Another 737 down

[ACE]

https://www.youtube.com/watch?v=aO7_indbfME 60 minutes in the land of OZ for some fuel to the fire.

Even the pilot was visibly upset when he said they haven’t trained us on how this system works. Wow.

[Vraciu]

FIFY.

Exactly. 

Every pilot typed on this jet should know how to stop a trim runaway.   If he doesn’t then he needs to turn in his ticket. 

[Busher]

I hate conspiracy theorists but it sure seems like someone needs to keep the "Evil Boeing" in the public's face.

These accidents are the first I can remember that the cause was determined before the professional investigators had a chance to draw their conclusions.

It does pi$$ me off that professional pilots would speak to the news before ALPA tech-safety released their contribution to the investigation.

[DmonSlyr]

I hate conspiracy theorists but it sure seems like someone needs to keep the "Evil Boeing" in the public's face.

These accidents are the first I can remember that the cause was determined before the professional investigators had a chance to draw their conclusions.

It does pi$$ me off that professional pilots would speak to the news before ALPA tech-safety released their contribution to the investigation.

Everything you hear about is a 'conspiracy theory" until you can research for yourself and find the conclusions for yourself. Everything in the MSM has a spin to fit their narrative. Of course there is an attack on Boeing. The question is why? Don't expect leftstream media to tell you that. You will probably never know the real reason any way due to national security concerns.

The fact that someone predicted a boeing crash a few days before 'that MSM will never tell you about' is the real concern. The guy could have got 'lucky' writing something like that. Though why would someone write that? Then it actually happens. Now there is a "conspiracy" for ya. If someone knew before hand that there would be a crash. That completely destroys the narrative.

[deSelys]

Exactly. 

Every pilot typed on this jet should know how to stop a trim runaway.   If he doesn’t then he needs to turn in his ticket.

Is it correct to call this a 'trim runaway' though?

• the electrical trim system was working fine
• the rate of nose down action was much faster when activated by MCAS than by the pilot trim controls (apparently this won't be the case anymore after the software fix https://www.businessinsider.com/boeing-reveals-737-max-software-fix-and-training-update-2019-3?r=US&IR=T)

So somebody decided that it would be better to require the shutdown of an entire system (electrical trim, which was not at fault) to deal with a software issue caused by a single* sensor failure... instead of giving to the pilots the option to just deactivate the software bit.

Maybe the pilots of Lion Air and Ethiopian Airlines didn't handle the crisis as they should have, but the design of the system doesn't look like it tried to make their flying a little less complicated after throwing a curveball at them.


*According to 60 minutes Australia, the decision to link MCAS to a single sensor instead of both was made to avoid extra level D training (at 35:30)...  if this is true =>

[Toad]

When the chips are down, any man claiming to be an aviator HAS TO BE ABLE TO FLY THE JET.

No professional aviator that knows anything about Boeings, let me repeat that, NO PROFESSIONAL AVIATOR that knows anything about Boeings thinks either the Lion Air crash or the Ethiopian crash was an unrecoverable situation. MCAS did not kill those people; the pilots did.

In other words, despite the AOA failures, these aircraft COULD have been flown to a safe landing. If you doubt this, review what happened with the exact same Lion Air aircraft. Same aircraft, same malfunction but ONE jumpseat pilot that knew how to FLY THE JET. Therefore, no accident, no crash, no nothing; just a safe recovery.

Now, Boeing should have put MCAS info in the Differences Training. No question. The fact that it isn't in there, however, is not a reason that a competent pilot would not be able to deal with an AOA malfunction.

As an aside, I will point out the has been an evolving trend in the industry that has moved pilot training away from detailed systems knowledge. By that I mean the industry no longer teaches the pilot to "build the aircraft" in the old description.

For instance, in the earlier years of my career when you took your oral exam they would give you a situation like this:

"You are a molecule of fuel in the left wing tank. Describe the routing to the #2 engine burner cans and tell me all the pumps and valves you go through on the way to the engine. Include alternate routes."

Now we teach that "you turn on the boost pump in the left tank, fuel flows through the shutoff valve to the engine fuel control. The engine will suction feed to 20,000 feets."

So systems knowledge has been dumbed down as well. Guess why.

[Puma44]

Spot on Toad!  Agree 110%! 

[Toad]

Is it correct to call this a 'trim runaway' though?

It was an AOA failure that triggered MCAS, a situation that can be easily and safely resolved by the Runaway Stab Trim procedure in the QRH. So, if the Stab Trim is doing something you don't want it to do (or just don't understand: why is it doing that?)...yes, it's a trim runaway. Or some manufacturer's call it Uncommanded Stab Trim.

So somebody decided that it would be better to require the shutdown of an entire system (electrical trim, which was not at fault) to deal with a software issue caused by a single* sensor failure... instead of giving to the pilots the option to just deactivate the software bit.

Two issues here.

One, single sensor. It is totally normal for a single sensor to trigger a stall warning or stall protective device. In many aircraft, there are two independent sensors and systems and EITHER ONE seeing an abnormally high AOA will trigger stall warning or stall protection. There does NOT need to be correlation and comparison between the two sensors to trigger the warning or protection. This is absolutely NOT uncommon throughout the industry.

Issue two: I have been told there is a circuit breaker that disables MCAS. I haven't confirmed it though and obviously, if it exists, it's not part of any Boeing procedure for uncommanded MCAS or whatever they would call it.

Maybe the pilots of Lion Air and Ethiopian Airlines didn't handle the crisis as they should have, but the design of the system doesn't look like it tried to make their flying a little less complicated after throwing a curveball at them.

