737 Max

because they just bought the "base model".

_

Here is an article that states this:

____________________ From the article:

Boeing sells two MCAS upgrades that weren?t installed on either the Lion Air jet or the Ethiopian Airlines craft, according to the New York Ti mes. The first is the ability to compare data from more than one AOA sensor via a display that would have shown readings from both at the same time. T he second was a ?disagree light? that would have activated when contradictory data was being received from both sensors. Either might have alerted the pilots that something was wrong with the MCAS system speci fically.

end of clip from article

-----------------------

I've seen zero evidence or any discussion of that being a problem. Boeing says MCAS was added because at very high level angles of attack the 737 can stall easier than previous 737s. These two crashes happened because MCAS can only function once the flaps are retracted. MCAS would have tried to nose down the plane on the runway, if it were not disabled due to the flaps.

Because there are no existing flight control algorithms. The 737s, including the Max are not fly-by-wire

Probably because AFAIK, there is no artificial horizon "sensor" and the artificial horizon is not a good measure for the angle of attack of the air over the wing.

That's correct, FAA screwed up too.

There actually isn't a switch to disable MCAS nor does it sound like Boeing is going to add one. There are two switches to disable the ELECTRIC TRIM, which is what MCAS uses to force the nose down. And those two switches are in every 737 and similar plane with electric trim. What the pilots failed to identify and deal with was that they had a runaway trim problem.

+1

e MCAS design even when the actual failure was in the AoA sensor.

Of course the design should be criticized. It's obviously a very bad desig n to have one sensor be able to go bad and forcefully and repeatedly shove th e nose of a plane down. If one designed an elevator system where the elevato r was held up by a single cable, with no emergency braking system and the cab le failed, would you say there is no design problem, just a bad cable?

suspect the airplane was not flyable. Other pilots have experienced this i ssue and flown the plane back to the airport. Had these pilots been on top of their game there is no reason to suspect they could have not also done the same thing. We will know more once the accident report is made public.

That is correct. All pilots are supposed to be trained on runaway trim procedure and that is what they had. They didn't know what exactly was causing it, but they could easily see that something was changing the trim to abnormal, nose down. Lion Air, they used the trim buttons for about

10 mins, correcting it and each time it went abnormal again. The procedure , which all pilots are supposed to have committed to memory, is to turn off electric trim and then trim manually. The one jump seat pilot on Lion Air the day before, correctly identified it and told the pilots flying the plan e what to do and the plane not only didn't crash, it flew on to it's destinat ion. Which points out something else, the lack of safety concern with some airli nes outside the US. Here, that plane would have made an emergency landing.

pable of "crashing the airplane" unless the pilot is not aware of what is h appening. The pilots can compensate for the MCAS or turn it off.

That's true, but MCAS is still a very poor design, it's shocking that could come out of Boeing.

air-crash/

o

tomated control. There are two of these sensors, but there seems to be no sanity checking. I expect a failure in the AoA sensor was considered in th e planning for use of the MCAS and we have seen in the reporting that there are instructions on what to do to deal with the MCAS not working right. S o clearly they did plan for this eventuality.

There were no instructions for what to do with MCAS. In fact, it's been widely reported that there was no mention of MCAS in the Boeing provided manuals for the plane at all, except maybe in the list of terms in the glossary. However, what the plane was exhibiting was runaway electric trim and all pilots are trained or are supposed to be trained in how to handle that, which is to turn off the electric trim.

rn off the MCAS???

.

ut a rational discussion?

n

e. They shut them down. They have many circuit breakers through out the c abin to turn off malfunctioning equipment. This is standard procedure.

Standard design procedure is also to make the engines as robust and safe as possible. Boeing failed that miserably with MCAS.

.

It's just pointing out that a bad design, is, a bad design.

On Tuesday, March 19, 2019 at 6:19:23 AM UTC-4, snipped-for-privacy@gmail.com wrot e:

ized that the horizontal stabilizer was moving uncommanded, and should have responded with a standard pilot checklist procedure to handle what? ?s called ?stabilizer runaway.?

deactivated the automatic stabilizer movement.

efore the crash experienced similar behavior to Flight 610 and did exactly that: They threw the stabilizer cutoff switches, regained control and conti nued with the rest of the flight.'

r-crash/

they just didn't do what they were supposed to do?

