I was basically asking, if I disabled MCAS and approached a stall at high AoA in a 737NG and a 737MAX, what would the differences be? I'm asking because clearly Boeing had enough data on some rather unfriendly discoveries during modeling / testing to justify the implementation of MCAS. I just want to know what exactly they found, and how severe it is.
One of the most pointed and impressively simple questions I've seen so far on here. My thoughts EXACTLY. It is high time that we got some answers as to the basic handling characteristics of this airframe, and what was discovered ruing testing/modeling that made the need for MCAS (or, if you are being pedantic - 'enhanced MCAS' on the MAX) to be implemented/allowed such aggressive and exclusive/recurring control of certain situations.
Geeze guys. You have your answer! The fact MCAS is there tells you as much. In high AOA high thrust situations the engines are forward enough of the cog to exacerbate the AOA situation. It is a situation that can be perfect cancelled with corrective actions on the flight controls but hands off the plane will flip itself over in theory.
The same may be true on the NEO with all protection controls disabled. Airbus's FBW system provides a lot of aircraft "feel" and behaviour enhancements for the pilots too. Airbus has had high alpha protection for decades now. This is, in effect the same thing.
The one thing I will agree with is MCAS should have a lower authority limit. Boeing agrees as well and is working on the software update already. As to why it isn't out yet, I would simply say that aircraft software takes FOREVER to validate due to regulatory oversight and requirements.
Boeing was (as I understand it) originally targeting this month for the change but it has apparently slipped a bit. Embedded QA is hard. Embedded QA in a highly regulated industry is infinitely harder (one of our old posters Astuteman had horror stories from back in the day as it related to software on nuclear subs).
And before anyone sounds off about "Boeing knew this or that":
1). Mcas if working properly is a perfectly acceptable solution to the CoG issue. Lots of frames use software compensation these days. It is not "new" and is totally acceptable.
2) sometimes when you design a system or certify one things happen that no one foresaw or could reasonably foresee. There is an old saying and hindsight being 20/20. This applies in all directions. Things are plainly obvious AFTER they happen but how many times have all of us done something that had an outcome we did not expect until we experienced that outcome. It happens. Welcome to humans.
3) there is still no evidence mcas had anything to do with this accident
4) ET's CEO just said the pilot had MCAS training recently.
I still think something very unrelated happened between the two crashes and I still maintain the grounding is in response to media and social media pressure and not facts. Others can disagree but again this isn't really the thread for grounding talk anyway (there is one elsewhere on this site).
I want to get the data from this crash. There could be any number of things at play from basic pilot error to mechanical failure to systems failure (mcas), etc. ANY of those can be made to fit the circumstances of this crash. And we can safely guess that some COMBINATION of those apply to Lion Air. Yet all anyone wants to talk about is MCAS and that is likely leading people down a very wrong path (anyone who has studied any aviation accident knows it is rarely as simple as "my first guess was right and the sole contributer")
I don't care what you think of my opinion. It's my opinion, so have a nice day :)