hivue wrote:

trnswrld wrote:

danj555 wrote:

Couldn't the pilots in any case of malfunction just turn off all electronic bs? Like you're a pilot. You know how to fly a plane. You have flown thousands of take-offs. You know the right speed, right angle, right altitude. You know how to do it without electronic interference if need be.

So why not hit the kill switch if the computer is having a fit?

I asked this exact question many pages ago. It got pretty much no response. Big problems in IMC is one thing, but to not be able to fly an airplane in clear blue VMC daylight conditions just baffles me....computer issues or not. How does this happen? Look out the window.....fly the airplane FIRST, then figure what the heck is going on. I know easier said than done.

Killing all computers operating on an airplane would have the same effect as killing all computer chips that are operating in your car while you're driving (assuming you are not driving a Stone Age car).

WIederling wrote:

dtw2hyd wrote:

This is a case of computer thinks it knows better than humans, which is historical with stall handing,

Also, everyone claims pilots need to flip two cut-off switches and they are good. Did anyone test this theory with MAX/MCAS (or) just based on runaway stab procedures?

There is no AI in safety critical computers.( at least not yet.)
Even heuristics are probably frowned on.
AI would result in action from stimulus being unpredictable.

MCAS acting on false input is not stab runaway.
Stab runaway is defined as continuous activation of trim in one direction
going by what has been posted here. like stuck contacts on a relay.

Interested wrote:

osiris30 wrote:

Interested wrote:

Until this week I would have blindly trusted every new Boeing plane in operation to be perfectly safe. I would only be worried about bird strikes and terrorists. Now if I was on a max plane I would want to sit near the front ready to remind the pilots of lion and Ethiopia issues if anything weird happened on takeoff!

Well, there is no reason for you to change your behavior. Even as a fan of Boeing's products I will be the first to admit there have been some critical flaws (every aircraft ever has had them, sometimes they manifest in accidents, other times incidents) and they get worked out over time. Remember the jackscrew issue with the 737. Fuel tank inerting problems (all types). Wiring issues leading to fires (all types at that time period), Dc 10 issues. More than a few gremlins in Airbus's computers over the years. 99% of the time the pilots flying deal with these issues and they get reported and fixed. Sometimes things go wrong. Even Concorde it could be argued had critical flaws (despite being an absolute marvel of engineering ESPECIALLY given when it was built). Dash 8s had wonky landing gear issues for a while. I mean the list is pretty much endless and that is the stuff we KNOW was fixed. All the stuff that was fixed silently would likely fill volumes.

People acting like this is a unique thing are forgetting their history.

It's a different world in 2019 though don't you think?

Health and safety rules. Any of my staff have any kind of accident at work I have to report it and do something to stop it happening again. I can't have them carry on working with the same risk in place? Whikst I spend 4 months trying to figure out what to do different?

I could get prosecuted and lose my business if if I did.

And that's me a small business owner. This is Boeing in 2019.

Interested wrote:

osiris30 wrote:

ikramerica wrote:

Are they retracting flaps with net elevation less than 1000 feet? So the initial loss of control isn't MCAS.

Now, after a minute or two, the pilot asks to continue "normal" (not sure who's words) climb out to 14,000. One might assume he has flaps retracted then? So maybe it's then that MCAS comes on? But he's very low and something is preventing climb. He's also very fast because all the high thrust setting is going forward (and down when they pitch down) rather than into the climb.

Still want a commercial jet pilot's take on this:

If you are below 1000 feet from the ground, is it safe to bank a fully functioning aircraft for a 180 return to the airfield? Is it safe when your aircraft is acting like a petulant child and you don't know why?

The aircraft wasn't climbing despite more than enough airspeed, ostensibly flaps and everything else. This tells me the AC was out of trim before it left the ground. It makes me think that the previous crew disabled auto-trim and this crew never even turned it on, until possibly way too late.