One Lion Air pilot did identify it and follow the procedure. He happened t o be in the cockpit jump seat the day prior to the crash. He told the other two pilots what to do. They may have figured it out themselves too, had he not told them, we won't know.

But it's worse than that. The trim wheels are large, about 6 inches in diameter and there is one on either side of the center console, right next to the pilot's legs. AS the trim is adjusted, they spin and make noticeable noise. They also indicate the trim position. So, while MCAS was forcing the nose down, the pilots would see and hear the trim wheels spinning, going to absurd nose down position. And as they used the trim buttons on the yoke to adjust trim back up, they would hear and see the trim wheels spinning in the opposite direction. That this happened again and again is runaway trim, something the pilots are all supposed to be trained on. And the two switches to turn off the electric trim are right there by the trim wheels. The procedure it to get the trim to about where it needs to be via the trim buttons, if possible, then turn off the electri c trim so the electric system can't move it any more, then use the trim wheel s to set it where needed by hand.

+1

And the FAA too. It will be interesting to see what the FBI determines and how bad this gets. For example, did anyone, eg test pilots point out how bad and unsafe this design was? Where they overruled and if so by whom and why? We know that Boeing sold an option of an AOA disagree light and sold an option of putting the AOA position on the cockpit display. Was that discussed and overruled with a profit motive?

On Tuesday, March 19, 2019 at 6:29:34 AM UTC-4, snipped-for-privacy@columbus.rr.com wrot e:

rote:

gnized that the horizontal stabilizer was moving uncommanded, and should ha ve responded with a standard pilot checklist procedure to handle what? ?s called ?stabilizer runaway.?

d deactivated the automatic stabilizer movement.

before the crash experienced similar behavior to Flight 610 and did exactl y that: They threw the stabilizer cutoff switches, regained control and con tinued with the rest of the flight.'

air-crash/

t they just didn't do what they were supposed to do?

this aircraft as another 737 which allows the pilots to sit right into the max variety with very little new training. The MCAS system was the magic b ox that made the new 737 handle like the old 737. This MARKETING GIMMICK le d the pilots to believe that this flys like the old 737. The literature pr ior to the Lions crash did not mention the MCAS so it was a roll of the dic e as to whether the pilots would figure out how to disable the system that they potentially did not even know existed . The MCAS info was deliberatel y with held from the pilots up until Lions. And After Lions , Boeing either did not adequately get the information out to other airlines or there is s ome other subtle thing going on that Boeing did not fully understand after the Lion crash

It should not have been a roll of the dice. What these planes exhibited wa s a runaway electric trim problem that can happen on any plane with electric trim. Pilots are trained for it, or are supposed to be trained for it. And the Ethiopian crash happened AFTER all the worldwide attention on Lion Air, all the attention on MCAS, Boeing putting out an urgent directive. I believe Ethiopian Air even says that those two pilots were then trained on it. The plane crashed anyway. Putting a pilot with only 200 hours into a commercial aircraft probably doesn't help....

On Tuesday, March 19, 2019 at 8:03:43 AM UTC-4, snipped-for-privacy@downunder.com wrot e:

g r l

he MCAS design even when the actual failure was in the AoA sensor.

Do we know that? It could be a digital sensor.

The

I guess then we don't know it. For that matter, I have not heard for sure that the AOA sensor itself was the actual problem, just that the computer was reading it as showing a high AOA. That could be the sensor, the wiring, a connection, the interface eg A/D in the electronics, etc. And beyond that, if it is the AOA sensor, then what is the root cause of these brand new sensors screwing up? Sticking? Manufacturing defect? You'd think there would have been an emergency directive to inspect, check, replace, but I never heard a peep. Very strange. Makes me wonder if they were unable to identify what the exact root cause was.

suspect the airplane was not flyable.

It's not going to act consistently when there is a malfunction. The plane exhibited runaway electric trim and the pilots were unable to identify that and follow the very simple procedure, which is to turn it off via the two switches right by the trim wheels and then trim manually. The trim wheels were going back and forth, extreme nose down via MCAS, then nose up via the pilots using the electric trim buttons. Hello? How many times have these pilots flown? The plane will fly all day long with 75% power and trim at 4 deg nose up. It doesn't fly very well with trim going back and forth all over the place.

