Originally Posted by
Big Pistons Forever
I am guessing that the nacelle strakes would have added drag and thus marginally reduced the fuel savings of the MAX over the NG. Since everything at Boeing is about the money that alone would be enough for senior management to tell staff to find some software cludge that would allow them to smoke it past the FAA...
A B37Max 8... as produced. Note large vane on inboard of nacelle.
Note similarity of vane on the nacelle on the B737NG below:
Instead of curing an aerodynamic problem with common sense and using aerodynamics, the operators got Heath Robinson's repurposed "all things to all people" speed trim system.
The manufacturer is a collective of individually competent and dedicated professionals, working within the lines of communications that unfortunately appear to act to inhibit cross discipline questioning, resulting in lost opportunities. The lack of inquisitive input to issues gives inevitable results; to a carpenter, every problem is cured with a hammer, etc. Our regulatory requirements lead towards the current structure as a natural consequence, not just in aviation, IMHO.
Given the problem that was encountered, as I stated over 2 years ago on the public disclosure of MCAS as a system, the suggested solution would have been to reduce the size of the nacelle vane; the fundamental issue being the nacelles generating excessive Cm component from excessive CL at high AOA. That the nacelles would be causing excessive CL compared to the earlier design was stated by me in an appropriate forum in Aug 2016, but what had been done to fix that was never disclosed. It is improbable that the system architecture would ever have been disclosed which would have been necessary to ask what on earth they were smoking in Renton with the system architecture.
Would urge that the OEM implement specialist team(s) of generalists to assess systems and designs unfettered by discipline divisions. FWIW, QA per sew is not the solution, they have their place, in assessing system integrity (of course, victimizing your QA Inspectors is hardly reasonable and comes with it's own set of inevitable, forseeable consequences) But QA itself doesn't evaluate assumptions against common sense. What "Critical Design Reviews" are essentially supposed to be but are not.