As time has gone on I have continued to flesh out what *I* feel the chain of events is and to my mind now it starts before the take-off roll:

1) Either on prior flight or before commencing this flight; pilots of last flight or this flight disable MCAS as a precatuion (stab cut-off)
2) PIlots of this flight miss (or knew it was off), but fail to trim plane correctly.
3) Take off roll starts. IAS is broken.
4) Pilots attempt to rotate too early based on broken IAS. Nose comes off by AC doesn't unstick from the ground until 160kts (FR24 data). This is pretty high for a max IIRC.
5) Aircraft won't climb (bad trim). Pilots apply more pressure.
6a) Pilots fight with AC while continuing to increase speed to dangerous levels (no one watching the GPS ground speed). Cockpit is FULL of alarms at this point.
6b) Someone withdraws flaps during this time (or they come clean off depending on the extent of deployment, but probably the first option)
7) More time passes
8a) Someone in the cockpit notices the auto-trim is off and flips it on. Manual trim should have been used but for whatever reason wasn't (pilot may have thought they were fighting MCAS the entire time and they weren't).
8b) MCAS or autotrim (it could be either) kick in
(OR)
8a) Pilots notice trim is out and trim the AC the wrong way in error. At that altitude and speed it does not take much to cause really bad things to happen.

everything up to 7 is pretty solid in my mind based on the data we have (1/2 are obvious extrapolations of how it starts). 8 is obviously conjecture.

Which of the above (if any) are caused by software failings?

CO953 wrote:

osiris30 wrote:

[...snip......]

People acting like this is a unique thing are forgetting their history.

I would respectfully submit that this is the first new aircraft type that repeatedly tries to commit suicide by diving toward the ground at low altitude.

ikramerica wrote:

osiris30 wrote:

ikramerica wrote:

Are they retracting flaps with net elevation less than 1000 feet? So the initial loss of control isn't MCAS.

Now, after a minute or two, the pilot asks to continue "normal" (not sure who's words) climb out to 14,000. One might assume he has flaps retracted then? So maybe it's then that MCAS comes on? But he's very low and something is preventing climb. He's also very fast because all the high thrust setting is going forward (and down when they pitch down) rather than into the climb.

Still want a commercial jet pilot's take on this:

If you are below 1000 feet from the ground, is it safe to bank a fully functioning aircraft for a 180 return to the airfield? Is it safe when your aircraft is acting like a petulant child and you don't know why?

The aircraft wasn't climbing despite more than enough airspeed, ostensibly flaps and everything else. This tells me the AC was out of trim before it left the ground. It makes me think that the previous crew disabled auto-trim and this crew never even turned it on, until possibly way too late.

As time has gone on I have continued to flesh out what *I* feel the chain of events is and to my mind now it starts before the take-off roll:

1) Either on prior flight or before commencing this flight; pilots of last flight or this flight disable MCAS as a precatuion (stab cut-off)
2) PIlots of this flight miss (or knew it was off), but fail to trim plane correctly.
3) Take off roll starts. IAS is broken.
4) Pilots attempt to rotate too early based on broken IAS. Nose comes off by AC doesn't unstick from the ground until 160kts (FR24 data). This is pretty high for a max IIRC.
5) Aircraft won't climb (bad trim). Pilots apply more pressure.
6a) Pilots fight with AC while continuing to increase speed to dangerous levels (no one watching the GPS ground speed). Cockpit is FULL of alarms at this point.
6b) Someone withdraws flaps during this time (or they come clean off depending on the extent of deployment, but probably the first option)
7) More time passes
8a) Someone in the cockpit notices the auto-trim is off and flips it on. Manual trim should have been used but for whatever reason wasn't (pilot may have thought they were fighting MCAS the entire time and they weren't).
8b) MCAS or autotrim (it could be either) kick in
(OR)
8a) Pilots notice trim is out and trim the AC the wrong way in error. At that altitude and speed it does not take much to cause really bad things to happen.

everything up to 7 is pretty solid in my mind based on the data we have (1/2 are obvious extrapolations of how it starts). 8 is obviously conjecture.

I hope that's not the cause. It would, however, match with what I think two of the main failure modes of the Lion air crash was:
1. lack of transfer of knowledge from the previous flight crew to the next. Not informing the fateful crew what the previous crew turned on/off and why.
2. lack of information provided by Boeing/Aircraft that something isn't working right, a safety mechanism is activating, something is disable, etc.