That's right and they could have if they had followed the training. In the case of Ethiopia, the co-pilot had 200 hours PERIOD, another glaring problem.

airport. Had these pilots been on top of their game there is no reason to suspect they could have not also done the same thing. We will know more o nce the accident report is made public.

All pilots are trained, or are supposed to be trained in runaway trim procedure. What did they think those two switches that turn off electric trim are there for?

g .

apable of "crashing the airplane" unless the pilot is not aware of what is happening. The pilots can compensate for the MCAS or turn it off.

-air-crash/

:

to

e

utomated control. There are two of these sensors, but there seems to be no sanity checking.

use of the MCAS and we have seen in the reporting that there are instructio ns on what to do to deal with the MCAS not working right. So clearly they did plan for this eventuality.

urn off the MCAS???

t.

out a rational discussion?

a

an

re. They shut them down. They have many circuit breakers through out the cabin to turn off malfunctioning equipment. This is standard procedure.

Then they should not be pilots. And it's not some obscure circuit breaker either. It's two switches right next to the trim wheels beside the pilot. The two trim wheels that are spinning, making noise, going back and forth showing extreme nose down trim, then nose up, classic example of an electri c trim running amok. The LA pilots had about 10 mins to figure it out.

On Tuesday, March 19, 2019 at 8:10:25 AM UTC-4, snipped-for-privacy@gmail.com wrot e:

ote:

e

neer coding a loop badly. That is a systematic failure of the whole engine ering process of Boeing.

icles about this the single point of failure with the ability of the pilot to override the system is an acceptable system in an airplane.

Apparently to Boeing it was. Not so clear that it was acceptable to the FA A. It looks like FAA only had the initial design targets for MCAS, which had the system only pushing the nose down a fraction of what it later was changed to. Boeing told the FAA X, later figured out that wasn't enough and increased it to 3 or 4X, but never told the FAA. FBI is looking at all that. And I can tell you it's pretty obvious that no one considers this design acceptable anymore.

It does appear that the FAA failed to question the issue of the impact of the failure. It was listed as Hazardous rather than Catastrophic which is clearly what has proven to be true... assuming the MCAS proves to be the pr oblem.

Actually, the hazardous rating is probably accurate, it's not a structural failure, the wings didn't fall off. It's just that Boeing put too much faith in pilots being able to indentify and respond to a hazardous situation and apparently something is seriously wrong with the AOA sensor, wiring, interface, etc, because these sensors are reading incorrectly in brand new planes.

least three of the 737 MAX flights apparently on take off. Is this not in spected prior to flight??? If they are that prone to failure, eventually a plane will take off with both not working and then they'll be royally scre wed no matter what the MCAS does.

I brought that up too. Why have we not heard the root cause? AFAIK, no one has even said that it was the actual AOA, as opposed to wiring, connect ion, A/D interface, etc. Why not? Do they even know for sure? You'd think that after LA there would have been an urgent directive to inspect or replace, something..... Why are there these failures in brand new planes? Why couldn't maintenance at LA fix it on their previous attempts?

ote:

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the MCAS design even when the actual failure was in the AoA sensor.

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Your poor analogy does not make any sense. The MCAS can do unexpected thin gs when presented with bad data. That does not mean the plane will crash a s can be seen from the Lion Air flight prior to the fatal flight.

o suspect the airplane was not flyable. Other pilots have experienced this issue and flown the plane back to the airport. Had these pilots been on t op of their game there is no reason to suspect they could have not also don e the same thing. We will know more once the accident report is made publi c.

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I agree.

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capable of "crashing the airplane" unless the pilot is not aware of what is happening. The pilots can compensate for the MCAS or turn it off.

ld

Not a bad design, the problem is the pilots were not properly informed/trai ned in using it. It appears that Boeing may have not presented the info pr operly.

