
Can Boeing Trust Pilots? - skybrian
https://airfactsjournal.com/2019/03/can-boeing-trust-pilots/
======
tuna-piano
Assuming the author is correct, and the reaction to the MCAS issues is a
simple reaction that every pilot should know by memory: Is it really
acceptable that once every 3 months a 737-Max will attempt a nose dive and
require a vigilant pilot who can identify and correct the issue before the
plane crashes into the ground?

And this likely happened at least twice, while there were 300 MAXs in service.
If there were 3,000 MAXs in service, MCAS misfires would presumably be
happening 3x a month worldwide - each misfire requiring a proper pilot
reaction. How can you defend Boeing in that case?

~~~
lagolinguini
I feel like this is a strong argument for the airbus alpha protection. And I
think Boeing agrees with that given the way the 777 fly by wire system is
designed.

There are plenty of people (on this site and on reddit) who jump on to
criticize airbus for the way it puts the aircraft's computer systems ahead of
the pilots and claim that the 737's flight controls are preferable to pilots
because the pilots have full control. I don't want to spark any airbus vs
boeing debate, but I want to point out these accidents seem to discredit that
line of thinking.

~~~
snowwrestler
Before we get excited about computer protections, let’s acknowledge that the
MCAS system under debate on the 737 Max is itself a computerized system
designed to protect pilots from themselves—in this case, from pitching too
high and creating a stall.

In the Lion Air accident, a malfunctioning sensor caused this system to react
incorrectly, surprising the pilots.

Let’s also remember that a malfunctioning sensor was a contributing factor in
the crash of Air France 447... a problem which was exacerbated by human
interface choices in Airbus’s fly by wire system. In particular, stick input
is not physically synchronized and conflicting inputs were averaged; neither
of which is true on a Boeing aircraft. Even on a 787 the yokes move together.

Human factors matter a lot if the computers hand control back to the humans
unexpectedly. That can happen even in fly by wire systems on Airbus.

Edit: fixed 737 reference up top

~~~
Someone1234
Unclear why you're trying to conflate the MCAS issue with AF447. Or are even
bringing up AF447 at all.

On the Max 8 a bad sensor is causing an automated system to misbehave, and may
have resulted in crashes.

On AF447 ice blocking the pitot-static system caused automated systems to go
offline (enter Alternative Law), and loss of situational awareness caused the
pilots to crash their aircraft under manual control.

If you read the final report[0] you'll see that pilot error and loss of basic
airman-ship caused the accident. There's always improvements to the airframe
to mitigate the human component, but acting like these two are somehow
different sides of the same coin is disingenuous.

I'm not actually sure why you brought it up. Comes across as "look they're
both just as bad" while ignoring key details about AF447.

[0]
[https://en.wikipedia.org/wiki/Air_France_Flight_447#Final_re...](https://en.wikipedia.org/wiki/Air_France_Flight_447#Final_report)

~~~
snowwrestler
Did you read the comment I’m replying to?

The common element between Lion Air and Air France crashes is bad sensor data:
AOA and airspeed, respectively. A computerized system, no matter how
sophisticated, cannot protect pilots from themselves in the absence of
accurate sensor data.

~~~
lagolinguini
> The common element between Lion Air and Air France crashes is bad sensor
> data

Agreed but the context is completely different. The airbus flight computers
rely on data from three sensors and thus are triply redundant. AF447 happened
in severe icing conditions with water ingressing into the pitot tubes on the
ground. All three pitot tubes froze, causing all three sensors to report bad
data. The aircraft identified the discrepancy and degraded from normal law to
alternate law as expected so it would not make any decisions based on the
faulty data. The crash ultimately was caused by the pilots being disoriented
because of the very low visibility. The sidestick issue is a different
discussion, but its not related to the 737MAX accidents.

The MCAS system on the other hand is not triply redundant, and that's what
people have issue with. Boeing itself has more redundant envelope protections
on the newer models like the 777 and 787.

------
amluto
Here’s what I don’t get about this whole situation:

AIUI 737 MAX has an instability such that, in near stall conditions, some
attempts to recover can make the stall worse. To mitigate this, Boeing added
MCAS, and MCAS can malfunction with a single sensor failure. Imagine that this
failure occurs and the pilot successfully turns off MCAS but ends up in a
dive, too close to the ground, or otherwise in a bad situation. Now the pilot
has to recover, but they are facing a faulty AoA indicator (if they have one
at all) as well as a plane that, because MCAS is off, is unstable in near-
stall conditions. And the pilot has never been trained in the handling of type
737 MAX under these conditions.

Am I wrong for some reason, or is this a potentially rather dangerous
situation that could be caused by a single instrument failure?

~~~
neom
You're not wrong by my estimation. If a function provided to recover from a
stall activated at low altitude, regardless of flight control at < 5k ft, I'm
not a pilot but depending on how aggressive the MCAS was, I can't imagine
recovery would be easy.

