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Boeing Didn't Tell Southwest Or FAA That It Had Disabled Critical Safety Alerts On 737 MAX

A report in the Wall Street Journal published on Sunday that neither Southwest Airlines nor the FAA (Boeing's primary federal regulator) were aware that a safety feature intended to alert pilots to a potentially malfunctioning 'angle of attack' sensor - in other words, a feature that might have prevented both the crash of ET302 and the Oct. 29 crash of a 737 owned by Lion Air - had been disabled on the new 737s is simply staggering. ( More...

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Kinda makes you wonder what else.
mariofer 3
It is what you don't know you don't know that gets you.
paul gilpin 1
if mark twain were posting in these comments he'd kick your a s s for bastardizing his quote.

it ain't what you don't know that gets you into trouble.
it's what you know for sure that just ain't so.

and yes, mark twain said "ain't".
Actually it was Josh Billings who said that (including the "ain't." The quote is often wrongly attributed to Mark Twain. See Wikipedia or just Google "Josh Billings."
don't think so...unlike the demeanor of your reply, Mr. Clemens was more forgiving and accepting of well-meaning commentary, errors and all.
mariofer 1
And where does it say I am quoting Mark Twain and when did he have it copyrighted? And if you are so proper, why don't you properly use upper case on his name? As far as kicking my a s s, I figure you have to let Mark Twain do it because I don't think you AIN'T got the fiber to do it yourself.
lynx318 2
No capitals suggests triggered phone-rager. Some just have to complain to feel good instead of appreciating humour.
mariofer 2
You may be right. Never though of it.
SmokedChops 19
the whole "we'll police ourselves" concept will hopefully end very shortly [not just in the aerospace industry] Independent oversight is critical. The industry I work in, we have independent inspectors. If they find issues, it gets flagged, not buried in a pile of finished parts, to meet an artificial deadline - apparently 'getting it right now' is more important than 'getting it right'. [granted, failure in this field means a $1 million harvester is sitting idle, not a $100 million passenger jet plummeting to earth because the customer did not pay enough for a 'premium platinum package' ] There are a whole host of failures in this scenario. Rule $1 in any flight emergency "Keep Flying The Plane", it sounds like that is what both crews were trying to do, for want of a functioning AOA probe, and a system that relied solely on that errant sensor. However, Boeing has demonstrated that profit above safety is an acceptable business model. My guess is that things will get worse before they improve in Chicago (Boeing Corporate HQ, I have a feeling there are many more 'they did what?!?' moments coming.
Greg77FA 8
Absolutely Unacceptable. Starting to look like a lot of process failures of checks/balances, or even basic checks. Heads should roll, and they should not have belonged to the poor souls on those doomed flights.
Timothy Sknar 4
I am retired avionics integration engineer , I would require official documents to make a official decision.
sharon bias 13
Seems like not telling the FAA is a huge flag. What else haven't they told the FAA about any of their aircraft? With any regulatory agency, if you find one problem, you look for more problems. With Medicare, they look at 15 patient charts. If they find a single problem, they look at 30 more. One more problem, 60 more reviews. Boeing has put a target on their back, and it's going to take them years to get past this. If I was a FAA employee, I'd be looking for a house in Seattle, because I'm going to be there for a long time.
randy ellis 3
been flyin 47 yrs. As a pilot, when I want the airplane, as in when I want to control the plane myself such as during many types of emergencies, a go-around (if i dont have a flight director), or I just want to have fun, then I just push that very small but very conveniently located button right under my right thumb labeled "A/P off". At that very point in time I would want all forms of automated flight control to be OFF and out of my way. Without any delay, or calculation to do, or any hysteresis, or additional buttons to push. This is the way it is in every single or twin w/autopilot that I have flown. The heavy planes, of course, need power assist. fine. Thats not what im talking about here at all. Just give control of the planes back to the pilots. They know how to fly them. How dare Boeing take that away. There is NO excuse that warrants locking the PIC out of basic flight control. And how dare the FAA to allow such a misguided design. I believe the mellenials have finally infiltrated Boeings engineering dept. and especially the FAA (Gov.) They now think in one mode: computerize. Computer solve this. Computer control that. They are not thinking the problem through. They dont have the ability to sort this problem out. IF they did the MCAS would never have existed and two planeloads of people would still be alive. Now it is a problem that once again they are going to try to solve the wrong way. So, you can see why the flying public has a dim future. Remember, too, that Boeing being so large is scrutinized at every turn to comply with affirmative action laws. They must accept employees NOT because they are the best and brightest. Feeling safer yet? While a limited amount of affirmative action was well-intentioned, it now has been going on for decades and Boeing is by now infected by this cancer so you can expect the systemic bad designs to cause more crashes.