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automated control. There are two of these sensors, but there seems to be n o sanity checking. I expect a failure in the AoA sensor was considered in the planning for use of the MCAS and we have seen in the reporting that the re are instructions on what to do to deal with the MCAS not working right. So clearly they did plan for this eventuality.

im

If there was no mention and no instructions, then how did the deadheading p ilot know how to deal with the situation. Perhaps it is because of what yo u wrote in elsewhere, the issue is runaway trim which was already an issue the pilots should have known how to deal with.

turn off the MCAS???

ft.

bout a rational discussion?

a

an

ire. They shut them down. They have many circuit breakers through out the cabin to turn off malfunctioning equipment. This is standard procedure.

That remains to be seen. I don't agree.

re.

You are entitled to your opinion, but it is just your opinion.

--

  Rick C. 

  - Get a 1,000 miles of free Supercharging 
  - Tesla referral code - https://ts.la/richard11209

"Overruled"??? They sold it and US airlines have both is my understanding. Do you mean the pilots for the airlines who bought planes without the indicators get overruled by someone?

--

  Rick C. 

  + Get a 1,000 miles of free Supercharging 
  + Tesla referral code - https://ts.la/richard11209

It was a bad SYSTEM design, not an issue of software failure. As far as we know, the software did what the specs called for it to do. And there was a kill switch, every 737 and every plane with electric trim has it. It's the kill switch for the electric trim. They had an electric trim system running amok, the exact cause is irrelevant. The procedure is the same, you turn off the electric and then trim MANUALLY. The trim wheels were right next to the pilots legs, spinning back and forth to totally abnormal trim settings.

It doesn't have to be a new, untested design. It could be a manufacturing defect, for example. AFAIK, no one has even said that it was actually the AOA, as opposed to a short in wiring, bad connection, bad interface circuit, etc.

It's not a software failure period. It's a system design failure. The software engineer isn't the aeronautical engineer, not a test pilot, not the FAA.

I used to think that too, but this screw up is shockingly bad and there are obviously some very serious problems at Boeing and FAA. Also serious problems with competency of some pilots, airline procedures, etc.

rote:

gnized that the horizontal stabilizer was moving uncommanded, and should ha ve responded with a standard pilot checklist procedure to handle what? ?s called ?stabilizer runaway.?

d deactivated the automatic stabilizer movement.

before the crash experienced similar behavior to Flight 610 and did exactl y that: They threw the stabilizer cutoff switches, regained control and con tinued with the rest of the flight.'

air-crash/

t they just didn't do what they were supposed to do?

light why was the AOA sensor not replaced ? And why did the pilots not inform the next crew of the problem?

All good question and so far, no answers. You would think there would be a procedure where if any pilots have experienced a significant problem, they would be required to log and the next crew would be required to be aware of it.

On Tuesday, March 19, 2019 at 9:41:04 AM UTC-4, snipped-for-privacy@gmail.com wrot e:

ote:

ing

for

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p.

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the MCAS design even when the actual failure was in the AoA sensor.

Show us another aircraft manufacturer that has a system with a single sensor that can strongly and continually shove the nose down and I'll show you another shockingly bad design. Do you have examples?

something else that would pretty much be unstoppably fatal. The AoA sensor failed BEFORE take off, the MCAS responded in a dangerous way and the pilo ts failed to handle the situation appropriately.

But a single sensor failure should not be capable of producing an extremely dangerous event to begin with. I agree, the pilots screwed up badly too, especially the LA pilots that had 10 mins to solve it.

chances of this happening again.

ious reasons. In fact, they filed paperwork with Boeing and the FAA about this issue four days before the second accident. Interesting...

r-crash/

to suspect the airplane was not flyable.

when that happens... consistently. I think I'm missing your point.

ould a lack of training be tolerated and more than the operation of the pla ne???

Do we have any indication that it was a training problem? AFAIK, no one has said what training any of these pilots had on runaway trim. It's certainly supposed to be part of the most basic and critical training.

ose.

Correct. And he's supposed to be an equal to the captain, not an apprentic e who is totally subordinate to the captain. We learned that decades ago from other crashes.

he airport. Had these pilots been on top of their game there is no reason to suspect they could have not also done the same thing. We will know more once the accident report is made public.

hould be able to fly the plane or he shouldn't be there.

+1

How many flights had these pilots been on where the trim was set to ~4 deg nose up and the plane flew fine? This flight it's going from full nose down, back to nose up (by the pilots trim buttons). Hello? Planes don't fly so well like that. How about turning off the electric trim with the two switches so marked, that are right next to the violently spinning trim wheels and then trimming by hand?

