wonkazoo
2nd May 2019, 04:44
This thread might belong in Tech, but given the significance of MCAS and Boeing’s future I decided this was the place for it. Apologies in advance if I chose poorly…
Dear PPRUNE,
I realized earlier today that I have a problem.
Over the past month and a half I’ve read almost 5000 posts on a thread on some rumor blog/forum, and much to my chagrin I’d actually posted on the site…
And yet, despite that effort, insight, shared knowledge and my own experience I am no closer to understanding the fundamental details behind what happened and why than I was when I started. This is primarily due to the fact that MCAS is (right now) an enigma. Various sources have the certification requirements to be no less than three that MCAS was intended to insure compliance with.
I haven’t seen anyone work out step by step what MCAS does, and how it does it. Sure, we all know that MCAS will trigger at a threshold AOA and run for 9.26 seconds if the AOA doesn’t drop into an acceptable range. But after that the list of questions is almost endless.
I want to challenge PPRUNE and our vast technical resources here (and those (including me) who have spent the better part of four weeks arguing over Boeing vs. four dead pilots...) to parse MCAS to a level that no one else will likely achieve. Why was it needed, what problem was it intended to solve, why was it chosen over other more technically robust solutions, why is it a “dumb” system that does not adapt in any way, why did Boeing use an actual control system when (they say??) it was just a control force augmentation system??
Think about it- if we are to properly judge the remediation and return of service of the MAX then it is up to us to have an intimate understanding of the systems the fix is intended to remediate.
To do this we need to start at the beginning:
Is there anyone out there who has verified source material that states explicitly why MCAS was created?? (After 5000 posts I am no better informed now than I was when I started…)
Let’s start there- what exactly was MCAS designed to deal with. What FAR, what aerodynamic or control feel problem… Please provide any original source material you have, no matter whether or not it is probative.
Let’s ID the problem first. Then we can look at the solution and whether or not it was a good one.
Thank you in advance for your entertainment of this quest. I should live in the Netherlands given how many windmills I seem to go tilting at…
dce
Dear PPRUNE,
I realized earlier today that I have a problem.
Over the past month and a half I’ve read almost 5000 posts on a thread on some rumor blog/forum, and much to my chagrin I’d actually posted on the site…
And yet, despite that effort, insight, shared knowledge and my own experience I am no closer to understanding the fundamental details behind what happened and why than I was when I started. This is primarily due to the fact that MCAS is (right now) an enigma. Various sources have the certification requirements to be no less than three that MCAS was intended to insure compliance with.
I haven’t seen anyone work out step by step what MCAS does, and how it does it. Sure, we all know that MCAS will trigger at a threshold AOA and run for 9.26 seconds if the AOA doesn’t drop into an acceptable range. But after that the list of questions is almost endless.
I want to challenge PPRUNE and our vast technical resources here (and those (including me) who have spent the better part of four weeks arguing over Boeing vs. four dead pilots...) to parse MCAS to a level that no one else will likely achieve. Why was it needed, what problem was it intended to solve, why was it chosen over other more technically robust solutions, why is it a “dumb” system that does not adapt in any way, why did Boeing use an actual control system when (they say??) it was just a control force augmentation system??
Think about it- if we are to properly judge the remediation and return of service of the MAX then it is up to us to have an intimate understanding of the systems the fix is intended to remediate.
To do this we need to start at the beginning:
Is there anyone out there who has verified source material that states explicitly why MCAS was created?? (After 5000 posts I am no better informed now than I was when I started…)
Let’s start there- what exactly was MCAS designed to deal with. What FAR, what aerodynamic or control feel problem… Please provide any original source material you have, no matter whether or not it is probative.
Let’s ID the problem first. Then we can look at the solution and whether or not it was a good one.
Thank you in advance for your entertainment of this quest. I should live in the Netherlands given how many windmills I seem to go tilting at…
dce