Funny the Lion Air jumpseat pilot figured it out rather quickly though, isn't it? Maybe experience is a factor? Maybe this overwhelming need to "make their flying a little less complicated" has its roots in the fact that current standards for pilot training are rather low? That maybe the regulatory agencies should take a closer look at their standards?

*According to 60 minutes Australia, the decision to link MCAS to a single sensor instead of both was made to avoid extra level D training (at 35:30)...  if this is true =>

As I said above, single sensor activation is not at all unusual.

Think about this: the proposed change to dual sensor confirmation will likely occur; it appears to be in the "fix".

Now suppose there's another bad single sensor situation on a MAX and the MCAS does not trigger because it is not confirmed by the other sensor. However, in this situation the CORRECT sensor is the one sensing the stall. So, the pilots are stalling the aircraft but MCAS does NOT trigger. Assume the incompetent pilots that got it into a stalled condition in the first place fail to recover and crash.

Now where to place the blame? We usually err on the side of safety. Doing the thing that is the safest thing. I think they may be going the other way on this fix.

[Vraciu]

As an example, stall sensors on the Falcon 900 are not only independent, they're triggered at DIFFERENT angles of attack.    They are in effect a single source.

[Mister Fork]

So are all pitot tubes to the airspeed gauges.

[Vraciu]

So are all pitot tubes to the airspeed gauges.

Airspeed indicators get information via the pitot static system.    Modern jets use Air Data Computers to provide more accurate info that accounts for all sorts of factors. 

[Vraciu]

When the chips are down, any man claiming to be an aviator HAS TO BE ABLE TO FLY THE JET.

No professional aviator that knows anything about Boeings, let me repeat that, NO PROFESSIONAL AVIATOR that knows anything about Boeings thinks either the Lion Air crash or the Ethiopian crash was an unrecoverable situation. MCAS did not kill those people; the pilots did.

In other words, despite the AOA failures, these aircraft COULD have been flown to a safe landing. If you doubt this, review what happened with the exact same Lion Air aircraft. Same aircraft, same malfunction but ONE jumpseat pilot that knew how to FLY THE JET. Therefore, no accident, no crash, no nothing; just a safe recovery.

Now, Boeing should have put MCAS info in the Differences Training. No question. The fact that it isn't in there, however, is not a reason that a competent pilot would not be able to deal with an AOA malfunction.

As an aside, I will point out the has been an evolving trend in the industry that has moved pilot training away from detailed systems knowledge. By that I mean the industry no longer teaches the pilot to "build the aircraft" in the old description.

For instance, in the earlier years of my career when you took your oral exam they would give you a situation like this:

"You are a molecule of fuel in the left wing tank. Describe the routing to the #2 engine burner cans and tell me all the pumps and valves you go through on the way to the engine. Include alternate routes."

Now we teach that "you turn on the boost pump in the left tank, fuel flows through the shutoff valve to the engine fuel control. The engine will suction feed to 20,000 feets."

So systems knowledge has been dumbed down as well. Guess why.

https://bbs.hitechcreations.com/smf/index.php/topic,397004.msg5264565.html#msg5264565

http://www.b737.org.uk/images/mcas-mtm.jpg



I still haven’t received an explanation on this...and why it is there yet magically nobody heard of it before.


Yeah, “building the jet” is important—I am glad I learned to fly jets when this was the norm. 

[Busher]

Again I thank Toad and Vraciu for their posts. Although, I have to ask, are you not getting tired of trying of trying to explain to those who have never flown a jet and likely have little respect for those who do, that the "Big Nasty Boeing 737 Pitbull" didn't kill anyone. I don't think its possible at this stage of technology to dumb down a transport jet enough to protect people against what is being called a pilot in the third world.
To those that are arguing 2 sensors versus 1 is the obvious solution, I have to ask them, what happens when those 2 sensors disagree. The fact is, technology on airplanes breaks and when it does, the lives of those aboard relies upon two well trained and experienced airman to fly the jet.
All of the opinions of the experienced airmen here are academic anyway; the jury is in because the walter cronkites have concluded who the culprit was; and with the quantity of public opinion and press, I can see the Boeing Company in chapter 11 before too long.

[Vraciu]

Again I thank Toad and Vraciu for their posts. Although, I have to ask, are you not getting tired of trying of trying to explain to those who have never flown a jet and likely have little respect for those who do, that the "Big Nasty Boeing 737 Pitbull" didn't kill anyone. I don't think its possible at this stage of technology to dumb down a transport jet enough to protect people against what is being called a pilot in the third world.
To those that are arguing 2 sensors versus 1 is the obvious solution, I have to ask them, what happens when those 2 sensors disagree. The fact is, technology on airplanes breaks and when it does, the lives of those aboard relies upon two well trained and experienced airman to fly the jet.
All of the opinions of the experienced airmen here are academic anyway; the jury is in because the walter cronkites have concluded who the culprit was; and with the quantity of public opinion and press, I can see the Boeing Company in chapter 11 before too long.

It’s wearying but my audience isn’t the closed-minded drum-banging trolls, it is my fellow aviators like you (because I can still learn something) and the open-minded lurkers...   Also folks like Bustr who are using logic and reasoning to try and reach a proper conclusion.   

The speculation has made me crazy, but since the lemmings want to speculate and blame the jet we might as well speculate ourselves from an informed, professional perspective with the hope someone will find it edifying. 

 

[guncrasher]

as a matter of fact I know vraciu tells his students where to add magnets to correct problems with software and hardware in the planes. that way if they crash it's pilot error.


semp