Noshow
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 11:09 am

A second AoA sensor IS onboard as we speak.
Currently they are used alternating in the future their measurements will be compared before triggering MCAS.
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 2:55 pm

Dutchy wrote:
FluidFlow wrote:


Still no timeline. Boeing might still be a bit optimistic for the return of the MAX. Will the authorities demand there will be a second AoA sensor on board? Or will it just be a software update, the latter is much easier to implement of course. And some extra training after this for the aircrew. If so, this will push the return into service to September / October at the earliest.

If the authorities were going to require anything beyond software they'd have told Boeing by now. This isn't like a defendant waiting for the jury to reach a verdict. From all reports, the unknown is what additional training is needed before pilots can fly it again.
 
OldAeroGuy
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 2:58 pm

chiad wrote:
I haven' read all the posts here so I don't know if anyone has linked this already about "Could US pilots have saved the 737 MAX8 ?"
https://www.youtube.com/watch?v=ZtHBz2-YpWE


Thanks, but already posted.

Of course, the simulation starts with the horizontal stabilizer electric motor switched off with the airplane out of trim.

It would be interesting to see what would have happened if the simulation started with the airplane trimmed before switching off the stab motor.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
planecane
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 3:15 pm

OldAeroGuy wrote:
chiad wrote:
I haven' read all the posts here so I don't know if anyone has linked this already about "Could US pilots have saved the 737 MAX8 ?"
https://www.youtube.com/watch?v=ZtHBz2-YpWE


Thanks, but already posted.

Of course, the simulation starts with the horizontal stabilizer electric motor switched off with the airplane out of trim.

It would be interesting to see what would have happened if the simulation started with the airplane trimmed before switching off the stab motor.


It would be "informative" but probably not vey "interesting" to watch them have no trouble with the trim wheel when starting in trim.
 
SELMER40
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 4:11 pm

http://flightaware.com/live/flight/BOE393
What kind of flying has Boeing 393 been doing/is doing now?
Teaching this old dog a new trick
 
kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 4:19 pm

SELMER40 wrote:
http://flightaware.com/live/flight/BOE393
What kind of flying has Boeing 393 been doing/is doing now?

There is also BOE320 also heading to SKF, a USAF field. Some demos/tests over there maybe?
 
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Revelation
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 4:34 pm

zckls04 wrote:
Revelation wrote:
One of many posts with absurd distortion of other people's positions, presumably because people are intensively triggered by investigation of the actions of the pilots. sigh.

No, it's intentional hyperbole to help you understand how you can say one thing, but mean another.

Absurd distortion, intentional hyperbole, whatever, don't we have enough of that here already?

zckls04 wrote:
Revelation wrote:
    B) Some criticism for the accident will be directed towards the pilots and some will be directed to Boeing FAA, the airlines, etc.

I've got a better idea. Let's not do that, since everybody agrees the answer is B, as it has been in virtually every aviation incident since the dawn of time. Let's instead recognize that whilst there may be a consensus that Boeing is at fault, there is no consensus at all on exactly what they are at fault for, nor to what extent, even among those who are fiercely inclined to defend them. Thus an A or B answer doesn't really get to the root of the issue, since it conveniently negates any discussion of these nuances.

At the same time there is no consensus over what role pilot actions played in the tragedy, and plenty of push back to negate any discussion of its nuances:

American Airlines’ pilots’ union has hit back at Boeing for insinuating that some responsibility for the two crashes of its 737 Max jets lies with the pilots, and claimed AA pilots made several suggestions to Boeing to fix the plane’s anti-stall systems before the second crash.

Describing Boeing’s position as “inexcusable”, Dennis Tajer, a spokesman for the Allied Pilots Association, accused Boeing of unfairly blaming foreign pilots involved in the Lion Air and Ethiopian Airlines crashes.

Tajer told CNN: “Shame on you. We’re going to call you out on it. That’s a poisoned, diseased philosophy.”

Ref: https://www.theguardian.com/business/20 ... union-mcas

Clearly Tajer wants no discussion of the nuances.

zckls04 wrote:
Remember there's a good reason many might be skeptical, and that's the reliability with which this scenario repeats itself across many industries. If you can find a human being to blame, it's the cheapest and easiest way to avoid addressing systemic failures in your organization. (side note- it's not by chance that we have a specific term for such an individual). Virtually every major corporate screwup in history has followed the same pattern. First, deny. If you can't deny, obfuscate. If you can't obfuscate, reframe.

You seem to be employing that same tactic above by directing the discussion away from the pilot's actions and towards Boeing's actions.

Both need consideration, IMHO.

I think in this case we will find that the human beings to get the most blame will be employees of Boeing and not employees of airlines.
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7BOEING7
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 5:02 pm

kalvado wrote:
SELMER40 wrote:
http://flightaware.com/live/flight/BOE393
What kind of flying has Boeing 393 been doing/is doing now?

There is also BOE320 also heading to SKF, a USAF field. Some demos/tests over there maybe?


Production flights to storage and maybe paint. Boeing has a large presence at SKF I believe (unless I have the wrong San Antonio airport).
 
sgbroimp
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 6:18 pm

Maybe an interesting question, given the pilots of the two aircraft presumably upgraded from pre-Max 737's, is would they have likely been able to successfully diagnose and deal with a runaway trim on the older aircraft?
 
SEU
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 7:14 pm

sgbroimp wrote:
Maybe an interesting question, given the pilots of the two aircraft presumably upgraded from pre-Max 737's, is would they have likely been able to successfully diagnose and deal with a runaway trim on the older aircraft?


The older generations didnt have MCAS, so the plane probably wouldnt have been nose diving into the ground resulting in frantic attempts. One of the heartbreaking things for me to read was the time scale in the report, it was about 3.5 minutes from when the plane started to go wrong, to it nose diving into the ground.
 
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zckls04
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 7:52 pm

Revelation wrote:
Absurd distortion, intentional hyperbole, whatever, don't we have enough of that here already?


Hyperbole and exaggeration exist in language for a reason. They do come in useful to highlight a point sometimes. I get that these days we all have to pretend absolutely everything anybody says is literally what they mean and then act all outraged, but I'm not really on that bandwagon yet.

Revelation wrote:
Tajer told CNN: “Shame on you. We’re going to call you out on it. That’s a poisoned, diseased philosophy.”
Clearly Tajer wants no discussion of the nuances.


Good grief- that's a labor union representing pilots. What exactly do you expect him to say? That's literally his job.

Revelation wrote:
You seem to be employing that same tactic above by directing the discussion away from the pilot's actions and towards Boeing's actions.


Not really- I'm trying to explain why it might appear to others that the discussions of pilot actions are not entirely in good faith. It's not an attempt to "destroy Boeing" as several posters have rather ludicrously opined. It's a result of seeing those who agree that Boeing is more than 50% at fault spending 98% of their time talking about pilot error.