And number 2 seems to me is a broader issue of the 737NG as well, just not showing itself because the implications have YET to lead to a crash. I'm sure in the history of the 737NG there have been many incidents where the crew was not aware of some issues with the aircraft that were impacting flight control, and the aircraft wasn't designed to make them aware, but crashes didn't ensue, just white knuckles and dirty knickers.

rideforever wrote:

Too much ? Too greedy ? Was it done without the careful process in the original selection ?

airkas1 wrote:

Work on the FDR has started.
https://twitter.com/bea_aero/status/110 ... 87361?s=21

osiris30 wrote:

Interested wrote:

osiris30 wrote:

Well, there is no reason for you to change your behavior. Even as a fan of Boeing's products I will be the first to admit there have been some critical flaws (every aircraft ever has had them, sometimes they manifest in accidents, other times incidents) and they get worked out over time. Remember the jackscrew issue with the 737. Fuel tank inerting problems (all types). Wiring issues leading to fires (all types at that time period), Dc 10 issues. More than a few gremlins in Airbus's computers over the years. 99% of the time the pilots flying deal with these issues and they get reported and fixed. Sometimes things go wrong. Even Concorde it could be argued had critical flaws (despite being an absolute marvel of engineering ESPECIALLY given when it was built). Dash 8s had wonky landing gear issues for a while. I mean the list is pretty much endless and that is the stuff we KNOW was fixed. All the stuff that was fixed silently would likely fill volumes.

People acting like this is a unique thing are forgetting their history.

It's a different world in 2019 though don't you think?

Health and safety rules. Any of my staff have any kind of accident at work I have to report it and do something to stop it happening again. I can't have them carry on working with the same risk in place? Whikst I spend 4 months trying to figure out what to do different?

I could get prosecuted and lose my business if if I did.

And that's me a small business owner. This is Boeing in 2019.

While I get it, but also; what is your point? It is 2019, yes. Mistakes will still happen and things will have unintended consequences. We can think we have somehow gotten magically better and things don't go wrong anymore and people and processes don't miss things but guess what; aerospace is f***ing hard, and things ARE going to be missed. All the legislation, whatif'ing, wishing, etc., will not change that things will go wrong. Physics itself says you cannot possibly have a perfect system. Not that any of this replaces the lives lost or is in any way an excuse for the loss of life, but I won't delude myself into thinking we are somehow less fallible than we were 20-30 years ago. The only difference is the level of arrogance has increased many-fold to the point where we THINK we are so much better than we used to be.

Interested wrote:

osiris30 wrote:

Interested wrote:

It's a different world in 2019 though don't you think?

Health and safety rules. Any of my staff have any kind of accident at work I have to report it and do something to stop it happening again. I can't have them carry on working with the same risk in place? Whikst I spend 4 months trying to figure out what to do different?

I could get prosecuted and lose my business if if I did.

And that's me a small business owner. This is Boeing in 2019.

While I get it, but also; what is your point? It is 2019, yes. Mistakes will still happen and things will have unintended consequences. We can think we have somehow gotten magically better and things don't go wrong anymore and people and processes don't miss things but guess what; aerospace is f***ing hard, and things ARE going to be missed. All the legislation, whatif'ing, wishing, etc., will not change that things will go wrong. Physics itself says you cannot possibly have a perfect system. Not that any of this replaces the lives lost or is in any way an excuse for the loss of life, but I won't delude myself into thinking we are somehow less fallible than we were 20-30 years ago. The only difference is the level of arrogance has increased many-fold to the point where we THINK we are so much better than we used to be.

My point is once the first accident happened and that Boeing knew the plane wasn't safe and they needed to upgrade the software they should have not flown again until it was fixed

I accept there will always be faults even in this day and age. But once you identify the risks with health and safety you HAVE to address them. This wasn't a minor fault with minor consequences they identified in November.

osiris30 wrote:

rideforever wrote:

Too much ? Too greedy ? Was it done without the careful process in the original selection ?

