Bricktop
Posts: 1359
Joined: Fri Jan 22, 2016 11:04 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:13 pm

keesje wrote:
PlanesNTrains wrote:

I think he means the implication in this:

keesje wrote:

Is there pressure on the FAA to be helpful, constructive and speed things up to, make national programs (American public, Boeing as Stakeholder) successful? Where does efficiency and global leadership meet safety? [/url]


Nope, it is FAA Vision from https://www.faa.gov/about/mission/

None of what you imply is in the FAA Mission Statement. You do your already diminishing credibility no favors with this line of argument.
 
Bricktop
Posts: 1359
Joined: Fri Jan 22, 2016 11:04 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:14 pm

keesje wrote:
PlanesNTrains wrote:

I think he means the implication in this:

keesje wrote:

Is there pressure on the FAA to be helpful, constructive and speed things up to, make national programs (American public, Boeing as Stakeholder) successful? Where does efficiency and global leadership meet safety? [/url]


Nope, it is FAA Vision from https://www.faa.gov/about/mission/

None of what you imply is in the FAA Mission Statement. You do your already diminishing credibility no favors with this line of argument.
 
User avatar
keesje
Topic Author
Posts: 12944
Joined: Thu Apr 12, 2001 2:08 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:15 pm

Bricktop wrote:
PlanesNTrains wrote:
ELBOB wrote:

No it's not anti-American, it's anti-corporate.

If the regulators ( of any country ) truly put safety as Priority #1 then the 737Max ( and A350, and whatever ) would still be in flight-testing status. Shall we say five years of testing, funded by the manufacturer and launch customers? Maybe seven? That should iron-out the bugs.

But the priority actually appears to get the frame into revenue service whilst ticking the boxes of safety.


I think he means the implication in this:

keesje wrote:

Is there pressure on the FAA to be helpful, constructive and speed things up to, make national programs (American public, Boeing as Stakeholder) successful? Where does efficiency and global leadership meet safety? [/url]

It's more of the same parochial silliness. Did EASA not certify the MAX also? Are they in Boeing's pocket too? It nauseates me that people try to score points for their "team" when people died. Pathetic.


It worries me when people try to steer away from a flight safety / certification discussion they maybe do not like.

Btw EASA take over FAA certification & the other way around. Unless e.g. FAA sees their certification requirements not met in a satisfactory way.
"Never mistake motion for action." Ernest Hemingway
 
brindabella
Posts: 562
Joined: Fri Apr 30, 2010 10:38 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:18 pm

Francoflier wrote:
brindabella wrote:
Oh Dear. So much confusion and so little understanding.

I have carefully read-through all the gibberish and can only say:

"Please read Post #15".


The stab-trim ran-away.


THAT IS WHAT YOU DO!


sheesh!


Are you a pilot?
Do you know at what speed the MCAS would run the stab towards Nose Down?
Do you know the control forces needed to counteract even relatively minor stab movements?
How long do you reckon it would take the pilots to recognize a stab runaway scenario? When they do, how far would the stab have gone, how hard would the PF be pulling on that yoke and would he have enough spare capacity to either grab the trim wheel or hit the cutout switches?
When they eventually do that, how far would the stab have gone and would it even be possible to counteract with elevator control?
Considering all that, how much time would they have at the altitude they were at when it happened to recover?

The fact that it is written on a checklist doesn't mean that it is a practical solution to every stab runaway scenario.
I can very well imagine a timeline in which, depending on how aggressively the stab moves during MCAS activation and considering the low altitude and the average reaction time from even an experienced pilot, they simply would not have recovered the aircraft even when doing the right actions.


Well - only 30,000 hours plus command on many of the big jets. Boeing and Airbus.

Oh - and substantial Sim training/checking.

So yes, I think I have some input to add.


And you?

What the hell do you have to add? Do you have any idea at all about the cutout switches on the pedestal?

And what training the pilots receive?


Meh.
Billy
 
kalvado
Posts: 1783
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:18 pm

And since that wasn't brought up, I want to explain why I don't like Boeing's solution.
One of the things about traditional airplane - it has to stall gracefully. Meaning it loses lift on the wing - and it has to have the tendency to naturally recover. This is why canrads are tempting idea for performance and efficiency - but not implemented on pax aircraft, loss of lift behind CoG pitches nose up and makes stall worse.
I remember a paper about A-380 wing where they discussed that the wing has to stall at the root first. FOr swept wing design, that means losing lift forward of center and pitch down, aircraft helps the pilot to recover. This is not a factor in regular flying, but if plane somehow becomes close to a stall - you better have all the help you can get.
What Boeing got with their engine placement, from Leeham article, is that as aircraft approaches stall pitch, engine nacelles start producing lift forward of CoG, and aircraft receives an uppercut, sending it into the stall without a graceful warning about dangerous conditions. That is counteracted by MCAS trim movement - and it makes some sense, but nonetheless makes an approach to stall AoA a much more dangerous exercise. And I am not sure if such approach matches my gut feeling of how stable aircraft should be.
Maybe I am not an expert, but this looks as a very serious change in fundamental aircraft behavior principles and possible departure from design concepts mandated by certification rules. Way more serious than a missing line in a manual.
 
PlanesNTrains
Posts: 9527
Joined: Tue Feb 01, 2005 4:19 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:26 pm

keesje wrote:
It worries me when people try to steer away from a flight safety / certification discussion they maybe do not like.


:rotfl: :rotfl: :rotfl: :rotfl: :rotfl:
-Dave


MAX’d out on MAX threads. If you are starting a thread, and it’s about the MAX - stop. There’s already a thread that covers it.
 
Bricktop
Posts: 1359
Joined: Fri Jan 22, 2016 11:04 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:27 pm

The same poster who says this

keesje wrote:
It worries me when people try to steer away from a flight safety / certification discussion they maybe do not like.

