# Boeing 737 MAX - software wouldn't fix faulty airframe

#### WBahn

Joined Mar 31, 2012
26,398
That was a simple fix, A rudder actuator as I recall. If this indeed is an airframe design issue the fix is going to be way more complicated.
I actually didn't mean to post the response to your post because I realized that the two situations were different as far as the criticisms being leveled, if nothing else. I left and came back later and responded to the other post but the one I had composed was still in the buffer.

ASIDE: Underscores why it's a good idea not to even write something that you aren't willing to post even when you have no intention of posting it -- I've seen people write scathing, hate-filled crap saying all the things that "they wanted to say" but had no intention of actually saying, until they accidentally hit "Send", that is.

That is unless pilots and passengers are willing to live with the fact it is going to take software to keep the plane in the air (assuming there is an actual software fix for this).
But that's already the way it is.

#### nsaspook

Joined Aug 27, 2009
8,906
Why did Boeing charge for the MCAS upgrade?
Some airlines opted not to have the MCAS upgrade.

http://www.b737.org.uk/mcas.htm
It seems all the pilot had to do to re-stabilize the aircraft from the MCAS induced trim errors was to pull the STAB TRIM breakers/switches. Per the link this was already the stated procedure for a runaway stabilizer.

From PPRUNE:

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#### Glenn Holland

Joined Dec 26, 2014
705
A few things I'm aware of they did very wrong:
• Added the MCAS system without emphasising the nature of the change (it's right there in the middle of the pilots manual ) and not having the pilots trained to understand it (because they wanted to be able to say the pilots didn't need retraining from the standard 737).
• Allowing the MCAS system to generate so much downward trim that it couldn't be corrected by pulling up on the yoke.
• Not automatically disabling the MCAS when the pilot pulled up on the yoke.
• Making some safety features, such as a light to show when the MCAS was active, optional and extra cost.
• Not grounding the plances, retraining the pilots, and/or modifying the system after the first accident where the MCAS system was suspected.
I think Boeing is up for some huge liability for those two crashes.
Boeing is also getting hit with liquidated damages for all the 737 Max's that have been purchased by the airlines, but have been mothballed because of the the FAA grounding order. Liquidated damages accrue for every day the planes are out of service. The airlines may also file a "Breach Of Merchantability" suit which claims the product (the 737 Max 8) cannot be used for its intended purpose (providing commercial air transport).

#### MrChips

Joined Oct 2, 2009
24,623
If I purchase an autonomous vehicle, can I opt out of buying an expensive collision detection software option?

#### WBahn

Joined Mar 31, 2012
26,398
The airlines can charge for baggage so why can't Boeing charge for safety features ?
Agreed.

I would imagine that Boeing would be just fine with a bunch of those features being required equipment. The article pretty clearly assumes that if Boeing, either voluntarily or via regulation, included those features on every aircraft that they would be free and Boeing would be out the profit that they currently make on upgrades. But if the base plane currently costs $120 million and options that currently cost$1 million become required equipment, does anyone really think that the cost of a base plane with all of those features is going to stay at $120 million? Of course not! It will be closer to$121 million and now Boeing gets the associated profit not only from those purchasers that chose the upgrades, but from every purchaser. The only reason for Boeing to not support it would be the concern that it would move the price point up to a level that would drive potential purchasers to purchase fewer aircraft (and not just to a different airliner since, presumably, all manufacturers would be required to include comparable equipment on all comparable aircraft). Given the relatively small number of hulls that are sold, this is likely a real concern. There are currently fewer than 400 737 MAX aircraft that have been produced, so if total sales was reduced by just 3 or 4 aircraft as a result of the higher price, their revenues would go down. So the real question would be just how price-elastic is the demand for airliners? Does a 1% increase in price result in more than a 1% decrease in volume of sales?

#### MrChips

Joined Oct 2, 2009
24,623
Agreed.

