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Boeing 737 Max Software Fixes Due to Lion Air Crash Delayed

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Boeing 737 Max Software Fixes Due to Lion Air Crash Delayed

Old 4th May 2019, 11:05
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Originally Posted by fred81 View Post


Not necessarily. If it was demonstrated during test flights that with the original MCAS longitudinal stability criteria (i.e. required stick force) were not met, that would have been all the pilots knew at that time.

The subsequent authority increase to 2.5 degrees could have been kept from the test pilots. They would just demonstrate that the revised MCAS now meets the FAA requirements.
When I/we have had issues to deal with (just in maintenance) I/we always inform the pilot/s prior to the flight what we have changed and what we expect they should expect. We expect them to give us feed back after the flight.

I find it impossible to believe the test pilots would carry out a "test flight", without being told of the changes made and what they should expect.

That said I will not be surprised if comment turns out to be correct.
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Old 4th May 2019, 15:31
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Originally Posted by Bend alot View Post
When I/we have had issues to deal with (just in maintenance) I/we always inform the pilot/s prior to the flight what we have changed and what we expect they should expect. We expect them to give us feed back after the flight.

I find it impossible to believe the test pilots would carry out a "test flight", without being told of the changes made and what they should expect.

That said I will not be surprised if comment turns out to be correct.
Flight test policy and procedures of a test program would normally oblige substantial discourse on changes being tested, and the THA would require disclosure of such information within the test team. would be shocking if a change such as that had occurred, and the guys in the program are capable and competent. Would need clear proof of that to believe it. Stuff does happen in test, but what is suggested is pretty wild and outside of expected norms.
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Old 5th May 2019, 10:55
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Originally Posted by Bend alot View Post
When I/we have had issues to deal with (just in maintenance) I/we always inform the pilot/s prior to the flight what we have changed and what we expect they should expect. We expect them to give us feed back after the flight.

I find it impossible to believe the test pilots would carry out a "test flight", without being told of the changes made and what they should expect.

That said I will not be surprised if comment turns out to be correct.
Well, it appears that Boeing and the FAA were prepared to keep mere mortal line pilots in the dark about MCAS!
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Old 6th May 2019, 00:57
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Wow.....if anyone was lucky enough to watch 60 Minutes Australia last night, about the MAX and how it was certified....I wonder how Boeing management sleep at night.
Among the damning parts were the AA pilot showing what the "training package" they received was....made no mention of MCAS and how it could override pilot input.
Also, clarification of why MCAS is solely reliant on a single AOA sensor.....if Boeing had put redundancy, then they would have been required to do simulator testing before certification....just to clarify here...the people who were interviewed were all in the USA, and representatives of pilot and engineering groups
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Old 6th May 2019, 08:34
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Originally Posted by Smythe View Post
Simple fix:

Increase the height of the landing gear (which should have been done 15 years ago) and put the damn motors back where they are supposed to be.

That $2 billion it was gonna cost looks pretty cheap right now...
Boeing, you had ONE JOB! The 757 wing, if they still have the drawings, obviously accommodates longer, "stick-insect" landing gear. and only a couple of metres (7ft) wider span.

Put on new engines and a modern avionics package, a new interior, and smooth out the nose la 787 (to get rid of all that noise on the flight deck) and voila, you have a new aircraft to compete with AB320Neo.

If only...
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Old 6th May 2019, 09:38
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Now Boeing admits it was aware of AoA Disagree issues well before the Lion Air disaster from a time before the first sales had been delivered. They now say this issue was to be addressed in a later software update but didn't get round to mentioning it to the FAA until a month after the Lion Air crash.
They also claim the AoA Disagree alarm was included as an optional extra "inadvertantly".
https://www.bbc.co.uk/news/business-48174797
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Old 6th May 2019, 09:51
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Originally Posted by KelvinD View Post
Now Boeing admits it was aware of AoA Disagree issues well before the Lion Air disaster from a time before the first sales had been delivered. They now say this issue was to be addressed in a later software update but didn't get round to mentioning it to the FAA until a month after the Lion Air crash.
They also claim the AoA Disagree alarm was included as an optional extra "inadvertantly".
https://www.bbc.co.uk/news/business-48174797
Incorrect! That's not what the BBC says, nor the NYT, nor Boeing:
When Boeing began delivering its 737 Max to customers in 2017, the company believed that a key cockpit warning light was a standard feature in all of the new jets.But months after the planes were flying, company engineers realized that the warning light worked only on planes whose customers had bought a different, optional indicator.In essence, that meant a safety feature that Boeing thought was standard was actually a premium add-on.
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Old 6th May 2019, 10:04
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Originally Posted by GordonR_Cape View Post
Incorrect! That's not what the BBC says, nor the NYT, nor Boeing:
"When Boeing began delivering its 737 Max to customers in 2017, the company believed that a key cockpit warning light was a standard feature in all of the new jets.But months after the planes were flying, company engineers realized that the warning light worked only on planes whose customers had bought a different, optional indicator.In essence, that meant a safety feature that Boeing thought was standard was actually a premium add-on."

