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-   -   B737MAX Recertification - Archive (https://www.flyertalk.com/forum/united-airlines-mileageplus/2031779-b737max-recertification-archive.html)

augias84 Mar 21, 2019 10:09 am

So, is the United 737Max less safe than AA because it is lacking these safety features? Or is it really true that for UA it's not necessary because their pilots have other systems in place that would detect a malfunction, and would know what to do?
After reading the NYT article just now, I am also surprised that AA (the most penny-pinching airline in the US), would install all the safety features and UA would not.

IADFlyer123 Mar 21, 2019 10:24 am


Originally Posted by augias84 (Post 30913323)
So, is the United 737Max less safe than AA because it is lacking these safety features? Or is it really true that for UA it's not necessary because their pilots have other systems in place that would detect a malfunction, and would know what to do?
After reading the NYT article just now, I am also surprised that AA (the most penny-pinching airline in the US), would install all the safety features and UA would not.

Maybe they got discounts/ complimentary for the promise of a future large purchase? I am guessing it might be common in the airline market.

Say Vandelay Mar 21, 2019 10:48 am

Back to the car analogy, do the pilots at UA have any say in which safety options are chosen?

mduell Mar 21, 2019 10:51 am


Originally Posted by Say Vandelay (Post 30913481)
Back to the car analogy, do the pilots at UA have any say in which safety options are chosen?

Their union has a pretty loud voice on safety issues.

spin88 Mar 21, 2019 12:32 pm


Originally Posted by justatourist (Post 30912408)
Food for thought.

Everyone should read this post, as it (a) suggests that even on the "saved" lion Air flight the pilots got lucky, they did not diagnose the issue, and (b) the 737 pilot's response is very honest in admitting that these events don't just happen when everyone is quietly sitting listening to opera, and would be VERY hard to diagnose, let along fix, without a lot of elevation to work with. I will simply say what I have said several times upthread, in the 2010 LH A321 AoA trim issue, the pilots only managed to find/fix the issue because they had 30K to work with. Had they been at take-off, the results might well have been different. This just highlights how Boeing ought to - as part of a TS16949/DFMEA review - identify the issue, and have multiple redundancies to address it.

There is a lot of protective responses on this board that - they/us pilots, etc - would have easily diagnosed the problem. The hard truth is that a lot is going on, and diagnosing the problem on a 737 in particular, and then manually trying to fix the trim, appears to not be so easy.


Originally Posted by Bear96 (Post 30912638)
But did it really present as runaway trim? Runaway trim presents itself as a constant, continuous increase or decrease in trim. Here it was intermittent. Sure at some point they may have figured out that cutting out the trim was the correct response, but I can see how it might not have been the first thing they thought about, and they didn't have the luxury of altitude to think about everything.

Of course now we have the benefit of 20/20 hindsight to see that the runaway trim procedure would have been the correct response, but I am not sure it is fair to say (at least for the Lion Air pilots) that they should have realized that right away.

A key point. Had this happened once, the "pilots should have figured it out" defense might work, but the hard truth is that two sets of pilots (one at a well respected airline, after getting Boeings "new" training, such as it was) did not figure out the issue in time. This is all on Boeing at the end of the day.


Originally Posted by Michael899 (Post 30912782)
According to the same article, UA is the only US carrier that opted not to outfit its Maxes with at least one of the AOA alert features (AA has both). I wonder what "other data" UA pilots may be relying on that AA and SWA are not.

I'm going with a few extra cents into the value of each share of UAL, resulting in a few extra $$$ into the value of Jeff Smisik's stake in the airline...


Originally Posted by mduell (Post 30912831)
I'd guess airspeed and attitude, but that's just guessing.

Well then you would be guessing exactly what the Lion Air pilots were looking at, and freaked out about, as they tried to save the plane. So hopefully, UA was relying on more than that.....


Originally Posted by Bear96 (Post 30912998)
Right. That is why I think it might be unfair to expect a pilot who thinks he may be experiencing unscheduled trim to immediately know to execute the runaway trim procedure.

Eventually he may decide to try that after nothing else is working (and here there was very little time to troubleshoot), but I would think there might be a bit of hesitation about the procedure not being the right one, or even making the situation worse, since it really isn't the procedure for what he appeared to be experiencing.

Hind sight-bias works in two ways. Here, knowing the problem, one would immediately cut off the system and do the hard physical work of moving the trim (described above by a 737 pilot), but that does not suggest that the failure mode was so easy to determine, particularly right after take off, and for a NEW system that Boeing did not train folks on.

again, this is 100% on Boeing.

MSPeconomist Mar 21, 2019 12:38 pm


Originally Posted by IADFlyer123 (Post 30913321)
If the crew was focused on solving the problem that they were previously made aware of, did they fail with CRM (Crew Resource Management) by just being fixated on faulty readings? Additionally, not having enough airspace to work with, only complicated matters. They were fixated on not-crashing. Could they have reached out to their ops teams and asked for help? Or have the ops team reach out to the last crew? We will never know what could have gone through their mind before the crash.

