On Thursday, January 23, 2020 at 2:31:12 PM UTC-5, Scott Lurndal wrote:
trader_4 writes:
On Thursday, January 23, 2020 at 1:05:11 PM UTC-5, wrote:
On Thu, 23 Jan 2020 07:20:19 -0800 (PST), trader_4
wrote:

Totally wrong. There is ZERO evidence that I have seen, that this was
a problem created by the programmers. The program did what it was
designed to do.

So I guess you have the specs the programmers were working with.
Please give us a link so we can all see.

If you followed this at all, it's been very clear that Boeing, FAA and
all involved have made it clear that it was a DESIGN issue, not a coding
problem, not a programmer's error.

The primary factor here was the need for a more efficient engine
in order to reach the per-pax-per-flight cost reduction targets. The
737 (design started in 1964) was specifically designed to use unimproved
airfields (i.e. airstairs) so it was designed very close to the ground.

This worked well with the engines of the day. The next generation (NG)
models (-700, -800) used a larger fan diameter for efficiency, but needed
to flatten the bottom of the cowl in order for the engine to fit under the
wing.

The MAX (-7, -8) needed an even larger fan (and bypass ratio) to achieve
their fuel efficiency goals (the main reason a customer would buy a MAX
over an NG), unfortunately, there was no room left under the wing and a
redesign of the undercarriage would push the schedule out and raise the
development cost. The engineers moved the engine forward on the
pylon moving the fan ahead of the wing. This changed the 'pitch moment'
of the airplane (moving the engine forward made it more likely that the
engine would cause the airplane to pitch up (nose up)). To ameliorate
the unsafe pitch moment they implemented the MCAS subsystem, which
will force the pitch back down under certain conditions (and of course,
the mechanism wasn't designed with appropriate fail-safe; only one of the two angle
of attack (aoa) sensors was used by the MCAS system.

Note that this design was a direct result of the refusal of management
to do the right thing and either redesign the undercarriage and associated
structural elements (which would mean they'd need a new production line
for MAX instead of sharing with -NG) or do a clean-sheet design to replace
the 737 (which is what they should have done, but they had a lot of pressure
from the A321LR at the high-end of the NG product range and the MAX -8
was intended to be the short term competition for the A321LR until the NMA
(New Midmarket Aircraft - a replacement for the 757) hit the market
(it's been delayed yet again, as has the 777X).

Granted, there was incompetence all the way up and down the chain.


I think what you're saying there is that you agree it was not a programming
error, a coding error, that the software did what it was designed to do,
it implemented MCAS as the aeronautical folks designed it to operate.