
The Boeing 737 Max 8 Crashes: The Case for Pilot Error - hsnewman
https://seekingalpha.com/instablog/398764-vaughn-cordle-cfa/5290930-boeing-737-max-8-crashes-case-pilot-error
======
PaulHoule
Sure, the pilots did the wrong thing.

But they weren't trained to do the right thing. It is normal to get flustered
in a stressful situation, the answer is to prepare for it.

If Boeing doesn't want pilots to make the same mistake it should insist that
they get trained. My suspicion is that return-to-flight for the MAX is being
delayed by Boeing trying to avoid a simulator training requirement for the MAX
because the whole point of the MAX was that pilots did not need to be
retrained.

------
salawat
Oh, it's this song and dance again.

Let me touch on a couple points:

>On overspend and throttle management

The article asserts:

>The Pilots left the throttles at 94% power (normal ascent power) for the
entirety of the emergency. >this exaggerated aerodynamic load forces on the
horizontal stabilizer, rendering manual wheel retrimming infeasible >This
occurred due to lack of pilot training

First off; not managing the throttles at that time is completely
understandable.

The AoA sensor being bad causes absolute havoc with the data available to the
pilots since the AoA is a value utilized to calibrate several key data points
required for successfully flying the plane, the most important being;
airspeed. As soon as that AoA sensor was rendered out of whack, they were
essentially flying in an airspeed unreliable state, to which the remedy is...

You guessed it: advance throttles to appropriate position for desired flight
regime, move on to resolving next problem.

Now; there's not actually any documentation or training material that
specifically mentions that remedying an airspeed unreliable could be
contraindicated in the presence of some other problems. If you do both have an
explicit call out for this sort of thing, you never even incorporate the
possibility into a mental fault diagnostic tree; you just try to correct the
seeming most present issue.

Also note: there's an immediately observable effect to throttle retardation in
engine underslung aircraft. Every pilot would know this. No pilot in their
right mind would naturally make the problem worse until they absolutely
exhausted their checklist items. It's simply not good form. So, into Stab Trim
Runaway we go!

>On the trim oops The monitoring pilot had about 200 hours; the pilot in
command had about 8000 hours, alarms and glaciers going off, and a painful
amount of pressure having to be held on the controls to try to keep things
from getting worse.

They had both seen the emergency bulletin from Boeing, and we're therefore
primed for stab trim runaway. In that bulletin, airspeed gets a minor callout
at the end. Almost an afterthought really. Somewhat lost in retrospect to the
list of symptoms that may arise due to AoA sensor malfunction, and the news of
this MCAS thing that might try to kill you.

Now: They cutout the trim switches. I have a question; how many, dear reader,
have, when faced with something highly resistive to turning, naturally,
without thinking tried turning the thing in question the other way? It takes
40 turns per unit of trim if I recall cotrectly; this means no more than 8
turns of the wheel (which would smoothly actuate in the nose down direction
since the screw jack in back is being assisted by the aerodynamic load)
accounts for the change from 2.1 to 2.3 units. This strikes me as just about
the right amount of time for the human eye to discern movement on an analog
gauge if that is what is used, or to filter out from a chaotic interface that
the trim problem is being exacerbated.

I can hear the protest from everyone in the back, but the fact remains, that
when under pressure, and in the absence of a visual cue, it is more than
possible that either pilot fell victim to this most human of heuristics before
quickly realizing their mistake.

>on departing from the checklist Having run through everything they had from
an authoritative source, the pilot's found themselves in a position where the
choice was improvise or die.

They improvised. They reactivated the electric trim motor and slipped the
thumb switch to make sure the system could respond.

Unfortunately, this also reset MCAS to activate 5 seconds later, before they
could hit the trim again. They had no clue as to the coupling between the trim
switches, or disabling of the air-trim override switches in the yokes. They
did the best they knew how with the cards they were dealt.

>Conclusion: Did pilot error doom those flights?

In the sense that lithobreaking with the ground is the physical cause of
death, yes; but we aren't discussing the physics, we're discussing
culpability. The primary point of interest in questions of culpability is:
_Were they negligent? Did they unreasonably endanger the plane by doing
anything other than a best faith demonstration of mechanical and piloting
aptitude in the face of incomplete information and malfunctioning equipment?_
I assert that no, the pilot's acted in good faith, and to the extent of their
training and beyond as well as any human being trying to operate a highly
complex and unknowingly dangerous piece of equipment can be expected to under
the circumstances.

