I'd love to know:

1) How much it costs Boeing to fit the indicator and light
2) How much it was going to charge customers for them

And then there's the other question-

… were not equipped with an angle of attack indicator or an angle of attack disagree light, the paper said. The angle of attack indicator determines how much the plane's nose is tilted, and the disagree light is activated if the jet's sensors are giving contradictory signals.

3) If the plane can indicate that there is a problem with the inputs, why isn't/wasn't the automatic anti-stall system automatically disabled when such a condition occurs? The anti-stall system needs accurate airspeed & angle of attack data to actually determine if a stall condition is likely to occur. If it doesn't have this information, it can't make any judgment on the likelihood of a stall & so it shouldn't activate the anti-stall prevention actions under such conditions.

Not sure about the media reporting what was said accurately. If there isn't some kind of sensor then how can the Lion Air flight have had bad sensor input and written up for maintenance to fix on the prior flight? Ergo there is a sensor. There has to be as there is a stick shaker. Likely a bit more sophisticated than a stall switch on a Cessna 150, but perhaps operating in the same manner. I'm wondering if air pressure transducers and perhaps some phase of flight and flap angle looking like there is a flight condition that fools the sensor. Unless it was the bug in the sensor hole problem.

Because, as installed, it only uses ONE sensor to do the detection, and the system is "too frisky" in its operation.
The intended function is to counteract the normal increase in nose-up attitude of a 737 (and other aircraft with underwing pod engines) when the throttles are ramped up. With MCAS on the 737-max it way over-compensates, thinks the aircraft is entering a stall, fire-walls the engines, and jacks the leading edge of the tail-plain up as high as it will go and as fast as it can, effectively over-riding any pilot attempt to correct this using his control column controls, eventually the tail-plain is at such an attitude that there is no way for the pilot to correct this and the plane enters an increasing terminal dive at full power.
In addition to only using one of the angle--of-attack sensors (bad enough) the training material for the 737-max does not describe this fault and thus does not describe how to get out of it. Unlike a "normal" MCAS fault which can push the nose GENTLY up or down, this is a full on command, and can only be counter-commanded by turning the system off, but the flight manual and in-flight checklists don't cover this fault.

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

So far the issue isn't the system being overly aggressive, or not working correctly, when it has valid input- the issue has been the system responding to invalid inputs.

The Lion Air crash (still under investigation, but based on preliminary results) was a result of a difference in the reported AoA (Angle of Attack) between the left & right sensors. On it's previous flight, the issue was caused by an IAS (Indicated AirSpeed) DISAGREE error.

One of the early findings in the current investigation was-

In the initial stages of the investigation, it was found that there is a potential for repeated automatic nose-down trim commands of the horizontal stabilizer when the flight control system on a Boeing 737 MAX aircraft receives an erroneously high single AOA sensor input.

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Grant
Darwin NT

Because, as installed, it only uses ONE sensor to do the detection, and the system is "too frisky" in its operation.
The intended function is to counteract the normal increase in nose-up attitude of a 737 (and other aircraft with underwing pod engines) when the throttles are ramped up. With MCAS on the 737-max it way over-compensates, thinks the aircraft is entering a stall, fire-walls the engines, and jacks the leading edge of the tail-plain up as high as it will go and as fast as it can, effectively over-riding any pilot attempt to correct this using his control column controls, eventually the tail-plain is at such an attitude that there is no way for the pilot to correct this and the plane enters an increasing terminal dive at full power.
In addition to only using one of the angle--of-attack sensors (bad enough) the training material for the 737-max does not describe this fault and thus does not describe how to get out of it. Unlike a "normal" MCAS fault which can push the nose GENTLY up or down, this is a full on command, and can only be counter-commanded by turning the system off, but the flight manual and in-flight checklists don't cover this fault.

From what I've read the New FREE upgrade reads both sensors, if both sensors are not in agreement, then MCAS turns off and triggers a light denoting that MCAS is off and the pilots have total control.
Boeing is in deep doo doo and someone may have to pay the piper, the CEO is reputed to be a friend of trump or at least a trump supporter and yes I've read this too.

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's

I have to ask, "Why two sensors?".
If you have two time pieces, do you know what the time is? and the same applies with two thermometers.

Redundancy.
If you have only one, and it's faulty, you're up that particular creek with no paddle.

Generally when it comes to things such as air speed and angle of attack, erroneous values tend to stand out from correct ones so you can tell which sensor is good & which one is faulty. Things get really ugly when both systems are giving erroneous values.

Re-reading my post, I should have asked "Shouldn't there be three, not two sensors?"

