Aircraft becoming far too complex to fly...

VimFuego

I just hope all them airlines that own the plane kept the receipts, else it can be a bugger get your money back

goldtop

FAA asked to audit its 737 Max decision-making: https://www.nytimes.com/2019/03/19/business/boeing-elaine-chao.html

Deadman

I was in an A400M cockpit yesterday and couldn't believe how basic it looked with the power off. There are no controls. It's obviously a different story with power on, but it's still all very clean and modern looking, and sparse. Computers are king nowadays.

m_c

https://www.straitstimes.com/asia/se-asia/cockpit-voice-recorder-of-doomed-lion-air-jet-depicts-pilots-frantic-search-for-fix

Original Lion Air flight that had problems had an off-duty captain who found the solution, and the next flight the co-pilot didn't put as much effort in while the captain tried to find a suitable checklist.

goldtop

First airline cancels order of 50 Boeing 737 Maxs: https://www.theguardian.com/business/2019/mar/22/indonesian-airline-garuda-cancels-order-for-49-boeing-737-max-8-jets

ICBM

It's getting even worse, if this is correct...

https://leehamnews.com/2019/03/22/bjorns-corner-the-ethiopian-airlines-flight-302-crash-part-2/

Not only is the aircraft unstable at high AOA due to the larger engines causing additional pitch-up, to which MCAS was the 'solution', but at high speed the elevators may lose effectiveness due to being unable to overcome the aerodynamic forces, so the aircraft will dive further and thus speed up even more. If so this would exactly explain the increasing speed and increasingly steep dive on the charts for both crashes, from which the pilots could not recover.

Both of these are very dangerous positive-feedback characteristics which are in contravention of basic civil aircraft design principles and safety regulations. If so then the Max is done for, since it's simply unsafe.

martinw

Reading all this stuff is astonishing to me as an ex-RAF aircraft technician.
That there seems to be no way to switch off all the augmentation in an emergency and let the pilot fly the damned aircraft.
The only incident that didn't result in a crash was the one with THREE aircrew on the flight deck! That strongly implies that the answer to the OP question is 'yes'.
I don't think the answer is yes for every aircraft in fact, but the Max seems to be a mess, needing band-aid fixes to an inherent lack of flyability.

Reverend

VimFuego said:

I just hope all them airlines that own the plane kept the receipts, else it can be a bugger get your money back

I think they used PayPal so should be ok. 

JezWynd

ICBM

I'm not sure I would describe Jeff Wise as an aviation expert - he's a writer, blogger and quite a bit of a conspiracy theorist, although he seems to know a fair amount of detail as well. Which doesn't mean he's wrong, of course.

http://jeffwise.net

olafgarten

martinw said:

Reading all this stuff is astonishing to me as an ex-RAF aircraft technician.
That there seems to be no way to switch off all the augmentation in an emergency and let the pilot fly the damned aircraft.
The only incident that didn't result in a crash was the one with THREE aircrew on the flight deck! That strongly implies that the answer to the OP question is 'yes'.
I don't think the answer is yes for every aircraft in fact, but the Max seems to be a mess, needing band-aid fixes to an inherent lack of flyability.

It seems that there was a way to disable it but the pilots weren't told how to and they couldn't work out what they needed to disable fast enough. 

It wouldn't really have helped, even if they did disable it they wouldn't be able to fly very effectively as the aerodynamics would be completely unfamiliar. 

martinw

olafgarten said:

martinw said:

Reading all this stuff is astonishing to me as an ex-RAF aircraft technician.
That there seems to be no way to switch off all the augmentation in an emergency and let the pilot fly the damned aircraft.
The only incident that didn't result in a crash was the one with THREE aircrew on the flight deck! That strongly implies that the answer to the OP question is 'yes'.
I don't think the answer is yes for every aircraft in fact, but the Max seems to be a mess, needing band-aid fixes to an inherent lack of flyability.

It seems that there was a way to disable it but the pilots weren't told how to and they couldn't work out what they needed to disable fast enough. 

It wouldn't really have helped, even if they did disable it they wouldn't be able to fly very effectively as the aerodynamics would be completely unfamiliar. 

But that's the point; an override like that needs to be quick and easy, not something you have to get cheat sheets out for.

Obviously, commensurate with that, there needs to be thorough training to fly the aircraft without those systems active.

I think the initial issue here was who's flying the plane, the aerodynamic problems only added to it later.

All passenger aircraft should have a basic level of aerodynamic flyability. This isn't a fighter that needs to be unstable to do it's job and needs a computer to make it flyable.

There's a parallel with modern cars here, with complex software that interprets the drivers commands for emissions and suchlike. The difference is that there's no 'limp-home' mode for an aircraft.

olafgarten

martinw said:

olafgarten said:

martinw said:

Reading all this stuff is astonishing to me as an ex-RAF aircraft technician.
That there seems to be no way to switch off all the augmentation in an emergency and let the pilot fly the damned aircraft.
The only incident that didn't result in a crash was the one with THREE aircrew on the flight deck! That strongly implies that the answer to the OP question is 'yes'.
I don't think the answer is yes for every aircraft in fact, but the Max seems to be a mess, needing band-aid fixes to an inherent lack of flyability.

It seems that there was a way to disable it but the pilots weren't told how to and they couldn't work out what they needed to disable fast enough. 