Too simplistic a view of it. Engineers looked at it and felt they could go larger. MAYBE the made an error, maybe they didn't. Maybe whatever is plaguing the Max right now will be fixed and the plane will go 20 years and 1000s of copies without another incident.

osiris30 wrote:

airkas1 wrote:

Work on the FDR has started.
https://twitter.com/bea_aero/status/110 ... 87361?s=21

Also note the attendees are EXACTLY as predicted they would be for all the people worrying about governmental interference ... sigh... luckily the industry is far more professional than our posters.

VS11 wrote:

MCAS may have its issues and like all software it is work in progress

mcdu wrote:

You won’t see pilots operating at those speeds normally. First of all in the USA and many other places the limit is 250kts below 10k.

SheikhDjibouti wrote:

That is an ATC restriction, and nothing to do with aircraft structural issues.
The 250kt limit would apply to a Piper Malibu just as it would apply to Concorde (if it was still flying)
..
Is there nobody here with actual verifiable figures from Boeing?

mcdu wrote:

But no one flies around at the barber pole even when allowed (offshore). If you are on the barber pole there is no margin if you hit a bump and causes a momentary overspeed. That is a required maintenance inspection when you land. Also it is terrible inefficient to fly on like that.

osiris30 wrote:

At 380kts at 8600' alt, the aircraft was definitely in a 'severe overspeed' condition. That is a speed that can incur structural failure unless managed very well.

BaconButty wrote:

osiris30 wrote:

airkas1 wrote:

Work on the FDR has started.
https://twitter.com/bea_aero/status/110 ... 87361?s=21

Also note the attendees are EXACTLY as predicted they would be for all the people worrying about governmental interference ... sigh... luckily the industry is far more professional than our posters.

Of course - that's all set out by ICAO annex 13. But by sending the FDR to France, it enabled another party to be present. Dress it up how you like, but this was a symptom of distrust in the US authorities - whether warranted or not.

WIederling wrote:

VS11 wrote:

MCAS may have its issues and like all software it is work in progress

Outch, Outch, Outch.
This is not "beta test by user" stuff from Microsoft.
This is a qualitycontrolled certfied piece of software. ( at least that is the requirement.)

and small chance that this is due to bad production sensors.
much higher chance this is from bad design software.

SheikhDjibouti wrote:

mcdu wrote:

You won’t see pilots operating at those speeds normally. First of all in the USA and many other places the limit is 250kts below 10k.

SheikhDjibouti wrote:

That is an ATC restriction, and nothing to do with aircraft structural issues.
The 250kt limit would apply to a Piper Malibu just as it would apply to Concorde (if it was still flying)
..
Is there nobody here with actual verifiable figures from Boeing?

mcdu wrote:

But no one flies around at the barber pole even when allowed (offshore). If you are on the barber pole there is no margin if you hit a bump and causes a momentary overspeed. That is a required maintenance inspection when you land. Also it is terrible inefficient to fly on like that.

Absolutely correct. But that wasn't my point, so your reply whilst mildly interesting, is irrelevant.

In your haste to show my logic as faulty, you have somehow managed to isolate my response, totally ignoring the context and the original comment.
Here it is one more time.

osiris30 wrote:

At 380kts at 8600' alt, the aircraft was definitely in a 'severe overspeed' condition. That is a speed that can incur structural failure unless managed very well.

Neither Osiris30 nor myself were suggesting flying at (or near, or beyond) Vmo was a smart thing to do. Or "normal" procedure.
ET302 found themselves at high speed (381 kts has been quoted), but was it "severe overspeed"?
Osiris30 says it is (severe overspeed)

I still, after all this time, would like some source to confirm that.
Did the pilots of ET302 damage the plane simply by flying too fast, too low.
It is not an unreasonable question.

And it should be a simple matter to confirm, except here we are still dancing around.