In industrial environments where the information required was critical, the only time I can think of a case where we only used two sensors without them being monitored in some other way, we used two different sensors made by two different companies.

edit] Just seen this FT - Indonesia’s Garuda seeks to cancel order of 49 Boeing 737 Max 8s

I think the answer to Nick's question is that there are very few locations on the nose of of an aircraft that have suitably smooth airflows, and be in "comparable" positions. With two sensors it is a "simple" case of identifying a location on the side of the nose where the airflow is stable and its direction is linearly indicative of the angle of attack. With three sensors you would have to do some very careful real time modelling of the airflows at the three locations to ensure you had comparable data to feed into the comparator. Four might be simpler, but then the comparator has to take into account the variation between the two pairs of sensors...
As has been said by Vic, the "simple" solution is the "if the two disagree turn off and tell the pilot". And it would appear that this is part of a solution package being developed by Boeing - we will have to wait and see "how free free really is".

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

Grant - this is actually only partially true.
If the pilot uses his manually uses his trim control button to attempt to re-trim the aircraft if does interrupt the adjustment, but shortly after he releases his control the automatic system jumps back in again, winds the tailplane back to where it was before the pilot interruption, the continues to move the tailplane in the direction it was being moved in, until it hits the stops, at the same time it resets the throttles to max if the pilot had set them to anything less than max.
One can only imagine the panic on the flight deck while this is going on, with the pilot-none-flying grabbing the manual, and pilot-flying struggling to get the nose back up and the engines back down, thinking he's managed it, wiping his brow for it all to happen again, and again.
Here's a link to a 25 minute video by an airline pilot where this is discussed and described https://www.youtube.com/watch?v=9Ts_AjU89Qk&feature=youtu.be&fbclid=IwAR0vy9wmF74rl_EUrejYLDJfzeVQIUoE2Ko9vQPiwsKRbs-hr2DuOl-F3hg

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

Interesting video.
FAA understaffed & under qualified deferred all engineering oversight back to Boeing.
That's going to cost both Boeing & the FAA.

Interesting video.
FAA understaffed & under qualified deferred all engineering oversight back to Boeing.
That's going to cost both Boeing & the FAA.

Maybe, not only Boeing, until the FAA gets its act together, which countries are going to accept any FAA certificates, and therefore by implication any US plane maker.

That could open the doors to others. As Airbus books are full for some time, that door is wide open for others to fill the requirement.

Garuda has requested that Boeing cancel the remaining 49 aircraft of the 50 order. Will any more airlines follow suit?

The warning system to alert pilots when sensor readings of the angle of attack do not match has so far been optional, according to the Financial Times. The airlines have thus been able to choose to include the warning system at an extra cost.

The news came as another 737 MAX customer, Norwegian Air, played down the significance of a move by Boeing to make a previously optional cockpit warning light compulsory.
Norwegian said that, according to Boeing, the warning light would not have been able to prevent erroneous signals that Lion Air pilots received before their new 737 MAX plane crashed off Indonesia in October, killing 189 people.
"We have chosen not to install this particular option on our Boeing 737 Max aircraft, which is a decision that other airlines have made, as it is not a safety-critical function nor is it a requirement of any aviation authority, no matter what anybody can claim ”, writes Norwegian in an email to Reuters.
Boeing now plans to make compulsory a light to alert pilots when sensor readings of the angle of attack do not match - meaning at least one must be wrong -, according to two officials briefed on the matter.
Investigators suspect a faulty angle-of-attack reading led the doomed Lion Air jet’s computer to believe it had stalled, prompting the plane’s anti-stall system, called MCAS, repeatedly to push the plane’s nose down.

The A380 is not in the same class as the 737-max, thus Airbus cancelling the A380 production, while being a shame, may actually be to their advantage in that it frees up a lot of floor space in its plants to produce more of the A32x family. The A32x & the B737 are in the same class (100-200 seat, mid-range), and that's where the big growth in aircraft demand is just now.
The other contenders in that class are a long way behind in terms of passenger environment than either the A32x or B737 planes, and I can't see anything else on the horizon to rock the A-B duopoly for a few years. While both Embraer & Bombardier have "visually similar" aircraft, they are smaller and feel more cramped inside, and scaling up to the 100-200 seat size may not be as simple as sticking a bit more fusalage in before and after the wings as both their offerings are based on ~75 seats not ~125 seats....

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?