Btw EASA take over FAA certification & the other way around. Unless e.g. FAA sees their certification requirements not met in a satisfactory way.


says this

keesje wrote:
Is there pressure on the FAA to be helpful, constructive and speed things up to, make national programs (American public, Boeing as Stakeholder) successful? Where does efficiency and global leadership meet safety?


and this

keesje wrote:
Nope, it is FAA Vision from https://www.faa.gov/about/mission/


Most posters know you would be singing from a different hymnbook if this was an A320neo. Again, your credibility isn't helped by your conspiracy theory nuttiness, best left to our friend in Germany.
 
parapente
Posts: 3061
Joined: Tue Mar 28, 2006 10:42 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:46 pm

Question.
Why is this condition specific to the MAX and not the NG?One imagines it's something to do with having higher bypass engines but perhaps not.
 
mm320cap
Posts: 297
Joined: Wed Jul 14, 2004 12:35 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:54 pm

zeke wrote:
7BOEING7 wrote:
NO!!

Even Sullenberger while gliding his A320 to a ditching didn't know that envelope protections would cut him out of the loop -- as far as pitch was concerned he was just a passenger for the last 150ft or so. Nothing like moving the sidestick and nothing happens. That could have been interesting but it all worked out ok. After that it was recommended that AB let the flight crews have a little more information about what was going on in the FBW system as will occur with this accident.

The philosophy for many, many years (30+) has been for manufacturers to not tell the pilots every little detail like in the old days. Among other things they don't want pilots adlibing -- Air Asia 8501. It remains to be seen if two or three sentences in the FCOM would have prevented this accident.


Could I ask you stay on topic and stop trying divert make this out as an Airbus fault.

As for alfa protection every Airbus pilot knows about, it is in the FCOM, and it is practiced in GPWS and windshear recovery procedures, you pull back as far as you can and the aircraft gives the best performance.

As per the NTSB report the Alfa protection provided the best performance for the weight and configuration. Raising the pitch attitude would not have improved performance.


I know we are getting off track here, but I was an A320 pilot when the AF accident occurred. After the data was collected and analyzed I was extremely surprised to discover that the audible “STALL STALL” warning would actually cease when the AOA reaches a certain level. So when the PF pushed forward the STALL STALL warning recommenced. This made him do the opposite of what he just did, and he pulled back again - STALL STALL warning goes away. This was NOT something that had been discussed or known about at my airline.

Reminds me also of how surprised I was after the AA A300 crash in NYC where the tail was ripped off by rudder PIO. Up until that time, I had no clue that you could structurally rip the airplane apart below Va.

It would be impossible for any manufacturer to mention every single nuanced scenario, as they may not have even thought of them all. Sadly, sometimes it takes an accident to uncover these unintentional discoveries. I read each report with an open mind and humility and try to forever add to my “Captain’s Bag of Tricks”
Last edited by mm320cap on Thu Nov 15, 2018 4:06 pm, edited 1 time in total.
 
mm320cap
Posts: 297
Joined: Wed Jul 14, 2004 12:35 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 3:56 pm

brindabella wrote:
Oh Dear. So much confusion and so little understanding.

I have carefully read-through all the gibberish and can only say:

"Please read Post #15".


The stab-trim ran-away.


THAT IS WHAT YOU DO!


sheesh!


You’re a 30,000 hour pilot and this is your response?? Wow. You’ve got me by 5,000 hours or so, but we are light years apart on how we see this.

I fly the NG/MAX currently and this accident sends shivers down my spine. The runaway trim training scenario in the sim consists of flying along, trimming, releasing the trim and it doesn’t stop. It’s very obvious and the recovery is simple and quite obvious. This is most likely not at ALL what this crew was experiencing. 3 different airspeed readings, stick shaker, warnings everywhere.... all the while a slow, subtle trim nose down input is being applied from a system you weren’t told anything about and didn’t know existed. All this at low altitude. It’s a confusing environment, and not NEARLY as simple as you make it out to be.
 
User avatar
7BOEING7
Posts: 3017
Joined: Fri Oct 12, 2012 5:28 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 4:05 pm

zeke wrote:
7BOEING7 wrote:
NO!!

Even Sullenberger while gliding his A320 to a ditching didn't know that envelope protections would cut him out of the loop -- as far as pitch was concerned he was just a passenger for the last 150ft or so. Nothing like moving the sidestick and nothing happens. That could have been interesting but it all worked out ok. After that it was recommended that AB let the flight crews have a little more information about what was going on in the FBW system as will occur with this accident.

The philosophy for many, many years (30+) has been for manufacturers to not tell the pilots every little detail like in the old days. Among other things they don't want pilots adlibing -- Air Asia 8501. It remains to be seen if two or three sentences in the FCOM would have prevented this accident.


Could I ask you stay on topic and stop trying divert make this out as an Airbus fault.

As for alfa protection every Airbus pilot knows about, it is in the FCOM, and it is practiced in GPWS and windshear recovery procedures, you pull back as far as you can and the aircraft gives the best performance.

As per the NTSB report the Alfa protection provided the best performance for the weight and configuration. Raising the pitch attitude would not have improved performance.


How am I making this out to be AB's fault???

I was on topic, we're discussing information that was left out of the FCOM and I was pointing out it happens to everybody.

If the A320 documentation on alpha protection was adequate the NTSB wouldn't have recommended better documentation.

"The investigation also found that Airbus' training curricula did not contain information on the effects of alpha-protection-mode features that might affect the airplane's response to pilot sidestick pitch inputs."

Sullenberger wasn't reacting to a GPWS or windshear, he was trying to ditch an airplane -- entirely different operation.
 
User avatar
Francoflier
Posts: 4819
Joined: Wed Oct 31, 2001 12:27 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 4:07 pm

brindabella wrote:
And you?

What the hell do you have to add? Do you have any idea at all about the cutout switches on the pedestal?

And what training the pilots receive?


I know that on the Boeings I flew, pulling the yoke should cut the stab working against me. I also know that the cutout switches cut hydraulic power to the stab and prevent it from being moved again. Meaning that if it has gone too far by that stage, there's nothing much you can do.

The 737 has a trim wheel, and I don't know if that comes with a manual reversion that would allow to move the stab even after snuffing hyd power. But even if it did, I'm guessing that'd be a pretty time consuming process and would take some crew coordination as the PF would have both hands busy wrangling the yoke.