I would imagine that Boeing would be just fine with a bunch of those features being required equipment. The article pretty clearly assumes that if Boeing, either voluntarily or via regulation, included those features on every aircraft that they would be free and Boeing would be out the profit that they currently make on upgrades. But if the base plane currently costs $120 million and options that currently cost$1 million become required equipment, does anyone really think that the cost of a base plane with all of those features is going to stay at $120 million? Of course not! It will be closer to$121 million and now Boeing gets the associated profit not only from those purchasers that chose the upgrades, but from every purchaser. The only reason for Boeing to not support it would be the concern that it would move the price point up to a level that would drive potential purchasers to purchase fewer aircraft (and not just to a different airliner since, presumably, all manufacturers would be required to include comparable equipment on all comparable aircraft). Given the relatively small number of hulls that are sold, this is likely a real concern. There are currently fewer than 400 737 MAX aircraft that have been produced, so if total sales was reduced by just 3 or 4 aircraft as a result of the higher price, their revenues would go down. So the real question would be just how price-elastic is the demand for airliners? Does a 1% increase in price result in more than a 1% decrease in volume of sales?
And that supports my initial contention.

#### WBahn

Joined Mar 31, 2012
26,398
And that supports my initial contention.
So, in this utopian world where airline companies and aircraft manufacturers care only about passenger safety and don't have to be profitable, who is supposed to pay for all of these safety features?

Are the aircraft manufacturers expected to operate at a loss if that's what is required to incorporate every conceivable safety feature?

Are the airlines expected to operate at a loss if that's what's required to buy aircraft that have every conceivable safety feature?

Maybe the government should pay for every conceivable safety feature on every aircraft as a means of promoting the general welfare.

Maybe people should be barred from purchasing tickets from any airline that operates aircraft that don't have every conceivable safety feature.

#### MrChips

Joined Oct 2, 2009
24,623
So, in this utopian world where airline companies and aircraft manufacturers care only about passenger safety and don't have to be profitable, who is supposed to pay for all of these safety features?

Are the aircraft manufacturers expected to operate at a loss if that's what is required to incorporate every conceivable safety feature?

Are the airlines expected to operate at a loss if that's what's required to buy aircraft that have every conceivable safety feature?

Maybe the government should pay for every conceivable safety feature on every aircraft as a means of promoting the general welfare.

Maybe people should be barred from purchasing tickets from any airline that operates aircraft that don't have every conceivable safety feature.
Who said anything that the aircraft manufacturer will be operating at a loss?
Boeing's profit for 2018 was $10.5 billion. https://www.flightglobal.com/news/articles/boeings-2018-profit-hits-105bn-as-production-soar-455407/ #### WBahn Joined Mar 31, 2012 26,398 Who said anything that the aircraft manufacturer will be operating at a loss? Boeing's profit for 2018 was$10.5 billion.

https://www.flightglobal.com/news/articles/boeings-2018-profit-hits-105bn-as-production-soar-455407/
So how much profit should they have made?

Should they have provided every conceivable non-required safety feature on every aircraft without increasing the price of the aircraft? After all, if they increased the price that would have motivated potential buyers (who clearly care only about profit and not passenger safety) to buy a cheaper aircraft that doesn't have all of those non-required safety features from another manufacturer which would only prove that Boeing doesn't care about passenger safety.

#### crutschow

Joined Mar 14, 2008
28,204
No, it's obvious they can't likely put in every conceivable safety feature, but when an added/new software feature is operating to take control of the pitch to correct a perceived plane's incorrect attitude, the light/warning to inform the pilots that this is happening should not be optional.
This result of this omission is two crashed planes, where both sets of pilots apparently did not know/understand that their plane was being driven into the ground by the software.

#### WBahn

Joined Mar 31, 2012
26,398
No, it's obvious they can't likely put in every conceivable safety feature, but when an added/new software feature is operating to take control of the pitch to correct a perceived plane's incorrect attitude, the light/warning to inform the pilots that this is happening should not be optional.
This result of this omission is two crashed planes, where both sets of pilots apparently did not know/understand that their plane was being driven into the ground by the software.
Could you please provide the link to the investigation's conclusions that this omission is the probable cause of both of these crashes?

I'd love to read it and I can't find anything on the NTSB's website.