Grant - this is actually only partially true.
If the pilot uses his manually uses his trim control button to attempt to re-trim the aircraft if does interrupt the adjustment, but shortly after he releases his control the automatic system jumps back in again, winds the tailplane back to where it was before the pilot interruption, the continues to move the tailplane in the direction it was being moved in, until it hits the stops, at the same time it resets the throttles to max if the pilot had set them to anything less than max.
One can only imagine the panic on the flight deck while this is going on, with the pilot-none-flying grabbing the manual, and pilot-flying struggling to get the nose back up and the engines back down, thinking he's managed it, wiping his brow for it all to happen again, and again.
Here's a link to a 25 minute video by an airline pilot where this is discussed and described https://www.youtube.com/watch?v=9Ts_AjU89Qk&feature=youtu.be&fbclid=IwAR0vy9wmF74rl_EUrejYLDJfzeVQIUoE2Ko9vQPiwsKRbs-hr2DuOl-F3hg

Rob, MCAS has no control over throttle https://theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/ It doesn't even pitch the nose down, it moves the trim tab on the horizontal stabilizer. A pilot should have the muscle to over ride the trim tab. But in any case if you saw the pictures in the link, that big wheel in one, if the pilot moves it the system disconnects. If the pilot turns off the electric trim switches, shown in another picture, the system disconnects. If the pilot uses the switch on his "wheel", the lazy method, it doesn't disconnect. Any pilot training that does not include at least one simulated emergency with a runaway electric trim motor, is a failure. That's why simulators. Every possibility should get tossed at the trainee so when - not if - the real thing happens he has been through it already.

Rob, MCAS has no control over throttle...

I think that needs checking. The pilot on the video ('blancolirio') says:

"MCAS is going to push the throttles full forward in an effort to recover from a stall."

The MCAS description starts at about 16 minutes, and that quote is at minute 21.

As was the 707 & 727. I also had the pleasure of flying in a British built aircraft which holds the record for the fastest Atlantic crossing for a sub-sonic jetliner - Vickers VC10.

Rob, MCAS has no control over throttle...

I think that needs checking. The pilot on the video ('blancolirio') says:

"MCAS is going to push the throttles full forward in an effort to recover from a stall."

The MCAS description starts at about 16 minutes, and that quote is at minute 21.

I think that "you tube person" doesn't fly the max and I think I believe Boeing's description of what the system does is correct. In addition I think I believe the reason for the system to exist is at odds with what the "you tube person" says would be the response.

https://theaircurrent.com/aviation-safety/what-is-the-boeing-737-max-maneuvering-characteristics-augmentation-system-mcas-jt610/

When Boeing set out to develop the 737 Max, engineers had to find a way to fit a much larger and more-fuel efficient engine under the wing of the single-aisle jet's notoriously low-riding landing gear. By moving the engine slightly forward and higher up and extending the nose landing gear by eight inches, Boeing eked another 14% improvement in fuel consumption out of the continually tweaked airliner.

That changed, ever so slightly, how the jet handled in certain situations. The relocated engines and their refined nacelle shape. At high angles of attack the CFM Leap-1B's engine nacelle generates its own lift An earlier version of this story referred to the "higher thrust" effect of the engines. caused an upward pitching moment -- in essence, the Max's nose was getting nudged skyward. Boeing quietly added a new system "to compensate for some unique aircraft handling characteristics during it' (sic) Part 25 certification" and help pilots bring the nose down in the event the jet's angle of attack drifted too high when flying manually, putting the aircraft at risk of stalling, according to a series of questions and answers provided to pilots at Southwest Airlines, the largest 737 Max operator reviewed by The Air Current.

The Maneuvering Characteristics Augmentation System (MCAS) was designed to address this, according to Boeing engineers and pilots briefed on the system, now at the center of the inquiry into the crash of Lion Air 610, a brand new Boeing 737 Max 8. MCAS is "activated without pilot input" and "commands nose down stabilizer to enhance pitch characteristics during step turns with elevated load factors and during flaps up flight at airspeeds approaching stall."

"Its sole function is to trim the stabilizer nose down," according to the system's description to pilots, who were learning about it for the first time this week.

Perhaps you would prefer this source http://www.b737.org.uk/mcas.htm

MCAS was introduced to counteract the pitch up effect of the LEAP-1B engines at high AoA. The engines were both larger and relocated slightly up and forward from the previous NG CFM56-7 engines to accomodate their larger diameter. This new location and size of the nacelle causes it to produce lift at high AoA; as the nacelle is ahead of the CofG this causes a pitch-up effect which could in turn further increase the AoA and send the aircraft closer towards the stall. MCAS was therefore introduced to give an automatic nose down stabilizer input during steep turns with elevated load factors (high AoA) and during flaps up flight at airspeeds approaching stall.

Regardless, 346 people are dead due to 2 fatal crashes with the same aircraft. Both of which are showing similar issues.

It seems to me that both Boeing and the airliners are both "guilty as charge".
Boeing knew very well about the problem.
And the airliners didn't include the new procedures in the pilot's manuals about the changes in the 737 MAX.
I read somewhere that the information of the changes of how to turn the "anti-stall system" off, only was available with an app downloaded to your smartphone!

The main reason that the airlines didn't include the information is apparently that Boeing didn't tell them as Boeing didn't consider MCAS to be a "safety" system, only an "assistance" system :-(

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Bob Smith
Member of Seti PIPPS (Pluto is a Planet Protest Society)
Somewhere in the (un)known Universe?