I think in this case we will find that the human beings to get the most blame will be employees of Boeing and not employees of airlines.


Likely true. But what matters is not who is blamed, but what actually changes as a result.
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Absynth
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 8:47 pm

The people in this thread laying blame onto the pilots, should take a step back and have a long, hard look at the international safety standards for catastrophical failures. Which is less than one in a billion per flight hour.

I will brake that number down to make it more specific. We had almost 400 planes in service up to the grounding. It was in service for almost two years. On average that was 200 planes for 660 days and ~8 hours per day average flight hours, or about 1000000 flight hours. We've had two known AoA vane failures but for the sake of it let's assume there were two more that the pilots had managed to prevent. Not counting the LionAir flight prior to the crash since a) the plane were saved by a third pilot not on duty and b) the same AoA vane failure caused the crash of the subsequent flight.

Now, we have an assumed failure rate of 1 million/4 is one in 250.000 hrs. To reach the 1 in a billion standard this means Boeing expected the pilots to be succesful 39999 out of 40000 AoA vane failures, or a succes rate of 99.9975%. Instead, the succesrate was about ~50%. Maybe a bit more, maybe a bit less. That's a deviation from expected behaviour of ~20000x.

The deviation form expected behaviour to comply with catastrophical failure standards is almost the same as the failure rate per average flight for an A0A vane. Let this just sink in before you start blaming pilots they did the wrong failure tree analysis in the few seconds they had to their disposal.
 
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Revelation
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 8:58 pm

zckls04 wrote:
Revelation wrote:
Tajer told CNN: “Shame on you. We’re going to call you out on it. That’s a poisoned, diseased philosophy.”
Clearly Tajer wants no discussion of the nuances.

Good grief- that's a labor union representing pilots. What exactly do you expect him to say? That's literally his job.

Some here don't seem to understand that.

zckls04 wrote:
Revelation wrote:
You seem to be employing that same tactic above by directing the discussion away from the pilot's actions and towards Boeing's actions.

Not really- I'm trying to explain why it might appear to others that the discussions of pilot actions are not entirely in good faith. It's not an attempt to "destroy Boeing" as several posters have rather ludicrously opined. It's a result of seeing those who agree that Boeing is more than 50% at fault spending 98% of their time talking about pilot error.

Feel free to read in to others behaviors any way you want, but keep in mind it is your interpretation/projection of others, which may or may not be reality.

Although some don't allow for it, IMO it is perfectly plausible that some find Boeing's actions are adequately understood and the pilot's actions are not, especially in regard to what Boeing and the FAA suggest they expected of the pilots.

zckls04 wrote:
Revelation wrote:
I think in this case we will find that the human beings to get the most blame will be employees of Boeing and not employees of airlines.

Likely true. But what matters is not who is blamed, but what actually changes as a result.

I agree. Unfortunately the word "blame" gets tossed around a lot here.
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Wake now, discover that you are the song that the morning brings
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kalvado
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 9:46 pm

Absynth wrote:
I couldnt edit my post anymore, but let's assume my assumption of 4 vane failures was wrong and instead there were 8 vane failures. The failure rate for pilots halves to 25%. But 8 vane failures means mean time to failure for the vane is also halved to 125k hours, and the failure rate for pilots needs to halve to 0.00125% (or one in 80k AoA failures) to compensate for the reduced reliability. The deviation is still 20.000x the expected failure rate for pilots.


AoA sensors installed on CRJs have 70k hours MTBF; I bet 737 is on the same page. And your estimate of 1 million hours is probably on a high side. Assume 30 AoA failures at most; 10-15 is probably more realistic. Half occured on non-MCAS side. However sensors can fail in a different way - stuck, offset down, no signal. It is only a certain failure mode - high positive value - which excites MCAS.
 
Absynth
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 10:05 pm

kalvado wrote:
Absynth wrote:
I couldnt edit my post anymore, but let's assume my assumption of 4 vane failures was wrong and instead there were 8 vane failures. The failure rate for pilots halves to 25%. But 8 vane failures means mean time to failure for the vane is also halved to 125k hours, and the failure rate for pilots needs to halve to 0.00125% (or one in 80k AoA failures) to compensate for the reduced reliability. The deviation is still 20.000x the expected failure rate for pilots.


AoA sensors installed on CRJs have 70k hours MTBF; I bet 737 is on the same page. And your estimate of 1 million hours is probably on a high side. Assume 30 AoA failures at most; 10-15 is probably more realistic. Half occured on non-MCAS side. However sensors can fail in a different way - stuck, offset down, no signal. It is only a certain failure mode - high positive value - which excites MCAS.


It doesnt really matter (apart from actual total accumulated flight hours on which i was erring to the positive side for the 737MAX) since the catastrophic failure condition is one in a billion hours. Pilot behaviour needs to compensate for critical hardware failures in order to reach that norm. The less frequent a critical hardware failure, the less frequent a pilot needs to be able to compensate for that failure.

I could have also specified the AoA failures as failures in critical condition (which would be well above that 70k hours MTBF BTW) and it still wouldn't matter. You see, we have the mean time to catastrophical failure condition on one hand, and flight hours and crashes on the other. Pilots are expected to compensate for hardware failure modes up to that one billion hours MTBCFC. And since the deviation was not in hardware failure (we didnt have 20.000x more critical AoA failures than expected), the deviation is in how pilots reacted versus how Boeing / FAA expected them to react to the failure modes in order to meet the standard.
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 10:49 pm

Revelation wrote:
Feel free to read in to others behaviors any way you want, but keep in mind it is your interpretation/projection of others, which may or may not be reality.

Although some don't allow for it, IMO it is perfectly plausible that some find Boeing's actions are adequately understood and the pilot's actions are not, especially in regard to what Boeing and the FAA suggest they expected of the pilots.

.


It is hardly plausible to call Boeing's actions adequately understood.

How did MCAS live through a vigorous Boeing review. How did MCAS live through a rigorous certification process. Were all safety reviews bypassed? If so than why? Was it time pressure? Was it simple greed? Why is Boeing so reluctant to admit fault? Why the inaction of Boeing after the first accident? Why did Boeing wait for a second accident and seem to have been prepared to wait for a third?
Very few seem to be interested to look behind the veil at Boeing and the FAA. Does it hurt the the US American pride to much?
 
morrisond
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 10:51 pm

Absynth wrote:
The people in this thread laying blame onto the pilots, should take a step back and have a long, hard look at the international safety standards for catastrophical failures. Which is less than one in a billion per flight hour.

I will brake that number down to make it more specific. We had almost 400 planes in service up to the grounding. It was in service for almost two years. On average that was 200 planes for 660 days and ~8 hours per day average flight hours, or about 1000000 flight hours. We've had two known AoA vane failures but for the sake of it let's assume there were two more that the pilots had managed to prevent. Not counting the LionAir flight prior to the crash since a) the plane were saved by a third pilot not on duty and b) the same AoA vane failure caused the crash of the subsequent flight.