Union pilots of all affected airlines: strike until you get unabated control of your airplane back. With the push of one button.
This statement is not an opinion. It is not negotiable and not arguable so dont expect it.
skylab72 1
Exactly. I suggest you never board an Airbus.
Adolfo Rosado 3
Corporate greed strikes again, coming to a family member near you...
Peter Cooper 3
What would Preacher1 be saying now. I think even he would be struggling to defend Boeing in the face of what appears to be a complete abrogation of their responsibility as aircraft manufacturers to the airlines and the passenger public.
lynx318 3
He would have said, "Remember what happened to McDonnell Douglas after the DC10, please don't let it happen again."
milehighou 6
Boeing needs to answer to someone for this. This sounds like corporate greed, plain and simple. Sickening that so many people had to die because of Boeing's screwups.
Roger Curtiss 2
The article asks, "Will Boeing be held accountable?" I imagine that a legion of lawyers are gearing up to ensure just that.
Bisham Singh 2
I'd love to get Boeing's respose to this article.
I have gone from true-blue Boeing fanboy to wondering what the hell we're going to find out about them next. Maybe Air Force 1 should be an A-380.
skylab72 1
Rethink that. In spite of MCAS, Boeing still has a fundamentally pilot centered flight control system. Airbus is full-up fly-by-wire. The pilot tells the computer what he wants to be done and the flight control 'package' flies the plane.
James Tobias 1
I'm new here, so go easy on me. I'm not an airline pilot, just a civilian private pilot. But I never heard either way....were the pilots hand flying both of these planes when they went down, or were they flying themselves?
skylab72 1
Technically undetermined. Indications do point to pilots attempting to control the aircraft well before impact.
Sorry for the error it was Irvin Lambert. I have a sister who is a Wheeler living in Andrews, SC where the flight originated.
It will cost Boeing a lot of lost orders over this issue.
I still cannot understand why no trace of debris has been found from the crash of a Piper PA31T,
# N555PM, 10/25/2018 when radar showed exactly where it lost contact, and Irvin Wheeler radioed that they had an emergence, and as last reported aswere descending 4,00 fpm. I knew Irvin.
Tim Hollars 1
I think I will short Boeing stock for a while.
paul gilpin -4
it's going up.
it's not going to be allowed to falter.
teslas run into a tree and fry the driver. musk turns another promise into a lie. tesla is not a car company it is a money laundering company. look at the saw tooth pattern of pump & dump.
i got off topic i know on tesla, but boeing stock, in today's financial/political climate is not going to be allowed to be shorted.
you probably think flightaware is an aviation blog. LOL
John Orman 1
Many are hoping Southwest Airlines has learned a lesson through all this. Diversify your fleet and avoid, as much as possible, these issues in the future. The acquisition of JetBlue would assist in this endeavor.
Kevin Heath 1
It's all about the money. Safety be damned.
robin cooper 1
isn't the basic problem one of design in the beginning, they only had to contrive this software to fix the issue that the engines were heavier than previous models and would change the COG. So shouldn't they have done a redesign of the whole plane or done a new model, but then competitive pressures from Airbus precluded that, so corporate greed???
Highflyer1950 2
Heavier engines would be calculated into the Basic Operating Weight of the aircraft and final C of G calculations done with known fuel, pax & baggage loads. More important, at lighter take off weights the engines being mounted further forward gave a pitch up tendency at high thrust settings which is unlike all the rest of the B737 variants. So to keep one type rating, Boeing engineered MCAS to allow the Max to feel like the others. Like when in a climbing turn, normally the nose has a tendency to fall, but apparently the Max wants to increase nose attitude while manually flying, so the MCAS rolls in a little nose down trim to make it feel identical to other B737 models. It seems that Boeing didn’t take into account just how strong the MCAS forces were, and neglected to do the what if scenario of a a damaged or faulty AOA sensor causing repeated activation of MCAS resulting in the stab being driven to the stops. Aerodynamic forces at high speeds would likely have rendered the use of opposite manual elevator trim almost impossible, but so far there is no explanation as to why the crew failed to reduce thrust from take off settings. Just sayin’
Richard Loven -4
I trust and have more faith in Boeing than the New York Times and the Wall Street Journal.
Jim Mitchell 8
You sir are an idiot.
Bob Keeping 0
I understand that the AOA sensors are used one at a time for MCAS instead of using both along with a comparator. The port and starboard units were used on alternate flights - making trouble detection even more difficult. That design is moronic if you ask me, given all the alternatives.