Perhaps the actual answer doesn't suit somebody's agenda...

osiris30 wrote:

Interested wrote:

osiris30 wrote:

While I get it, but also; what is your point? It is 2019, yes. Mistakes will still happen and things will have unintended consequences. We can think we have somehow gotten magically better and things don't go wrong anymore and people and processes don't miss things but guess what; aerospace is f***ing hard, and things ARE going to be missed. All the legislation, whatif'ing, wishing, etc., will not change that things will go wrong. Physics itself says you cannot possibly have a perfect system. Not that any of this replaces the lives lost or is in any way an excuse for the loss of life, but I won't delude myself into thinking we are somehow less fallible than we were 20-30 years ago. The only difference is the level of arrogance has increased many-fold to the point where we THINK we are so much better than we used to be.

My point is once the first accident happened and that Boeing knew the plane wasn't safe and they needed to upgrade the software they should have not flown again until it was fixed

I accept there will always be faults even in this day and age. But once you identify the risks with health and safety you HAVE to address them. This wasn't a minor fault with minor consequences they identified in November.

False assumption there; you are assuming Boeing "knew the plane wasn't safe". That is a false statement. Boeing knew there could be IMPROVEMENTS made. Just because something isn't perfect doesn't mean it is unsafe.

WIederling wrote:

VS11 wrote:

MCAS may have its issues and like all software it is work in progress

Outch, Outch, Outch.
This is not "beta test by user" stuff from Microsoft.
This is a qualitycontrolled certfied piece of software. ( at least that is the requirement.)

and small chance that this is due to bad production sensors.
much higher chance this is from bad design software.

N14AZ wrote:

osiris30 wrote:

Interested wrote:

My point is once the first accident happened and that Boeing knew the plane wasn't safe and they needed to upgrade the software they should have not flown again until it was fixed

I accept there will always be faults even in this day and age. But once you identify the risks with health and safety you HAVE to address them. This wasn't a minor fault with minor consequences they identified in November.

False assumption there; you are assuming Boeing "knew the plane wasn't safe". That is a false statement. Boeing knew there could be IMPROVEMENTS made. Just because something isn't perfect doesn't mean it is unsafe.

Wow, I really hope no one of the ET crash victim’s families will read this statement.

VS11 wrote:

WIederling wrote:

VS11 wrote:

MCAS may have its issues and like all software it is work in progress

Outch, Outch, Outch.
This is not "beta test by user" stuff from Microsoft.
This is a qualitycontrolled certfied piece of software. ( at least that is the requirement.)

and small chance that this is due to bad production sensors.
much higher chance this is from bad design software.

But the root cause for Lion jet was a faulty indicator that triggered MCAS, no? Where is the quality control in that? I am not downplaying the contributing factor of MCAS and all the associated shortcomings of it but let’s not forget it was not the root cause .

ikramerica wrote:

hivue wrote:

Killing all computers operating on an airplane would have the same effect as killing all computer chips that are operating in your car while you're driving (assuming you are not driving a Stone Age car).

My car would shut off, the steering would lock, the brakes would not work (other than the parking brake) and I'd be in trouble. My wife's car, even the e-brake wouldn't work.

osiris30 wrote:

N14AZ wrote:

osiris30 wrote:

False assumption there; you are assuming Boeing "knew the plane wasn't safe". That is a false statement. Boeing knew there could be IMPROVEMENTS made. Just because something isn't perfect doesn't mean it is unsafe.

Wow, I really hope no one of the ET crash victim’s families will read this statement.

Why? Because it is logical. Good grief. Everyone is falling all over themselves. This thread is discussing an accident. Accidents need to be dissected in a logical manner, not an emotional one. Emotional dissections lead to biases. Biases lead to erroneous decisions and data favoring. The families of the people on BOTH ET and JT flights have my most sincere condolences, as do the families of the folks on the Atlas '67, as do the families of the folks in NZ this morning. Condolences don't do jack squat to make anything safer or better. Calling out a false assumption is not some horrible heartless act as much as people here like to think it is when they climb aboard their trusty tall steed of moral righteousness.

The statement is 100% true because: There is NOT ONE single piece of man-made equipment on the planet that is PERFECT. Every aircraft has errors, so does every car, building, bridge, toaster, fridge, stove, lightbulb, etc. It does NOT (in and of itself) make them unsafe. If you can't grasp that, perhaps this thread isn't the one for you. The poster I was replying to was conflating imperfection with unsafe. That was and still is a false assumption and I called them on it.