------
larkinrichards
I don’t believe this author understands the issue here. His description of the
force feedback on the wheel is not correct. The automatic trim adjustment from
the MCAS would not be detected if the pilot is trimmed in and at neutral
stick. They may detect the pitch change and pull up/retrim for level flight,
which disables the MCAS temporarily and gives the impression that trim is
under control.

~~~
gjhan
The author understands the issue fine and their description is correct. MCAS
is a trim-and-feel system that exists to satisfy the stick force gradient
requirements of 14 CFR 25.143 [1] within a relatively normal flight envelope.
A stick pusher is a stall warning/prevention device that exists to satisfy 14
CFR 25.207 and 25.103, and which doesn't activate in a normal flight envelope.

[1]
[https://www.law.cornell.edu/cfr/text/14/25.143](https://www.law.cornell.edu/cfr/text/14/25.143)

------
everdev
> What’s critical to the current, mostly uninformed discussion is that the 737
> MAX system is not triply redundant. In other words, it can be expected to
> fail more frequently than one in a billion flights, which is the
> certification standard for flight critical systems and structures.

How was the plane delivered if it didn't pass certification?

~~~
ams6110
It's grandfathered under the original 737 type certificate from the 1960s.

The aircraft would not meet today's certification requirements as a new type

~~~
JauntyHatAngle
As someone with limited knowledge into airplane engineering/certifications, on
the surface that seems wrong.

I understand (I think) that they made changes to make it essentially handle
and act like the 737 therefore it can apply to the same certificate, but
surely there should be some kind of time restriction on a certificate applying
to new models - even ones that are "similar".

Can someone illuminate me as to why this does or does not make sense?

~~~
tyingq
Boils down to money. A brand new type certificate for a big passenger jet is
in the hundreds of millions of dollars in time and money. Therefore you can
justify spending quite a lot on lobbying (actual and metaphorical) to get away
with reusing one.

Edit: And the airlines will lobby on your behalf too. They don't want to have
to certify pilots on a new type, or have yet another split of who can fly
what.

------
anoncoward111
Does it have any choice? The official FAA incidents log has US pilots stating
that the MAX is different to fly from normal 737s...

...and using their own words, is "unsafe!" to fly without additional training.
It is unsafe to fly a plane with different layout and handling.

~~~
cryptonector
Did you read TFA?

------
ilaksh
It seems like FBW is the way to go and that this particular subsystem was
tacked on and not adequately tested and the overall subsystem missing
redundancy. Main problem is greedy executives trying to pass it off as a
normal 737 when it was completely different. So some executives at Boeing and
the FAA should go to prison.

MCAS needs another layer of redundancy and whole thing needs to be entirely
retested and certified under a new type.

------
theobeers
I found this article informative on several points, and the conclusion is
correct ("I am sure the future belongs to FBW"), but it sets up a test that
has already been failed. Can Boeing trust pilots? Well, if that's how he wants
to put it, then no, evidently they cannot. We're talking about two crashes in
a short period, in which hundreds of people died. There's a kind of tautology
here.

~~~
snowwrestler
Of course we can’t trust pilots, that why airliners have at least two of them,
and check lists for everything, and all sorts of warnings, etc.

We just had a truly historic near-miss where a crew lined up to land on a
crowded taxiway at SFO instead the runway. If they had not gone around at the
last second we would be talking about it as the most deadly accident in
aviation history. Fly by wire was not going to prevent that; the descending
aircraft was an Airbus A320.

Whether fly by wire makes pilots more trustworthy—that’s a good question.

But I think the author is addressing a subtly different question, which is:
what _seems_ more trustworthy to people? People like: the public and
politicians. Is it still acceptable to say “the human, despite its flaws,
still belongs in the critical path of safety.” Or, is the reputation of
computers so strong now that all planes will have to work that way to satisfy
modern notions of what is safe?

~~~
salawat
The sad thing is that more than anything else, this is starting to veer into
the realm of a philosophical question:

Who is more eeliable, the instrument, or the instrument user?

A machine can only be guaranteed to function on information it has. Same with
the human being behind the yoke.

The human by far has the greatest capacity as the only General Intelligence in
the room, but technically, that GI's performance is limited by it's access to
accurate information regarding the functionality of the tool he is using.

------
lisper
Something about this piece doesn't smell right. The author claims to be a
pilot with 45 years of experience, writing in a publication that bills itself
as "by pilots, for pilots", but I'm a pilot (with 23 years of experience) and
I've never before heard a pilot refer to the yoke as "the wheel". ("If you
don’t believe me, sit in a Bonanza A36 or Cessna 210, or just about any other
high-performance piston airplane, and pull the wheel back while sitting still
on the ramp.")

I'm also very skeptical of his thesis that these accidents were pilot error,
that there is nothing different about the Max 8 than any previous generation
of the 737. The 737 in general has an excellent safety record. The Max 8 has
had two crashes within two years of its introduction. The odds of that just
being a coincidence are pretty damn low.

So I can't help but wonder if this guy is a shill. Maybe the question we
should be asking is: can pilots trust Boeing?

~~~
nerdponx
The fact that it's called "Air Facts Journal" is suspicious.

~~~
skybrian
It's well-known in the field. The name was chosen in 1938:

[https://airfactsjournal.com/air-facts-
history/](https://airfactsjournal.com/air-facts-history/)

~~~
nerdponx
Good to know, thank you. Without context the name sounds very odd.

------
ryantgtg
Am I the only one who immediately stops reading when a writer says, "let me
explain"?

I was totally going to let you explain. After all, I'm reading your article
and I intended to read more than just the first paragraph. But your sudden
insistence that I just give you a few more minutes to explain your provocative
argument presumes too much about what I'm thinking. And it's over-used. And
it's an annoying tone.

