Lion Air crash: Jakarta Boeing 737 'had prior instrument error'

[Brumby]

You don't get me.  Any so-called "solution" isn't a fix when it introduces other risks.


Edit: BTW - it was you who was doing the trading - but you don't seem to realise that.

[KL27x]

Mechatrommer is just making a general point. Nitpicking his post is stupid.

I just have to love it when the pilot police show up to demonstrate their knowledge of stupid-shit-no-one-cares-about. (When it's not germane to the point).

Of course an accelerometer would be useful if the pitot tubes went out. At least it could tell the pilot an continuing approximation of his air speed based on the last valid readings. And it could be fairly accurate for at least some duration. This would be highly useful if the pilot hadn't happened to be watching his airspeed at the time of sensor malfunction. Maybe it could also display a second figure, increasing over time/conditions, to let the pilot know how much salt to take with that reading.

GPS plus elevation and pitch could also be used for some ballpark figure, at least.

It seems bizarre that a failed pitot tube can result in AF447. The pilots can't even tell they're in a stall. And even after the sensor thaws and works perfectly fine, again, more than a minute before they could have saved the plane, they just didn't trust it.

With some backup that said: "yes.... your super low airspeed reading sounds right to me, too" that could have changed the outcome.

Human beings are apparently completely incapable of estimating airspeed devoid of visual reference. Any sort of backup might be useful.

[Mechatrommer]

You don't get me.  Any so-called "solution" isn't a fix when it introduces other risks.

yeah like what boeing did to their new invention 737...

Edit: BTW - it was you who was doing the trading - but you don't seem to realise that.

i know but who am i to enforce that? you dont want my piece of advice is fine. what i was saying is if...... crash is imminent. rather that doing nothing. and most importantly, this kind of fault never happening before, so why they insist on new training scheme? this is just cover up of their mistake. i believe a total callback will put scar into their reputation, or the fear of bankruptcy paying compensation to the families. nuts.

Of course an accelerometer would be useful if the pitot tubes went out. At least it could tell the pilot an continuing approximation of his air speed based on the last valid readings. And it could be fairly accurate for at least some duration. This would be highly useful if the pilot hadn't happened to be watching his airspeed at the time of sensor malfunction. Maybe it could also display a second figure, increasing over time/conditions, to let the pilot know how much salt to take with that reading.

when someone put their brain ON (working), this is the comment. i hate typing too long english is not my strong point. and there will be always people to push you behind, but its ok for the sake of brainstorming. but then what? will boeing listen to this thread? if yes, i will elaborate in pages if i have to.

[Brumby]

Sorry if I took your point too literally.

[Towger]

In the Mentour Pilot video it looked at if someone was at the simulator controls hitting/clicking on in the trim button every second or two.  It has now been reported that each time MCAS triggers it runs/trims for 11 seconds.  Which I assume would lead to a more intense situation.

[donotdespisethesnake]

Of course an accelerometer would be useful if the pitot tubes went out. At least it could tell the pilot an continuing approximation of his air speed based on the last valid readings.

Wow, so much stupid in one post. A gyro can't tell you airspeed. 

I just have to love it when the electronics guys show up to demonstrate their complete ignorance of the-actual-topic-of-the-thread.

[Mechatrommer]

Of course an accelerometer would be useful if the pitot tubes went out. At least it could tell the pilot an continuing approximation of his air speed based on the last valid readings.

Wow, so much stupid in one post. A gyro can't tell you airspeed. 
I just have to love it when the electronics guys show up to demonstrate their complete ignorance of the-actual-topic-of-the-thread.

who say it can? do you know what is "approximation"? nobody say it will be accurate for prolonged period. the bigger problem is when people dont read carefully and esp they dont have experience (off topic link) if calling someone's post stupid, then i should be already in good hand

[Gixy]

Hum, airspeed and grounspeed can be very different (wind and attitude) and unfortunally aircraft need airspeed to fly.