Now, we have an assumed failure rate of 1 million/4 is one in 250.000 hrs. To reach the 1 in a billion standard this means Boeing expected the pilots to be succesful 39999 out of 40000 AoA vane failures, or a succes rate of 99.9975%. Instead, the succesrate was about ~50%. Maybe a bit more, maybe a bit less. That's a deviation from expected behaviour of ~20000x.

The deviation form expected behaviour to comply with catastrophical failure standards is almost the same as the failure rate per average flight for an A0A vane. Let this just sink in before you start blaming pilots they did the wrong failure tree analysis in the few seconds they had to their disposal.


Isn't 1 billion divided by 250,000 equal to 4,000?

It doesn't matter how many times the vanes failed - the pilots still failed to follow procedures. It's about as silly as my ET has 50% of the pilot error fatal crashes (2 out of 4) in the last ten years with .5% of the worldwide fleet - a crash rate 100x the industry average.
 
snowkarl
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Wed May 29, 2019 11:16 pm

morrisond wrote:
Absynth wrote:
The people in this thread laying blame onto the pilots, should take a step back and have a long, hard look at the international safety standards for catastrophical failures. Which is less than one in a billion per flight hour.

I will brake that number down to make it more specific. We had almost 400 planes in service up to the grounding. It was in service for almost two years. On average that was 200 planes for 660 days and ~8 hours per day average flight hours, or about 1000000 flight hours. We've had two known AoA vane failures but for the sake of it let's assume there were two more that the pilots had managed to prevent. Not counting the LionAir flight prior to the crash since a) the plane were saved by a third pilot not on duty and b) the same AoA vane failure caused the crash of the subsequent flight.

Now, we have an assumed failure rate of 1 million/4 is one in 250.000 hrs. To reach the 1 in a billion standard this means Boeing expected the pilots to be succesful 39999 out of 40000 AoA vane failures, or a succes rate of 99.9975%. Instead, the succesrate was about ~50%. Maybe a bit more, maybe a bit less. That's a deviation from expected behaviour of ~20000x.

The deviation form expected behaviour to comply with catastrophical failure standards is almost the same as the failure rate per average flight for an A0A vane. Let this just sink in before you start blaming pilots they did the wrong failure tree analysis in the few seconds they had to their disposal.


Isn't 1 billion divided by 250,000 equal to 4,000?

It doesn't matter how many times the vanes failed - the pilots still failed to follow procedures. It's about as silly as my ET has 50% of the pilot error fatal crashes (2 out of 4) in the last ten years with .5% of the worldwide fleet - a crash rate 100x the industry average.


I've seen you do this for about 100 pages now - purposely derailing the thread whenever someone gets a bit too close to the truth.

It's really not the same because your logic is not solid. You can't make a system designed to have a fatal crash if ONE sensor (no back up systems) but put a bulletin out that says if you do this procedure (once you've diagnosed this very obscure error under enormous pressure and humans regardless of experience and training get tunnel vision) you might have a CHANCE to save the airplane.

That might have worked 100 years ago when they were building the first prototypes but it is 100% unacceptable in 2019 and Boeing very well knew this but compromised in order to sell more planes.

You also know this very well yet for some reason keep going on about how this was the pilots' fault. It isn't. Boeing fundamentally failed in their design and put the plane and pilots into a position where one mistake they hadn't been adequately briefed about would cause the death of almost 200 people. That is ONE HUNDRED PERCENT Boeing's fault and we should not even be talking about whether or not the pilots could have saved it - because guess what: even if they'd saved the plane Boeing should still have had the MAX grounded indefinitely because its design is fundamentally flawed and should have to go through a complete recert to fly again.

There should also be a limit on what percentage someone can have in a thread so people like you and planecrane can't be responsible for close to 50% of the thread's posts... :roll:
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 1:38 am

morrisond wrote:
Absynth wrote:
The people in this thread laying blame onto the pilots, should take a step back and have a long, hard look at the international safety standards for catastrophical failures. Which is less than one in a billion per flight hour.

I will brake that number down to make it more specific. We had almost 400 planes in service up to the grounding. It was in service for almost two years. On average that was 200 planes for 660 days and ~8 hours per day average flight hours, or about 1000000 flight hours. We've had two known AoA vane failures but for the sake of it let's assume there were two more that the pilots had managed to prevent. Not counting the LionAir flight prior to the crash since a) the plane were saved by a third pilot not on duty and b) the same AoA vane failure caused the crash of the subsequent flight.

Now, we have an assumed failure rate of 1 million/4 is one in 250.000 hrs. To reach the 1 in a billion standard this means Boeing expected the pilots to be succesful 39999 out of 40000 AoA vane failures, or a succes rate of 99.9975%. Instead, the succesrate was about ~50%. Maybe a bit more, maybe a bit less. That's a deviation from expected behaviour of ~20000x.

The deviation form expected behaviour to comply with catastrophical failure standards is almost the same as the failure rate per average flight for an A0A vane. Let this just sink in before you start blaming pilots they did the wrong failure tree analysis in the few seconds they had to their disposal.


Isn't 1 billion divided by 250,000 equal to 4,000?

It doesn't matter how many times the vanes failed - the pilots still failed to follow procedures. It's about as silly as my ET has 50% of the pilot error fatal crashes (2 out of 4) in the last ten years with .5% of the worldwide fleet - a crash rate 100x the industry average.


Still trying to divert blame from Boeing to the pilots. What procedure exactly? The standard runaway procedure? Or a modified procedure because your are faced with MCAS instead of a trim runaway?

Standard procedure and they are dead, not enough height above ground.

The modified procedure has not been shown to work yet, we do not know if the manual electrical trim worked to counter MCAS sufficiently.
 
barney captain
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 1:51 am

The Director of IATA wants a lifting of the ban to occur in unison -

IATA director general and CEO Alexandre de Juniac urged global regulators to lift the grounding of the Boeing 737 MAX in unison, even while acknowledging that the model’s return to service is still likely a few months away.


Of note is this statement however -

Representatives from at least two key foreign regulators also made it clear to FAA that they are facing political pressure to deviate from the US timeline, regardless of what technical reviews show.


IOW, it doesn't matter how conclusive the fix is, we're going to drag our feet to make a point.


https://atwonline.com/airframes/iata-ag ... JBhHuLH9aQ
Last edited by barney captain on Thu May 30, 2019 1:52 am, edited 1 time in total.
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SheikhDjibouti
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 1:52 am

RickNRoll wrote:
The problem for Boeing now is what happens when a real runaway trim event occurs. It rapidly takes the plane out of trim. What happens next? You can't use electric trim because it has to be disabled since any electric trim is instantly going to move the trim all the way to the extremes, so it can't help you. The only option is the manual trim wheel. One pilot is physically struggling with the control column and one is physically struggling with the trim wheel. (See Mentour Pilot video for an example).