SheikhDjibouti wrote:

Neither Osiris30 nor myself were suggesting flying at (or near, or beyond) Vmo was a smart thing to do. Or "normal" procedure.
ET302 found themselves at high speed (381 kts has been quoted), but was it "severe overspeed"?
Osiris30 says it is (severe overspeed)

I still, after all this time, would like some source to confirm that.
Did the pilots of ET302 damage the plane simply by flying too fast, too low.
It is not an unreasonable question.

And it should be a simple matter to confirm, except here we are still dancing around.

Perhaps the actual answer doesn't suit somebody's agenda...

VS11 wrote:

But the root cause for Lion jet was a faulty indicator that triggered MCAS, no?

osiris30 wrote:

The statement is 100% true because: There is NOT ONE single piece of man-made equipment on the planet that is PERFECT. Every aircraft has errors, so does every car, building, bridge, toaster, fridge, stove, lightbulb, etc. It does NOT (in and of itself) make them unsafe. If you can't grasp that, perhaps this thread isn't the one for you. The poster I was replying to was conflating imperfection with unsafe. That was and still is a false assumption and I called them on it.

chicawgo wrote:

SomebodyInTLS wrote:

dragon6172 wrote:

The Lion Air crew prior to the accident flight tested this procedure and it worked as advertised.

You forgot to add "by luck"! They had no idea what was going on but happened to guess correctly that trim could be involved. THERE WAS NO PROCEDURE.

Just absolutely spreading lies. They didn't just blindly guess. They made an educated decision based on experience and the situation. The trim was running wild so they cut the auto trim switches.

osiris30 wrote:

At 380kts at 8600' alt, the aircraft was definitely in a 'severe overspeed' condition. That is a speed that can incur structural failure unless managed very well.

SheikhDjibouti wrote:

Neither Osiris30 nor myself were suggesting flying at (or near, or beyond) Vmo was a smart thing to do. Or "normal" procedure.
ET302 found themselves at high speed (381 kts has been quoted), but was it "severe overspeed"?
Osiris30 says it is (severe overspeed)

I still, after all this time, would like some source to confirm that.
Did the pilots of ET302 damage the plane simply by flying too fast, too low.
It is not an unreasonable question.

osiris30 wrote:

The maximum permitted speed of most models of B737 is 340 knots CAS (Calibrated Airspeed) or Mach 0.82, whichever is slower. (Ref: Detailed Technical Data ).

Edit: This flight was doing approximately: 350kias airspeed when the FR data cut out. based on 380kt ground speed, 1.12 scaling factor for air density and 10kt head wind.

SheikhDjibouti wrote:

osiris30 wrote:

At 380kts at 8600' alt, the aircraft was definitely in a 'severe overspeed' condition. That is a speed that can incur structural failure unless managed very well.

SheikhDjibouti wrote:

Neither Osiris30 nor myself were suggesting flying at (or near, or beyond) Vmo was a smart thing to do. Or "normal" procedure.
ET302 found themselves at high speed (381 kts has been quoted), but was it "severe overspeed"?
Osiris30 says it is (severe overspeed)

I still, after all this time, would like some source to confirm that.
Did the pilots of ET302 damage the plane simply by flying too fast, too low.
It is not an unreasonable question.

osiris30 wrote:

The maximum permitted speed of most models of B737 is 340 knots CAS (Calibrated Airspeed) or Mach 0.82, whichever is slower. (Ref: Detailed Technical Data ).

Edit: This flight was doing approximately: 350kias airspeed when the FR data cut out. based on 380kt ground speed, 1.12 scaling factor for air density and 10kt head wind.

Brilliant!
And thank you.

350kias in perfect conditions is probably ok. It would warrant a ground-check afterwards, much as a heavy landing requires.

But 350kias whilst riding a rollercoaster may have twisted or warped some surfaces.

I'll leave it to others to take it from here.

dragon6172 wrote:

SheikhDjibouti wrote:

ET302 found themselves at high speed (381 kts has been quoted), but was it "severe overspeed"?
Osiris30 says it is (severe overspeed)

Did the pilots of ET302 damage the plane simply by flying too fast, too low.
It is not an unreasonable question.