[Mechatrommer]

accelerometer cant measure both ground nor air (relative to plane) speed, its an inertial sensor, it can only measure change of its motion (v = u + at) so it can approximate motion by dead reckoning from the last known "good reading" for quite sometime. but maybe this is different discussion as the problem is buggy MCAS. maybe i was not clear enough combined with nitpicking... accelerometer combined with magnetometer can be used to estimate gravitation pull/direction or free fall condition and plane's attitude as well, this is available in any china $30 drones that has no eye, no GPS and no beacon no tringulation tower comm etc, the only thing left is the operator's stupidity. those $5 sensors are lacking in that 100 mills plane, no backup AI to prevent this (maybe FAA regulation to ban complete AI control?) to put injury to the insult, MCAS only cares about nose up stall, it doesnt care if the plane is in military dive nose down condition i dont see how is this acceptable. someone must have a good answer, the FAA if not Boeing.

[Kjelt]

On a sidenote here are some numbers on the economical impact.
TUI is a small airliner having 150 planes from which 15 are MAX that have been grounded.
If the MAX is allowed to fly in july the damage is 200 million euro, if allowed in september it is 300 million euro.
This is only one airliner, we are talking tens of billions of dollars total global I guess.

Dutch only so use google translate
https://www.nu.nl/economie/5816484/aan-de-grond-houden-boeing-737-max-kost-tui-200-miljoen.html

[Mechatrommer]

Magnetometers are prone to interference. Many AHRL modules nowadays don't use magnetic sensors anymore.

right, magnetometer needs to be constantly calibrated for true north under controlled condition if someone is rely to it as a compass. i guess thats why they are not fan of it and there's kalman filter to deal with unreliable sensors. from experience playing with "toyish grade" umanned vehicles/robot, a calibrated magnetometer can greatly improve dead reckoning compared to accelerometer alone on XY plane. although it may help on determining roll condition when airplane heading in Z axis (gravity), never tried that. both of this 6 axis accel and magnet sensors someone called them as complete attitude control. but this explanation is moot as i'll be surprised if boeing has no better attitude control than $30 one hung low drones.

[soldar]

The emerging 737 MAX scandal, explained. It’s more than bad software.

The FAA did not do their due diligence. The FAA is short on resources and pretty much let Boeing certify themselves figuring they would not cut corners and make an unsafe plane. Kind of reminds me of Chernobyl.

[Mechatrommer]

hmm wait for Comac C919 then we'll have more dive down occurrence pressure. Financial problem is not an excuse, 737 is bigger engines from predecessor, and that thing can dive up and down fine. this is just few lines of codes, imho.

[GeorgeOfTheJungle]

The emerging 737 MAX scandal, explained. It’s more than bad software.

Hmm, I like the name of that newspaper...   

[soldar]

cbsnews.com: Relationship between FAA and Boeing under scrutiny after deadly crash.

nytimes.com; After Boeing Crashes, Sharp Questions About Industry Regulating Itself

[tooki]

The emerging 737 MAX scandal, explained. It’s more than bad software.

The FAA did not do their due diligence. The FAA is short on resources and pretty much let Boeing certify themselves figuring they would not cut corners and make an unsafe plane. Kind of reminds me of Chernobyl.

I like a lot of Vox's work, but not this piece. It seems to be kinda lacking in technical background and a bit too biased IMHO. Like… no, the engines aren't "too big" for this plane, they simply change its characteristics — the larger, higher engines simply magnify an effect that exists on all 737 aircraft.

[dzseki]

On a sidenote here are some numbers on the economical impact.
TUI is a small airliner having 150 planes from which 15 are MAX that have been grounded.
If the MAX is allowed to fly in july the damage is 200 million euro, if allowed in september it is 300 million euro.
This is only one airliner, we are talking tens of billions of dollars total global I guess.

Dutch only so use google translate
https://www.nu.nl/economie/5816484/aan-de-grond-houden-boeing-737-max-kost-tui-200-miljoen.html

So is it better for everyone to let them fly sooner than later? 

[soldar]

I like a lot of Vox's work, but not this piece. It seems to be kinda lacking in technical background and a bit too biased IMHO. Like… no, the engines aren't "too big" for this plane, they simply change its characteristics — the larger, higher engines simply magnify an effect that exists on all 737 aircraft.

The way I understand it is that the engines being moved forward and up make this a totally new airplane which should have been subject to new certification but they went with the pretense that it is just a variation of the old 737 in order to simplify certification and gain time.

That is what I gather from everything I have read.

[soldar]

Hmm, I like the name of that newspaper...   

I have no idea what this is supposed to mean and I have no idea who Vox are or what their name is supposed to mean (other than "voice") so I went to Wikipedia and found out that they "target educated households with six-figure incomes and a head of house less than 35 years old."

