
Boeing proposal to avoid 737-MAX wiring shift does not win U.S. support - ars
https://www.reuters.com/article/us-boeing-737max/boeing-proposal-to-avoid-max-wiring-shift-does-not-win-u-s-support-idUSKBN20W018
======
ggm
We aren't only arguing about _how much_ money is going to have to be spent,
we're arguing about how the money is going to come from shareholders, or
customers, or passengers, or the tax payer.

If you think this isn't an argument about money and who pays, I think you
misunderstand why we are here.

There is no other reason we are here, than money. An unwillingness to incur
cost, or cause customers to incur cost, that made other choices of provider
more attractive drove Boeing to make decisions which now will cost money, to
them, to the customer, and probably to everyone else at large.

Boeing is not in pursuit of the "best" fix, its in pursuit of the "least worst
(in cost terms) fix"

~~~
jl6
Tangentially, I believe the root cause of all software architecture debates is
an argument over who pays what aspect of cost.

Language goals such as expressivity, readability, brevity, composability; and
features such as static typing; and patterns such as monoliths and
microservices, ship-fast-fix-later, agile and waterfall design, centralized vs
distributed; and aphorisms such as DRY and YAGNI - can be evaluated in the
framework of shifting cost between original programmer, future maintainer,
service provider, service user, or library/module reuser (and one individual
may assume all of those roles at different points in the software’s
lifecycle!).

~~~
ggm
Well yea, I guess the underlying trueism is that "its turtles all the way
down" in all things. We like to act like over-arching things (safety) weigh
higher, and so we speak like the decision to go for safety isn't an economic
decision, but in truth, it always is.

Free software has costs, so its not like FOSS is outside this loop either.

Once you start modelling everything in cost/benefit terms, it all gets a bit
odd. I think "because I want to" looses out.

But in Aircraft design, and regulatory oversight, I think we might want to
shift the knobs on the control box a bit.

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jlawer
Not an aircraft safety expert but I am curious if shifting the wires may not
introduce more potential issues in existing planes, as the existing risk
factor seems to be proven low (i.e. they are not requiring all 737-NG
airframes to have the work)

I would imagine there is a non-trivial risk of a worker introducing a higher
risk factor (drilling a little too far, creating metal shavings, putting too
much weight on a support).

The rules were made for a reason, and Boeing should follow them. However I
wonder if it would be safer to simply fine Boeing a similar cost to what the
rectification would cost and grandfather it in for existing airframes.

I am just glad there are people more qualified to make this decision.

~~~
rbanffy
Boeing wants to have a quick and cheap fix (no fix) and get a pass on
international aviation norms based on the argument it's not "too unsafe" and
that fixing it would risk making the 737 MAX fleet non-flightworthy.

Well... It's not like it's flightworthy right now. If Boeing can't offer a fix
that makes the plane flightworthy, then the airplanes should be scrapped.
Remember we only are experiencing this because Boeing wanted a plane of the
same type rating as the 737 NG and opted for that instead of a new design
(that would be in accordance to all current safety norms, unlike the MAX)
because it'd increase their profit.

Two planes fell from the sky, killing everyone on board, for no other reason
than Boeing wanting to increase its profits.

~~~
onlyrealcuzzo
I thought the planes would be fine if Boeing just dropped the idea that they
could be flown by pilots only trained to fly the 737.

Is the plane not safe to fly in general AND it needs pilots trained to fly it
specifically?

~~~
rbanffy
IIRC, on a high AoA the lift generated by the larger engines moves the center
of lift ahead of the center of gravity, making the plane unstable. This is
what MCAS was arguably designed to prevent, forcing the plane behave like a
737 with smaller engines.

Without MCAS, this would be a crappy experience for the pilots, but, with
_proper_ training, they'd be able to fly it just like you and me can safely
drive cars like a Reliant Robin (just never think about hitting the brakes in
a curve). If you feel the plane wanting to point up a bit too
enthusiastically, you can push the stick forward (or adjust the trim) and make
it more cooperative.

It just turns out that, with MCAS, little training, and a defective AoA
sensor, the experience was lethally crappy.

~~~
foldr
>lift generated by the larger engines moves the center of lift ahead of the
center of gravity

Do you have a reliable source for the center of lift behind CoG shift? I've
not seen that claim before.

~~~
Tempest1981
This doesn't mention CoG, but it mentions "dynamic instability":

[https://spectrum.ieee.org/aerospace/aviation/how-the-
boeing-...](https://spectrum.ieee.org/aerospace/aviation/how-the-
boeing-737-max-disaster-looks-to-a-software-developer)

 _In the 737 Max, the engine nacelles themselves can, at high angles of
attack, work as a wing and produce lift. And the lift they produce is well
ahead of the wing’s center of lift, meaning the nacelles will cause the 737
Max at a high angle of attack to go to a higher angle of attack. This is
aerodynamic malpractice of the worst kind._

~~~
foldr
Yes, that doesn't claim that the center of lift shifts ahead of the CoG. Nor
is it a reliable source.

------
chriscatoya
Aside from the gallon of blood and pound of flesh we'll see called for in the
public/political arena, I really doubt there's any viable fix that won't
require pilot training.

