Re: [OT] “Raise the nose, HAL.” “I’m sorry, Dave, I’m afraid I can’t do that.”

[Walter Bright]

On 4/21/2019 10:18 AM, Paolo Invernizzi wrote:
> I'm finding this article [1] amazing, looking at all the anecdotical stories 
> that Walter has told us during all that 15 years regarding engineering in 
> avionic industry.
> 
> Without specifically discussing the Boing case, but looking at industry in 
> general...
> Really, things will go horribly wrong, before starting to go better again?
> 
> Happy Easter to everybody!
> 
> [1] 
> https://spectrum.ieee.org/aerospace/aviation/how-the-boeing-737-max-disaster-looks-to-a-software-developer 

I have my beefs with the article.

For example,

"They want to have one airplane that all their pilots can fly because that makes 
both pilots and airplanes fungible, maximizing flexibility and minimizing costs."

Safety is a factor in having different airplanes fly the same. Many accidents 
have occurred because the pilot, in a moment of stress, applied a solution that 
would have been correct on the aircraft type he had more experience on.


He argues that airplanes are stable without augmentation. This isn't true for 
any jetliners, they have an active yaw damper:

   https://en.wikipedia.org/wiki/Dutch_roll

In particular:

   https://en.wikipedia.org/wiki/Dutch_roll#Accidents


He argues that it would be safer to develop a whole new airframe. Any new 
airframe, by definition, will be an unproven design, and everything in it would 
need to be re-proven, which has its limits.


"Neither such coders nor their managers are as in touch with the particular 
culture and mores of the aviation world as much as the people who are down on 
the factory floor, riveting wings on, designing control yokes, and fitting 
landing gears. Those people have decades of institutional memory about what has 
worked in the past and what has not worked. Software people do not."

This is sheer nonsense. People on the shop floor assembling airplanes do indeed 
have institutional knowledge about what works in manufacturing. They have no 
idea what works when flying or various failure modes. They have zero experience 
with stability issues. They do not do design work. Even more ignorant, the 757 I 
worked on back in 1980 had many computer systems that controlled the airplane, 
such as the autopilot. Last I checked that was 4 decades ago, and software 
programmers and managers implemented it.


Boeing did indeed make mistakes with the MCAS software design. I won't defend 
that, I don't understand the causes of those mistakes. But it wasn't about cost 
saving, another scurrilous charge by the author. The fact that the fix is a 
software update is evidence enough that it was a mistake, not some blind greed.

Absent from his article is anything about Airbus. Airbus has had crashes due to 
avionics software problems, too.

The author is a pilot, but has never flown airliners and has no experience with 
them.

There's more, but I should stop here. I'm just tired of these hit pieces from 
people who only partially know what they're talking about. I'll fly in a 737Max 
any day.