Recall the French airbus that was stalled by the crew at FL 320 and fluttered into the ocean. with full aft controls held by humans with little knowledge of flight principles. The problem is in the MIX of human vs automation. We need smarter people up front

electroman00 1
All pilots are smart...not all are experienced or train properly worldwide.

"I understand that the AOA sensors are used one at a time for MCAS instead of using both along with a comparator."

Your source ??
source? almost every article read on the topic says there are two AOA vanes standard on all 737 MAX planes. The optional feature was a display that would show the readout of BOTH AOA sensors and a DISAGREE light when they didn't match. Otherwise the MCAS system relies on the data input of only one sensor for flight. Each flight the MCAS would alternate to the other AOA sensor.
Peter Steitz 4
Juan Browne, a highly regarded pilot on 727's, 737's, 777's and everything else in aviation has a You Tube channel. You should go there and look and listen. He clearly stated that the AOA sensors are rotated every flight. He even shows a pic of the PFD where the miscompare is seen.
Other displays on different systems have this miscompare feature. I flew with one for 8 years but it always used both sensors--no MCAS, only shaker and pusher.

I wonder how the system knows to use the other sensor. Is it every landing? Is it a powerdown and powerup? Does the crew know which sensor is controlling?

The use of only a single sensor is absurd.
electroman00 1
The use of only a single sensor is absurd. Why you don't need any AOA to fly!

>>>"I wonder how the system knows to use the other sensor."

As a systems programmer I asked myself that as well...try this.

I makes no sense !! LOL
electroman00 2
Yeah thanks...
I fired up my friend google again...I hadn't since ET302 where I did find info that said Max8 had optional dual AOA sensors.

Meaning standard config is one AOA sensor.

Also people are concerned about single point failure, why...there are two gyro's onboard streaming attitude data and then add that to dual air speed and if the puter can't keep it flying then hand it to the pilots.

I have toys with less electronics that fly flawlessly...where is the problem!
I think it's good to wait to see what they find!
Jim Goldfuss 1
This was one of the first details of how the MCAS System worked.

[This comment has been downvoted. Show anyway.]

Jim Myers 10
You could not be further away from the reality of this situation.

[This comment has been downvoted. Show anyway.]

Not quite the whole story Highflyer, according to the article, Boeing didn't let anyone know about the change. In fact, it seems nobody knew about the change until after the first crash. See article below:

"Boeing had turned off the alerts which, in previous versions of the 737, informed pilots if a sensor known as an “angle-of-attack vane” was transmitting errant data about the pitch of a plane’s nose. In the MAX, which featured a new automated stall-prevention system called MCAS, Boeing made those alerts optional; they would be operative only if carriers bought additional safety features.