Maybe a bit of SIM training events may have picked this up?

Seems Boeing are way behind the 8 ball on the reports released in the last week - Good chance they are also well behind the 8 on training required.

Sloppy, sloppy, sloppy is a very big understatement it seems.

What news will tomorrow bring?
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Old 6th May 2019, 10:24
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Originally Posted by Bend alot View Post
"When Boeing began delivering its 737 Max to customers in 2017, the company believed that a key cockpit warning light was a standard feature in all of the new jets.But months after the planes were flying, company engineers realized that the warning light worked only on planes whose customers had bought a different, optional indicator.In essence, that meant a safety feature that Boeing thought was standard was actually a premium add-on."

Maybe a bit of SIM training events may have picked this up?

Seems Boeing are way behind the 8 ball on the reports released in the last week - Good chance they are also well behind the 8 on training required.

Sloppy, sloppy, sloppy is a very big understatement it seems.

What news will tomorrow bring?
The training/testing problem is an extension of the software fault tree analysis problem, and the consistent shifting of risk. If you aren't "aware" that AOA is a critical parameter, you won't include testing for AOA disagree, or MCAS, or anything else...

In any case there were never, and are still not, enough simulators to actually test the MAX properly, so your question is moot. That goes back to the whole issue of timetable pressures.

I don't know how much of this is "news", but rather confirmation of what many suspected months ago. Prolonging the release of information may be justified on legal grounds, but the drip-drip of revelations does nothing to regain confidence.
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Old 6th May 2019, 11:23
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When Boeing began delivering its 737 Max to customers in 2017, the company believed that a key cockpit warning light was a standard feature in all of the new jets.But months after the planes were flying, company engineers realized that the warning light worked only on planes whose customers had bought a different, optional indicator.In essence, that meant a safety feature that Boeing thought was standard was actually a premium add-on.
Sorry, but I don't believe them. This statement has been crafted by lawyers, to divert attention away from the whole MCAS design, and indeed the poor aerodynamics that led to it being knocked up in the first place.

Furthermore, this all hangs on the overall management of the programme, and whoever on the sales and marketing side decided to make it a nickel-and-dimed chargeable option that could be discarded to shave pennies off the price. Sticking it on the engineers, who seem to be the one group who are acting professionally in all this, is quite inappropriate.

Last edited by WHBM; 6th May 2019 at 13:14.
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Old 6th May 2019, 16:08
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Originally Posted by Willoz269 View Post
Wow.....if anyone was lucky enough to watch 60 Minutes Australia last night, about the MAX and how it was certified....I wonder how Boeing management sleep at night.
Among the damning parts were the AA pilot showing what the "training package" they received was....made no mention of MCAS and how it could override pilot input.
Also, clarification of why MCAS is solely reliant on a single AOA sensor.....if Boeing had put redundancy, then they would have been required to do simulator testing before certification....just to clarify here...the people who were interviewed were all in the USA, and representatives of pilot and engineering groups
It probably didn't mention how MCAS could override pilot input because MCAS could not override pilot input. It is the other way around any trim input by the flight crew would (and did) override MCAS. That is how the penultimate Lion Air flight continued to a safe landing and how the first 6 minutes or so of the Lion Air crash flight proceeded. It was only when the PM on that flight took over and ceased to trim back to unloaded just 'blipped' the trim to stop MCAS that nose down trim increased to uncontrollable levels.

Is trimming not a standard practice anymore?
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Old 6th May 2019, 21:48
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Charging for features that are pin changes or already included in the hardware has been standard Boeing practice for a while. The Ryanair 738s has black and white FMCs as that was what they paid for despite the units being colour screened, as was obvious from the power up screen.

Similar issue with some performance data - Boeing have it, but you can only have it if you at for it.
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Old 7th May 2019, 01:40
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It probably didn't mention how MCAS could override pilot input because MCAS could not override pilot input. It is the other way around any trim input by the flight crew would (and did) override MCAS. That is how the penultimate Lion Air flight continued to a safe landing and how the first 6 minutes or so of the Lion Air crash flight proceeded. It was only when the PM on that flight took over and ceased to trim back to unloaded just 'blipped' the trim to stop MCAS that nose down trim increased to uncontrollable levels.

Is trimming not a standard practice anymore?
Exactly. This is the crux of the issue.

Of course the crew should never had to deal with it by design but it was controllable.
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Old 7th May 2019, 08:53
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Originally Posted by Icarus2001 View Post
Exactly. This is the crux of the issue.

Of course the crew should never had to deal with it by design but it was controllable.
Very, very, easy to say with weeks to think about it from the comfort of your armchair. The 'crux' of the issue is that today, with all the technology actually available and design and testing regimes that should be adhered to, no MUST be adhered to, the MAX design should never have got off the CAD drawing board. Boeing should have gone to a brand new design, but for business reasons we are all now well aware of, they decided not to. It's too easy to let the detail of procedures and switches and trimming and Christ knows what else get in the way of seeing things for what they are; look at the big picture; the very fact that systems like MCAS are necessary at all tells you all you need to know about the compromised design of the MAX.