It wouldn't really have helped, even if they did disable it they wouldn't be able to fly very effectively as the aerodynamics would be completely unfamiliar. 

But that's the point; an override like that needs to be quick and easy, not something you have to get cheat sheets out for.

Obviously, commensurate with that, there needs to be thorough training to fly the aircraft without those systems active.

I think the initial issue here was who's flying the plane, the aerodynamic problems only added to it later.

All passenger aircraft should have a basic level of aerodynamic flyability. This isn't a fighter that needs to be unstable to do it's job and needs a computer to make it flyable.

There's a parallel with modern cars here, with complex software that interprets the drivers commands for emissions and suchlike. The difference is that there's no 'limp-home' mode for an aircraft.

I agree completely, Boeing essentially got the old 737, changed the way it flew, added a computer to fix it, didn't test the computer, didn't make it clear to the pilots and did this all to save a bit of money.

In future I think I'll fly Airbus. 

JezWynd

Boeing essentially got the old 737, changed the way it flew, added a computer to fix it, didn't test the computer, didn't make it clear to the pilots and did this all to save a bit of money.

and made the safety features that might have alerted the crew 'optional extras'. Unbelievable.

The connivance between the FAA and Boeing is a stain on both organisations that's going to take a long time to fade.

ICBM

This sounds like Boeing is in danger of becoming the Gibson of the aircraft industry...

https://www.nytimes.com/2019/04/20/business/boeing-dreamliner-production-problems.html

viz

@ICBM said:

PC_Dave said:

Yes, this whole thing is an awful tragedy, but to say that Boeing have been lax in their approach is simply not true.

If the cause of these crashes is something to do with MCAS, exactly that is true. A safety-critical software system without enough redundancy and error-checking built into how it handles sensor data *is* lax.

boogieman said:

I always presumed there’d be at least one redundancy system in the case of a faulty sensor, but it doesn’t look to be the case. Unless I’ve misread it, a system where the software polls all the other sensors to see if they agree with the faulty one is “an optional extra”??!!  Madness. 

Making anything like that an optional cost item reminds me of some early calculators which had some features deliberately crippled in order to market an apparently different model at a lower price point.

When we upgraded my Dragon 32 computer to a Dragon 64 (in 1982 ), all that was needed was for a jumper lead to be removed. 

Emp_Fab

There’s a lot of misunderstanding and incorrect assumptions in this thread.  The bottom line is that yes, it does appear that there is something wrong with Boeing’s MCAS system.  However - it is perfectly possible to disable it.  (Unless it transpires that the disablement system is also fatally flawed - which would be another issue altogether).

This chap, a 737 Training Captain, explains it well:

https://m.youtube.com/watch?v=xixM_cwSLcQ

m_c

One of the things I've read about MCAS, is it runs faster than normal trim, and has more authority.

So yes, you can disable it, but it would appear that when it activates, it activates far faster than a typical trim runaway. Now when you're dealing with a stick shaker, and trying to work out why you've got a stick shaker, you have MCAS pushing the nose down far faster than you've ever been trained to handle.

The big question I want answered, is why did the pilots on both crashes manage to contain the problem with trim, yet once things got really bad, couldn't trim the nose up. I suspect there is more to the crashes than simply MCAS pushing the nose down, and that's without considering how Boeing came to use this sticking plaster approach to maintain grandfather rights.

ICBM

Emp_Fab said:

There’s a lot of misunderstanding and incorrect assumptions in this thread.  The bottom line is that yes, it does appear that there is something wrong with Boeing’s MCAS system.  However - it is perfectly possible to disable it.  (Unless it transpires that the disablement system is also fatally flawed - which would be another issue altogether).

That's exactly the problem - they can't do that because by turning off MCAS, it would then mean that the Max has very different handling characteristics to the NG under some conditions, so wouldn't pass certification as the 'same' aircraft type and would require a different pilot type rating - that's what Boeing has been trying to avoid, for commercial reasons. Hence, although it is possible to turn off the electrically-powered trim, it's *not* possible to disable MCAS by itself. But you need electric trim to recover the aircraft quickly and effectively when you're in a nose-down situation close to the ground, because the manual trim wheel isn't powerful enough and may actually be too difficult to turn under high load conditions.

Catch-22.

Boeing have absolutely hoist themselves by their own petard, and if the Max is ever going to fly again in its current form it will probably have to be fully re-certified as a new aircraft type, which it always should have been in the first place. And even that's not a certainty since it contravenes a couple of basic stability regulations.

There's far too much in this thread to read it all really, but this has been gone round again and again - http://www.airliners.net/forum/viewtopic.php?f=3&t=1417545

boogieman

Emp_Fab said:

There’s a lot of misunderstanding and incorrect assumptions in this thread.  The bottom line is that yes, it does appear that there is something wrong with Boeing’s MCAS system.  However - it is perfectly possible to disable it.  (Unless it transpires that the disablement system is also fatally flawed - which would be another issue altogether).

This chap, a 737 Training Captain, explains it well:

https://m.youtube.com/watch?v=xixM_cwSLcQ

What he said ^
I also thought the other main issue is that although yes it is possible to disable the system, it requires “quick action” and the procedure to do it isn’t that straightforward. Plus the fact that a lot of pilots seemingly either weren’t trained to do it or just didn’t know.