More MAX information

[Vraciu]

I think SWA is the worlds largest user of the 737. Right now SWA's fleet has been simplified to NG -700 and -800, and MAX 8.  SWA and SWAPA (our union) were happy to continue flying the MAX.  SWA does not have a MAX sim yet.  The 40+ year old checklist for runaway trim is effective against inadvertent MCAS activation, and in the MAX the switches are in the same location so differences training in a sim hasn't been seen as necessary at SWA even after MCAS was highlighted.

At this point Boeing could slap a big sticker on the glareshield that reads "in the event of runwaway trim, do that pilot $hXt" and it would be all good, as far as I'm concerned, and people who place their lives in the hands of a 200 hr pilot are gonna get what they get because to put it mildly, it's an unforgiving environment.  But nobody asked me to make the rules so I'm gonna do whatever the company and the FAA tells me.

I was just saying that at some point even a common type isn’t that common. 

Even SWA realized this toward the end of the -200’s tenure, and that was with pilots of high experience. 

Now imagine some low-time Nigerian -200 pilot over at some place like Aero suddenly thrust into a MAX-8 having never seen the sim.   Not good. 

Heck, I remember the looks of fear in EMB-145 Captains being sent to fly a 140 on Reserve over the FMS alone.   The only time they had seen it was in paper.   

Good points overall.   

[Vraciu]

Did these last two crashes happen becasue the AOA was not updated to the visual screen?

We have no idea yet.    But if they fought it to the ground it appears they failed Basic Airmanship 101 in not disabling the trim stab system.

[Busher]

Gentlemen, I would never presume to have the answers to this issue but a couple of items are obvious to me.
Returning to the era of highly experienced new hires entering the airlines is an impossible dream. The cost and time for the candidate would be prohibitive and we all know the airlines would simply not pay for it. I laugh when I recall the candidates on my initial course in 1979. I was not the high time pilot with 5300 hours, a lot of turboprop time and almost 100 hours of jet time. The low time pilot on my course had recently left the Air Force but he still had over 3000 hours command time on C-130s.
Maybe as Toad alluded to with his Airbus observations, the answer lies in the development of automation that is so advanced and so redundant that it can be certified as fail-safe. Remembering an old adage "never fly an airplane anywhere that your brain didn't visit 5 minutes ago" does not seem to be possible anymore.

[eagl]

Did these last two crashes happen becasue the AOA was not updated to the visual screen?

As far as we know or can guess, the crash was a sequence of events.  One AOA sensor failed, which triggered MCAS after takeoff when the flaps were raised.  The crews failed to accomplish the runaway trim checklist, while the whole time the trim wheels between the pilots whirred and whirred away as the trim went full nose down.  At some point whoever was flying was unable to keep fighting the nose down trim by hauling on the yoke, and the planes crashed.

Having the AOA on the screen wouldn't have changed anything.  What *might* have prevented them from taking off in the first place however could have been an "AOA mismatch" warning on the screen, telling them that the two AOA sensors did not agree with each other.  My understanding is that warning is only enabled on planes that have the AOA gauge display option.  Even then, I am not convinced that the crews would have correlated "AOA mismatch" with runaway trim since they didn't know this most basic of emergency procedures.

Regardless of whether they have the AOA gauge option or not, the corrective action for this malfunction is the relatively simple checklist posted earlier in this thread. It basically tells the pilot to hold the controls firmly (ie. keep flying the plane), use the electric trim switches to try to counteract the runaway trim (which would have temporarily stopped the runaway trim in the case of MCAS failure), and then if the trim keeps running away to use the trim disconnect switches.  After that, use the gigantic trim wheels between the pilots to change pitch trim.  Every pilot who flies an aircraft with powered trim should be able to accomplish this checklist (or their aircraft's equivalent) quickly with their eyes closed, because any aircraft with a powered trim system can potentially have runaway trim AT ANY TIME for any number of reasons.

I don't think we'll ever know why 3 crews in a row failed to accomplish this checklist (the first Lion Air crew that had this malfunction was apparently saved by a jumpseater the day prior to the flight that crashed).  For that matter, the previous flight's crew was so ignorant of what happened that they also apparently couldn't even write up the malfunction in the logbook correctly to get it fixed.  But it makes for better "news" to blow this up into a big business and government conspiracy theory, which is why 90% or more of the media coverage of these crashes has been inflammatory nonsense.

[Oldman731]

They’re betting that most of the time HAL can handle it with data input managers. When HAL fails it’s acceptable losses.

I can tell you that this rationale did not work out well (for the manufacturer) in the Ford Pinto case.

- oldman (the actual Pinto Memo is available at a few places; this is one:  https://www.autosafety.org/wp-content/uploads/import/phpq3mJ7F_FordMemo.pdf)

[Vraciu]

Just wait until “the cure is worse than the disease” meets The Law of Unintended Consequences.   I used to bring airplanes out of storage and they were sometimes a mess.    The longer they were mothballed the more trouble it was to fix things. 