I also know than in the 10 or so years I flew these Boeings (and any other airplane for that matter), I can't recall ever getting a training event for stab runaway. Maybe a non-severe one that came with an ECAM and that would be pretty straightforward to deal with, but no more.

I also am starting to realise, along with everyone else it seems, that this MCAS was a certification workaround that Boeing didn't talk much about until now, which wouldn't be that bad apart from the fact that the system, which very positively, and apparently very quickly, acts on longitudinal control, is based on non-redundant indications, and possibly transparently to the pilots.

So when I see that all you have to say about it is essentially point at the checklist and say 'duh', when you (or anyone else) aren't able to tell whether you'd have done better than those poor sods that day, well it irks me a bit, especially given your background.

And way to thow your colleagues under the bus...
Isn't it enough that manufacturers and airlines actively try to blame the dead guys who can't defend themselves anymore every time this happens that we have to turn against our own too without even knowing the facts?

We are a sorry bunch sometimes.
I'll do my own airline. With Blackjack. And hookers. In fact, forget the airline.
 
kalvado
Posts: 1783
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 4:12 pm

parapente wrote:
Question.
Why is this condition specific to the MAX and not the NG?One imagines it's something to do with having higher bypass engines but perhaps not.

Bigger engine more forward of the wing. I am a bit surprised this became that important, difference is not that huge.
Figure 2 in this article: https://leehamnews.com/2018/11/14/boein ... he-pilots/
 
greendot
Posts: 203
Joined: Sat Aug 19, 2017 6:08 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 4:15 pm

BoeingGuy wrote:
Finn350 wrote:
Sooner787 wrote:
I know there are some MAX customers that have yet to take delivery of their new jets ,
Alaska for instance..... Might AS decide to cancel their MAX orders , especially since they
now have A321NEOS on property. I would also guess Lion Air might be reconsidering
their Max order book as well.


Not likely that there are any contractual clauses to justify deferrals or cancellations on 737 MAX orders based on thuis defect.


Let’s be very clear. The defect was the AOA probe, not the airplane design.


Isn't the design the defect? I would never design a mission critical system with the possibility of a fail_fail condition. It should have a fail_safe design where an AOA probe failure would be detected, isolated, disregarded, and an alternative system would outvote the defective system. This whole thing was designed with only 1 layer to fail.
 
User avatar
7BOEING7
Posts: 3017
Joined: Fri Oct 12, 2012 5:28 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 4:25 pm

Francoflier wrote:

I know that on the Boeings I flew, pulling the yoke should cut the stab working against me. I also know that the cutout switches cut hydraulic power to the stab and prevent it from being moved again. Meaning that if it has gone too far by that stage, there's nothing much you can do.

The 737 has a trim wheel, and I don't know if that comes with a manual reversion that would allow to move the stab even after snuffing hyd power. But even if it did, I'm guessing that'd be a pretty time consuming process and would take some crew coordination as the PF would have both hands busy wrangling the yoke.

I also know than in the 10 or so years I flew these Boeings (and any other airplane for that matter), I can't recall ever getting a training event for stab runaway. Maybe a non-severe one that came with an ECAM and that would be pretty straightforward to deal with, but no more.

.


IIRC the 757/767 don't have a runaway trim procedure, the 737/744/777/787 do. All have "memory items" except the 744 which is all read and do.

On the 737 there's a physical wheel which has handles that can be extended and the stabilizer can be manually positioned when hydraulics are off. Its flyable but not pretty.
 
WIederling
Posts: 8357
Joined: Sun Sep 13, 2015 2:15 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 4:48 pm

kalvado wrote:
parapente wrote:
Question.
Why is this condition specific to the MAX and not the NG?One imagines it's something to do with having higher bypass engines but perhaps not.

Bigger engine more forward of the wing. I am a bit surprised this became that important, difference is not that huge.
Figure 2 in this article: https://leehamnews.com/2018/11/14/boein ... he-pilots/

also mounted higher relative to the wing ( resp. the airframe ).
The pitch up angle where positive feedback starts is smaller the drag force higher to begin with.
A similar effect comes up with full thrust from a below the wing engine ( works against pitch down )
Murphy is an optimist
 
User avatar
william
Posts: 3068
Joined: Thu Jun 10, 1999 1:31 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 5:13 pm

mm320cap wrote:
zeke wrote:
7BOEING7 wrote:
NO!!

Even Sullenberger while gliding his A320 to a ditching didn't know that envelope protections would cut him out of the loop -- as far as pitch was concerned he was just a passenger for the last 150ft or so. Nothing like moving the sidestick and nothing happens. That could have been interesting but it all worked out ok. After that it was recommended that AB let the flight crews have a little more information about what was going on in the FBW system as will occur with this accident.

The philosophy for many, many years (30+) has been for manufacturers to not tell the pilots every little detail like in the old days. Among other things they don't want pilots adlibing -- Air Asia 8501. It remains to be seen if two or three sentences in the FCOM would have prevented this accident.


Could I ask you stay on topic and stop trying divert make this out as an Airbus fault.

As for alfa protection every Airbus pilot knows about, it is in the FCOM, and it is practiced in GPWS and windshear recovery procedures, you pull back as far as you can and the aircraft gives the best performance.

As per the NTSB report the Alfa protection provided the best performance for the weight and configuration. Raising the pitch attitude would not have improved performance.


I know we are getting off track here, but I was an A320 pilot when the AF accident occurred. After the data was collected and analyzed I was extremely surprised to discover that the audible “STALL STALL” warning would actually cease when the AOA reaches a certain level. So when the PF pushed forward the STALL STALL warning recommenced. This made him do the opposite of what he just did, and he pulled back again - STALL STALL warning goes away. This was NOT something that had been discussed or known about at my airline.

Reminds me also of how surprised I was after the AA A300 crash in NYC where the tail was ripped off by rudder PIO. Up until that time, I had no clue that you could structurally rip the airplane apart below Va.

It would be impossible for any manufacturer to mention every single nuanced scenario, as they may not have even thought of them all. Sadly, sometimes it takes an accident to uncover these unintentional discoveries. I read each report with an open mind and humility and try to forever add to my “Captain’s Bag of Tricks”


Wow, did not know that little bit of info. This board (me included) vilified the pilots for not knowing basic flying 101. If you have an aircaft telling you "Stall, Stall" when you are initiating stall recovery and silent when you do the opposite.......Wow, just wow.........puts things in a WAY different perspective.
 