Vmo 340 knots or 0.82 mach. They were not high enough to be near the mach limit, so 340 knots would be the limit. As for "severe"? Not sure without seeing maintenance manual required inspections. Sometimes overspeeds of up to 10 knots just need a logbook entry, higher speeds may have inspection criteria, etc.

All that being said, in the below linked incident a 737 reached 429 knots at 5600 feet in a dive (according to FDR) and there was no damage to the aircraft
https://assets.publishing.service.gov.u ... _09-10.pdf

VS11 wrote:

WIederling wrote:

VS11 wrote:

MCAS may have its issues and like all software it is work in progress

Outch, Outch, Outch.
This is not "beta test by user" stuff from Microsoft.
This is a qualitycontrolled certfied piece of software. ( at least that is the requirement.)

and small chance that this is due to bad production sensors.
much higher chance this is from bad design software.

But the root cause for Lion jet was a faulty indicator that triggered MCAS, no? Where is the quality control in that? I am not downplaying the contributing factor of MCAS and all the associated shortcomings of it but let’s not forget it was not the root cause .

SomebodyInTLS wrote:

Unlike what dragon6172 says; there was no runaway trim, therefore the fact they followed that checklist based - indeed - on an educated decision is lucky... SINCE THERE WAS NO PROCEDURE TO OVERRIDE MCAS. (Nor did they even know of the existence of MCAS or what it does.)

I'm sorry if that fact offends you, but it is what it is.

osiris30 wrote:

If MCAS just shouted 'I AM DOING STUFF' all this would be squarely pilot error.

SomebodyInTLS wrote:

chicawgo wrote:

SomebodyInTLS wrote:

You forgot to add "by luck"! They had no idea what was going on but happened to guess correctly that trim could be involved. THERE WAS NO PROCEDURE.

Just absolutely spreading lies. They didn't just blindly guess. They made an educated decision based on experience and the situation. The trim was running wild so they cut the auto trim switches.

No, you and dragon6172 would like me to have interpreted it as blind guess but that's not at all what I said. I wish people wouldn't be so partisan.

Unlike what dragon6172 says; there was no runaway trim, therefore the fact they followed that checklist based - indeed - on an educated decision is lucky... SINCE THERE WAS NO PROCEDURE TO OVERRIDE MCAS. (Nor did they even know of the existence of MCAS or what it does.)

I'm sorry if that fact offends you, but it is what it is.

flyingturtle wrote:

osiris30 wrote:

If MCAS just shouted 'I AM DOING STUFF' all this would be squarely pilot error.

When MCAS is active, then the crew must trust it's doing the right thing.

Given two deadly crashes, an announcement like "I AM DOING STUFF" will just make the pilots do the Runaway Trim Procedure.


David

osiris30 wrote:

flyingturtle wrote:

osiris30 wrote:

If MCAS just shouted 'I AM DOING STUFF' all this would be squarely pilot error.

When MCAS is active, then the crew must trust it's doing the right thing.

Given two deadly crashes, an announcement like "I AM DOING STUFF" will just make the pilots do the Runaway Trim Procedure.

David

MCAS should never be active frankly. It is only designed to be a corner case 'you are about to stall the plane idiot' type of system. If MCAS goes active during normal parts of flight they probably SHOULD be running that procedure.

estorilm wrote:

For 50 years, normal stall recovery procedures were perfectly adequate on prior aircraft, even when it came time to certify the NG. For some reason, that's not the case with the MAX. It's not really a "feature" Boeing added as an upgrade with the new plane or something - it's a requirement for certification.

Jetty wrote:

Chemist wrote:

If they had problems almost immediately after takeoff, then would MCAS be the issue? MCAS doesn't go into effect until flaps are retracted.