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me.

capable of "crashing the airplane" unless the pilot is not aware of what i s happening. The pilots can compensate for the MCAS or turn it off.

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AA:

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into

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automated control. There are two of these sensors, but there seems to be no sanity checking.

r use of the MCAS and we have seen in the reporting that there are instruct ions on what to do to deal with the MCAS not working right. So clearly the y did plan for this eventuality.

ensor.

Actually, they couldn't. To be able to have the AOA displayed at all was a Boeing extra cost option, as was a AOA disagree light.

I don't recall the details of the Lion Air flight, but a flight that crash ed because of a faulty air speed indication from a clogged pitot tube (faul ty ground maintenance was suspected) showed the pilot wrong numbers and he asked the co-pilot to call out from his air speed indicator. Once off the ground the pilot's indicator increased the reading and he started to trust it rather than read the other TWO indicators where he could have picked two our of three that agreed.

indow. If you see ground in front of you, your angle of attack mostly like ly is not too positive.

turn off the MCAS???

aft.

about a rational discussion?

we don't have the accident report yet. But my comment was not about his ar gument, but his language. "dangerous automatic safety system" is just fear mongering.

I disagree. A safety system is supposed to make the plane safer. If there had been no MCAS it's extremely unlikely there would have been any crashes due to stalls. Those high speed stalls only happen in very unusual, high angle of attack situations that rarely occur to begin with.

Another flaw in his argument is that by the aviation rules having a disab le switch *is* an acceptable way to mitigate the possibility of the MCAS ma lfunctioning. Ask the aviation industry. I'm pretty sure they have fairly similar rules across the globe or international air travel would be very, very difficult.

r a

n

s an

rdless of the ultimate cause of the crashes. I'm not so certain that turni ng the system off is appropriate. In reality they should have three sensor s so the system has an idea of what is right.

fire. They shut them down. They have many circuit breakers through out th e cabin to turn off malfunctioning equipment. This is standard procedure.

ose down and the pilot corrects with a thumbwheel. The process repeats, mu ltiple times before the plane goes into a dive. The pilot should immediate ly know the MCAS needs to be turned off in addition to other potential caus es. This is clearly explained in the article linked above.

Actually, the plane would never go into a fatal dive at all, if the pilots just kept doing nose up trim to counter MCAS. The LA crash, the pilot was doing that for ~10 mins. Then he handed control to the co-pilot, who only applied weak nose up a couple times and let the plane plummet.

ading was bogus???

Because they had no AOA read out. Per Boeing, that was thousands of dollar s extra, as was the disagree light.

t

ure.

It is trimming the elevator. The pilot can override it and if the MCAS con tinues to do the same thing repeatedly, it can be turned off. This is not like a full self driving car or an automated assembly line. The pilot is s upposed to be aware and in control at all times.

+1

ar power plants get a lot of training as well and yet they make mistakes. What is your point?

the design of the MCAS.

Of course it is! It's a stupid design that relies on just one sensor. Boeing is in the process of fixing it right now.

I think they failed to underline the importance of knowing how to handle t his event and the pilots failed to pick up on the notices that were sent ou t. I would have no concerns flying on the 737 MAX just the way it is if th e pilots are correctly trained.

I'm afraid that is a very big if. Witness the Ethiopian crash. The LA crash was all over the news, brand new plane crashes, exactly how quickly came out. Boeing puts out an emergency directive on it. I saw all this in the news. Ethiopian Air says their pilots were aware of it, received the Boeing directive. Yet, apparently exactly the same thing happened agai n.

l

e d

The fix will do that, take more into account. It also will not persist in shoving the nose down. You're right, these planes had plenty of airspeed, were not performing any extreme moves, there was no bizarre pilot input on the controls, a stall was implausible.