This question has troubled me for weeks now - I just couldn't summon up the courage to post it myself.
It almost boils down to how quickly are pilots expected to detect runaway trim? (not necessarily just a Boeing problem!)

If it is a 737 MAX, do you wait 9.2 secs to see if it is simply MCAS doing what it is supposed to do?
Do you stop it as soon as you can, maybe after 6-7 secs, leaving you not knowing whether it was MCAS or genuine runaway stab?
Do you attempt to interrupt it with a short burst of thumb switch trim, knowing that MCAS would be interrupted, whereas runaway stab would continue regardless?
With MCAS v1.0 you had the option of allowing the full 9.2 sec cycle, and then count to five and see if a second activation occurred, and then interrupting it a.s.a.p.
With MCAS v2.0 there will be no second cycle, so you could be left wondering.

If you interrupt MCAS with the thumb switch, have you just stopped MCAS from saving you from an impending stall that for some reason you were unaware of?

In the case of a genuine runaway stab situation, knowing that you have probably failed to register the event until after two, three or four seconds have passed, how many more seconds do you wait before deciding it has exceeded the normal 9.2s MCAS cycle? Having belatedly diagnosed genuine runaway stab trim, how far out of trim will you be when you disable electric trim and have to bring it all back using only the manual trim wheel? Remember; in this scenario there is no option to neutralize control forces with electric trim first before flipping the stab cut-out.

Alternatively, if you are not prepared to wait the full 9.2 secs because you fear it might take you to a bad place, then what is the point of MCAS at all? It becomes akin to flipping the circuit breaker on the GPWS because the sudden noise might interrupt your cat-nap.
OAG wrote:
Of course, the simulation starts with the horizontal stabilizer electric motor switched off with the airplane out of trim.

It would be interesting to see what would have happened if the simulation started with the airplane trimmed before switching off the stab motor.

About as interesting as watching paint drying.

I would much rather see some pilots tested to see how quickly they correctly identified a mysterious trim movement as either
a) normal STS or Mach trim
b) electric thumb switch trim by the PF (Pilot Flying), but viewed from the perspective of the PNF who is initially unaware of the PF's actions.
c) genuine MCAS (due to high AoA &/or impending stall maybe in a steep turn)
d) rogue/malfunctioning MCAS
e) genuine runaway stab

Some of the above require prompt (corrective) action, some require no action at all.
Any action to hit the stab trim cut-out before 9.2s could be interference with a necessary safety feature
Any delay after 9.2s could prove fatal

Catch-22?

(taking MCAS out of the equation, it might be equally interesting to see the procedure executed on some Airbus a/c too, maybe after disabling FBW and engaging direct law? Am I correct that Airbus trim wheels do not have any provision for flip out handles to increase manual grip? And additionally they are somewhat smaller in diameter than those typically found on 737s?)
Nothing to see here; move along please.
 
morrisond
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 1:59 am

mjoelnir wrote:
morrisond wrote:
Absynth wrote:
The people in this thread laying blame onto the pilots, should take a step back and have a long, hard look at the international safety standards for catastrophical failures. Which is less than one in a billion per flight hour.

I will brake that number down to make it more specific. We had almost 400 planes in service up to the grounding. It was in service for almost two years. On average that was 200 planes for 660 days and ~8 hours per day average flight hours, or about 1000000 flight hours. We've had two known AoA vane failures but for the sake of it let's assume there were two more that the pilots had managed to prevent. Not counting the LionAir flight prior to the crash since a) the plane were saved by a third pilot not on duty and b) the same AoA vane failure caused the crash of the subsequent flight.

Now, we have an assumed failure rate of 1 million/4 is one in 250.000 hrs. To reach the 1 in a billion standard this means Boeing expected the pilots to be succesful 39999 out of 40000 AoA vane failures, or a succes rate of 99.9975%. Instead, the succesrate was about ~50%. Maybe a bit more, maybe a bit less. That's a deviation from expected behaviour of ~20000x.

The deviation form expected behaviour to comply with catastrophical failure standards is almost the same as the failure rate per average flight for an A0A vane. Let this just sink in before you start blaming pilots they did the wrong failure tree analysis in the few seconds they had to their disposal.


Isn't 1 billion divided by 250,000 equal to 4,000?

It doesn't matter how many times the vanes failed - the pilots still failed to follow procedures. It's about as silly as my ET has 50% of the pilot error fatal crashes (2 out of 4) in the last ten years with .5% of the worldwide fleet - a crash rate 100x the industry average.


Still trying to divert blame from Boeing to the pilots. What procedure exactly? The standard runaway procedure? Or a modified procedure because your are faced with MCAS instead of a trim runaway?

Standard procedure and they are dead, not enough height above ground.

The modified procedure has not been shown to work yet, we do not know if the manual electrical trim worked to counter MCAS sufficiently.


Sorry - I forgot to say it was a failure of training - that can't learn what they aren't taught. I'm not blaming the pilots - especially the ET pilots who I think were probably never even taught the MCAS recovery procedures.

What standard procedure? Are you referring to the Roller Coaster Procedure and 8,000' Height loss to recover? If they needed extra height they only had to fly slightly to the right of the take off path - the Great Rift Valley was straight ahead and they would have had about 13-14,000' to recover (as the Ground dropped from 7,500 above sea level to about 2,000' above sea level. . On ET they were actually able to climb at the trim setting they had - they could could have done half of the trim recovery and then climbed up some more to get some more height to finish the full recovery.

I'll agree with you on the last point - that is curious that it was stopping at 2.3 multiple times - the trim motor may not have had enough force to overcome the forces at really high speeds. But it could be coincidence.
 
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SheikhDjibouti
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 2:05 am

planecane wrote:
As far as the force feedback system, I'm curious what aircraft was used to make the elevator feel like. I'm sure the 737 was based on the 727 which was probably based on the 707 but what were they replicating the feel of with the 707?

Going right back in time it would originally have been based on how strong the company test pilot was feeling on that particular day.

The problem with that is there are days when I can toss a sack of potatoes into the trunk of my car with ease. And other days when I can barely lift a jar of coffee. :old:

If it was down to Boeing's Tex Johnston, he would probably be thinking in terms of his previous experiences with the B-47 and B-52.
Nothing to see here; move along please.
 
GalaxyFlyer
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 2:09 am

Standard procedure of flying the plane—apply trim to maintain neutral stock force. Yoke gets heavy as the trim inputs are made, counter with manual electric trim with the readily thumbed switches. Not a procedure—it’s called flying. Also, PULL THE POWER BACK. If you have no other means of controlling speed, leaving the power at TOGA is not helping. The problems only get worse with speed.