User avatar
crimsonchin
Posts: 523
Joined: Fri Feb 07, 2014 8:16 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 5:17 pm

Bricktop wrote:
The same poster who says this

keesje wrote:
It worries me when people try to steer away from a flight safety / certification discussion they maybe do not like.

Btw EASA take over FAA certification & the other way around. Unless e.g. FAA sees their certification requirements not met in a satisfactory way.


says this

keesje wrote:
Is there pressure on the FAA to be helpful, constructive and speed things up to, make national programs (American public, Boeing as Stakeholder) successful? Where does efficiency and global leadership meet safety?


and this

keesje wrote:
Nope, it is FAA Vision from https://www.faa.gov/about/mission/


Most posters know you would be singing from a different hymnbook if this was an A320neo. Again, your credibility isn't helped by your conspiracy theory nuttiness, best left to our friend in Germany.


And most of the people in this thread would be screaming flying Airbus deathtrap if it was the A320neo, your point?

I mean it's not like the American members/Boeing fanboys didn't spend a lot of time and effort on this very same site trying to make it out like Airbus FBW was some flying deathtrap for years (thank heavens for the efforts of people like Zeke who flew the damn things and were on hand to clear things up), even trying to insinuate Airbus tampered with black boxes and evidence to hide their faults. Spare me the bullshit moral grandstanding.
 
BoeingGuy
Posts: 6257
Joined: Fri Dec 10, 2010 6:01 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 6:11 pm

william wrote:
mm320cap wrote:
zeke wrote:

Could I ask you stay on topic and stop trying divert make this out as an Airbus fault.

As for alfa protection every Airbus pilot knows about, it is in the FCOM, and it is practiced in GPWS and windshear recovery procedures, you pull back as far as you can and the aircraft gives the best performance.

As per the NTSB report the Alfa protection provided the best performance for the weight and configuration. Raising the pitch attitude would not have improved performance.


I know we are getting off track here, but I was an A320 pilot when the AF accident occurred. After the data was collected and analyzed I was extremely surprised to discover that the audible “STALL STALL” warning would actually cease when the AOA reaches a certain level. So when the PF pushed forward the STALL STALL warning recommenced. This made him do the opposite of what he just did, and he pulled back again - STALL STALL warning goes away. This was NOT something that had been discussed or known about at my airline.

Reminds me also of how surprised I was after the AA A300 crash in NYC where the tail was ripped off by rudder PIO. Up until that time, I had no clue that you could structurally rip the airplane apart below Va.

It would be impossible for any manufacturer to mention every single nuanced scenario, as they may not have even thought of them all. Sadly, sometimes it takes an accident to uncover these unintentional discoveries. I read each report with an open mind and humility and try to forever add to my “Captain’s Bag of Tricks”


Wow, did not know that little bit of info. This board (me included) vilified the pilots for not knowing basic flying 101. If you have an aircaft telling you "Stall, Stall" when you are initiating stall recovery and silent when you do the opposite.......Wow, just wow.........puts things in a WAY different perspective.


That’s not how Stall Warning works on Boeing airplanes. More misinformation.

Boeing airplanes have the stick shaker. There is no voice aural.
 
smartplane
Posts: 977
Joined: Fri Aug 03, 2018 9:23 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 6:44 pm

Francoflier wrote:
brindabella wrote:
And you?

What the hell do you have to add? Do you have any idea at all about the cutout switches on the pedestal?

And what training the pilots receive?


I know that on the Boeings I flew, pulling the yoke should cut the stab working against me. I also know that the cutout switches cut hydraulic power to the stab and prevent it from being moved again. Meaning that if it has gone too far by that stage, there's nothing much you can do.

The 737 has a trim wheel, and I don't know if that comes with a manual reversion that would allow to move the stab even after snuffing hyd power. But even if it did, I'm guessing that'd be a pretty time consuming process and would take some crew coordination as the PF would have both hands busy wrangling the yoke.

I also know than in the 10 or so years I flew these Boeings (and any other airplane for that matter), I can't recall ever getting a training event for stab runaway. Maybe a non-severe one that came with an ECAM and that would be pretty straightforward to deal with, but no more.

I also am starting to realise, along with everyone else it seems, that this MCAS was a certification workaround that Boeing didn't talk much about until now, which wouldn't be that bad apart from the fact that the system, which very positively, and apparently very quickly, acts on longitudinal control, is based on non-redundant indications, and possibly transparently to the pilots.

So when I see that all you have to say about it is essentially point at the checklist and say 'duh', when you (or anyone else) aren't able to tell whether you'd have done better than those poor sods that day, well it irks me a bit, especially given your background.

And way to thow your colleagues under the bus...
Isn't it enough that manufacturers and airlines actively try to blame the dead guys who can't defend themselves anymore every time this happens that we have to turn against our own too without even knowing the facts?

We are a sorry bunch sometimes.

Yes. Hopefully the FAA is keen to identify pilots so confident in their abilities and checklists, they will volunteer to recreate the final minutes of this flight in the air with a real aircraft (as opposed to a simulator).
 
aaexecplat
Posts: 495
Joined: Tue Sep 29, 2009 2:49 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 6:58 pm

iamlucky13 wrote:
aaexecplat wrote:
One thing is very clear to me. There are a lot of posters who don't understand or don't want to understand the totality of the issues that are piling up in this case. Nor the implications of cutting the MCAS system. For all we know, the pilots mag have cut the STS and made the aircraft thereby uncontrollable. I think Kalvados gave the best succinct summary in the other thread. If anyone read and understood it, it would have helped to serve as a basis for evaluating Boeing's role, the operating airline's role and the pilots' role in this crash. And I hope the CVR is found soon so as to allow tne authorities to assess what exactly was going on in that cockpit.


Can you provide a link to the referenced post by Kalvados? I would like to read it, but there's been a couple JT610-related threads, and it sounds like you know better than I where to find it.