Sad.  Just sad.

https://losangeles.cbslocal.com/2019/03/25/southwest-737-max-8-storage-victorville/

[Vraciu]

40 seconds?   Sheesh.   Try an aileron or rudder hardover.

40 seconds is a lifetime comparatively speaking. 

The press is detestable. 

https://www.nytimes.com/2019/03/25/business/boeing-simulation-error.html

[Toad]

The NY Times and I have an agreement. I will read their fish wrapper of a newspaper every now and then when an article appeals to me. They in turn will limit me to 5 articles a month. I absolutely refuse to give them any money for a subscription due to their complete and total lack of journalistic integrity. I guess I'll read that in April.

Oldman, I suspect most companies learned from Ford/Pinto to NOT put their cold-blooded actuarial decisions in print or in media that can later be used against them in court. I'm sure all the aircraft makers do calculations to determine if a feature or system is cost effective. You can see that in Boeing's decision to make the AOA Miscompare light an optional feature. I think they figured the AOA Miscompare light would very rarely illuminate (one bad AOA) and that experienced pilots would know what to do anyway, light or no light. Bean counters made a mistake there.

As for the One AOA vs Two AOA trigger, IMO that's just "doing something". Either system works as is evidenced by the FAA Gulfstream 550 vs JAA Gulfstream 550 situation I posted earlier.

They are going to change from the pilots having to know the Runaway Stabilizer procedure to the pilots having to recognize an impending stall and recovering without the MCAS backup. The new dual AOA system is going to require more pilot situational awareness and possibly more skill/ability/training depending on the state of the particular airline's pilot cadre.


The way it is now, single AOA trigger, it's not the system. It's whether or not the pilots can

1. Maintain aircraft control - Counter runaway with electric trim
2. Analyse the situation - Stabilizer runaway
3. Take the proper action. - Turn off trim

Which is pretty much the exact same Boeing Runaway Stab procedure that's been around since the B-707.

[Busher]

40 seconds?   Sheesh.   Try an aileron or rudder hardover.

40 seconds is a lifetime comparatively speaking. 

The press is detestable. 

https://www.nytimes.com/2019/03/25/business/boeing-simulation-error.html

Not really detestable. You forgot that it takes the average airline executive 10 meetings over at least a week to solve their "life and death" issues.

[Ciaphas]

Coming from an aircraft MX background (22 years and 25 more to go... .), I find it hard to understand how anyone operating or maintaining any system with tech manuals, checklists and/or SOPs available can with good faith operate or maintain their respective systems without being familiar with them.

Complacency and ignorance are the top two killers of operators and maintainers.   


Sent from my iPhone using Tapatalk

[Puma44]

It's whether or not the pilots can

1. Maintain aircraft control - Counter runaway with electric trim
2. Analyse the situation - Stabilizer runaway
3. Take the proper action. - Turn off trim

Which is pretty much the exact same Boeing Runaway Stab procedure that's been around since the B-707.

And

4. Maintain situational awareness.

[bustr]

If this experienced body of pilots and professionals are able to deduce the general series of events and subsequent solutions to the recent MAX accidents. Then worldwide a larger body of pilots and professionals have also. So I would assume a fix is already in place while the rest is a global circus of CYA to make news copy, make bones off executives humiliation, and find a fall guy to pin this on. Otherwise is there really anything wrong with the MAX itself?

[Vraciu]

If this experienced body of pilots and professionals are able to deduce the general series of events and subsequent solutions to the recent MAX accidents. Then worldwide a larger body of pilots and professionals have also. So I would assume a fix is already in place while the rest is a global circus of CYA to make news copy, make bones off executives humiliation, and find a fall guy to pin this on. Otherwise is there really anything wrong with the MAX itself?

Good summation of the situation.   

The guys I know who fly the MAX say it's fine.   I only know people at two of the three US Majors though and anecdotal evidence is what it is.

[Vraciu]

https://www.airlinepilotforums.com/2781863-post30.html

Hmmmmmmmm.

[Toad]

Otherwise is there really anything wrong with the MAX itself?

Probably only that due to the new engines it has a pitch up tendency and that shouldn't be a showstopper for any experienced Boeing pilot:

It was found that this new positioning of the engines caused the 737 MAX to pitch up slightly during certain maneuvers, especially when the aircraft was already at a high angle-of-attack (AoA). In other words, when the nose of the aircraft was raised to gain altitude, the plane would start to climb higher than the pilot intended. If left unchecked, this tendency could potentially lead to a disastrous stall condition; where the aircraft has pitched up so far that it’s no longer able to produce lift. To counteract this quirk of the design, the MCAS system was introduced.

Now, MCAS only is a player when:
1. AOA is high
2. A/P is off
3. Flaps are up

I haven't flown the 737-800 since about 1999. I wouldn't hesitate to go fly a MAX right now. I think I still remember how to counter a pitch up tendency.