On Wednesday, March 20, 2019 at 2:01:40 AM UTC-4, snipped-for-privacy@columbus.rr.com wr ote:

one

the

e more

guy who said the whole thing rests on a single engineer who wrote a crappy control loop. I was basically saying that if a single engineer can write a loop that brings down a plane then it is not on that guy but rather reflec ts a systematic failure in the whole engineering process. I am sure the lo op was vetted

planes ( 2 of them for God's sake) crashed due to a far more insidious pois on that has taken hold into Boeing's culture.

ng this MCAS design is clear it will be so obviously horrible that any 10 y ear old will see the folly in it.

e. NEVER NEVER NEVER. I know there are engineers at Boeing (not personall y but I know corporate culture) that said out loud "We have a situation whe re an AOA failure can crash this plane" And you know what??? the AOA failu re crashed the plane. That is what I am talking about . I am not an aeron autics engineer, but I know that an AOA failure should not crash a plane. I really boils down to this level of non sense. Why did Boeing design a pla ne where an AoA senser failure takes the plane down? It is unacceptable. And then through some unbelievable convoluted burst of arrogance they encou raged people to keep flying this and a 2nd plane went down

why the planes HAD to crash even assuming this was what happened. The PIL OTS could have flown the plane if they did what they were supposed to do. If you blamed the lack of education or specifically drawing the pilots atte ntion to this issue before they entered the planes, then I might agree. Bu t I don't see a problem with the MCAS that meant the plane had to crash whe n the AoA failed to work.

It's likely that the pilots will be criticized and found partly to blame, but we won't know until the final reports are issued. They failed to identify runaway trim and take the simple actions to deal with it. It's supposed to be part of the most basic and most important flight training.

On Thursday, March 21, 2019 at 1:48:59 AM UTC-4, snipped-for-privacy@columbus.rr.com wro te:

of one

of the

d be more

the

he guy who said the whole thing rests on a single engineer who wrote a crap py control loop. I was basically saying that if a single engineer can writ e a loop that brings down a plane then it is not on that guy but rather ref lects a systematic failure in the whole engineering process. I am sure the loop was vetted

se planes ( 2 of them for God's sake) crashed due to a far more insidious p oison that has taken hold into Boeing's culture.

rding this MCAS design is clear it will be so obviously horrible that any 1

0 year old will see the folly in it.

lane. NEVER NEVER NEVER. I know there are engineers at Boeing (not person ally but I know corporate culture) that said out loud "We have a situation where an AOA failure can crash this plane" And you know what??? the AOA fa ilure crashed the plane. That is what I am talking about . I am not an ae ronautics engineer, but I know that an AOA failure should not crash a plane . I really boils down to this level of non sense. Why did Boeing design a plane where an AoA senser failure takes the plane down? It is unacceptable . And then through some unbelievable convoluted burst of arrogance they en couraged people to keep flying this and a 2nd plane went down

son why the planes HAD to crash even assuming this was what happened. The PILOTS could have flown the plane if they did what they were supposed to do . If you blamed the lack of education or specifically drawing the pilots a ttention to this issue before they entered the planes, then I might agree. But I don't see a problem with the MCAS that meant the plane had to crash when the AoA failed to work.

s

No, it just looks like the pilots in the second crash didn't follow the AD. The co-pilot had 200 hours. You think that might have something to do with it? Actually, I'm not sure. Because a brand new pilot might remember his train ing and how planes fly better than one with 3000 hours, who knows.

snipped-for-privacy@optonline.net wrote in news:6f9ca8e1-55c3-4212-841c- snipped-for-privacy@googlegroups.com:

Doesn't help? No. It should be internationally illegal and should be deemed as a criminal act by the airline.

The industry and world needs to crack down on just who is at the helm of the worlds passenger jets.

A few years ago, it was all about being at the helm enebriated.

Hell, I want to know if the guy has the chops to even sit in the seat at this point. 200 hours ain't it.

snipped-for-privacy@optonline.net wrote in news:ac160487-cbfc-46f0-a027- snipped-for-privacy@googlegroups.com:

You do not belong in the discussion if you do not know what the term 'transducer' means.

In the early days of the audio CD, everyone was interested in how early the information became digital.

Technically, a "DDD" disc is not possible.

And "air vanes" do not sense angle of attack.

It is an internal device having nothing to do with the air passing over the plane.

Proper AOA would require an IRU.

You fisrt need to know what a transducer is, then... what an IRU is.

snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:

This has nothing to do with the engines.

And the dope talking about the flat bottomed shrouds was wrong too. That is a different 737 model. The Max 8 has round engine nacelles.