It shouldn’t go into effect until flaps are retracted. That doesn’t mean it doesn’t go into effect until flaps are retracted. From the Lion Air crash we know it has gone into effect when it shouldn’t before and there’s no way of knowing if this is isolated to one specific set of circumstances or an wider issue.

cat3appr50 wrote:

In response to post #2340
Regarding the Lion Air JT610 accident flight, at 23:22:05 UTC, the DFDR recorded the aircraft altitude was approximately 2,150 feet and the flaps were retracted. After the flaps reached 0, the DFDR recorded automatic aircraft nose down (AND) trim active for 10 seconds followed by flight crew commanded aircraft nose up (ANU) trim. MCAS was not activated on this flight until the flaps were up.

Trin wrote:

If MCAS "should never be active frankly", why did Boeing bake it in to the MAX in such a way that it:

1. Can be activated at any altitude;
2. Relies only on one point of data that has no redundancy;
3. Can overrride pilot input repeatedly to the point of increasing control surface forces to the point of making the plane difficult to control;
4. Is required in order to get certification for the new type to operate legally.

I realize at this point I am poking someone who is already triggered into yet another response.....but somewhere deep down I really do want to know your opinions to those points.

Finn350 wrote:

Based on the current information, the defective AoA vane is definitely a contributing factor.

Trin wrote:

osiris30 wrote:

flyingturtle wrote:

When MCAS is active, then the crew must trust it's doing the right thing.

Given two deadly crashes, an announcement like "I AM DOING STUFF" will just make the pilots do the Runaway Trim Procedure.

David

MCAS should never be active frankly. It is only designed to be a corner case 'you are about to stall the plane idiot' type of system. If MCAS goes active during normal parts of flight they probably SHOULD be running that procedure.

If MCAS "should never be active frankly", why did Boeing bake it in to the MAX in such a way that it:

1. Can be activated at any altitude;
2. Relies only on one point of data that has no redundancy;
3. Can overrride pilot input repeatedly to the point of increasing control surface forces to the point of making the plane difficult to control;
4. Is required in order to get certification for the new type to operate legally.

I realize at this point I am poking someone who is already triggered into yet another response.....but somewhere deep down I really do want to know your opinions to those points.

flyingturtle wrote:

osiris30 wrote:

If MCAS just shouted 'I AM DOING STUFF' all this would be squarely pilot error.

When MCAS is active, then the crew must trust it's doing the right thing.

Given two deadly crashes, an announcement like "I AM DOING STUFF" will just make the pilots do the Runaway Trim Procedure.
David

WIederling wrote:

Finn350 wrote:

Based on the current information, the defective AoA vane is definitely a contributing factor.

don't make things simpler than they are.

What we know is that one downstream AoA value was wrong ( #1 showing offset vs .#2)
AoA sensors, other sensors -> ADIRU -> downstream sinks ( for air data sets ).
The initially replaced "defective" AoA is said to have been ok in a bench test aftewards !?

hivue wrote:

trnswrld wrote:

danj555 wrote:

Couldn't the pilots in any case of malfunction just turn off all electronic bs? Like you're a pilot. You know how to fly a plane. You have flown thousands of take-offs. You know the right speed, right angle, right altitude. You know how to do it without electronic interference if need be.

So why not hit the kill switch if the computer is having a fit?

I asked this exact question many pages ago. It got pretty much no response. Big problems in IMC is one thing, but to not be able to fly an airplane in clear blue VMC daylight conditions just baffles me....computer issues or not. How does this happen? Look out the window.....fly the airplane FIRST, then figure what the heck is going on. I know easier said than done.

Killing all computers operating on an airplane would have the same effect as killing all computer chips that are operating in your car while you're driving (assuming you are not driving a Stone Age car).

ikramerica wrote:

hivue wrote:

trnswrld wrote:

I asked this exact question many pages ago. It got pretty much no response. Big problems in IMC is one thing, but to not be able to fly an airplane in clear blue VMC daylight conditions just baffles me....computer issues or not. How does this happen? Look out the window.....fly the airplane FIRST, then figure what the heck is going on. I know easier said than done.

Killing all computers operating on an airplane would have the same effect as killing all computer chips that are operating in your car while you're driving (assuming you are not driving a Stone Age car).

My car would shut off, the steering would lock, the brakes would not work (other than the parking brake) and I'd be in trouble. My wife's car, even the e-brake wouldn't work.