Was Boeing negligent? Did they in good faith do everything they could in order
to ensure the safety of these planes while wholeheartedly complying with
aerospace design regulations, free of any form of malicious compliance, or
free of any willingness to unreasonably sacrifice the soundness of the
finished product in the name of greed/dedication to maintaining market share?
I assert so. This unfortunate series of reactions could _only have come to
fruition through the combined negligence in creating an unsafe design,
patching over this danger through poorly evaluated or extrapolated code,
removing all mention of the danger from the training material, and refusing to
perform their duty as a maker of complex equipment to make sure pilots knew
enough to safely handle the plane. All with the intent of maintaining market
share, and shareholder value creation at the expensive of the quality of the
product, and the process by which said product is handed off to its users_.

No pilot should stand by and let these men be disparaged. No _professional_
should either. This company, on whose auspices and assurances they placed
their lives and the lives of their passengers willingly abrogated their
responsibility in the name of financial expediency. "The customer already
expects the box to be of high quality; we must focus on shareholder value",
should clearly illustrate where Boeing's priorities were at the time. That in
trying to recover from this negligence on Boeing's part does not justify or
release Boeing from ultimate culpability.

If we as a people accept the logic whereby these men must carry ultimate
culpability, we accept that it is fine for an organization of people to be
negligent in the execution of their duty, just so long as the poor sod who
pays the price for it makes a mistake.

Please don't be that group of people.

~~~
mannykannot
When you write "Also note: there's an immediately observable effect to
throttle retardation in engine underslung aircraft", are you referring to the
airplane pitching downwards, on account of the thrust line being below the
center of drag?

~~~
salawat
Yeppers. That is what I'm referencing.

------
mannykannot
The authors of this article repeatedly ask why Ethiopian Airways did not train
the pilots for the situation they faced, ignoring the fact that their training
was in accordance with the requirements set out by Boeing and the FAA.

Prior to the Max variants, trim runaway was normally stopped by the pilot
resisting it with an opposing force on the yoke; this caused the system
driving the trim change to stop. consequently, trim runaways rarely resulted
in the airplane being much out of trim.

This is also the case for the Max variants, _except_ for MCAS-commanded
changes, as this would defeat its purpose. Training for trim runaway in a
simulator goes through the checklist memory items, ending with the toggling of
the cutout switches. Any use of the trim wheels, let alone in the 'roller-
coaster' maneuver for when they are hard to move, was dropped from training a
long time ago [1].

The 737 AFM mentions the possible difficulty of using manual trim when the
jack screw is under high load, and outlines the roller-coaster maneuver, but
the checklist for trim runaway makes no mention of it and does not say
anything about slowing down. Furthermore, the AD, issued after the cause of
the Lion Air crash was found, says nothing about these issues. Nor does there
seem to be any consideration that the roller-coaster maneuver is infeasible at
low altitudes, or of the complication that, as mentioned by Salawat, reducing
thrust results in the airplane pitching downwards, on account of the low-slung
engines.

So, MCAS raises the possibility of trim runaway being a qualitatively
different experience than before, and significantly more difficult to handle,
yet Boeing's and the FAA's response was to merely reiterate the existing
procedures. Most significantly, they did not require, or even propose, any
additional simulator training, even after the Lion Air crash. I think it is
likely that no-one in these organizations connected the dots to anticipate the
problem, but we should also consider the possibility that someone did, but it
was downplayed to avoid the question of additional MCAS-specific training.

As I have written elsewhere, the more you argue that the pilots made mistakes,
the more you simultaneously argue that Boeing's and the FAA's response to the
Lion Air crash was inadequate. The authors of this hatchet job say that "with
hindsight", the situation could have been saved, and maybe they are right, but
the one thing no-one has when they need it is hindsight. Boeing and the FAA
had a responsibility to substitute training for hindsight, and if they
intentionally defaulted on this, and especially if they did so in the name of
sales, they are culpable.

[1]
[https://www.youtube.com/watch?v=n4qDLR4s45U&t=296s](https://www.youtube.com/watch?v=n4qDLR4s45U&t=296s)

