Originally Posted by
Swiss51
So we can only hope that the FAA management still feels the scars from the nose rings that were put on them by B. If I understand you correctly the knowledgable engineers would require the change on the NT as well. And probably not only through an AD.
If you look at the FAA's TARAM handbook, which contains internal guidelines for determining whether an unsafe condition exists on transport airplanes, it has a discussion of the fail safe design expectation for transport airplanes in section 6.1. It says, "If you determine that the condition violates the fail-safe philosophy, you should consider the condition unsafe regardless of the calculated TARAM uncorrected fleet or individual risk values." Here's a link to that document. Section 6.1 is on page 33.
https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgPolicy.nsf/0/4e5ae8707164674a862579510061f96b/$FILE/PS-ANM-25-05%20TARAM%20Handbook.pdf
If the same type of stab trim wiring fault vulnerability as has been described for the Max exists on the NG, the FAA's own guidelines would classify that as an unsafe condition requiring corrective action via design change and an AD. However, it also would be an expensive change. In such cases, the decisions are often made by the leaders rather than via the normal process for more routine AD decisions. There's nothing necessarily wrong with that - as long as they make good decisions.