Ask yourself; mmm, is this a good idea? I mean really, is it?

Anyone with the slightest understanding of safety and risk management will know you must design problems out from the very start, not try to overcome them with additional systems and procedures that add layers of complexity and increased room for error and so increasing risk - and catastrophic risk at that. To have non-redundant sensor input tells you what about the design. Safety first is it?

I know forums are full of mischief makers, but this constant "oh the crew could have staved the situation" narrative is a total diversion from the 'crux' of the issue. It's almost as if you forget that hundreds of PAX and crew have died appalling deaths as a result of flight crew being put in a position they should never ever have been put in. The problem is the big picture, not the setting of trim.
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Old 7th May 2019, 09:16
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Absolutely. The technical 'fix' to this problem is probably relatively simple but it is becoming more clear that such a fix would have brought commercial irritation.

Shuffling risk - inexcusable in modern aviation.

Whilst I'm at it, trim runaways. In non-MCAS aircraft, how likely was a trim runaway, how often did it happen and, if it ever did, how often was it successfully handled? Ask the same questions of an MCAS aircraft. My point is that if you increase the likelihood of an event (trim runaway) you are also increasing the likelihood that your last line of defence (pilots) may get it wrong, especially if you don't reinforce specific training. MCAS increased the risk of a catastrophic trim runaway and where was the training? The statistics, if ever divulged, will be interesting.
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Old 7th May 2019, 09:55
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Cows,

Certainly when I did the trim runaway in the sim, the TRE pointed out that the condition that would cause this was both the trim switches failing independently, at exactly the same time. The twin switches provide excellent redundancy, and I'd bet that there has never been a trim runaway performed for real, ever.
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Old 7th May 2019, 09:57
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RTM Boy :
The problem is the big picture, not the setting of trim.
Absolutely . we see this in other industries and probably this Boeing issue will act as a wake up call for every company that put commercial interests and costs above a safety culture.
The passage in the recent Seattle Times and the drawing on how DER and AR worked was an highlighter : the AR had to submit their comments to management before going to the FAA was made to be allowing exactly this : making sure management commercial views and schedule were not compromised. This is for me the real issue, MCAS or trim are just the by-products of this philosophy..
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Old 7th May 2019, 13:34
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Originally Posted by Cows getting bigger View Post

Whilst I'm at it, trim runaways. In non-MCAS aircraft, how likely was a trim runaway, how often did it happen and, if it ever did, how often was it successfully handled? Ask the same questions of an MCAS aircraft. My point is that if you increase the likelihood of an event (trim runaway) you are also increasing the likelihood that your last line of defence (pilots) may get it wrong, especially if you don't reinforce specific training. MCAS increased the risk of a catastrophic trim runaway and where was the training? The statistics, if ever divulged, will be interesting.
A quick search of the ASRS database returns three reports of runaway trim on 737's. The search engine is a bit fiddly, so there may be more in there. Also, ASRS would only have a report if it was voluntarily submitted by the aircrew. I believe the FAA maintains a more comprehensive database, but I have not seen any reporting from them.
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Old 7th May 2019, 13:56
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Thanks 737 driver. It was a bit of a rhetorical question used to highlight that if we’re now in the realms of ‘more’ trim runaways, we’ve weakened one of the layers of safety and, in an ideal world, need to reinforce the safety system somewhere else to maintain the same level of safety.
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Old 8th May 2019, 02:00
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Originally Posted by GordonR_Cape View Post
The training/testing problem is an extension of the software fault tree analysis problem, and the consistent shifting of risk. If you aren't "aware" that AOA is a critical parameter, you won't include testing for AOA disagree, or MCAS, or anything else...

In any case there were never, and are still not, enough simulators to actually test the MAX properly, so your question is moot. That goes back to the whole issue of timetable pressures.

I don't know how much of this is "news", but rather confirmation of what many suspected months ago. Prolonging the release of information may be justified on legal grounds, but the drip-drip of revelations does nothing to regain confidence.
GordonR

As claimed by a whistle blower working with the FBI. The single AoA for MCAS to obtain data was intentional move by Boeing. The whistle blower claims that using both AoA vanes would lead to the FAA to require extra training in the simulator. This was not an option for Boeing as the sales was dependant on minor training.

Boeing sold the MAX on it NOT requiring simulator training.

That is the reason there are "not enough" simulators.

Had Boeing used both AoA sensors and the FAA did then decide that MAX did require a similar training event, we would have MANY more simulators than we do today.

Not enough simulators is a direct result of Boeing's words to customers.

Right now Boeing is trying to get everyone including NASA to put pressure on the FAA to say "no simulator training is required" MCAS is good now, even if originally we would have called for simulator training.

In my opinion FAA should throw out the MAX certification and redo it with direct oversight regardless of how long it takes and what training is then decided. Yes it will also hurt airlines around the World but if it looks too good to be true - someone is taking a short cut! and the airlines were/are happy to look away.
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