Sorry it took me a while, but here you go:

https://www.airliners.net/forum/viewtopic.php?f=3&t=1407217&start=1150#p20855643
 
greendot
Posts: 203
Joined: Sat Aug 19, 2017 6:08 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 7:03 pm

BoeingGuy wrote:
Sooner787 wrote:
I know there are some MAX customers that have yet to take delivery of their new jets ,
Alaska for instance..... Might AS decide to cancel their MAX orders , especially since they
now have A321NEOS on property. I would also guess Lion Air might be reconsidering
their Max order book as well.


Isn’t that a little overly dramatic and childish? Airplane accidents have unfortunately occurred since the beginning of time. What, do you think every airline has cancelled orders for every model that’s had an accident? So I guess all A330 orders should be cancelled too?


I don't think so. Particularly with the 737. It's a jurassic jet with bandaids on top of bandaids. It's horrible in terms of pilot ergonomics, human factors, and knowledge requirements. There are many exceptions to the rule when flying it. It might be time for airlines to stop choosing the cheapest airplane and maybe exert market forces on Boeing/Airbus/Embraer/etc. to design better aircraft and bring them to market faster.
 
greendot
Posts: 203
Joined: Sat Aug 19, 2017 6:08 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 7:15 pm

mm320cap wrote:
It would be impossible for any manufacturer to mention every single nuanced scenario, as they may not have even thought of them all.


This isn't 1950 anymore. Computer simulation through things like computational fluid dynamics and first principles based flight models (simulator) allow aircraft to be designed with all modes of failure mostly known ahead of time. The F-35 is a perfect example of this. It was virtually created and most every issue was identified before it ever actually flew. Test flights simply validated the calculated performance envelopes. I'm greatly oversimplifying things but the point is that Alpha Protection is not something that cannot be 100% understood through software. The problem is the airplane is being repurposed as a bigger airplane well beyond its original design specifications. Every part of the airframe's envelope is being approached (hence "max"). Boeing added this alpha protection system as an aftermarket consideration to fix an aerodynamic limitation. I'm concerned that Boeing didn't tell people about it.
 
User avatar
7BOEING7
Posts: 3017
Joined: Fri Oct 12, 2012 5:28 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 7:20 pm

greendot wrote:
BoeingGuy wrote:
Sooner787 wrote:
I know there are some MAX customers that have yet to take delivery of their new jets ,
Alaska for instance..... Might AS decide to cancel their MAX orders , especially since they
now have A321NEOS on property. I would also guess Lion Air might be reconsidering
their Max order book as well.


Isn’t that a little overly dramatic and childish? Airplane accidents have unfortunately occurred since the beginning of time. What, do you think every airline has cancelled orders for every model that’s had an accident? So I guess all A330 orders should be cancelled too?


I don't think so. Particularly with the 737. It's a jurassic jet with bandaids on top of bandaids. It's horrible in terms of pilot ergonomics, human factors, and knowledge requirements. There are many exceptions to the rule when flying it. It might be time for airlines to stop choosing the cheapest airplane and maybe exert market forces on Boeing/Airbus/Embraer/etc. to design better aircraft and bring them to market faster.


Please get your "quote" correct -- I didn't say that!!!!!
 
greendot
Posts: 203
Joined: Sat Aug 19, 2017 6:08 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 7:33 pm

7BOEING7 wrote:
greendot wrote:
BoeingGuy wrote:

Isn’t that a little overly dramatic and childish? Airplane accidents have unfortunately occurred since the beginning of time. What, do you think every airline has cancelled orders for every model that’s had an accident? So I guess all A330 orders should be cancelled too?


I don't think so. Particularly with the 737. It's a jurassic jet with bandaids on top of bandaids. It's horrible in terms of pilot ergonomics, human factors, and knowledge requirements. There are many exceptions to the rule when flying it. It might be time for airlines to stop choosing the cheapest airplane and maybe exert market forces on Boeing/Airbus/Embraer/etc. to design better aircraft and bring them to market faster.


Please get your "quote" correct -- I didn't say that!!!!!


Sorry... whoever said it then. I don't know you personally and that's a good thing because we can focus on ideas rather than personalities.
 
User avatar
AirlineCritic
Posts: 1626
Joined: Sat Mar 14, 2009 1:07 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 7:59 pm

mm320cap wrote:
I am guessing that with all that was going on in the cockpit in those short minutes the pilots never imagined that this was creeping up on them until it was too late. In other words, it would seem to me that they may have never considered (or had time) going through the runaway trim procedure which may have led them to a different outcome."


Yup, this. IF the cause of this accident ends up being an MCAS event brought about by faulty AOA inputs, then it would be hard to fault the crew for not going to the “Runaway Stab Trim” QRC. During our stall training on the NG, there is no trim down bias. I was mighty surprised to hear that on the MAX (which we fly) there WILL be nose down trim applied and that if left unchecked it could become unrecoverable. I don’t think Boeing purposely left this out of the differences training; more likely they just didn’t think it was necessary to mention. Of course it looks necessary NOW with the benefit of 20/20 hindsight.

If the airplane is showing 3 different airspeeds, the stick shaker is going off (possibly at the same time as the clacker), there is probably a significant amount of confusion on the flight deck. This is something that can take awhile to digest and sort out. In the meantime, the airplane is constantly trimming nose down, which based on the training you’ve had you aren’t expecting. That’s a handful. I’m glad we are all aware of it now. But to except a crew to diagnose runaway stab trim as being the most serious fault at the time is asking a lot.[/quote]

Thank you for this as well.

And I agree; I'll add that in addition to the many things going on, there may be a time factor as well. Time within which one must react before the aircraft is not controllable or is nearing ground. We don't know how fast one gets to that situation, but if you are confused _and_ have to react in N seconds, that's not good.
 
salttee
Posts: 3149
Joined: Wed Jul 13, 2016 3:26 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 8:06 pm

AirlineCritic wrote:
Yup, this. IF the cause of this accident ends up being an MCAS event brought about by faulty AOA inputs

How could it be that when the actual precipitating event was the loss of airspeed information which disconnected the AP and left the PF blind?
 
frmrCapCadet
Posts: 2925
Joined: Thu May 29, 2008 8:24 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 8:12 pm

Wikipedia
Unintended consequences can be grouped into three types:

Unexpected benefit: A positive unexpected benefit (also referred to as luck, serendipity or a windfall).
Unexpected drawback: An unexpected detriment occurring in addition to the desired effect of the policy (e.g., while irrigation schemes provide people with water for agriculture, they can increase waterborne diseases that have devastating health effects, such as schistosomiasis).
Perverse result: A perverse effect contrary to what was originally intended (when an intended solution makes a problem worse). This is sometimes referred to as 'backfire'.