#### MrChips

Joined Oct 2, 2009
24,623
Both aircrafts did not have the AOA (Angle-of-Attack) disagree light.

The New York Times reports that both vehicles lacked an "AOA disagree" light—a warning light that indicates when the aircraft's two AOA sensors provide different readings—and an angle of attack indicator. Since the MCAS system relied only on one of the aircraft's AOA sensors, the disagree light and AOA indicator would have given the flight crew visible evidence of a sensor failure and prompted them to disable the MCAS. But both of these features were sold by Boeing as expensive add-ons. And many discount and smaller airlines declined to purchase them, as they were not required by regulators.

https://arstechnica.com/information...-have-prevented-737-max-crashes-as-an-option/

#### nsaspook

Joined Aug 27, 2009
8,906
I'm glad that the "AOA disagree" light will be standard now but it was not required by regulators in the countries that ordered the planes that crashed and I sure Boeing would have gladly charged them for the addition on the initial order if it was mandatory for that country.
https://www.aviationtoday.com/2018/...-analyzes-pilot-struggle-737-max-trim-system/
Lion Air’s managing director confirmed to Reuters that they did not install the feature because it is not mandatory.

A review of the crashed aircraft’s maintenance logs showed that it had been experiencing problems on each of the four flights that occurred prior to JT610. Both AOA sensors were replaced Oct. 27, two days prior to JT610, but pilots flying the aircraft the very next day experienced similar automatic nose down trim conditions that occurred on JT610. During the Oct. 28 flight, the pilot in command noticed an indicated airspeed error message on the aircraft’s primary flight display and activation of the stick shaker. Eventually the pilot disengaged the autopilot and STAB TRIM switches while his co-pilot continued the flight with manual trim and the remainder of the flight was uneventful.

#### MrChips

Joined Oct 2, 2009
24,623
Hah! Now the finger points to inadequate pilot training?

#### nsaspook

Joined Aug 27, 2009
8,906
Hah! Now the finger points to inadequate pilot training?
Unfortunately that might be the difference here with a system that can mislead one set of pilots to their deaths while another set of pilots on the exact same plane follows procedures to an otherwise uneventful flight.

#### crutschow

Joined Mar 14, 2008
28,204
Could you please provide the link to the investigation's conclusions that this omission is the probable cause of both of these crashes?
I'm not aware that any investigation conclusions have been released.
It's my conclusion based upon what I've read about the system and the lack of warning indicators.
It's seems apparent that the pilots didn't know what was happening, and the likely cause of that was a lack of warning that the system was trying to correct a perceived problem (apparently in error) that then drove the planes into the ground.

But certainly a lack of pilot training/awareness about the new system could have contributed to their not recognizing what was happening.

#### MrChips

Joined Oct 2, 2009
24,623
And as discussed in so many places, Boeing sold the 737 MAX 8 as the same 737 that required no pilot retraining, as a sales advantage, i.e. it saved the airlines money... it satisfies and retains Boeing's customers.

#### justtrying

Joined Mar 9, 2011
435
Finger pointing is an interesting thing. We have the manufacturer, the regulator, the companies using the equpment and the operator. Ultimately, an experienced pilot can compensate for many shortcomings of the manufacturer and his employer. A pilot probably does not want to die on the job. But what does that mean? What is the goal of the manufacturer and their sales team? To pitch you a product and convince you that it requires minimal investment.

Working with medical equipment, I have learned the perils of talking to sales people, dealing with inexperiences tech support and having to constantly catch up with software upgrades designed to make said equipment safer and less prone to errors. Oh, and to eliminate human errors as well. Guess what is one of the leading causes of issues in medical devices - "smart" infusion pump... From what I have seen , software is only useful when users are fully aware of its limitations and when it can be easily overridden.

#### Glenn Holland

Joined Dec 26, 2014
705
The Airline Passengers Association now has a new motto:

"If It's On A Boeing, I Ain't Going".

The way this 737 Max 8 debacle is turning out, looks like Boeing and the FAA must have been recent graduates of the Richard Nixon School Of Ethics with a major in lying and covering up.