It wasn’t the pilots that crashed to planes, but they could have saved it.


Gf
Last edited by GalaxyFlyer on Thu May 30, 2019 2:18 am, edited 1 time in total.
 
barney captain
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 2:14 am

GalaxyFlyer wrote:
It wasn’t the pilots that crashed to planes, but they could have saved it.


Gf


As proven by the first two Lior Air crews.
Southeast Of Disorder
 
TropicalSky
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 2:25 am

Where have you been BARNEY? Your input have been sorely missed around these threads

barney captain wrote:
GalaxyFlyer wrote:
It wasn’t the pilots that crashed to planes, but they could have saved it.


Gf


As proven by the first two Lior Air crews.
 
DenverTed
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 3:34 am

Taking the hypothetical that JT and ET were US airlines, don't you think they would have been grounded based on flying unairworthy planes and not reporting problems, or, problems with training being exposed by poor flying? So who's putting profit ahead of safety now, or the convenience of having a functioning air system over safety? Obviously there is a balance, but as long as JT and ET are flying, I'm not sure grounding the MAX for the busy summer season makes sense. Especially in the context of the world's agencies trying to create a global consensus on safety.
 
DenverTed
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 3:42 am

mjoelnir wrote:
Revelation wrote:
Feel free to read in to others behaviors any way you want, but keep in mind it is your interpretation/projection of others, which may or may not be reality.

Although some don't allow for it, IMO it is perfectly plausible that some find Boeing's actions are adequately understood and the pilot's actions are not, especially in regard to what Boeing and the FAA suggest they expected of the pilots.

.


It is hardly plausible to call Boeing's actions adequately understood.

How did MCAS live through a vigorous Boeing review. How did MCAS live through a rigorous certification process. Were all safety reviews bypassed? If so than why? Was it time pressure? Was it simple greed? Why is Boeing so reluctant to admit fault? Why the inaction of Boeing after the first accident? Why did Boeing wait for a second accident and seem to have been prepared to wait for a third?
Very few seem to be interested to look behind the veil at Boeing and the FAA. Does it hurt the the US American pride to much?

One would hope for an independent third party review of the entire MCAS design. That way the process could be improved. Either they broke the process and that error should be highlighted for future avoidance, or the process was flawed and needs to be fixed.
Last edited by DenverTed on Thu May 30, 2019 3:43 am, edited 1 time in total.
 
morrisond
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 3:42 am

snowkarl wrote:
morrisond wrote:
Absynth wrote:
The people in this thread laying blame onto the pilots, should take a step back and have a long, hard look at the international safety standards for catastrophical failures. Which is less than one in a billion per flight hour.

I will brake that number down to make it more specific. We had almost 400 planes in service up to the grounding. It was in service for almost two years. On average that was 200 planes for 660 days and ~8 hours per day average flight hours, or about 1000000 flight hours. We've had two known AoA vane failures but for the sake of it let's assume there were two more that the pilots had managed to prevent. Not counting the LionAir flight prior to the crash since a) the plane were saved by a third pilot not on duty and b) the same AoA vane failure caused the crash of the subsequent flight.

Now, we have an assumed failure rate of 1 million/4 is one in 250.000 hrs. To reach the 1 in a billion standard this means Boeing expected the pilots to be succesful 39999 out of 40000 AoA vane failures, or a succes rate of 99.9975%. Instead, the succesrate was about ~50%. Maybe a bit more, maybe a bit less. That's a deviation from expected behaviour of ~20000x.

The deviation form expected behaviour to comply with catastrophical failure standards is almost the same as the failure rate per average flight for an A0A vane. Let this just sink in before you start blaming pilots they did the wrong failure tree analysis in the few seconds they had to their disposal.


Isn't 1 billion divided by 250,000 equal to 4,000?

It doesn't matter how many times the vanes failed - the pilots still failed to follow procedures. It's about as silly as my ET has 50% of the pilot error fatal crashes (2 out of 4) in the last ten years with .5% of the worldwide fleet - a crash rate 100x the industry average.


I've seen you do this for about 100 pages now - purposely derailing the thread whenever someone gets a bit too close to the truth.

It's really not the same because your logic is not solid. You can't make a system designed to have a fatal crash if ONE sensor (no back up systems) but put a bulletin out that says if you do this procedure (once you've diagnosed this very obscure error under enormous pressure and humans regardless of experience and training get tunnel vision) you might have a CHANCE to save the airplane.

That might have worked 100 years ago when they were building the first prototypes but it is 100% unacceptable in 2019 and Boeing very well knew this but compromised in order to sell more planes.

You also know this very well yet for some reason keep going on about how this was the pilots' fault. It isn't. Boeing fundamentally failed in their design and put the plane and pilots into a position where one mistake they hadn't been adequately briefed about would cause the death of almost 200 people. That is ONE HUNDRED PERCENT Boeing's fault and we should not even be talking about whether or not the pilots could have saved it - because guess what: even if they'd saved the plane Boeing should still have had the MAX grounded indefinitely because its design is fundamentally flawed and should have to go through a complete recert to fly again.

There should also be a limit on what percentage someone can have in a thread so people like you and planecrane can't be responsible for close to 50% of the thread's posts... :roll:


On the other hand People shouldn't be allowed to post unless they fully realize what went on. You make a good case for Lionair - but by ET they had a valid procedure and the Flight was saveable. They showed a real lack of hand flying skills and procedures. They re supposed to be trained to deal with emergencies.

iIf you had absorbed what you read you would realize that I believe Boeing is totally at fault as well - but the crashes uncovered some real deficiencies in training as well - that need to be corrected just like Boeing Design and FAA oversight.

I only respond when people keep insisting that Pilots were not a contributing factor. They were. However if you had read what I wrote you would have also noted that I'm blaming ET302's failure to respond right on ET training for many reasons which you can read in these threads.

Have a good day.
 
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zckls04
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 4:17 am

Revelation wrote:
Feel free to read in to others behaviors any way you want, but keep in mind it is your interpretation/projection of others, which may or may not be reality.


I'm not attempting to read into others' behaviors; I hold no position on what anybody else thinks. I'm merely commenting on how it appears, and I suspect I'm not alone in my opinion.

Although some don't allow for it, IMO it is perfectly plausible that some find Boeing's actions are adequately understood and the pilot's actions are not, especially in regard to what Boeing and the FAA suggest they expected of the pilots.


I think it's plausible too. I strongly disagree with it though- the pilots' actions are by an order of magnitude better understood than Boeing's at this stage, at least to this untrained eye.
Four Granavox Turbines!
 
Elshad
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 4:24 am

It really sucks that it seems like Boeing is going to get away with murder, perhaps with a slap on the wrist. Really unfair for the victims etc.
 
barney captain
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 4:42 am

TropicalSky wrote:
Where have you been BARNEY? Your input have been sorely missed around these threads

barney captain wrote:
GalaxyFlyer wrote:
It wasn’t the pilots that crashed to planes, but they could have saved it.