As I understand, the 737-MAX blunder is at the core a result of bad incentive
alignment baked into their deal with Southwest: Boeing was trying to avoid any
FAA "differences" simulator training requirements to make more money in a
fleet sales order to Southwest Airlines. If the FAA required level-D simulator
training, Boeing agreed to rebate Southwest $1 million for each MAX bought.
The training would have cost Southwest $2000 per head. That's $18M for their
9,000 pilots.

source: [https://newrepublic.com/article/154944/boeing-737-max-
invest...](https://newrepublic.com/article/154944/boeing-737-max-
investigation-indonesia-lion-air-ethiopian-airlines-managerial-
revolution?utm_source=pocket-newtab)

~~~
tyingq
List price for a single MAX8 is $120M. I'd be surprised if $18M total of
upside was the primary driver across an initial qty 40 aircraft order. They
could have just offered that as an additional discount.

~~~
NikkiA
The 737-MAX800 is something like $10M more than a A321-NEO, when the A321-NEO
meant retraining your pilots and the 737 didn't, that $10M difference closed a
lot, now both are going to require retraining.

------
cletus
One wonders if the problem of the MAX won't be effectively solved by the
Covid-19 triggered recession. With people flying less, it's a pretty good
reason to cut aircraft orders, no?

At some point the 737 gravy train was going to end. There's only so long you
can maintain the same type rating on a traditional (ie not fly-by-wire) plane
where you eventually want to change the handling (as the MAX did by putting on
large engines and moving them to compensate).

So those who made the decision to go with the MAX rather than the engineer-
favoured solution of a complete redesign (because the MAX was going to be ~2
years faster to market and have a captive market of 737 type rating airlines
like Southwest) are ruing that decision. Or at least if they hadn't collected
huge bonuses for years and were in any way held accountable for a bad call,
which sadly they are not.

~~~
WalterBright
There's nothing wrong with the concept of MCAS. Just it's implementation.

~~~
kovac
I don't know, I feel like designing a system to prevent a pilot from lifting
nose too high up seems to make more sense than a system that actively pushes
the nose down after it being lifted. If nothing else, passengers would feel a
bit of a discomfort of a sudden nose down movement. Not sure if I missed
something in the current design.

~~~
numpad0
No it's not about comfort. MAX engine shroud is too far forward to the point
it act as canards creating pitch up force at high AoA, in a self reinforcing
manner into a belly up into irrecoverable stall. MCAS prevents this by quickly
pushing nose down back into airstream.

I believe there were discussions earlier on that the FAA requires all civilian
airliners to have positive static stability, aka CoL comfortably behind CG so
air resistance straightens the attitude without inputs.

The opposite of positive static stability is Fly By Wire based 4th-gen onwards
jet fighters like F-16, that has CoL only barely aft of CG, that replace
aerodynamic stability with electronic PID controllers multiplexed with manual
axis inputs for each axes. Those planes could go into a spin over some axis
that make sense if at any moment FBW loses control.

The fact that MAX needed MCAS, an FBW-like system, to meet FAA standards is
itself wrong, and implementation to make it a ghetto nonredundant trim system
rather than full FBW is also wrong.

~~~
rbanffy
> The opposite of positive static stability is Fly By Wire based 4th-gen
> onwards jet fighters like F-16

The risks introduced by fighter jet lack of static stability are mitigated by
the installation of ejection seats. That's a tough sell for passenger
aircraft.

~~~
foldr
The 737 MAX is statically stable. There are quite a lot of uninformed comments
floating around that compare the plane to fighter jets like the F-16, but
these are pure nonsense. An F-16 would tear itself to pieces in seconds if the
flight control software malfunctioned.

~~~
bkor
It seems more to be that people use the word "stable" while maybe another word
should've been used. The main criticism during the "stable" criticisms is that
something like MCAS was added. The design of the plane should've been in such
a way that MCAS wouldn't be needed. So instead of adding MCAS, the problem
leading to MCAS should've been solved with a (huge) redesign.

Note: Purely responding to the "stable" word. If people compare it to stuff
like an F-16, then yeah.. they don't know / nonsense.

------
CivBase
Does saving face mean nothing to Boeing? Wont this kind of behavior decrease
Boeing sales as the public continues to loose confidence in their planes?

At this point just do it. Do _anything_ to at least appear like you're taking
the matter seriously. Just let the regulators have their way for a while.
Surely it's better to just take the short term hit.

I know the stock market doesn't generally reward short term sacrifices for
long term gains, but does public image really mean this little anymore?

------
rjsw
One factor that could be important here is that one CAD exchange standard
doesn't currently do a very good job of modelling wiring harnesses. This
problem first showed up on the A380 when different CATIA versions were being
used at the two Airbus design centres.

A solution is being worked on by a joint Boeing and Airbus group but will be a
while before it is published.

------
code4tee
Boeing’s argument is that the issue really isn’t an issue based on available
data.

The FAA’s argument is that a rule is a rule and Boeing seems to have a problem
following the rules.

Boeing is probably right but given the mess they got themselves in it’s
probably best to just fall in line and follow the rules. They’re not helping
their cause trying to apply logic here.

~~~
bkor
> Boeing is probably right

From the article: "New safety rules on wiring were adopted in the aftermath of
the 1998 Swiss Air 111 crash."

These recommendations were added as a result of a crash. The crash happened a
bit after the 737NG started flying (AFAICS 737NG=1997), so I guess existing
certified aircrafts didn't need to be modified. It does make sense for a new
aircraft though.

------
droithomme
Good.