Evidence of bad corporate behavior usually can be a 'follow the money' sorts of investigation.This is not where Boeing's fault in this, if any, is. It is rather of the unintended consequences sort. They made a minor change in the plane, and thought the previous directions were adequate, along with certain other documentations. Pilots are saying the changes were not well communicated. It is not known at this point what were all the factors in the crash. The aviation world wants to know, and we all want a thorough and sound investigation.
Buffet: the airline business...has eaten up capital...like..no other (business)
 
greendot
Posts: 203
Joined: Sat Aug 19, 2017 6:08 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 8:24 pm

frmrCapCadet wrote:
Wikipedia
Unintended consequences can be grouped into three types:

Unexpected benefit: A positive unexpected benefit (also referred to as luck, serendipity or a windfall).
Unexpected drawback: An unexpected detriment occurring in addition to the desired effect of the policy (e.g., while irrigation schemes provide people with water for agriculture, they can increase waterborne diseases that have devastating health effects, such as schistosomiasis).
Perverse result: A perverse effect contrary to what was originally intended (when an intended solution makes a problem worse). This is sometimes referred to as 'backfire'.


Evidence of bad corporate behavior usually can be a 'follow the money' sorts of investigation.This is not where Boeing's fault in this, if any, is. It is rather of the unintended consequences sort. They made a minor change in the plane, and thought the previous directions were adequate, along with certain other documentations. Pilots are saying the changes were not well communicated. It is not known at this point what were all the factors in the crash. The aviation world wants to know, and we all want a thorough and sound investigation.


I wonder how this will unfold in comparison to the 737's historical rudder hardover problem.
 
salttee
Posts: 3149
Joined: Wed Jul 13, 2016 3:26 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 8:27 pm

greendot wrote:
I wonder how this will unfold in comparison to the 737's historical rudder hardover problem.

Probably people who stoop to that level will be ignored.
 
User avatar
7BOEING7
Posts: 3017
Joined: Fri Oct 12, 2012 5:28 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 8:40 pm

AirlineCritic wrote:
During our stall training on the NG, there is no trim down bias. .


That's makes sense considering you execute the manueuver as soon as the stickshaker goes off. If you continued to pull back on the control column trying to stall the airplane you would see both the increase feel force and the nose down trim bias activate. IMHO the issue with Lion Air is when the AOA went south it signaled they were at or near stall speed so both the increased feel and nose down trim activated.

If you've got an NG FCOM around check out "Stall Identification" in the "Flight Controls System Decription " chapter.
Last edited by 7BOEING7 on Thu Nov 15, 2018 8:43 pm, edited 1 time in total.
 
B737900ER
Posts: 1028
Joined: Thu Aug 31, 2006 10:26 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 8:41 pm

Everyone here is missing the most important point. The aircraft was not airworthy.

It wasn’t airworthy after the first discrepancy was pencil whipped

It wasn’t airworthy after the second discrepancy was pencil whipped

It wasn’t airworthy after the third discrepancy was shotgunned.

Keep an aircraft in the air for that long when it’s not airworthy and this will happen, no matter the manufacturer or operator. After the third write up the aircraft should have had a complete pitot static system test. Lion air decided to blindly throw parts at it and hope it worked, instead of actually troubleshooting. That decision doomed the aircraft.
 
strfyr51
Posts: 3774
Joined: Tue Apr 10, 2012 5:04 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 8:46 pm

That's a bunch of Bunk!! Had they been trained properly? They would have known that!! Why is it that you haven't seen this problem at United, Delta, American, or Southwest, or Alaska 00?? United flies a Bunch of B737's and if this "problem were surely a Problem? it would have manifested itself LONG before NOW wouldn't it?? This a failure of Training!!
 
User avatar
7BOEING7
Posts: 3017
Joined: Fri Oct 12, 2012 5:28 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 8:47 pm

Quick question:

Were there write ups on all three flights or just the one before the crash. When they read out the DFDR they said there were anomalies on all four flights but I haven't seen anything about writeups on the first two. Did I miss something?
 
buzzard302
Posts: 150
Joined: Sat Jun 06, 2015 12:06 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:00 pm

B737900ER wrote:
Everyone here is missing the most important point. The aircraft was not airworthy.

It wasn’t airworthy after the first discrepancy was pencil whipped

It wasn’t airworthy after the second discrepancy was pencil whipped

It wasn’t airworthy after the third discrepancy was shotgunned.

Keep an aircraft in the air for that long when it’s not airworthy and this will happen, no matter the manufacturer or operator. After the third write up the aircraft should have had a complete pitot static system test. Lion air decided to blindly throw parts at it and hope it worked, instead of actually troubleshooting. That decision doomed the aircraft.


I questioned a while back wondering if the crew had any reservations about flying the plane that day. The plane had shown problems too many times to be trusted. I'm not a pilot, but I am a very technical person. I would not be volunteering to fly any plane that showed continuous problems of this nature. The issues here are so multi layered, starting from Boeing, to the airline maintenance practices, to the decisions of the pilots to go ahead and fly the plane despite knowing the previous faults. This is typical in accidents, a chain of events and poor decisions which result in a bad outcome.
 
mikejepp
Posts: 210
Joined: Tue Aug 12, 2008 11:47 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:08 pm

So does this mean, once and for all, everyone can stop using that dumb term "Scarebus"?

The 737 was great..... 40 years ago. They're just warmed over garbage now.
 
WkndWanderer
Posts: 258
Joined: Sat Oct 21, 2017 6:36 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:17 pm

Erebus wrote:
WkndWanderer wrote:
Where are you getting that MCAS wasn't described or that Boeing delivered a plane without giving the customer information on how it worked? As another poster described, the MCAS is described in MAX maintenance manuals and procedures that address it are in at least some airline's MAX QRH's, do you think they just guessed?