Gf


As proven by the first two Lior Air crews.


So kind of you.

But It's best if I stay out of this frey as much as I can stand. ;)
Southeast Of Disorder
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 5:56 am

FluidFlow wrote:


The Boeing CEO was interviewed yesterday and would only commit that the plane will be back flying before the end of the year!

Clearly this fix is proving far harder than Boeing imagined it would. They keep missing their own stated deadlines to submit their "fixes”. They were also due a test flight with FAA in mid May that got cancelled.

Right now if Boeing keep putting back their software submission and test flight dates themselves then they must be worried it's a harder problem to solve than they had thought it would be

One of the news articles today also claims that FAA are asking questions of Boeing that they've not provided the answers to yet and suggests there is some friction developing between FAA and Boeing over disclosure of what is happening with the fix. They've discovered more technical issues to solve etc.

At the end of the day we've seen on here there are lots of very hard questions to be asked of Boeing before these planes can fly again. And there are even bigger experts out there to ask the difficult questions than we have on here.

Right now it appears Boeing have not been able to even submit answers to all of the questions let alone satisfy the people asking the questions with their answers

Boeing themselves have moved from not wanting the planes grounded at all - to saying the planes will be back in the air very soon - to now only promising before the end of the year

We've spent months apportioning blame on here. But at the end of the day Boeing simply CANNOT afford another disaster with these planes. There is no way the plane and even the Boeing brand could survive another disaster. So whether we trust them or not - they simply have to make these planes safe enough to hit those safety stats above. The CEO in his interview has accepted the trust needs winning back. He's clung on to his job - but he wouldn't survive another crash. You can argue the Boeing brand itself wouldn't survive another crash after coming under this amount of scrutiny.

Let's be honest - it's not just people on here that should be challenging the safety of Boeing. Boeing themselves SHOULD have internal employees asking the difficult questions. If they put these planes back in the air for short term gain but don't get it right and there is another disaster then it could literally destroy the whole Boeing brand for good.

Talk is cheap. Blaming pilots is easy. Boeing NEED to put a plane back in the air that is virtually impossible to crash (regardless of human intervention) as that's what the public expect and have grown accustomed to.

It doesn't need us to ask the difficult questions - Boeing will be asking them internally - they know they won't get away with anything from now on with these planes. They've got one chance to get it right. - and I think now the real focus is on (internally and externally) it's proving really hard to get it right.

They've designed a plane that's going to prove really hard to hit those acceptable risk stats above that other planes can hit.

There's no real point people defending or attacking Boeing on here anymore - Boeing themselves don't have a solution yet
they feel they can even submit.

Boeing MUST put safety first now or they will just put themselves out of business regardless of anything we say positive or negative about them

Getting the planes back in the air is only half the problem. The even harder bit for Boeing is making sure one of these planes CANNOT crash again in the next 10 years plus. And they have to do that taking account of human error that all planes need to expect and be able to deal with.

And the design flaws with this plane are clearly making this very hard for them to achieve. If Boeing can't submit solutions yet - nobody can either approve or turn down those solutions.
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 6:41 am

Absynth wrote:
The people in this thread laying blame onto the pilots, should take a step back and have a long, hard look at the international safety standards for catastrophical failures. Which is less than one in a billion per flight hour.

I will brake that number down to make it more specific. We had almost 400 planes in service up to the grounding. It was in service for almost two years. On average that was 200 planes for 660 days and ~8 hours per day average flight hours, or about 1000000 flight hours. We've had two known AoA vane failures but for the sake of it let's assume there were two more that the pilots had managed to prevent. Not counting the LionAir flight prior to the crash since a) the plane were saved by a third pilot not on duty and b) the same AoA vane failure caused the crash of the subsequent flight.

Now, we have an assumed failure rate of 1 million/4 is one in 250.000 hrs. To reach the 1 in a billion standard this means Boeing expected the pilots to be succesful 39999 out of 40000 AoA vane failures, or a succes rate of 99.9975%. Instead, the succesrate was about ~50%. Maybe a bit more, maybe a bit less. That's a deviation from expected behaviour of ~20000x.

The deviation form expected behaviour to comply with catastrophical failure standards is almost the same as the failure rate per average flight for an A0A vane. Let this just sink in before you start blaming pilots they did the wrong failure tree analysis in the few seconds they had to their disposal.


There should be staff at Boeing doing similar number crunching and warning the CEO we've got a hell of a lot of work to do to get to the safety levels we require. Boeing know they have to account for human error. All plane designs have to account for it. They can't use training of humans to get them to the safety stats they need. It can help but that's all it can do. Whatever training humans get at the end of this needs to be training they NEVER have to call on regardless.

If systems fail then we've got problems as we know humans will fail and as I've said before there are way too many of these planes going to be flying to get away with humans always making the right decisions when the systems fail.

Like I say the easier bit for Boeing is getting the planes back in the air. The worrying bit is what happens once the planes are flying again.

At least Boeing staff can go to sleep at night right now without worrying about another Max disaster overnight. Once these planes start flying again surely they want to be able to sleep at night without worrying as well?

It's a scary situation for the Boeing CEO to get right

Short term financial pressure to get flying again. Long term need for no more disasters.

I wouldn't fancy that job and pressure right now. No matter what he gets paid.

The fact is though that the "coming soon" fix from Boeing that was supposedly 2 weeks away back when these planes were first grounded has proven to be months away and still is months away even now

Now the focus is on its clear this is a harder problem to solve than Boeing realised
 
Noshow
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 7:10 am

Boeing should be completely open about what the flight behavior of the MAX is and how to steer it manually in "MCAS-situations". Train the pilots for it bring back their confidence. Afterwards the public confidence will hopefully come back. Plus we need openess about how one system failure could cause such a chain of events. For my taste Boeing and the FAA are too quiet about it.

The Boeing lawyers might prefer to not say anything anymore but how can this bring back public confidence? It will just take longer and become even more expensive.
It looks like a zig-zag strategy. First they were quiet, then they were open for a moment, now they are quiet again. Not really convincing I have to say. I want the MAX to return but only after all things are fixed and all pilots feel good to go. Unfortunately I don't see us coming closer to it anymore.
 
sgrow787
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 7:28 am

Interested wrote:
Clearly this fix is proving far harder than Boeing imagined it would. They keep missing their own stated deadlines to submit their "fixes”. They were also due a test flight with FAA in mid May that got cancelled.


