS?

https://twitter.com/BoeingCEO/status/1113880952575549441?s=19

No, I'd say the software update would be an admission.

RiseToMe

Boeing has announced it is slowing production of the 737 MAX to concentrate on fixing the software:

http://news.sky.com/story/boeing-making-progress-on-737-max-software-update-11685354

murphaph

I won't be flying on one for at least a couple of years regardless of what the now discredited FAA says. The only data to trust will be the statistics which at present do not look at all good for this airplane.

The Boeing apology was barely that too.

Henry Ford III

GM228 wrote:

Boeing CEO Dennis A Muilenburg saying sorry on behalf of Boeing:-

Hands up it's our fault and we will fix it.

The trouble is that hundreds of innocent people are dead, and no fix will bring them back.

ZX7R

Silly question time,
If the problem is resolved with a program update,and plane is safe to fly.
Can they rename the plane like change the max part of the name so people won't be afraid to fly on them.

What happens if it can't be fixed and turns out to be a fundamental design flaw of air frame or something major.

Henry Ford III

Yes of course they could rename and relaunch it. People aren't stupid though.

If it's not inherently safe you'd hope it never gets certification to fly.

smurfjed

Is there any attention being given to the failures of the AOA sensors? For the Lion Air crash, I understand that the sensor failed on the previous flight and was replaced, so why did the 2nd new sensor immediately fail?

As for the Addis crash, there is talk that the sensor was damaged by a bird strike, is there anything official to support that?

DublinDilbert

smurfjed wrote: »

Is there any attention being given to the failures of the AOA sensors? For the Lion Air crash, I understand that the sensor failed on the previous flight and was replaced, so why did the 2nd new sensor immediately fail?

As for the Addis crash, there is talk that the sensor was damaged by a bird strike, is there anything official to support that?

From what i've seen about the Lion air crash is that there was no indication to the pilots that the angle of attack sensor was reading erroneous information when on taxi and on take off roll.

Does anyone know the min speed at which the AOA sensor should operate reliably at?

Its hard to believe there's no sanity checks on such an important input. I guess its something that can't be checked statically after maintenance, do they just verify its free to rotate without restriction?

cnocbui

RiseToMe wrote: »

Boeing has announced it is slowing production of the 737 MAX to concentrate on fixing the software:

http://news.sky.com/story/boeing-making-progress-on-737-max-software-update-11685354

More lies from Boeing. There is no way their riveters and machinists have been drafted in to write software.

jasper100

cnocbui wrote: »

More lies from Boeing. There is no way their riveters and machinists have been drafted in to write software.

Where did they say they are?

Bob24

jasper100 wrote: »

Where did they say they are?

I think the OPs point is that Boeing “slowing production of the 737 MAX so it can focus its attention on fixing the flight-control software” seems like a bit of a strange inference; as slowing production is unlikely to free up many ressources which would help solving software issues.

cnocbui

jasper100 wrote: »

Where did they say they are?

They didn't say it, but what they said was illogical nonsense. They said they were slowing production while they concentrate on software. Can you explain to me why you would have to do that - the connection between the two? In what way does slowing the mechanical task of physically making aircraft bodies, improve their capacity to write the software?

My son is a software developer. If I were to say I wasn't going to mow the lawn this weekend so that he could increase his output of lines of code you ought to say WTF?, because there is no logical connection between the activities.

What I am trying to get at is there must be some reason why they are slowing production, but since that function has no bearing on software development, why? Are they perhaps thinking the 'software' fix isn't going to be enough and that they will have to make actual changes to the aircraft?

Bob24

cnocbui wrote: »

What I am trying to get at is there must be some reason why they are slowing production, but since that function has no bearing on software development, why? Are they perhaps thinking the 'software' fix isn't going to be enough and that they will have to make actual changes to the aircraft?

Agree there must be another reason, although it’s hard to know what it is without internal knowledge.

Could be what you said, could be that they know the fix will take much longer than anticipated and since they can’t deliver airplanes to airlines in the meantime there is no point building them to then have to store them for a prolonged period at their own cost, could even be that some airlines have cancelled orders or put them on hold and the production pipeline is shrinking.

Jeff2

I'd say airlines have asked that the two optional extras are fitted to all of their plains ordered.

The disagree light will be fitted to all plains now as standard.

Bob24

Jeff2 wrote: »

I'd say airlines have asked that the two optional extras are fitted to all of their plains ordered.

The disagree light will be fitted to all plains now as standard.

Boeing has already announced this would be the case, and that it would be retrofitted to all planes which are already in service at no extra cost for the airline.

As far as I understand it’s basically just a small software update to always show the information on the cockpit displays whereby before the software was only displaying if the airline had purchased a certain extra package (i.e. it was an artificial software restriction but the planes are technically all capable of displaying the info already) . So I assume it is already done in the latest beta software and will simply be enabled for all planes whenever the MCAS software update is being rolled out.