It is coming from AA and WN pilots. From the Seattle Times...

Jon Weaks, president of the Southwest Airlines Pilots Association, said Monday the airline and the pilots “were kept in the dark.”

“We do not like the fact that a new system was put on the aircraft and wasn’t disclosed to anyone or put in the manuals,” he said in an interview. What’s more, he noted, Boeing and the Federal Aviation Administration have now warned “that the system may not be performing as it should.”


Early Saturday morning, Capt. Mike Michaelis, chairman of the safety committee of the Allied Pilots Association (APA) at American Airlines, sent out a message to pilots informing them of details Boeing had shared with the airline about this new 737 MAX system — called MCAS (Maneuvering Characteristics Augmentation System).

“This is the first description you, as 737 pilots, have seen,” the message from the pilots association at American reads. “It is not in the American Airlines 737 Flight Manual … nor is there a description in the Boeing FCOM (Flight Crew Operations Manual). It will be soon.”


Either these guys are not reading their manuals fully or they have been given inadequate versions. In any case it is still disconcerting to have pilots claiming that they are unaware of it.

Question: are pilots expected to know everything that is described in a maintenance manual?


Thanks for sharing the Seattle Times article, it does a better job with more information on what specific operator's pilots have said they were familiar with on the aircraft than the originally posted Leeham article. And of course it would be unreasonable to expect a pilot to be intimately familiar with every detail of the full maintenance manual and tech specs, but some of the original implications in the thread were that Boeing deliberately or surreptitiously "hid" the changes made instead of letting it's customers know how the planes they were getting actually worked, which seems far-fetched. Training or reference material at different airlines may have not picked up on or have been updated to the degree needed, but the idea some have put forward that Boeing somehow withheld info on its product with all the nefarious undertones seems a little implausible. It seems more likely that the info was in the tech material for the plane and the full range of every failure permutation that could occur and training implications those could have either weren't fully realized, or they thought existing recovery procedures would address them.
Last edited by WkndWanderer on Thu Nov 15, 2018 9:20 pm, edited 3 times in total.
 
User avatar
caoimhin
Posts: 447
Joined: Thu Oct 23, 2014 12:30 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:18 pm

mikejepp wrote:
So does this mean, once and for all, everyone can stop using that dumb term "Scarebus"?

The 737 was great..... 40 years ago. They're just warmed over garbage now.


Seems like the same type of people who are likely to say “Scarebus” have equally ignorant counterparts on the other side of the aisle who suggest that for the past 40 years the 737 has been “warmed over garbage”.

Be sure to forward your thoughts to the countless airlines who happily operate the NG without incident.
 
greendot
Posts: 203
Joined: Sat Aug 19, 2017 6:08 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:22 pm

salttee wrote:
greendot wrote:
I wonder how this will unfold in comparison to the 737's historical rudder hardover problem.

Probably people who stoop to that level will be ignored.


Stoop to what level? It's legitimate to know how the various government agencies handle this. I can't control what you think.
 
PlanesNTrains
Posts: 9527
Joined: Tue Feb 01, 2005 4:19 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:24 pm

mikejepp wrote:
So does this mean, once and for all, everyone can stop using that dumb term "Scarebus"?

The 737 was great..... 40 years ago. They're just warmed over garbage now.


smh...

strfyr51 wrote:
That's a bunch of Bunk!! Had they been trained properly? They would have known that!! Why is it that you haven't seen this problem at United, Delta, American, or Southwest, or Alaska 00?? United flies a Bunch of B737's and if this "problem were surely a Problem? it would have manifested itself LONG before NOW wouldn't it?? This a failure of Training!!


Because it hasn't happened yet??

Honestly, these threads seem to bring out the worst in people.
-Dave


MAX’d out on MAX threads. If you are starting a thread, and it’s about the MAX - stop. There’s already a thread that covers it.
 
fadecfault
Posts: 164
Joined: Mon Nov 05, 2007 8:44 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:28 pm

I going to leave this here as there is a LOT of bad information posted here.
Image
The views and opinions written here are my own and do not reflect those of my employer.
 
WIederling
Posts: 8357
Joined: Sun Sep 13, 2015 2:15 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:29 pm

7BOEING7 wrote:
greendot wrote:
BoeingGuy wrote:

Isn’t that a little overly dramatic and childish? Airplane accidents have unfortunately occurred since the beginning of time. What, do you think every airline has cancelled orders for every model that’s had an accident? So I guess all A330 orders should be cancelled too?


I don't think so. Particularly with the 737. It's a jurassic jet with bandaids on top of bandaids. It's horrible in terms of pilot ergonomics, human factors, and knowledge requirements. There are many exceptions to the rule when flying it. It might be time for airlines to stop choosing the cheapest airplane and maybe exert market forces on Boeing/Airbus/Embraer/etc. to design better aircraft and bring them to market faster.


Please get your "quote" correct -- I didn't say that!!!!!

This is what you wrote in answer to Sooner787 in post #3:
BoeingGuy wrote:
Sooner787 wrote:
I know there are some MAX customers that have yet to take delivery of their new jets ,
Alaska for instance..... Might AS decide to cancel their MAX orders , especially since they
now have A321NEOS on property. I would also guess Lion Air might be reconsidering
their Max order book as well.


Isn’t that a little overly dramatic and childish? Airplane accidents have unfortunately occurred since the beginning of time. What, do you think every airline has cancelled orders for every model that’s had an accident? So I guess all A330 orders should be cancelled too?


Looks identical!?
Murphy is an optimist
 
salttee
Posts: 3149
Joined: Wed Jul 13, 2016 3:26 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:31 pm

7BOEING7 and BoeingGuy are two different people.
 
User avatar
zeke
Posts: 13697
Joined: Thu Dec 14, 2006 1:42 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:35 pm

7BOEING7 wrote:
I was on topic, we're discussing information that was left out of the FCOM and I was pointing out it happens to everybody.