The problem is, Boeing not only needs to fix the root problem (two sensor redundancy, MCAS cycle repetition, possible cutout switches repurposed back to what they were for NG), they and the FAA (Foeing) are still trying to keep the type certificate and reduced [new] training. And they no doubt are spending a lot of time getting their stories straight. The pilots unions will be more malleable the longer the grounding continues, so expect the Foeing solution to include (a) getting pilots onboard and saying everything is "safe", (b) getting the US public flying again, using them as guinea pigs for (c) convincing other countries to fly.
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 7:33 am

Dp
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 7:45 am

sgrow787 wrote:
Interested wrote:
Clearly this fix is proving far harder than Boeing imagined it would. They keep missing their own stated deadlines to submit their "fixes”. They were also due a test flight with FAA in mid May that got cancelled.


The problem is, Boeing not only needs to fix the root problem (two sensor redundancy, MCAS cycle repetition, possible cutout switches repurposed back to what they were for NG), they and the FAA (Foeing) are still trying to keep the type certificate and reduced [new] training. And they no doubt are spending a lot of time getting their stories straight. The pilots unions will be more malleable the longer the grounding continues, so expect the Foeing solution to include (a) getting pilots onboard and saying everything is "safe", (b) getting the US public flying again, using them as guinea pigs for (c) convincing other countries to fly.


But my point is its all irrelevant - convincing others to fly the plane or not is just the first challenge

If it's not as safe as it needs to be it will surely crash again at some stage and the plane and Boeing are doomed as a result

Another 170 ish passengers sacrificed ??

The catastrophe stats are there for a reason. If the plane and it's systems can't hit those stats then what happens next?

Can this plane hit the safety stats required or not? Those stats are there for a reason?

Pilot training can't help it hit those stats. If Boeing are relying on pilots to be 100 per cent to save these planes then it's not a long term plane to invest in as pilots will fail again at some stage.

These same thoughts must go through Boeing decision makers heads?

Or do they gamble and roll the dice again with passenger lives?

I'm rambling on. I guess it has to hit the stats to be allowed to fly again? But surely Boeing would want it to hit those stats themselves. It either will or it won't I guess.
 
RandWkop
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 7:49 am

sgrow787 wrote:
Interested wrote:
Clearly this fix is proving far harder than Boeing imagined it would. They keep missing their own stated deadlines to submit their "fixes”. They were also due a test flight with FAA in mid May that got cancelled.


The problem is, Boeing not only needs to fix the root problem (two sensor redundancy, MCAS cycle repetition, possible cutout switches repurposed back to what they were for NG), they and the FAA (Foeing) are still trying to keep the type certificate and reduced [new] training. And they no doubt are spending a lot of time getting their stories straight. The pilots unions will be more malleable the longer the grounding continues, so expect the Foeing solution to include (a) getting pilots onboard and saying everything is "safe", (b) getting the US public flying again, using them as guinea pigs for (c) convincing other countries to fly.


They couldn't be that stupid or greedy. One more crash, with any similarity's to lion or Ethiopian, and the 737 program is finished. At best it would be grounded for a couple of years for a redesign to suit the new engines.
 
sgrow787
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 8:01 am

Noshow wrote:
Boeing should be completely open about what the flight behavior of the MAX is and how to steer it manually in "MCAS-situations". Train the pilots for it bring back their confidence. Afterwards the public confidence will hopefully come back. Plus we need openess about how one system failure could cause such a chain of events. For my taste Boeing and the FAA are too quiet about it.

The Boeing lawyers might prefer to not say anything anymore but how can this bring back public confidence? It will just take longer and become even more expensive.
It looks like a zig-zag strategy. First they were quiet, then they were open for a moment, now they are quiet again. Not really convincing I have to say. I want the MAX to return but only after all things are fixed and all pilots feel good to go. Unfortunately I don't see us coming closer to it anymore.


I'm still not convinced it was a single-sensor design, mainly because (a) Boeing to date hasn't come out and stated it was a single-sensor design, (b) all the news articles to date have been careful to say "single sensor" in a way that is ambiguous, and (c) all we have to support single-sensor is some anonymous Boeing engineer stating it was a single-sensor design to get around a disagree scenario (ie indicator) to meet the no-new-training requirement.

At the end of the day though, I'm not happy until the certification process is updated or rolled back to the days when FAA had more control. And I don't want a ex-pilot running the FAA. He or she should be a retired aerospace engineer, maybe in flight controls (is Peter Lemme listening?).
 
xmp125a
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 8:17 am

sgbroimp wrote:
Maybe an interesting question, given the pilots of the two aircraft presumably upgraded from pre-Max 737's, is would they have likely been able to successfully diagnose and deal with a runaway trim on the older aircraft?


Symptoms of stab trim runaway (possible on all 737s, but very rare, constant nosedown trim which cannot be fixed using electric trim switches) and MAX-specific MCAS misbehavior are different. Boeing assumed that crews will recognize MCAS failure (intermittent strong nosedown impulses that CAN be counteracted by electrical trim, but this has to be done persistently due to intermittent MCAS activations) as stab trim runaway (which as entirely different origins). Two crews did not, and this was contributing factor in both accidents.

Now the question is, who is to blame here. My purely personal opinion is, that 90% boeing and 10% the pilots.
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 8:26 am

RandWkop wrote:
sgrow787 wrote:
Interested wrote:
Clearly this fix is proving far harder than Boeing imagined it would. They keep missing their own stated deadlines to submit their "fixes”. They were also due a test flight with FAA in mid May that got cancelled.


The problem is, Boeing not only needs to fix the root problem (two sensor redundancy, MCAS cycle repetition, possible cutout switches repurposed back to what they were for NG), they and the FAA (Foeing) are still trying to keep the type certificate and reduced [new] training. And they no doubt are spending a lot of time getting their stories straight. The pilots unions will be more malleable the longer the grounding continues, so expect the Foeing solution to include (a) getting pilots onboard and saying everything is "safe", (b) getting the US public flying again, using them as guinea pigs for (c) convincing other countries to fly.


They couldn't be that stupid or greedy. One more crash, with any similarity's to lion or Ethiopian, and the 737 program is finished. At best it would be grounded for a couple of years for a redesign to suit the new engines.


That's the way I see it. They have to balance their desire to get the planes back in the air with their concerns about what happens if there's another crash.

Unlike those guys on here who are focussed on pilot error in all of this - Boeing will know that won't wash with the airlines or FAA etc or the public. They can't allow pilot error or not to even come into it. If this plane goes down again Boeing will be blamed for sure no matter what now. They already are let's be honest.

They know the realities of what is and isn't acceptable in safety. They know the impact on their brand. They have seen the impact on their share price already. It's steadily falling now as it is. Trust is gone and needs winning back.

This plane simply can't crash again. One way or another. The reality of that may be harder to achieve than anyone imagined.

And it's now actually Boeing delaying submitting what is needed that is slowing things down. What a turnaround from not even wanting these planes grounded. They know they can't hide facts any longer. They know they are responsible for whatever happens next and can't make another mistake.

It's actually possible they may not be able to solve this to the level of safety required for them to ever risk the relaunch.