Southwest’s cockpit crews and management didn’t know about the change for more than a year after the planes went into service. They and most other airlines operating the MAX globally learned about it only after the fatal Lion Air crash last year led to scrutiny of the plane’s revised design. The FAA office’s lack of knowledge about Boeing’s move hasn’t been previously reported.

"Southwest’s own manuals were wrong" about the status of the alerts, said Southwest pilots union president, Jon Weaks. Since Boeing hadn’t communicated the modification to the carrier, the manuals still reflected incorrect information."
The idea that any 'safety feature' could be a 'menu choice', and operators only get it if they pay money for it is RIDICULOUS! It should be CRIMINAL!!!

The idea that Boeing KNEW the sensors could be 'unbalanced', and KNEW that the 'software' could cause a crash, and STILL avoided the accountability and RESPONSIBILITY for their product (they didn't buy the options).

The damn plane should have come with the entire 'safety suite' and all the blinking lights, and secondary sensors. I mean, think about buying a car and the gas gauge is a $10,000 option, and side rear view mirrors are yet another 'option' for another $15,000, and the rear view mirror in the vehicle was available for another $12,000.

So people that don't buy the 'safety features' don't have a clue how far they can go, and what they have already run over. Or how about an engine overheat light, or oil level light, but anyway...

Boeing shot themselves in the head, and the FAA let them. The current CEO should be booted, and those on the board that supported him should be turned out too. Bye-bye!!! Shareholders will pay for that idiot for a long time. Like the next crash...
Highflyer1950 0
Looking over the optional equipment list for the flight displays I wonder if the AOA annunciator lights up during the warning lights test and is there a set of dashed lines where the actual AOA readout in degrees would appear if ordered?
Highflyer1950 0
sorry, not ordered.
What are you, some kind of commie?

If the airline doesn't want an optional feature, they shouldn't have to buy it. The airlines know their markets, pilots, and passengers better than Boeing ever could.
lynx318 1
So you would be willing to buy a car, for say, optioning out on the seat belts.
Jim Goldfuss 1
You can't because seat belts are required by law. A back up camera, Lane Keep Assist, Augmented Cruise Control, etc are options which are fantastic safety enhancements but are "options" on autos that you can choose or not choose, based on your preference or financial ability.
lynx318 1
That was a hypothetical seat belt option in line with what shouldn't have been an option with MCSAS.
Highflyer1950 0
I question “who” spec’d the aircraft out in the first place. Generally when a different variant is ordered by an airline the systems are gone over by flt ops, one by one until the build list is complete. You just don’t say I’ll take 25 737 Max, wait for delivery and then go fly without the thought process of what did you buy, what’s standard and what’s optional and most of all what’s different? I still agree Boeing sales did a very poor job of communications here but just who is running these airlines Flight Operations. The article states that there were aircraft delivered without an AOA disagreement annunciator or AOA instrumentation because it wasn’t ordered by the airline. Previous models may have had it as standard equipment but not the Max.......again, who spec’d this stuff out...a bean counter, a chief pilot or a senior pilot review board or “ sales”?
electroman00 2
It's something like that...but much worse !

You can't fit that many people into a Tesla !

Nice try the point !
That's not even remotely the same thing.
Highflyer1950 1
One would hardly expect an annunciator light to work on a option not paid for? However, it should have been standard equipment from the beginning.
toverfield 3
The “annunciator light”, actually “AOA disagree” alert, isn't needed just to enhance the optional "AOA display" feature. It is critically important even without the “AOA display” feature. It should not have been bundled with the “AOA display” feature at all.

The AOA sensors are not optional features. The previously undisclosed MCAS is not an optional feature. The MCAS depends almost completely on the left AOA sensor, thus greatly increasing the danger potential of an AOA sensor problem. The “AOA disagree” can detect the main condition that makes the MCAS dangerous.