But wouldn't a lot of these questions be answered by the cockpit voice recorder?

IADFlyer123 Mar 21, 2019 12:41 pm


Originally Posted by MSPeconomist (Post 30913892)
But wouldn't a lot of these questions be answered by the cockpit voice recorder?

Based on the initial data reported by the CVR, the pilots were frantically scrambling (given the low altitude). Seems like something they did not encounter in sim training and were trying to solve it on the fly.

MSPeconomist Mar 21, 2019 1:21 pm

Is it correct that we have no data whatsoever from the October 28th incident beyond the brief report by the pilot in charge of that flight? The cockpit voice recorder would have been written over and the data recorder information not retained either, right? What about data from third party tracking and warning systems, such as that which was utilized for the missing MH flight? (Was there a reference to such data for the ET crash that formed part of the basis for Canadian and American authorities to finally ground the MAX?)

DenverBrian Mar 21, 2019 2:41 pm


Originally Posted by Newman55 (Post 30912908)
That's something that is not unique to the 737Max, Boeing or to the aviation industry.

Many safety features in personal vehicles are options as well. I doubt many people demand every safety feature.

I haven't heard of a single four-door sedan ever killing 150 people in one fell swoop. @:-)


Airbus also has options for additional safety features. You think every airline in the world gets every safety feature available?
They should. If it enhances safety, especially in the critical phases of takeoff and/or landing, it ought to be mandatory on aircraft carrying hundreds of passengers.

raehl311 Mar 21, 2019 2:55 pm

Did someone tell United that the MCAS system only pays attention to one of two sensors and doesn't notice if their outputs don't match so that an indicator to the pilots is necessary?

Seems like the optional safety equipment is only really not optional because Boeing's system design sucks. A critical airline system reliant on ONE sensor?

Thought we learned our lesson after that Air France Airbus 330 broke up over the Atlantic because of Pitot tubes...

findark Mar 21, 2019 3:11 pm


Originally Posted by DenverBrian (Post 30914346)
I haven't heard of a single four-door sedan ever killing 150 people in one fell swoop. @:-)

Never mind that cars kill people at a rate almost one thousand times higher than passenger aircraft, on a per passenger-mile basis.

EmailKid Mar 21, 2019 3:18 pm


Originally Posted by findark (Post 30914462)
Never mind that cars kill people at a rate almost one thousand times higher than passenger aircraft, on a per passenger-mile basis.

Ya, not apples and oranges, apples and asteroids :rolleyes:

Let's stick to airplanes in this thread @:-)

cmd320 Mar 21, 2019 4:18 pm


Originally Posted by Newman55 (Post 30912908)
Many safety features in personal vehicles are options as well. I doubt many people demand every safety feature.

Yes, however when I purchase a car with a lack of said features, that's my choice. If I purchase a car without seatbelts, crash, get ejected, and die, I was well aware of the risk when I set off and opted to go ahead with it.

Conversely, we are talking about a form of mass transportation here wherein customers trust that the company and the agencies which regulate it have done what is reasonable to ensure their safety. And what is coming to light is that Boeing and a number of airlines have not done that and instead decided to save money by not fitting what are basically essential features. The question must be asked, why did Boeing even make this an option?

ExplorerWannabe Mar 21, 2019 4:38 pm


Originally Posted by DenverBrian (Post 30914346)
I haven't heard of a single four-door sedan ever killing 150 people in one fell swoop. @:-)

No but there have been frequent auto accidents with 100% fatalities and there are still more people killed on the road than in airplanes every year. People have died because they weren't wearing their seatbelts but people have also died because of the way airbags triggered. Some of the people who died due to not wearing their seatbelts would still be alive anyway had they not been speeding/distracted/poorly trained/etc.

I am suspicious due to the confluence of circumstances but I'm going to disagree with those who emphatically state right now with the information presented on this board and through mainstream media sources that this is definitively 100% Boeing's fault. There's still a lot of information that we don't know yet.

DenverBrian Mar 21, 2019 6:08 pm


Originally Posted by findark (Post 30914462)
Never mind that cars kill people at a rate almost one thousand times higher than passenger aircraft, on a per passenger-mile basis.

Of course I mind that. I can walk and chew gum at the same time. @:-)

I certainly WON'T accept that 300 people dead in two crashes five months apart in the same brand new model of plane is somehow "acceptable losses."


Originally Posted by ExplorerWannabe (Post 30914700)
No but there have been frequent auto accidents with 100% fatalities and there are still more people killed on the road than in airplanes every year.

I guarantee you that if 100 brand new 2020 Ford Unicorn cars suddenly ran into brick walls and killed their occupants on the same day, every single one of those cars would be impounded and not driven until Ford fixed the problem or took back the cars. That's the closest analogy we have between cars and planes, not the "hey, lots of people die in cars every day, so that makes plane crashes acceptable" ridiculous logic.


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