That seems unlikely given how huge this plane is to Boeing. But that's where it's at.

It's the Boeing CEO now only promising before the end of the year.

The FAA can't approve what Boeing haven't submitted

China and Europe can't be on a different timeline to US if even US aren't flying the plane

Boeing can no longer take any risks for their own sake let alone the sake of the passengers

They have to submit a fix that makes the plane safe to the levels required. And it can't be down to pilots bailing them out if and when systems go wrong again.
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 8:36 am

https://www.ft.com/content/74945d9e-821 ... e435b57a3b

This is where it states that yesterday the CEO declined to give a timetable for when the plane would fly again and instead just said it would be before the end of the year

That's such a change in approach from Boeing. It's others who are predicting earlier than that.

Like I say this is a huge problem to solve in so many ways
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 8:56 am

The big question for me is, if a serious safety revue is done, will that impact the NG too?

The standard run away procedure, cutting switches and trimming with the wheels, seems not to work on the MAX if the trim is already substantially away from normal.
It should be the same situation for the NG. Was the recovery procedure for runaway trim never revisited in any safety analysis in the last 30 years? Not at the move from classic to NG and now at the move from NG to MAX?
Does there have to be a review of the manual trim for all 737 still in operation?
 
mjoelnir
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 9:06 am

GalaxyFlyer wrote:
Standard procedure of flying the plane—apply trim to maintain neutral stock force. Yoke gets heavy as the trim inputs are made, counter with manual electric trim with the readily thumbed switches. Not a procedure—it’s called flying. Also, PULL THE POWER BACK. If you have no other means of controlling speed, leaving the power at TOGA is not helping. The problems only get worse with speed.

It wasn’t the pilots that crashed to planes, but they could have saved it.


Gf


Can you guaranty that manual electrical did work 100% in the Ethiopian crash? Do you have an explanation for why manual electrical trim stopped several times at the same angle, while trying to trim back from the MCAS action?

How about, does manual electrical trim really stop the movement commanded by MCAS?

I do not want to exclude the possibility that the pilots may have been able to stop the frame from crashing, but to declare that they were definitely able to refrain from crashing, is not yet supported by the evidence available at this time.
 
Interested
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Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 9:17 am

mjoelnir wrote:
The big question for me is, if a serious safety revue is done, will that impact the NG too?

The standard run away procedure, cutting switches and trimming with the wheels, seems not to work on the MAX if the trim is already substantially away from normal.
It should be the same situation for the NG. Was the recovery procedure for runaway trim never revisited in any safety analysis in the last 30 years? Not at the move from classic to NG and now at the move from NG to MAX?
Does there have to be a review of the manual trim for all 737 still in operation?


But at least we know with NG the amount of times pilots have ever needed to do this is so low and the challenges when they do so manageable that it's not got to that catastrophic risk concern

Even better if those pilots for NG are trained more for coping if it ever did happen

Isn't the challenge for Max making sure the chances of the training being needed are at same level as NG and that when it happens the risks of catastrophe are at same level as NG

It's the new risks Max 737 has brought in that have caused these crashes. Risks we need to eliminate.
 
asdf
Posts: 272
Joined: Tue Mar 18, 2014 12:03 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 1:15 pm

OldAeroGuy wrote:
chiad wrote:
I haven' read all the posts here so I don't know if anyone has linked this already about "Could US pilots have saved the 737 MAX8 ?"
https://www.youtube.com/watch?v=ZtHBz2-YpWE


Thanks, but already posted.

Of course, the simulation starts with the horizontal stabilizer electric motor switched off with the airplane out of trim.

It would be interesting to see what would have happened if the simulation started with the airplane trimmed before switching off the stab motor.


pointless.
why should one test a wheel to correct a wrong trim in a phase where trimming is not wrong?
 
morrisond
Posts: 1151
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 1:23 pm

xmp125a wrote:
sgbroimp wrote:
Now the question is, who is to blame here. My purely personal opinion is, that 90% boeing and 10% the pilots.


I'm not going to disagree with you on the Pilot's part in either crash - however I would add ET training for 40% on ET302 - Lionair 90% Boeing - 10% Pilots, ET302 - Boeing 50%, ET Training 40% - Pilots 10% (For leaving the Autothrotle in TOGA the whole flight). ET training - for their seemingly lack of focus on hand flying skills and quite possibly not even getting the MCAS procedure to there Pilots - or if they did in such an offhand manner it was basically useless.

I can't believe the ET pilots would have missed that much if they had been properly trained on the new MCAS procedure in the FCOM. It should have been top of mind and they should have had a copy in the cockpit.
 
GalaxyFlyer
Posts: 3160
Joined: Fri Jan 01, 2016 4:44 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 1:28 pm

DenverTed wrote:
Taking the hypothetical that JT and ET were US airlines, don't you think they would have been grounded based on flying unairworthy planes and not reporting problems, or, problems with training being exposed by poor flying? So who's putting profit ahead of safety now, or the convenience of having a functioning air system over safety? Obviously there is a balance, but as long as JT and ET are flying, I'm not sure grounding the MAX for the busy summer season makes sense. Especially in the context of the world's agencies trying to create a global consensus on safety.


Yes, falsification of logs is a Federal crime and has been prosecuted. I had a captain try to remove a log entry in hopes of moving the plane (a recurring problem that wasn’t necessarily a hazard). Maintenance said, “no way is out if the book, plane stays right here”. Maintainer was named Clever, always remember that.


GF
 
GalaxyFlyer
Posts: 3160
Joined: Fri Jan 01, 2016 4:44 am

Re: Boeing 737MAX Grounded Worldwide Q2 2019

Thu May 30, 2019 1:31 pm

mjoelnir wrote:
GalaxyFlyer wrote:
Standard procedure of flying the plane—apply trim to maintain neutral stock force. Yoke gets heavy as the trim inputs are made, counter with manual electric trim with the readily thumbed switches. Not a procedure—it’s called flying. Also, PULL THE POWER BACK. If you have no other means of controlling speed, leaving the power at TOGA is not helping. The problems only get worse with speed.

It wasn’t the pilots that crashed to planes, but they could have saved it.


Gf


Can you guaranty that manual electrical did work 100% in the Ethiopian crash? Do you have an explanation for why manual electrical trim stopped several times at the same angle, while trying to trim back from the MCAS action?

How about, does manual electrical trim really stop the movement commanded by MCAS?

I do not want to exclude the possibility that the pilots may have been able to stop the frame from crashing, but to declare that they were definitely able to refrain from crashing, is not yet supported by the evidence available at this time.


The stab moved every time their was commanded input. Stopped at 2.3 units very well could have been caused by the trim motor being overtorqued trying to overcome the pilot’s elevator input. I’d fault the pilots more for not pulling back the thrust at this point. Speed wasn’t gonna help them.

GF

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