The “AOA disagree” alert costs nothing, requires no hardware and should have always existed in every airplane with the ready capability to detect it.
Highflyer1950 0
But without the disagreement annunciator it’s just like the old comparator displays. If illuminated further action required to troubleshoot.
toverfield 1
You'd like to know which AOA is reading wrong, of course, but knowing that one is wrong is a big help when you have multiple systems complaining at once. First memory item is to disable any flight control systems that want to out-muscle the pilot based on AOA inputs (i.e. MCAS).
btweston 2
You assume.
lynx318 0
I trembled reading this article.
electroman00 -7
"Boeing Didn't Tell Southwest Or FAA That It Had Disabled Critical Safety Alerts On 737 MAX"

The statement is out of context...

If customers do not purchase dual AOA sensors then the AOA safety feature is not installed !!

Why...simple...since there is only one AOA sensor it cannot be compared to the other missing sensor the customer did not purchased...thus the safety feature has to be disabled aka not installed !!

"a feature that might have prevented both the crash of ET302 and the Oct. 29 crash of a 737 owned by Lion Air "

Lets feature is only available on dual AOA so if they had that option...then Possibly and most probably.

With a single AOA sensor...not a becomes a Pilot Training issue!

>>>>>>>> Like in the good ole days!!

Older aircraft have single AOA sensors and never had the safety software option, what are you going to say about those crashes...those will be pilot error or training or a failed sensor.

The safety software compares 2 AOA sensors to each other and to other aircraft sensed data and determines absolutely which sensor is not viable !

With one sensor you can only compare to sensed data and the AOA sensor...

Which one of the two is not a crap shoot !?!?

Thus the requirement of live pilots...if the systems can't decide then who/what !!

Fact both crashes were with foreign aircraft...and may or may not have had adequate pilot training !!

Most of the USA Planes had dual sensors and single sensor planes flown by better train pilots and zero incidents.

Lends one to surmise pilot training is critical on single sensor aircraft!

Boeing will end up making dual sensors standard and fine tune the software...problem fixed!

Oh...and Boeing will take a big hit close to Bankruptcy.

Mostly due to hysteria instead of FACTS !!

You people need to be careful how you convey your thoughts about the FAA and Boeing.
Foreign countries have vested legal interest in the FAA and Boeing at this time.
Compounding the problem in this blog (seen worldwide) is not a good idea.

Yes the bottom line is important...but hardly think it's Boeing's singular driving force.
Safety is and always will be #1 as we have all seen since Boeing's inception.

With a safety record unmatched in the industry !!

Boeing is America's Aviation Leader and challenged worldwide everyday!

Some of the post here are callus and harmful without direct knowledge or evidence or experience or technical skill.

Denounce Boeing and Jobs are lost...we don't need to hurt the respectful!!
"If customers do not purchase dual AOA sensors then the AOA safety feature is not installed !!" This statement is incorrect. All 737 MAX planes come with two AOA sensors. The optional safety feature is whether the data from both will be displayed, and a disagree light if they don't match. The MCAS system as it was, would only take input from one AOA sensor per flight, however.
electroman00 -3
That wasn't what I initially read a few months ago...

Since we will never see Boeing's option price list it's real hard to absolute verify.
Could the option be so expensive that customers would opt out??

What could it cost $10,00 bananas

"The MCAS system as it was, would only take input from one AOA sensor per flight, however."

That methodology makes no sense, although I've seen it before.

Without speaking to the Software engineers we are just speculating.

We also don't have testing data to support the rational for that methodology.

This whole thing isn't making any sense...even if you lose both AOA sensors you still have two attitude gyro's giving absolute position data stream.

Meaning you don't need AOA's to fly!

What is sound like to me is little to do with the AOA sensors and more of a software bug/s relating to MCAS.

MCAS is linking it into the existing AOA sensor system may have looked easy and something was overlooked or not tested a hurry maybe?

Be good if we had the Nixon tapes...

I read somewhere it was 80,000 bananas
lynx318 1
The Boeing Company has deposited $1 into your bank account
And someone put one euro in yours.


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