I hope I am not accused of impersonating something I am not.

[GeorgeOfTheJungle]

I have no idea what this is supposed to mean and I have no idea who Vox are

And you're a spaniard?

youtube.com / watch?v=5h-yGC7atBs
youtube.com / watch?v=wjphjb2lOE4

[RandallMcRee]

hmm wait for Comac C919 then we'll have more dive down occurrence pressure. Financial problem is not an excuse, 737 is bigger engines from predecessor, and that thing can dive up and down fine. this is just few lines of codes, imho.

<Needless to say what follows is speculation on my part....>

Well, the basic problem is that this is *not* a few lines of code because they f*ed up big time on this project. Their basic problem with MCAS is relying on a single sensor input. Think about that--you cannot have a life-critical <anything> reliant on a single sensor.  In the original design it was not life-critical (according to first docs given to FAA) because the control was limited in its effect on the aircraft. Later....later...(time passes) and deadlines approach...they realize that they need more control and up the control space for that system. It now becomes life-critical but too late in the project for the major changes necessary for the incorporation of the THREE sensors you now need. (Two sensors doesn't cut it--you need majority voting). I don't know but I suspect that three sensors are not available and the addition of another sensor would be quite a major effort. Remember, the whole project was supposed to be QUICK and a minor modification to the 737.

So now they have screwed themselves. But conveniently no-one knows this except internally withing Boeing. The executives decide to cut their losses as you have seen--by pretending that MCAS is not life-critical and not changing the design. The result is what you can see. 

[GeorgeOfTheJungle]

hmm wait for Comac C919 then we'll have more dive down occurrence pressure. Financial problem is not an excuse, 737 is bigger engines from predecessor, and that thing can dive up and down fine. this is just few lines of codes, imho.

<Needless to say what follows is speculation on my part....>

Well, the basic problem is that this is *not* a few lines of code because they f*ed up big time on this project. Their basic problem with MCAS is relying on a single sensor input. Think about that--you cannot have a life-critical <anything> reliant on a single sensor.  In the original design it was not life-critical (according to first docs given to FAA) because the control was limited in its effect on the aircraft. Later....later...(time passes) and deadlines approach...they realize that they need more control and up the control space for that system. It now becomes life-critical but too late in the project for the major changes necessary for the incorporation of the THREE sensors you now need. (Two sensors doesn't cut it--you need majority voting). I don't know but I suspect that three sensors are not available and the addition of another sensor would be quite a major effort. Remember, the whole project was supposed to be QUICK and a minor modification to the 737.

So now they have screwed themselves. But conveniently no-one knows this except internally withing Boeing. The executives decide to cut their losses as you have seen--by pretending that MCAS is not life-critical and not changing the design. The result is what you can see.

And I doubt very much it's the sensor's fault. I'd bet it's a dangling pointer somewhere or something like that, a software bug rather than a hardware sensor fault...

Why? Because I can't believe so many sensors can fail so many times, and only in these planes. I don't think the AoA sensors in the 737 MAX can be very different from the ones in other airplanes.

[floobydust]

Additional pilot training is penalized at $1M per plane, in the Boeing sales contract with Southwest Airlines.
Meaning Southwest would be paid by Boeing $1M/plane ($31M for 31 planes thus far of 280 ordered) if additional simulator training was required above the 737NG. Quite the sales gimmick and there's your incentive keep MCAS undocumented.

[soldar]

Remember, the whole project was supposed to be QUICK and a minor modification to the 737.

So now they have screwed themselves. But conveniently no-one knows this except internally withing Boeing. The executives decide to cut their losses as you have seen--by pretending that MCAS is not life-critical and not changing the design. The result is what you can see.

That's about the size of it IMHO.

[MT]

Imagine how loud YOU would be screaming if someone knowingly took off without EVERYTHING working and then crashed?

Well isnt that what actually happened? minus the screaming at take off rather at crash.

You do realize that's exactly what you just demanded, right?

You dont make sens in your reasoning, besides i'm not demanding anything, i just debate what others speculate in.

Nor would that fact have anything to do with how loud MT would rant when a crash is involved.

Im not ranting besides at armchair pilots like your self who claims to have a definitive answer to a crash every time it hapends. I dont see you spend time barking at fake news outlets ranting repeated news reels about these crashes and crockery inside Boing and FAA. How peculiar!