If the A320 documentation on alpha protection was adequate the NTSB wouldn't have recommended better documentation.

"The investigation also found that Airbus' training curricula did not contain information on the effects of alpha-protection-mode features that might affect the airplane's response to pilot sidestick pitch inputs."

Sullenberger wasn't reacting to a GPWS or windshear, he was trying to ditch an airplane -- entirely different operation.


You are making grand sweeping statements that are nothing more than your opinion and presenting them as facts. Your opinions are not factually correct here. It does not "happen to everybody", stop trying to point the finger at every other manufacturer to deflect this deficiency away from where it rests with this system on the 737MAX. When I went from the 747 classic to the 744 I saw a massive reduction in the detail of information that was made available to the crew. I just checked an old version of the A320 FCOM 1 and FM books comes in 1624 pages, the 737NG 1257 pages. The 787 Systems description is 1233 pages, the A350 4032 pages. You said "The philosophy for many, many years (30+) has been for manufacturers to not tell the pilots every little detail like in the old days", clearly the amount of information that can be conveyed in 4000 pages is not what is conveyed in 1200 pages. After the Asiana accident in SFO I went to read up on the 777 autothrottle, I was very surprised the FCOM only had half a page to describe the whole system. That is a complex system with many automatic features which is not disclosed to the crew.

I do not know what "Airbus' training curricula" the NTSB is referring to with that particular comment, the FCOM and FCTM does, see the high angle of attack protect on 1.27.20 P4 http://www.smartcockpit.com/docs/A320-F ... ntrols.pdf and FCTM page 01.0202 Page 11 http://www.smartcockpit.com/docs/FCTM_A318_to_A321.pdf

The NTSB report also did say the aircraft was achieving the best performance for the weight and configuration, pitching up further would only reduce performance, any further increase in pitch attitude would have just increased rate of descent and reduced glide performance.

"HIGH ANGLE OF ATTACK PROTECTION

Under normal law, when the angle of attack becomes greater than aprot, the system switches elevator control from normal mode to a protection mode, in which the angle of attack is proportional to sidestick deflection. That is, in the aprot range, from a prot to amax, the sidestick commands a directly. However, the angle of attack will not exceed amax, even if the pilot gently pulls the sidestick all the way back. If the pilot releases the sidestick, the angle of attack returns to aprot and stays there. This protection against stall and windshear has priority over all other protections. The autopilot disconnects at a prot + 1°."

"HIGH ANGLE-OF-ATTACK (AOA) PROTECTION
High AOA protection enables the PF to pull the sidestick full aft in dangerous situations, and thus consistently achieve the best possible aircraft lift. This action on the sidestick is instinctive, and the high AOA protection minimizes the risk of stalls or control loss. High AOA protection is an aerodynamic protection:
. The PF will notice if the normal flight envelope is exceeded for any reason, because the autopitch trim will stop, the aircraft will sink to maintain its current AOA (alpha PROT, strong static stability), and a significant change in aircraft behavior will occur.
. If the PF then pulls the sidestick full aft, a maximum AOA (approximately corresponding to CL Max) is commanded. In addition, the speedbrakes will automatically retract, if extended."
Human rights lawyers are "ambulance chasers of the very worst kind.'" - Sky News
 
User avatar
7BOEING7
Posts: 3017
Joined: Fri Oct 12, 2012 5:28 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:36 pm

salttee wrote:
7BOEING7 and BoeingGuy are two different people.


My fault, sorry
 
User avatar
longhauler
Posts: 6249
Joined: Sat Mar 06, 2004 12:00 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 9:47 pm

brindabella wrote:
"Please read Post #15".

The stab-trim ran-away.

THAT IS WHAT YOU DO!

And that drill was taught and practised in the simulator quite often when I flew the 737-200, 30 years ago!.

Looking at the MAX drills, I see it hasn't changed. It is very simple ... if the aircraft is not doing what you want, then make it do what you want and shut everything off as you do it! (Same thing on the Airbus, btw).

In day VFR conditions, this should have been a very simple exercise. So ... it makes me think that during recent events, there was more going on than just elevator trim issues.
Just because I stopped arguing, doesn't mean I think you are right. It just means I gave up!
 
kalvado
Posts: 1783
Joined: Wed Mar 01, 2006 4:29 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Thu Nov 15, 2018 10:01 pm

longhauler wrote:
brindabella wrote:
"Please read Post #15".

The stab-trim ran-away.

THAT IS WHAT YOU DO!

And that drill was taught and practised in the simulator quite often when I flew the 737-200, 30 years ago!.

Looking at the MAX drills, I see it hasn't changed. It is very simple ... if the aircraft is not doing what you want, then make it do what you want and shut everything off as you do it! (Same thing on the Airbus, btw).

In day VFR conditions, this should have been a very simple exercise. So ... it makes me think that during recent events, there was more going on than just elevator trim issues.

It is one of big sticking point here - with MCAS you cannot make things go your way before shutting off a few things.
As for extras... I for MCAS to kick in, plane has to be flown manually - not on autopilot; loss of airspeed data seems to be the reason.
 
neutronstar73
Posts: 792
Joined: Mon Mar 21, 2011 7:57 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Fri Nov 16, 2018 3:47 am

scbriml wrote:
spacecadet wrote:
The solution? Disclose it and put it in the manual. That's it. And half of that is already done.


Easy, eh?

Shame about all those dead bodies floating in the sea before this came to light.


Like AF447, right? Shame about all those dead bodies at the hands of Airbus.
 
User avatar
CLTRampRat
Posts: 154
Joined: Mon Sep 10, 2018 12:42 am

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Fri Nov 16, 2018 4:18 am

Rumor has it that Southwest is in the process of working the automatic dive feature into their landing procedures.
 
BoeingGuy
Posts: 6257
Joined: Fri Dec 10, 2010 6:01 pm

Re: Boeing’s automatic trim for the 737 MAX was not disclosed to the Pilots

Fri Nov 16, 2018 4:37 am

CLTRampRat wrote:
Rumor has it that Southwest is in the process of working the automatic dive feature into their landing procedures.


There’s no such thing as an automatic dive fearture. There is a feature that is supposed to aid in stall prevention and recovery.

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos